AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ALBANY NY                                              
924 PM EST THU DEC 20 2007                                                      
.SYNOPSIS...                                                                    
HIGH PRESSURE OVER QUEBEC WILL BUILD SOUTH INTO NEW ENGLAND AND                 
NEW YORK TONIGHT AND FRIDAY. SATURDAY IT WILL SLIDE OFFSHORE AND A              
SOUTHERLY FLOW OF MILDER AIR WILL BECOME ESTABLISHED OVER THE                   
EASTERN SEABOARD. A STORM WILL ORGANIZE IN THE MID MISSISSIPPI                  
VALLEY SATURDAY AFTERNOON AND INTENSIFY AS IT MOVES THROUGH THE                 
GREAT LAKES REGION TO HUDSON`S BAY SUNDAY. AHEAD OF IT INCREASING               
MOISTURE WILL BRING A WINTRY MIX OF PRECIPITATION AT FIRST...BUT                
IT WILL WARM ENOUGH TO CHANGE THE PRECIPITATION TO RAIN...WHICH WILL            
BE HEAVY AT TIMES SUNDAY AFTERNOON. THE STORMS COLD FRONT WILL SWEEP            
TROUGH THE REGION SUNDAY NIGHT...AND IT WILL TURN MUCH COLDER.                  
CHRISTMAS EVE AN UPPER LEVEL DISTURBANCE WILL PASS ACROSS THE                   
REGION AND IN THE CHILLY NORTHWEST FLOW WILL TRIGGER SCATTERED                  
SNOW SHOWERS. HIGH PRESSURE WILL BUILD INTO THE REGION FROM                     
ONTARIO CHRISTMAS DAY.                                                          
&&                                                                              
.NEAR TERM /UNTIL 6 AM FRIDAY/...                                               
IT SEEMS A NARROW YET PERSIST/INTERMITTENT  BAND OF LIGHT SNOW                  
CONTINUES TO IMPACT WESTERN NEW ENGLAND AND ATTEMPTING TO CROSS INTO            
EASTERN NEW YORK (NORTH OF THE MID HUDSON VALLEY).  LATEST RUN OF               
THE RUC13 AND 00Z NAM/WRF INDICATE THIS IS RESPONSE TO LOW LEVEL                
CONVERGENCE AND DEFORMATION WHICH IS EXPECTED TO BE INTERMITTENT                
THROUGH TONIGHT.  WILL UPDATE POPS ACCORDINGLY BUT KEEP IT IN THE               
SLIGHT CHANCE CATEGORY.  WHERE IT HAS SNOWED...VISIBILITIES HAVE                
DROPPED BACK 1-3 MILES...MAINLY ACROSS THE HIGHER ELEVATIONS. THE               
OTHER CONCERN IS THE TEMPERATURES OVERNIGHT.  WITH PERSISTENT CLOUD             
COVER AND LACK OF ADVECTION...WILL RAISE OVERNIGHT LOWS SEVERAL                 
DEGREES WHICH CORRESPONDS WELL WITH THE 00Z RUN OF THE GFS LAMP.                
&&                                                                              
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...                                        
THE SURFACE HIGH WILL BE CENTERED TO OUR EAST AND WILL SHIFT OFF                
THE NEW ENGLAND COAST FRIDAY NIGHT. IT WILL KEEP US DRY WITH A                  
DEVELOPING SOUTHEAST FLOW. LOW LEVEL CLOUDS WILL LIFT FRIDAY BUT                
HIGH LEVEL CLOUDS WELL IN ADVANCE OFF OF THE SYSTEM FOR THE WEEKEND             
WILL BE STREAMING IN...SO NOT MUCH SUN EXPECTED. TEMPERATURES WILL              
BE SEASONABLE.                                                                  
&&                                                                              
.LONG TERM /SATURDAY THROUGH THURSDAY/...                                       
HIGH PRESSURE SLIDES OFF THE ATLC COAST SATURDAY...AND SOUTHERNLY               
FLOW INCREASES THROUGH THE DAY.  500HPA RIDGE OVER THE EASTERN                  
SEABOARD. CLOUDS WILL BE VARIABLE AS WAA PRODUCES MID AND HI                    
CLOUDS. MEANWHILE THE LOW LEVEL SOUTHEAST FLOW WILL ALSO BRING                  
MOISTURE INTO THE REGION AND CONSIDERABLE LOW LEVEL MOISTURE                    
REMAINS THAT HAS LINGERED SINCE THURSDAY. SO ALOT OF CLOUDS AND BY              
SAT AFTN AND EVENING SPOTTY LIGHT DRIZZLE...FREEZING DRIZZLE AND                
FLURRIES.  TEMPERATURES MAY FALL A BIT DURING THE EVENING...BUT                 
INCREASING SOUTHERLY FLOW WILL RESULT IN STEADY OR SLOWLY RISING                
TEMPS OVERNIGHT. TEMPS WILL STILL BE AROUND OR BLO FREEZING IN                  
MANY AREAS AND PTYPE LIKELY TO BE ZR...BUT AMOUNTS WILL BE LIGHT.               
RAPIDLY DEEPENING SURFACE LOW IN THE GREAT LAKES SUNDAY WILL PUSH               
A CDFNT INTO NYS SUN AFTERNOON...WHICH SWEEPS EAST ACROSS REGION                
BY EVENING. WITH RAPIDLY INCREASE SOUTHERNLY INFLOW AHEAD OF THE                
SYSTEM TEMPS WILL RISE INTO THE 40S...AND KATAFRONT TYPE DYNAMICS               
OF SHOWERY/SQUALLY RAINS WILL DEVELOP ALONG AND AHEAD OF CDFNT.                 
ENSEMBLE QPF AMOUNTS FM PLUMES OF 1 TO 2 INCHES LIKELY IN 6 TO 9                
HOUR PERIOD. SIGNIFICANT SNOWMELT AND RUNOFF LIKELY. SEE HYDRO                  
SECTION FOR PARTICULARS. THE 500HPA CUTOFF...FOLLOWS ACROSS THE                 
REGION SUNDAY NIGHT AS VERY STRONG CAA FLASH FREEZES ANY REMAINING              
LIQUID...AND MELTED SNOW. ALSO THE PASSAGE OF THE CUT OFF WILL BE               
ACCOMPANIED BY SECONDARY ARCTIC CDFNT CHRISTMAS EVE WITH SCT -SHSN              
IN CAA...WITH STRONG UPPER DYNAMICS...BUT NOT IDEAL SETUP FOR LAKE              
EFFECT IN FCA. FINALLY SURFACE HIGH AND 500HPA RIDGE BUILD ACROSS               
THE REGION CHRISTMAS DAY...AND SEASONABLE TEMPS AND MAINLY CLEAR                
SKIES THE RESULT. BEYOND THEN THE SURFACE HIGH PASSES OFFSHORE...AND            
THE MODELS DIVERGE ON A VARIETY OF PASSING WEATHER SYSTEMS. WITH                
CUT OFF LOW ORGANIZING OVER GRTLKS REGION..ONE SFC LOW PASSES WELL              
SOUTH OF REGION OR THROUGH REGION THURSDAY OR FRIDAY. FOR NOW WENT              
WITH GFS MOS GUIDANCE AND SCT -SHSN AND CHC SNOW AT END OF EFP.                 
AFTER ALL THE 1.5 PVU ANOMALY THAT WILL ORGANIZE THIS SYSTEM IS                 
CURRENTLY NEAR TOKYO JAPAN.                                                     
&&                                                                              
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...                                       
RIDGING BUILDS...HOWEVER...LOW LEVELS ARE VERY MOIST AND HAVE LITTLE            
WIND FLOW (LIGHT NORTHEAST WIND). MVFR-VFR CONDITIONS WILL LOWER                
THIS EVENING BACK TO IFR CONDITIONS WHICH WILL PERSIST THROUGH                  
FRIDAY MORNING. THERE COULD ALSO BE PERIOD OF LIFR AFTER 06Z WITH               
NOCTURNAL COOLING OF THE COLUMN AND SHRINKING DEWPOINT DEPRESSIONS.             
WITH TEMPERATURES BELOW FREEZING...FREEZING FOG IS CONCERN                      
OVERNIGHT. CONDITIONS SLOWLY IMPROVE FRIDAY BUT LIKELY NOT MUCH                 
BETTER THAN MVFR.                                                               
OUTLOOK...                                                                      
SAT...VFR...NO SIGNIFICANT WEATHER EXPECTED.                                    
SUN...IFR MIXED PCPN...STRONG S-SE WINDS...POSSIBLE LLWS.                       
MON...VFR...EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS                         
            DOWNWIND OF LAKE ONTARIO...WINDY WITH LLWS POTENTIAL.               
TUE...VFR...NO SIGNIFICANT WEATHER EXPECTED AT THIS TIME.                       
&&                                                                              
.HYDROLOGY...                                                                   
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH SATURDAY. A STRONG STORM              
SYSTEM WILL IMPACT THE REGION ON SUNDAY. STRONG SOUTHERLY WINDS ARE             
EXPECTED TO DEVELOP ACROSS THE AREA ON SUNDAY. THIS WILL BRING A                
WARM SURGE OVER A SNOW PACK THAT CONTAINS 1 TO 3 INCHES OF WATER                
EQUIVALENT FROM ALBANY SOUTH AND 2 TO 4 INCHES OF WATER EQUIVALENT              
OVER NORTHERN AREAS. A COLD FRONT WILL CROSS THE AREA SUNDAY                    
EVENING. MODELS HAVE TRENDED WETTER BRINGING AROUND AN INCH OF RAIN             
TO ALL AREAS IN A 6 HOUR PERIOD SUNDAY AFTERNOON OR EVENING. THE                
UPPER MOHAWK...MOOSE...UPPER HUDSON AND VERMONT BASINS ARE EXPECTED             
TO SEE A 6 TO 12 HOUR WARM PERIOD LATE SUNDAY...WHICH WILL PROBABLY             
NOT BE ENOUGH TO RIPEN THE SNOW. NORTHERN SNOW COVER SHOULD ABSORB              
THE RAIN WITH MINIMAL RUNOFF BEFORE REFREEZING. HOWEVER...SOUTHERN              
AREAS MAY SEE 18 TO 24 HOURS OF ABOVE FREEZING TEMPERATURES. THE                
QUESTION IS HOW MUCH SNOW MELTS. LOCAL RIVER MODELS SHOW THAT                   
STREAMS CAN HANDLE AS MUCH AS TWO INCHES OF COMBINED MELT AND RAIN              
WITH MINIMAL FLOODING. 3 INCHES OR MORE OF MELT AND RAIN WOULD CAUSE            
SIGNIFICANT FLOODING. THE GROUND HERE AT ALBANY IS FROZEN TO A DEPTH            
OF 5 INCHES. FROZEN GROUND ENHANCES THE CHANCES THAT FLOODING...AND             
POSSIBLY FLASH FLOODING...MAY OCCUR. RIVER ICE COVER IS NOT THICK               
ENOUGH TO CAUSE ICE JAM PROBLEMS. THE HIGHEST CONFIDENCE IS FOR                 
TIDAL FLOODING LATE SUNDAY ALONG THE MID HUDSON RIVER NEAR KINGSTON             
AND POUGHKEEPSIE DUE TO STRONG SOUTHERLY WINDS. OTHER BASINS AT RISK            
FOR FLOODING INCLUDES THE SCHOHARIE...THE LOWER MOHAWK...THE                    
ESOPUS...THE BATTEN KILL...THE HOOSIC...WAPPINGERS CREEK AND THE                
HOUSATONIC AND ITS TRIBUTARIES FROM FALLS VILLAGE DOWN STREAM.                  
FREEZING TEMPERATURES ARE EXPECTED ACROSS THE ENTIRE AREA BY MONDAY             
MORNING WHICH WILL END THE RUNOFF. IF FLOODING WERE TO OCCUR IT                 
WOULD MOST LIKELY BEGIN SUNDAY AFTERNOON AND LINGER INTO MONDAY.                
&&                                                                              
.ALY WATCHES/WARNINGS/ADVISORIES...                                             
CT...NONE.                                                                      
NY...NONE.                                                                      
MA...NONE.                                                                      
VT...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...SNYDER                                                               
NEAR TERM...BGM                                                                 
SHORT TERM...IAA                                                                
LONG TERM...SNYDER                                                              
AVIATION...BGM                                                                  
HYDROLOGY...DIRIENZO                                                            
WWW.WEATHER.GOV/ALBANY                                                          
</pre> ct                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ALBANY NY                                              
654 AM EST THU DEC 20 2007                                                      
.SYNOPSIS...                                                                    
LOW PRESSURE WELL SOUTHEAST OF CAPE COD WILL MOVE EAST TODAY...AS               
THE UPPER LEVEL LOW ASSOCIATED WITH THE SYSTEM CONTINUES SCATTERED              
SNOW SHOWERS THROUGH THE AFTERNOON.  HIGH PRESSURE WILL BUILD IN                
FROM EASTERN QUEBEC THURSDAY NIGHT INTO FRIDAY.  THE HIGH WILL MOVE             
SOUTHWARD FRIDAY NIGHT TO NEAR THE GULF OF MAINE.  A RETURN                     
SOUTHERLY FLOW OF MILD AIR WILL OCCUR ON SATURDAY WITH TEMPERATURES             
ABOVE NORMAL FOR LATE DECEMBER.  A COLD FRONT PROGRESSING SLOWLY                
EAST FROM THE MISSISSIPPI RIVER VALLEY ON SATURDAY...WILL BRING RAIN            
AND WINDY CONDITIONS FOR SUNDAY.                                                
&&                                                                              
.NEAR TERM /UNTIL 6 PM THIS EVENING/...                                         
THE LATEST RUC ANALYSIS COUPLED WITH NEIGHBORING RADARS THIS MORNING            
DEPICTS SECONDARY COASTAL REDEVELOPMENT OCCURRING WELL SOUTHEAST OF             
NANTUCKET WITH THE PRIMARY CLIPPER WEAKENING OVER CNTRL NY.  A SHORT            
WAVE PIVOTING AROUND THE CLOSED 500 MB LOW IS MOVING ACROSS ERN                 
NY...WHICH IS HELPING TO FOCUS SOME OF THE -SN ACTIVITY.  MOST                  
SNOWFALL REPORTS IN OUR FCST AREA WERE IN THE HALF AN INCH TO TWO               
INCH RANGE EARLY THIS MORNING.  ADDITIONAL SNOW AMOUNTS OF A DUSTING            
TO AN INCH OR SO WILL BE POSSIBLE...EXCEPT A LITTLE MORE IS LIKELY              
OVER SRN VT.  THE SHORT WAVE ENERGY ROUNDING THE BASE OF THE LONG               
WAVE TROUGH SHOULD ALLOW THE COASTAL WAVE TO CONTINUE TO DEEPEN AND             
INTENSIFY...HOWEVER...THE AMOUNT OF MOISTURE/QPF DRAWN BACK UPSTREAM            
INTO OUR FCST AREA WILL BE LIMITED.  SOUTHEASTERN VT /WINDHAM                   
COUNTY/ MAY RECEIVE ANOTHER 1-4" OF SNOW TODAY...AS THE 850 MB                  
CLOSED CIRCULATION IS JUST EAST OF CAPE COD 12Z-18Z.  THE 850-700 MB            
DEFORMATION ZONE WITH WEAK TO MODERATE MID LEVEL FRONTOGENESIS                  
EXTENDS TO THE W/NW ENOUGH FOR PERIODS OF LIGHT TO POSSIBLY MODERATE            
SNOW NORTHEAST OF THE CAPITAL REGION.  FOR THE REST OF THE FORECAST             
AREA...STEEP LOW TO MID LEVEL LAPSE RATES...LOTS OF LOW LEVEL                   
MOISTURE...AND CYCLONIC VORTICITY ADVECTION WILL KEEP SCT SNOW                  
SHOWERS/FLURRIES AROUND THROUGH MOST OF THE DAY. ENOUGH WARMING IN              
THE BOUNDARY LAYER MAY EVEN ALLOW ONLY RAIN SHOWERS OR SPRINKLES IN             
THE MID HUDSON VALLEY.  850 MB TEMPS OF ABOUT -6C TO -8C SHOULD                 
ALLOW HIGHS IN THE L30S TO U30S IN THE VALLEYS...AND M20S TO L30S IN            
THE HILLS AND MTNS.  WE LEANED CLOSE TO THE GFSMOS MAX TEMP VALUES.             
&&                                                                              
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...                             
THURSDAY NIGHT...THE UPPER LEVEL LOW MIGRATES DOWNSTREAM WITH ANY               
LEFTOVER SNOW SHOWERS/FLURRIES ENDING AROUND MIDNIGHT.  WEAK 850 MB             
COLD AIR ADVECTION OCCURS WITH A 1037 HPA SFC ANTICYCLONE BUILDING              
SOUTH/SOUTHEAST FROM ERN QUEBEC/THE GULF OF ST LAWRENCE.  THIS IS               
NOT AN ARCTIC AIR MASS. IT WILL MORE OF THE POLAR VARIETY WITH                  
SEASONABLY COLD AIR AT BEST.  IT WILL TAKE SOME TIME TO SCOUR OUT               
ALL THE LOW LEVEL MOISTURE WITH THE UPPER LEVEL LOW.  THE BUFKIT                
PROFILES FROM KALB/KGFL/KPOU FROM THE GFS/NAM-WRF SHOW A FAIR AMOUNT            
OF MOISTURE LINGERING BELOW 5 KFT...SO CLOUDY/MOSTLY CLOUDY                     
CONDITIONS SHOULD DO IT HERE.                                                   
FRIDAY-SATURDAY...A FAIRLY QUIET STRETCH OF WEATHER WITH HIGH                   
PRESSURE BUILDING OVER NY AND NEW ENGLAND.  WE SHOULD SEE A FEW                 
BREAKS OF SUNSHINE BY FRIDAY AFTERNOON.  925 HPA TEMPS OVER THE                 
CAPITAL REGION WILL BE AROUND -5C...SO SEASONABLE HIGH TEMPS IN THE             
30S IN THE VALLEYS LOOK FINE.  HEIGHTS WILL CONTINUE TO RISE ALOFT              
AS A TROUGH FORMS UPSTREAM OVER THE 4 CORNERS AND EAST OF THE ROCKY             
MTN REGION.  THE 500 MB RIDGE AXIS BEGINS TO MOVE OVER THE NORTHEAST            
BY 12Z SAT.  FRIDAY NIGHT IS TRICKY IN TERMS OF TEMPS. LIGHT TO CALM            
WINDS AND CLEARING SKIES MAY ALLOW SOME RADIATIONAL COOLING.  THE               
NAM/GFS GUIDANCE WANTS TO INCREASE MID AND HIGH CLOUDS WITH THE                 
H850-700 WARM AIR ADVECTION.  WE WENT COLDER THAN THE MOS GUIDANCE              
AND LEANED TOWARD THE POSSIBILITY OF RADIATIONAL COOLING AND COLD               
TEMPS...ESPECIALLY NORTH OF THE CAPITAL REGION.  SATURDAY SHOULD BE             
MAINLY DRY...BUT WITH SOME INCREASING MID AND HIGH CLOUDS.  WE MAY              
SEE A SPRINKLE/FLURRY WEST OF THE HUDSON RIVER VALLEY LATE IN THE               
DAY.  WE LIKED THE DRY SCENARIO DEPICTED BY THE NAM/CAN GGEM. 850 MB            
TEMPS RISING CLOSE TO 0C SHOULD ALLOW TEMPS TO GET ABOVE NORMAL IN              
THE U30S TO L40S IN THE VALLEYS.  THE ETAMOS GUIDANCE LOOKED WAY TOO            
COLD WITH THE SFC HIGH SOUTH OF PRINCE EDWARD ISLAND SAT MORNING.               
&&                                                                              
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...                                
A STRONG SOUTHERLY FLOW IS EXPECTED TO DEVELOP ACROSS FA LATE                   
SATURDAY NIGHT AHEAD OF NEXT SHORT WAVE WHICH IS EXPECTED TO DEEPEN             
RAPIDLY AS IT LIFTS NORTHEAST THROUGH UPPER GREAT LAKES REGION                  
SUNDAY AND DRAGS A COLD FRONT THROUGH OUR REGION SUNDAY EVENING. AT             
THIS POINT IT LOOKS AS THOUGH TEMPS WILL BE STEADY OR SLOWLY RISING             
ON SATURDAY NIGHT WHICH WILL LIKELY RESULT IN SOME MIXED PCPN MAINLY            
IN THE FORM OF FREEZING RAIN AND SLEET SATURDAY NIGHT BASED ON                  
PARTIAL THICKNESS VALUES WITH A TRANSITION TO RAIN ACROSS THE ENTIRE            
FA BY SUNDAY MORNING. THE PCPN SATURDAY NIGHT LOOKS TO BE FAIRLY                
LIGHT WITH THE POTENTIAL FOR AT LEAST A HALF INCH TO AN INCH OF QPF             
ON SUNDAY WHICH WILL RESULT IN SOME HYDRO CONCERNS...SEE HYDROLOGY              
DISCUSSION. 00Z MREF PLUME DIAGRAM WOULD GIVE KALB 0.2 TO 2.0 INCHES            
WITH VERY LITTLE CLUSTERING RESULTING IN A LARGE SPREAD AMONGST                 
ENSEMBLE MEMBERS. QUITE A FEW ENSEMBLE MEMBERS ALSO INDICATE A BRIEF            
PERIOD OF FREEZING RAIN ON SATURDAY NIGHT BEFORE A QUICK CHANGEOVER             
TO RAIN AND MOSTLY RAIN UNTIL PCPN TAPERS OFF AS A LIGHT SNOW                   
ACCUMULATION SUNDAY NIGHT. 00Z MREFS ALSO HAS THE LOW PRESSURE                  
CENTER DEEPEN RAPIDLY AS IT TRACKS NORTH OF UPPER GREAT LAKES INTO              
CANADA ENDING UP 2-3 SD BELOW NORMAL AT 06Z MON WHILE H8 V COMPONENT            
WINDS NOW 3-4 SD ABOVE NORMAL IMPLYING STRONG SOUTHERLY COMPONENT AT            
18Z SUNDAY  THIS EVENT WILL NEED TO BE MONITORED CLOSELY FOR BOTH               
WIND CONCERNS AND HYDRO CONCERNS. AREAS PRONE TO STRONG SOUTHERLY               
WINDS SUCH AS TACONICS AND SOUTHERN VERMONT AND NORTHERN BERKSHIRES             
WOULD BE MOST AT RISK OF STRONGEST GUSTS WHICH COULD EASILY TOP 50              
MPH IN SOME OF THE MOST PRONE LOCATIONS SUNDAY. IN WAKE OF FRONT                
SUNDAY NIGHT WINDS EXPECTED TO SHIFT TO THE WEST WITH GUSTS STILL               
STRONG ACROSS HIGHER TERRAIN OF ADIRONDACKS. GFS 0-30 MB AGL WINDS              
INDICATE POTENTIAL FOR 50+ KNOT GUSTS FROM THE SOUTH SUNDAY AND FROM            
THE WEST SUNDAY NIGHT. THE WINDS ARE EXPECTED TO BE AMPLIFIED AS                
PRESSURE GRADIENT TIGHTENS ACROSS FA BETWEEN DEPARTING 1035 MB HIGH             
PRESSURE OFF NEW ENGLAND COAST AND LOW PRESSURE MOVING FROM UPPER               
GREAT LAKES INTO SOUTHERN CANADA AND DEEPENING TO BELOW 990 MB. THIS            
STRONG PRESSURE GRADIENT IS ALSO SUPPORTED BY ECMWF AND GEM GLOBAL              
WITH SOME DIFFERENCES IN EXACT LOCATION OF MAIN FEATURES. QPF                   
AMOUNTS OF AT LEAST 0.50 TO 1 INCH EXPECTED AND HYDRO CONCERNS ARE              
ADDRESSED IN HYDROLOGIC DISCUSSION. EVEN THOUGH THIS SYSTEM IS STILL            
3-4 DAYS OUT WILL INCLUDE MENTION OF POTENTIAL FOR FREEZING                     
RAIN...HIGH WINDS AND POSSIBLE FLOODING IN THE HWO.                             
LATE SUNDAY NIGHT AND MONDAY EXPECT SOME LAKE EFFECT SNOW ACROSS THE            
WESTERN ADIRONDACKS WHICH IS LIKELY TO BE ENHANCED BY A STRONG VORT             
AXIS ACROSS THIS REGION ON MONDAY.                                              
DRY WEATHER IS THEN EXPECTED TO RETURN ON CHRISTMAS EVE AND                     
CHRISTMAS DAY. ALTHOUGH A COASTAL SYSTEM LOOKS TO PASS FAR ENOUGH               
SOUTHEAST OF THE SOUTHERN NEW ENGLAND COAST ON TUESDAY NIGHT TO                 
SPARE FA SNOW...BUT DUE TO IT BEING A CLOSE CALL BASED ON THE ECMWF             
AND GFS WILL LEAVE SLIGHT CHANCE TO CHANCE POPS IN FORECAST FOR NOW.            
BOTH MODELS INDICATE THAT A STRENGTHENING RIDGE OF HIGH PRESSURE                
ACROSS FA IS EXPECTED TO DEFLECT COASTAL LOW OUT TO SEA. THIS WILL              
NEED TO BE MONITORED FOR FURTHER MODEL RUN CONTINUITY AS THIS IS                
MUCH FARTHER SOUTH AND EAST THAN TRACK WAS INDICATED YESTERDAY. IF              
THIS SYSTEM MISSES OUR FA THEN DRY WEATHER WILL CONTINUE THROUGH                
WEDNESDAY WITH NEXT SHORT WAVE NOT EXPECTED BEFORE THURSDAY.                    
OVERALL LONG TERM BEYOND MONDAY LOOKS COLD AND DRY AT THIS POINT IN             
TIME.                                                                           
&&                                                                              
.AVIATION /12Z THURSDAY THROUGH MONDAY/...                                      
VERY MOIST LOW LEVELS WITH TEMPS HOVERING AROUND THE FREEZING MARK              
ALONG WITH LITTLE AIR CIRCULATION AND STILL SOME LIGHT SNOW FALLING             
WILL KEEP LIFR/IFR CONDITIONS IN PLACE FOR MOST IF NOT ALL OF THE               
MORNING...ALTHOUGH THE SNOW WILL GRADUALLY DIMINISH IN COVERAGE AND             
INTENSITY DURING THE NEXT COUPLE OF HOURS. THE BIG QUESTION                     
CONTINUES TO BE HOW QUICKLY CIGS AND VSBYS WILL RISE LATER THIS                 
MORNING OR EARLY THIS AFTERNOON. BASED ON BUFKIT MODEL SOUNDINGS                
CLOUD AND INVERSION HEIGHTS REMAIN IN IFR RANGE THROUGH AT LEAST 15Z            
AT KGFL AND KPOU...BUT KALB MAY HAVE MOST DIFFICULTY BREAKING OUT OF            
LIFR/IFR RANGE AS SNOW SHOWER AND FLURRY ACTIVITY MAY END LAST IN               
CAPITAL DISTRICT. THERE IS ALSO SOME UNCERTAINTY HEADING INTO THIS              
EVENING...BUT WITH LOW LEVELS STILL MOIST AND LIGHT WINDS EXPECT AT             
LEAST A RETURN TO MVFR CONDITIONS AFTER 00Z. WINDS GENERALLY LIGHT              
AND VARIABLE THROUGH 12Z FRIDAY.                                                
OUTLOOK...                                                                      
FRI-SAT...VFR.                                                                  
SUN...IFR MIXED PCPN...STRONG S-SE WINDS.                                       
MON...VFR...EXCEPT MVFR/IFR IN LAKE EFFECT -SHSN DOWNWIND OF LK ONT.            
&&                                                                              
.HYDROLOGY...                                                                   
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH SATURDAY. WE HAVE                     
ANNOTATED BOTH THE RVDALY TEXT PRODUCT AND THE AHPS PAGES WHERE ICE             
IS CAUSING UNREPRESENTATIVE RIVER STAGE AND FLOW READINGS. SOME                 
PERIODS OF LIGHT SNOW EXPECTED TODAY. A STRONGER STORM SYSTEM MAY               
IMPACT THE REGION ON SUNDAY. THE STORM IS EXPECTED TO MOVE NORTH OF             
THE GREAT LAKES AND DRAG A COLD FRONT ACROSS OUR REGION LATE SUNDAY.            
AHEAD OF THE FRONT...TEMPERATURES ARE EXPECTED TO RISE ABOVE                    
FREEZING WITH THE WARMEST TEMPERATURES OVER ULSTER...DUTCHESS AND               
LITCHFIELD COUNTIES. SOME RUNOFF IS EXPECTED ON SUNDAY SOUTH OF I-90            
FROM A COMBINATION OF SNOW MELT AND RAINFALL. 00Z MREFS SHOW A 75               
PERCENT CHANCE OF A HALF INCH OF RAIN...AND 30 TO 50 PERCENT CHANCE             
OF OVER ONE INCH OF RAIN. AT THIS TIME RIVER FLOODING IS NOT                    
EXPECTED BUT THERE IS A THREAT THAT FLOODING COULD DEVELOP...                   
ESPECIALLY OVER SOUTHERN COUNTIES...IF TEMPERATURES TURN OUT WARMER             
AND RAINFALL IS HEAVIER. LOCALIZED FLOODING IS POSSIBLE IN SOUTHERN             
URBAN AREAS WHERE STORM DRAINS ARE BLOCKED BY SNOW.                             
&&                                                                              
.ALY WATCHES/WARNINGS/ADVISORIES...                                             
CT...NONE.                                                                      
NY...NONE.                                                                      
MA...NONE.                                                                      
VT...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...WASULA                                                               
NEAR TERM...WASULA                                                              
SHORT TERM...WASULA                                                             
LONG TERM...11                                                                  
AVIATION...11                                                                   
HYDROLOGY...11                                                                  
</pre> ct                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ALBANY NY                                              
1257 AM EST THU DEC 20 2007                                                     
.SYNOPSIS...                                                                    
A CLIPPER LOW PRESSURE SYSTEM WILL DISSIPATE IN IN THE EASTERN GREAT            
LAKES REGION THIS EVENING...WITH A SECONDARY LOW FORMING OFF CAPE               
COD OVERNIGHT. THESE LOWS WILL BRING PERIODS OF LIGHT SNOW TO THE               
REGION INTO THURSDAY. HIGH PRESSURE WILL BUILD BACK IN THURSDAY                 
NIGHT INTO FRIDAY AND SLIDE OFFSHORE SATURDAY. SATURDAY NIGHT AND               
SUNDAY A COLD FRONT WILL PUSH THROUGH THE REGION...WARMER AIR WILL              
STREAM INTO THE REGION AHEAD OF THE FRONT...RESULTING IN THE                    
THREAT OF MIXED PRECIPITATION CHANGING TO RAIN SUNDAY. HIGH                     
PRESSURE WILL BUILD FROM THE GREAT LAKES INTO QUEBEC MONDAY AND                 
TUESDAY.                                                                        
&&                                                                              
.NEAR TERM /UNTIL 6 AM THIS MORNING/...                                         
SHORT WAVE WAS PROGRESSING ACROSS UPSTATE NEW YORK WITH A WIDESPREAD            
AREA OF LIGHT SNOW IMPACTING MOST OF THE CWA (MAINLY THE EASTERN                
HALF).  IT SEEMS A LOCAL HUDSON VALLEY CONVERGENCE ZONE HAS EVOLVED             
COMBINING WITH FAVORABLE UPSLOPE CONDITIONS FOR A BAND OF                       
LIGHT-MODERATE SNOW.  18Z WRF/NAM AND LATEST RUC13 ALSO SHOW SOME               
HINTS IN THE LOW LEVEL CONVERGENCE FIELDS ALONG WITH INCREASING                 
DEFORMATION/TROWAL AXIS ACROSS WESTERN NEW ENGLAND INTO PORTIONS OF             
LAKE GEORGE AND SARATOGA REGION.  THESE REGIONS WILL LIKELY REMAIN              
WITHIN A FAVORABLE SNOWFALL REGION WHILE AREAS TO THE WEST...WE ARE             
LOSING ICE NUCLEI AS MID AND HIGHER LEVEL DRIER AIR ADVECTS INTO THE            
REGION.  WILL NEED TO MONITOR FZDZ BUT NOTHING REPORTED THUS FAR                
UPSTREAM.  TEMPERATURES ARE NOW AT OR BELOW THE FREEZING MARK WHICH             
SHOULD SIGNIFY SOME ACCUMULATIONS.  MADE SOME MODIFICATIONS TO THE              
FORECAST/GRIDS BASED ON THOSE AFOREMENTIONED TRENDS AND CURRENT                 
GUIDANCE.                                                                       
&&                                                                              
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM FRIDAY/...                          
BY 12Z/THURSDAY COASTAL LOW IS THE DOMINATE LOW WITH BAGGINESS IN               
THE PRESSURE FIELDS ACROSS THE FORECAST AREA. IN ADDITION...A                   
SHORT WAVE WILL ROTATE THROUGH THE UPPER LEVEL TROUGH OVER THE                  
REGION THURSDAY. LIGHT SNOW SHOULD LINGER OVER SOUTHERN VERMONT                 
WITH SOME SNOW SHOWERS ACROSS THE REST OF THE FORECAST AREA.                    
CHANCES FOR PRECIPITATION WILL DECREASE AS THE DAY WEARS ON DAY.                
HIGH PRESSURE TO THE NORTH OVER EASTERN CANADA WILL BUILD SOUTH                 
THURSDAY NIGHT.                                                                 
&&                                                                              
.LONG TERM /FRIDAY THROUGH THURSDAY/...                                         
FIRST PART OF PERIOD FRIDAY AND SATURDAY FAIRLY QUIET AS SFC HIGH               
PRESSURE BUILDS ACROSS GREAT LAKES INTO QUEBEC. SATURDAY NIGHT IT               
SLIDES OFF SHORE AS 500HPA RIDGE BUILDS ALONG EASTERN SEABOARD.                 
CDFNT PUSHES THROUGH GRTLKS SAT NIGHT AND ACROSS NY AND NEW ENG                 
SUNDAY. MAJOR DYNAMICS WITH SYSTEM ARE WELL NORTH OF REGION IN                  
QUEBEC WITH MAIN IMPACT BEING THE CDFNT. WITH PERIOD OF SOUTHERLY               
WINDS TEMPS WILL HOLD OR RISE SAT NIGHT...BUT WILL START                        
SUFFICIENTLY COLD TO RESULT IN MIXED PCPN TYPES INTO SUN MRNG.                  
PCPN WILL BE SPOTTY IN THE MOISTURE INFLOW AND BULK OF IT WILL BE               
ASSOCIATED WITH CFP. TEMPS WILL RISE ENOUGH TO TURN THE MIX TO                  
RAIN IN MOST OF FCA PRIOR TO CFP. IN GENERAL ENSEMBLES CENTERED                 
AROUND 0.75 INCH OF QPF WITH THIS EVENT..SOME PORTION OF WHICH                  
WILL BE FROZEN. TREND HAS BEEN TWRD LOWER QPF. THIS IS COVERED IN               
MORE DETAIL IN HYDRO SECTION. THIS IS A SYSTEM THAT THE MAIN LOW                
IS WELL TO THE NORTH...ESSENTIALLY A CLIPPER...HAS LIMITED PERIOD               
OF MOISTURE INFLOW FROM THE ATLC. CDFNT SWEEPS QUICKLY OFFSHORE                 
SUNDAY NIGHT AS HIGH PRESSURE BUILDS EAST FROM THE                              
GRTLKS...FOLLOWED BY A SECONDARY ARCTIC FRONT ON MONDAY. MONDAY                 
AND TUESDAY WILL BE MAINLY DRY EXCEPT FOR -SHSN ASSOCIATED WITH                 
SECONDARY FRONT AND FLOW INTERACTIONS WITH TRRN. TUESDAY INTO                   
WEDNESDAY THERE IS QUITE A BIT OF DIVERGENCE BETWEEN THE                        
GFSMOS...EUROPEAN AND HPC. WITH THE GFS TAKING A LARGE LOW                      
THROUGH THE TENNESSEE VALLEY AND THEN A SECONDARY FORMING OVER                  
DELMARVA AS EARLY AS CHRISTMAS DAY. THE OTHERS DEVELOP THIS                     
SYSTEM ALONG THE SE US COAST...AND TAKE IT UP THE SEABOARD EITHER               
AS SOME SORT OF SNOW EVENT...OR TOO FAR EAST TO AMOUNT TO                       
ANYTHING. FOR NOW CHC OF SNOW WILL SUFFICE...WE ARE TALKING ABOUT               
DAYS 7/8.                                                                       
&&                                                                              
.AVIATION /06Z THURSDAY THROUGH MONDAY/...                                      
VERY MOIST LOW LEVELS WITH TEMPS HOVERING AROUND THE FREEZING MARK              
ALONG WITH LITTLE AIR CIRCULATION AND STILL SOME LIGHT SNOW FALLING             
WILL KEEP LIFR/IFR CONDITIONS IN PLACE FOR MOST IF NOT ALL OF THE               
REMAINDER OF THE OVERNIGHT PERIOD. THE BIG QUESTION AT THIS POINT               
WILL BE HOW QUICKLY CIGS AND VSBYS WILL RISE AFTER SUNRISE AND                  
EXPECT THAT AT KGFL IT MAY TAKE UNTIL AFTERNOON AS LITTLE WIND FLOW             
EXPECTED. KALB AND KPOU HAVE A BETTER CHANCE TO MIX AND ALSO EXPECT             
LESS IN THE WAY OF SNOW SHOWER ACTIVITY AS CLIPPER TYPE SYSTEM PULLS            
AWAY FROM FA. EVEN AT KALB AND KPOU IT MAY TAKE MUCH OF THE MORNING             
BEFORE MVFR CONDITIONS GIVE WAY TO VFR. THERE IS SOME UNCERTAINTY               
HEADING INTO THIS EVENING...BUT WITH LOW LEVELS STILL MOIST AND                 
LIGHT WINDS EXPECT AT LEAST A RETURN TO MVFR CONDITIONS AFTER 00Z.              
WINDS GENERALLY LIGHT AND VARIABLE THROUGH 06Z FRIDAY...EXCEPT                  
NORTHWEST AT 5-8 KTS AT KALB BETWEEN 12Z AND 00Z.                               
OUTLOOK...                                                                      
FRI-SAT...VFR.                                                                  
SUN...IFR MIXED PCPN...STRONG S-SE WINDS.                                       
MON...VFR...EXCEPT MVFR/IFR IN LAKE EFFECT -SHSN DOWNWIND OF LK ONT.            
&&                                                                              
.HYDROLOGY...                                                                   
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH SATURDAY. WE HAVE                     
ANNOTATED BOTH THE RVDALY TEXT PRODUCT AND THE AHPS PAGES WHERE ICE             
IS CAUSING UNREPRESENTATIVE RIVER STAGE AND FLOW READINGS. SOME                 
PERIODS OF LIGHT SNOW EXPECTED TONIGHT AND THURSDAY. A STRONGER                 
STORM SYSTEM MAY IMPACT THE REGION ON SUNDAY. THE STORM IS EXPECTED             
TO MOVE NORTH OF THE GREAT LAKES AND DRAG A COLD FRONT ACROSS OUR               
REGION LATE SUNDAY. AHEAD OF THE FRONT...TEMPERATURES ARE EXPECTED              
TO RISE ABOVE FREEZING WITH THE WARMEST TEMPERATURES OVER                       
ULSTER...DUTCHESS AND LITCHFIELD COUNTIES. SOME RUNOFF IS EXPECTED              
ON SUNDAY SOUTH OF I-90 FROM A COMBINATION OF MELT AND RAINFALL.                
MODEL ENSEMBLES SHOW A 75 PERCENT CHANCE OF A HALF INCH OF                      
RAIN...AND LESS THAN 30 PERCENT CHANCE OF OVER ONE INCH OF RAIN. AT             
THIS TIME RIVER FLOODING IS NOT EXPECTED BUT THERE IS A THREAT THAT             
FLOODING COULD DEVELOP...ESPECIALLY OVER SOUTHERN COUNTIES...IF                 
TEMPERATURES TURN OUT WARMER AND RAINFALL IS HEAVIER. LOCALIZED                 
FLOODING IS POSSIBLE IN SOUTHERN URBAN AREAS WHERE STORM DRAINS ARE             
BLOCKED BY SNOW.                                                                
&&                                                                              
.ALY WATCHES/WARNINGS/ADVISORIES...                                             
CT...NONE.                                                                      
NY...NONE.                                                                      
MA...NONE.                                                                      
VT...NONE.                                                                      
&&                                                                              
$$                                                                              
AVIATION...11                                                                   
</pre> ct                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ALBANY NY                                              
1248 AM EST WED DEC 19 2007                                                     
.SYNOPSIS...                                                                    
A CLIPPER LOW PRESSURE SYSTEM WILL APPROACH FROM THE UPPER GREAT                
LAKES REGION TONIGHT. THIS LOW WILL BRING PERIODS OF LIGHT                      
SNOW TO EASTERN NEW YORK AND WESTERN NEW ENGLAND WEDNESDAY                      
AFTERNOON INTO THURSDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL                
PRODUCE SCATTERED SNOW SHOWERS THURSDAY AFTERNOON. A BROAD AREA OF              
HIGH PRESSURE WILL RIDGE BACK INTO THE REGION FROM QUEBEC THURSDAY              
NIGHT INTO FRIDAY.                                                              
&&                                                                              
.NEAR TERM /UNTIL 6 AM THIS MORNING/...                                         
THE COMBINATION OF MID LEVEL WARM ADVECTION (AS EVIDENCE PROVIDED BY            
THE 00Z SOUNDINGS FROM HERE AND AT BUF BETWEEN 800-900MB) UNDERWAY              
AND SLIGHT Q-VECTOR CONVERGENCE ALONG WITH DEPARTING UPPER JET HAS              
RESULTED IN MOISTURE CONVERGENCE IN THE FORM OF MID AND HIGH                    
CLOUDS.  LATEST RUC13 CONTINUES TO SUPPORT AN INCREASE IN RH FIELDS             
(ALTHOUGH THERE WILL BE SEVERAL BREAKS) AND WILL ADJUST ACCORDINGLY             
WITH THE SKY FORECAST/GRIDS.  IN ADDITION...THIS WILL HAVE AN IMPACT            
ON OVERNIGHT LOWS AND WILL RAISE THEM A FEW DEGREES.  THIS WAS                  
CAPTURED WELL WITH THE 18Z GFSMOS GUIDANCE AND CURRENT TRENDS SEEN              
IN THE LAMP NUMBERS.  HOWEVER...THE AFOREMENTIONED BREAKS IN THE                
CLOUDS AND FRESH SNOWPACK WILL PLAY A FACTOR SO WILL CONTINUE TO BE             
A LITTLE CONSERVATIVE WITH LOW TEMPS.                                           
OTHERWISE...UPSTREAM SHORT WAVE CONTINUES TO ADVANCE EAST FROM THE              
UPPER MISSISSIPPI RIVER VALLEY WITH LITTLE IN WAY OF UPSTREAM                   
OBSERVATIONS REPORTING PRECIP.  DTX AND PBZ SOUNDINGS THIS EVENING              
WERE QUITE DRY SO WILL BE INTERESTING TO SEE HOW THE 00Z GUIDANCE               
SHOWS THE PRECIP TRENDS FOR WEDNESDAY.                                          
&&                                                                              
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...                               
MID AND HIGH CLOUDS THICKEN THROUGH THE DAY WEDNESDAY IN ADVANCE                
OF THE NORTHERN STREAM UPPER SYSTEM. BOUNDARY LAYER WARM ADVECTION              
WILL INCREASE AS SOUTHWESTERLY LOW-LEVEL WINDS INCREASE...ALONG                 
WITH ISENTROPIC LIFT. SNOW WILL BEGIN IN MANY AREAS BY                          
SUNSET...BUT WILL BE LIGHT...THEN CONTINUE PERIODICALLY INTO THE                
NIGHT...ENDING IN MANY AREAS THURSDAY MORNING.                                  
BASED ON THE TRACK OF THE UPPER SYSTEM AND THE 850 MB LOW...MOST                
OF THE PRECIPITATION WILL FALL IN THE ADIRONDACKS...NORTHERN LAKE               
GEORGE REGION AND MOUNTAINS OF SOUTHERN VT. THE SYSTEM STRENGTHENS              
AS IT EXITS NEW ENGLAND...AND A QUICK EASTERLY WIND ANOMALY                     
DEVELOPS THAT NOSES INTO EASTERN AND NORTHERN NEW ENGLAND.                      
THEREFORE...SNOW WILL LINGER IN SOUTHERN VT THROUGH THURSDAY INTO               
THURSDAY NIGHT. BUT...AFTER THURSDAY MORNING...ANY LINGERING                    
SOUTHERN VT SNOWS WOULD BE LIGHT AND SHOWERY. SOME FLURRY ACTIVITY              
IS POSSIBLE ANYWHERE THURSDAY...WITH CHANCES FOR MORE SUBSTANTIAL               
SNOW SHOWER ACTIVITY DOWNWIND FROM LAKE ONTARIO.                                
BASED ON GUIDANCE INCLUDING SREF AND MREF PLUMES...AROUND A                     
QUARTER TO A THIRD OF AN INCH LIQUID EQUIVALENT POSSIBLE IN                     
ADIRONDACKS...NORTHERN LAKE GEORGE REGION AND SOUTHERN VT...WITH                
LESS FOR POINTS SOUTH. SO...2-4" POSSIBLE IN AREAS OF MAX...WITH                
PERHAPS AROUND AN INCH OR TWO MOHAWK VALLEY...CAPITAL DISTRICT AND              
BERKSHIRES AND POINTS SOUTH...WITH A COATING TO AN INCH                         
CATSKILLS...TACONICS AND NW CT. SYSTEM EXITS LATER THURSDAY AND                 
THURSDAY NIGHT...SO GRADUAL CLEARING LATER THURSDAY AND THURSDAY                
NIGHT. SOME LAKE EFFECT MOISTURE AFFECTING WESTERN AREAS INTO                   
THURSDAY NIGHT WITH NORTHWEST LOW-LEVEL FLOW. DRY WEATHER                       
CONTINUES FRIDAY.                                                               
TEMPERATURES WILL BE IN THE 20S AND 30S WEDNESDAY THROUGH                       
FRIDAY...SINCE TRUE ARCTIC AIR WILL HAVE RETREATED NORTH.                       
&&                                                                              
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...                                  
THE 500 HPA TROF CONTINUES TO DIG SOUTH AND ADVANCE EAST WITH A                 
CLOSED LOW DEVELOPING NORTH OF THE DAKOTAS AS THE RIDGE OVER THE                
EASTERN STATES SLOWLY DRIFTS EAST. THE SURFACE HIGH UNDER THE                   
RIDGE BUILDS EAST INTO THE MARITIMES WHILE A FRONTAL SYSTEM                     
ASSOCIATED WITH THE TROF MOVES TO THE MISSISSIPPI VALLEY. THE                   
POSSIBILITY OF OVERRUNNING PRECIPITATION DEVELOPS SATURDAY MORNING              
AS A LOW LEVEL FLOW FROM THE SOUTH RUNS UP AGAINST THE COLD DOME                
ASSOCIATED WITH THE HIGH OVER THE MARITIMES. BY MIDDAY TEMPERATURES             
OVER THE REGION WARM INTO THE MID TO UPPER THIRTIES OVER MOST OF                
THE AREA FROM THE MOHAWK VALLEY SOUTH...EXCEPT FOR THE HIGHER                   
ELEVATIONS OF THE CATSKILLS...RESULTING IN SNOW NORTH AND OVER                  
THE HIGHER TERRAIN...RAIN OVER THE MID HUDSON REGION...AND A MIX                
IN BETWEEN. LATE IN THE AFTERNOON TEMPERATURES AT 850 HPA WARM TO               
AROUND PLUS 2 AND THE WARMING ALOFT CONTINUES THROUGH THE NIGHT                 
WITH 850 HPA TEMPERATURES PLUS 6 TO PLUS 8 BY 12Z SUNDAY. THIS                  
BRINGS ABOUT THE POSSIBILITY OF FREEZING RAIN OVER COLDER AREAS...              
ESPECIALLY NORTH AND WEST WHERE TEMPERATURES ALOFT ARE EXPECTED TO              
WARM FASTER FROM THE LOW LEVEL FLOW UP THE OHIO VALLEY. THE                     
PRIMARY LOW ROCKETS INTO CENTRAL QUEBEC WHILE A SECOND LOW                      
DEVELOPS OVER SOUTHERN NEW ENGLAND AS THE FRONT MOVES THROUGH THE               
REGION SUNDAY AFTERNOON. BEFORE THE FRONT PASSES SURFACE TEMPS ARE              
EXPECTED TO WARM UP ENOUGH TO TURN THE PRECIPITATION TO RAIN OVER               
THE ENTIRE FORECAST AREA. AFTER THE FRONT PASSES THE RAIN WILL MIX              
AND TURN BACK TO SNOW SUNDAY NIGHT...THEN MIX WITH AND CHANGE TO                
RAIN IN OUR SOUTHERN ZONES LATE MONDAY MORNING BEFORE THE COLD AIR              
RETURNS AS THE COASTAL LOW LIFTS NORTHEAST BRINGING IN ANOTHER                  
BLAST OF COLD AIR MONDAY EVENING. CHRISTMAS MORNING WILL FIND US                
BETWEEN A DEEP LOW OVER THE MARITIMES...A WEAK HIGH JUST NORTH OF               
LAKE HURON...AND A STRONGER HIGH OVER THE OHIO VALLEY. THE GOOD                 
NEWS IS THAT THE HIGH OVER THE OHIO VALLEY IS FORECAST TO BUILD                 
NORTH ENOUGH TO SHIFT THE GRADIENT AND STRONG NORTH WESTERLY WINDS              
OFF INTO COASTAL NEW ENGLAND...RESULTING IN PARTLY TO MOSTLY                    
CLOUDY SKIES OVER THE REGION AND JUST A SLIGHT CHANCE OF SOME SNOW              
SHOWERS OVER THE HIGHER TERRAIN WEST OF THE HUDSON VALLEY.                      
&&                                                                              
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...                                     
VFR CONDITIONS EXPECTED TO HOLD THROUGH EARLY TO MID AFTERNOON WITH             
P6SM BKN120 OVC250 EXPECTED DURING MUCH OF THE PERIOD AS MID AND                
HIGH CLOUDS OVERSPREAD THE REGION AHEAD OF A CLIPPER TYPE SYSTEM.               
LIGHT SNOW EXPECTED TO DEVELOP MID TO LATE AFTERNOON AS CLIPPER                 
DIVES SOUTHEAST INTO EASTERN GREAT LAKES REGION. MVFR/IFR EXPECTED              
AT KGFL AFTER 19Z AND 21Z RESPECTIVELY AS LIGHT SNOW OVERSPREADS THE            
REGION. MVFR CONDITIONS EXPECTED AT KALB AND KPOU AFTER 20Z AND 21Z             
RESPECTIVELY WITH JUST VCSH AT KPOU AS VERY LITTLE QPF TO WORK WITH             
ACROSS SOUTHERN PORTION OF FA. WINDS EXPECTED TO BE LIGHT AND                   
VARIABLE OR SOUTH TO SOUTHEAST AT 5 KTS OR LESS.                                
OUTLOOK...                                                                      
THU...VFR/MVFR CIGS...WDLY SCT SNOW SHOWERS.                                    
FRI-SAT...VFR/MVFR...CHANCE -SN KALB/KGFL...-RA/-SN KPOU.                       
SUN...IFR MIXED PCPN.                                                           
&&                                                                              
.HYDROLOGY...                                                                   
NO HYDRO PROBLEMS ARE ANTICIPATED UNTIL THE WEEKEND. ICE WILL                   
CONTINUE TO FORM AND THICKEN ON THE RIVERS. THE ICE IS CAUSING                  
SEVERAL RIVER GAGES...PARTICULARLY MCKEEVER AND PRATTSVILLE...                  
TO READ HIGHER THAN THEY WOULD IF THE CHANNELS WERE CLEAR.                      
STARTING LATE SATURDAY NIGHT...WARM AIR OVERRUNNING THE COLDER                  
AIR IN THE REGION WILL BEGIN PRECIPITATION STARTING AS SNOW BUT                 
LIKELY CHANGING TO FREEZING RAIN AND EVENTUALLY RAIN ALONG WITH                 
A SIGNIFICANT WARM UP BY MIDDAY SUNDAY WITH HIGHS FROM THE UPPER                
30S TO THE MID 40S...ALONG WITH STRONG SOUTHERLY WINDS. THE                     
COMBINATION OF RAIN...MELTING SNOW...AND IN SOME CASES RIVER                    
CHANNEL BLOCKAGES WITH ICE...COULD BRING ABOUT SOME SIGNIFICANT                 
RISES IN WATER LEVELS AND POSSIBLY EVEN SOME FLOODING SUNDAY                    
NIGHT INTO MONDAY. AREAS MOSTLY LIKELY TO BE AFFECTED INCLUDE                   
THE CATSKILLS...BERKSHIRES...MID HUDSON REGION OF NY...AND THE                  
HOUSATONIC VALLEY IN WESTERN NEW ENGLAND.                                       
&&                                                                              
.ALY WATCHES/WARNINGS/ADVISORIES...                                             
CT...NONE.                                                                      
NY...NONE.                                                                      
MA...NONE.                                                                      
VT...NONE.                                                                      
&&                                                                              
$$                                                                              
AVIATION...11                                                                   
</pre> ct                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE CHARLESTON SC                                          
927 PM EST THU DEC 20 2007                                                      
.SYNOPSIS...                                                                    
SURFACE HIGH PRES WILL GIVE WAY TO AN APPROACHING UPPER-LEVEL                   
DISTURBANCE WHICH WILL PASS THROUGH THE REGION AND MOVE OFF THE                 
COAST EARLY FRI. THIS WILL ENHANCE A WEDGE PATTERN OVER THE                     
CAROLINAS THAT SHOULD BREAK DOWN ON SUN AS A COLD FRONT APPROACHES              
FROM THE W. THE FRONT WILL MOVE OFF THE COAST EARLY MON...BUT                   
UNSETTLED WEATHER COULD RETURN BY CHRISTMAS DAY AS ANOTHER UPPER-               
LEVEL DISTURBANCE IS POSSIBLE.                                                  
&&                                                                              
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...                                       
SURFACE OBSERVATIONS INDICATE COLD AIR DAMMING IS BEGINNING TO                  
TAKE SHAPE ACROSS INLAND AREAS WHILE COASTAL FRONTOGENESIS IS                   
ONGOING OFFSHORE. THE INLAND WEDGE AND ASSOCIATED COASTAL FRONT                 
WILL STRENGTHEN OVERNIGHT AS THERMAL GRADIENTS INTENSIFY DUE TO                 
DIABATIC COOLING AND INCREASING BAROCLINICITY OFFSHORE NEAR THE                 
WRN WALL OF THE GULF STREAM. OPTED TO RAISE LOW TEMPS A DEG OR TWO              
MOST AREAS BASED ON THE LATEST RUC-13 WET-BULB PROGNOSTICATIONS                 
BUT STILL EXPECT TEMPS TO BOTTOM OUT IN THE UPR 40S ACROSS WELL                 
INLAND WITH UPR 50S ALONG THE BEACHES. AN AREA OF WDSPRD RAINFALL               
THAT IS MOVING ACROSS SRN GA IS STEADILY EXPANDING AHEAD OF A                   
SHORTWAVE NOTED ALONG THE CENTRAL GULF COAST. THIS AREA OF RAIN                 
WILL INTENSITY THROUGH THE NGT AS INCRG OMEGA AHEAD OF THE                      
SHORTWAVE COMBINES WITH INCRG ISENTROPIC LIFT ATOP THE WEDGE. POPS              
NEAR 100 PCNT ARE ON TRACK AND AGREE WELL WITH CURRENT RADAR AND                
SHORT-TERM MODEL TRENDS.                                                        
WE ARE CAREFULLY WATCHING THE INTENSIFYING N-S ORIENTED SQUALL                  
LINE THAT IS MOVING ACROSS THE GULF WATERS SOUTH OF THE FL                      
PANHANDLE THIS EVNG. SO FAR THE LINE HAS SHOWN NO SIGNS OF                      
SIGNIFICANTLY DISRUPTING 850MB MOISTURE TRANSPORT N INTO SC/GA.                 
THUS EXPECT THE RAIN TO BECOME LCLLY HEAVY AT TIMES BY EARLY FRI                
AS LOW-LVL CONVG ALONG THE WEDGE FRONT INCRS AND PWATS CLIMB ABOVE              
1.25 INCHES. ALTHOUGH WDSPRD DEEP CONVECTION WILL BE LACKING...                 
BUILDING ASTRONOMICAL TIDES MAY PEAK DURING A PERIOD OF MODERATE                
TO HEAVY RAINS ACROSS THE COASTAL COUNTIES EARLY FRI MRNG WHICH                 
RAISES THE CONCERN FOR POSSIBLE FRESH WATER FLOODING PROBLEMS...                
ESPECIALLY IN THE DOWNTOWN CHARLESTON AREA. WILL DEFER THE                      
DECISION FOR A FLOOD WATCH TO THE MIDNGT SHIFT AND MAINTAIN A                   
MENTION OF POSSIBLE FLOODING PROBLEMS IN THE HAZARDOUS WEATHER                  
OUTLOOK.                                                                        
&&                                                                              
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...                        
THE LOW PRESSURE SYSTEM WILL SHIFT OFF THE GA/SC COASTLINE                      
FRI...WITH RAIN CHANCES SUBSEQUENTLY DECREASING THROUGH THE DAY                 
FROM SW TO NE. THE COASTAL LOW OFFSHORE WILL ACT TO AMPLIFY THE                 
PERSISTENT INLAND SURFACE WEDGE. THICK CLOUD COVER AND RESIDUAL                 
DRIZZLE DIABATICALLY ENHANCING THE COLD AIR DAMMING WILL CREATE                 
CHILLY CONDITIONS FOR THE NORTHERN AND WESTERN COUNTIES. EXPECT                 
HIGHS TO BE SUPPRESSED IN THE LOWER 50S NW ZONES...INCREASING TO                
THE LOWER TO MID 60S TOWARD THE S. A PINCHED GRADIENT ALONG THE                 
CHARLESTON COUNTY COAST WILL LIKELY SUPPORT BREEZY CONDITIONS                   
THERE FOR MUCH OF THE DAY.                                                      
LAKE WINDS...A LAKE WIND ADVISORY MAY BE NEEDED FOR LAKE MOULTRIE               
ON FRIDAY...BUT MUCH WILL DEPEND ON WHERE EXACTLY THE SFC LOW                   
DVLPS. WILL HOLD THE FCST JUST UNDER ADVISORY CRITERIA FOR NOW..BUT             
HEADLINE THAT AN ADVISORY MAY BE NEEDED.                                        
&&                                                                              
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...                                   
SOLID WEDGE WILL BE IN PLACE FRIDAY NIGHT INTO SATURDAY WITH                    
NORTHEAST WINDS...COOL TEMPS...NOT A LOT OF SUN...AND EVEN A FEW                
LIGHT SHOWERS/DRIZZLE ...MAINLY IN THE NORTHEASTERN HALF OF THE                 
CWA. WENT BELOW GUIDANCE FOR TEMPS ON SATURDAY.                                 
WINDS START TO VEER SATURDAY NIGHT AHEAD OF THE NEXT FRONT WITH A               
WARMER DAY SUNDAY ON SOUTH TO SOUTHWESTERLY WINDS. STILL...THE WEDGE            
MAY TRY TO HOLD ON FAR NORTH...BUT HAVE NOT GONE WITH THAT SOLUTION.            
AGAIN...THERE IS A SMALL CHANCE OF SHOWERS AHEAD OF THE FRONT.                  
COLD FRONT GOES THROUGH SUNDAY NIGHT CAUSING THE WINDS TO COME                  
AROUND TO THE NORTHWEST. THIS WILL INTRODUCE SOME DRYING WITH A                 
BETTER CHANCE FOR SUNSHINE MONDAY. TEMPS WILL BE SEASONABLE.                    
FORECAST BECOMES VERY UNCERTAIN FOR THE REMAINDER OF CHRISTMAS WEEK             
AS MODELS DIFFER SIGNIFICANTLY ON THE EVOLUTION OF A DEVELOP LOW.               
ONE SET OF SOLUTIONS DEVELOPS THE LOW OFF THE SOUTHEAST COAST AND               
SETS UP FOR A COOL CHRISTMAS WITH A CHANCE OF RAIN. ANOTHER SET                 
DEVELOPS THE SYSTEM QUITE A BIT FURTHER WEST AND KEEPS US DRY UNTIL             
WEDNESDAY. FOR NOW...I WENT WITH CONTINUITY WHICH IS MORE                       
PESSIMISTIC FOR CHRISTMAS DAY...BUT I DO NOT HAVE MUCH CONFIDENCE               
DUE TO THE DIVERGENCE OF MODEL SOLUTIONS.                                       
&&                                                                              
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...                                       
VFR CONDITIONS WILL DETERIORATE TONIGHT AT BOTH CHS AND SAV TERMINALS.          
MVFR CIGS AND VSBYS WILL BEGIN BY 07Z AT THE SAV TERMINAL AND 09Z               
AT THE CHS TERMINAL AS A SYSTEM OF LOW PRESSURE BRINGS RAIN OVER                
THE AREA. RAIN WILL BE HEAVY AT TIMES BY 12Z AT BOTH TERMINALS.                 
WILL LIKELY SEE IFR CONDITIONS BEGIN BY 10Z AT THE SAV TERMINAL                 
AND 12Z AT THE CHS TERMINAL AS HEAVY PRECIP PUSHES OCCURS. LIFR                 
CIGS OF 400 FEET WILL TEMPORARILY ACCOMPANY HEAVIER RAIN AT BOTH                
TERMINALS. CONDITIONS WILL BEGIN TO IMPROVE TOMORROW AFTERNOON AS               
THE COASTAL LOW BEGINS TO SHIFT NORTHEAST. MVFR VSBYS AND CIGS ARE              
ANTICIPATED THROUGH MOST OF TOMORROW AFTERNOON...WITH ACTIVITY                  
REMAINING OVER THE CHS TERMINAL LONGER THAN THE SAV TERMINAL. HAVE              
ADDED CB TO THE SAV TERMINAL FROM THE 12Z TO 18Z PERIOD AS                      
INSTABILITY INCREASES BEFORE THE LOW PUSHES EAST.                               
WILL SEE EAST WINDS BACK TO THE NORTHEAST TONIGHT AS THE LOW                    
PUSHES TOWARDS THE ATLANTIC. HAVE ADDED WIND GUSTS UP TO 20 KNOTS               
OVER THE CHS TERMINAL AS RAIN WILL ALLOW A STRONG GRADIENT WIND TO              
MIX TO THE SFC DURING THE 12Z TO 20Z TIME FRAME TOMORROW.                       
EXTENDED AVIATION OUTLOOK...A PERIOD MVFR OR IFR POSSIBLE FRIDAY                
NIGHT INTO SATURDAY NIGHT WITH LOW CLOUDS AND POSSIBLE FOG IN                   
WEDGE CONDITIONS. THERE SHOULD BE SOME IMPROVEMENT BY SUNDAY NIGHT              
AND MONDAY...BUT ANOTHER ROUND OF LOW CIGS IS POSSIBLE TUESDAY AND              
TUESDAY NIGHT.                                                                  
&&                                                                              
.MARINE...                                                                      
THE PRESSURE GRADIENT IS SLOWLY INTENSIFYING ALONG THE SC COAST                 
THIS EVNG BTWN HIGH PRES BUILDING INLAND AND A DVLPG COASTAL FRONT              
OFFSHORE. THE GRADIENT WILL CONTINUE TO PINCH ACROSS THE SC WTRS                
OVRNGT AND INTO FRI AS LOW PRES DVLPS OFF THE SC/GA COAST AND                   
COLD AIR DAMMING STRENGTHS INLAND. THE 21/00Z MODELS ARE BEGINNING              
TO TRICKLE IN AND STILL SUGGEST THERE IS A POTENTIAL FOR GALE                   
FORCE WINDS...AT LEAST IN FREQUENT GUSTS...ALONG THE CHARLESTON                 
COUNTY COASTAL WATERS OUTSIDE OF THE HARBOR. THEY HAVE BEEN HINTING             
AT THIS POSSIBILITY FOR THE LAST SEVERAL RUNS SO WILL GO AHEAD AND              
ISSUE A GALE WATCH FOR THE WATERS N OF EDISTO BEACH BEGINNING                   
AROUND SUNRISE FRI AND CONTINUING THROUGH FRI NGT. THE WATCH MAY                
BE UPGRADED TO A GALE WARNING WITH THE EARLY MRNG FCST PKG. WHILE               
GALE FORCE WINDS ARE A POSSIBILITY IN THE CHARLESTON HARBOR...                  
CONFIDENCE IS NOT HIGH ENOUGH ATTM TO JUSTIFY A GALE WATCH THERE.               
SMALL CRAFT ADVISORIES LOOK GOOD ACROSS THE REMAINDER OF THE                    
MARINE AREA...ALTHOUGH THE START TIME FOR THE CHARLESTON HARBOR                 
NEEDS TO BE MOVE UP TO FRI MRNG BASED ON CURRENT TRENDS.                        
WINDS HAVE DROPPED TO LESS THAN 10 KT ACROSS THE GA NEARSHORE WTRS              
NEAR THE COASTAL FRONT BUT SHOULD BECOME N-NE 10-15 KT AFTER                    
MIDNGT AS LOW PRES DVLPS JUST OFFSHORE. PINNING DIRECTIONS IN THE               
GA WATERS WILL BE TRICKY UNTIL THE LOW PRES AREA CONSOLIDATES.                  
WINDS WILL GO SOLIDLY NE ACROSS ALL WATERS BY FRI AFTN AS LOW PRES              
PULLS AWAY FROM THE AREA AND HIGH PRES WEDGE EXPANDS OFFSHORE.                  
SEAS WILL BUILD QUICKLY NGT AND FRI AS NE WINDS INTENSIFY.                      
FRIDAY NIGHT THROUGH TUESDAY...STRONGEST WINDS THROUGH THE PERIOD               
ARE EXPECTED FRIDAY NIGHT AND SATURDAY THANKS TO THE WEDGE. SCA                 
CONDITIONS EXPECTED THROUGH A GOOD PART OF THE WEEKEND...AND EVEN               
INTO EARLY NEXT WEEK FOR THE OUTER GEORGIA WATERS.                              
&&                                                                              
.TIDES/COASTAL FLOODING...                                                      
WILL WATCH FOR THE POTENTIAL OF SOME SHALLOW COASTAL FLOODING                   
AROUND HIGH TIDE FRI MORNING IF HEAVY RAINFALL OCCURS. OTHERWISE...             
ASTRONOMICALLY HIGH TIDES EARLY SATURDAY MORNING AND AGAIN EARLY                
SUNDAY MORNING SETS US UP FOR THE POSSIBILITY ON MINOR COASTAL                  
FLOODING EACH MORNING IN THE USUALLY VULNERABLE SPOTS. WIND MAY                 
STILL BE ENOUGH OFFSHORE SATURDAY MORNING TO KEEP FROM HAVING MANY              
PROBLEMS...BUT A SLIGHT SHIFT TO MORE EASTERLY WOULD CHANGE THAT.               
ULTIMATELY...RESIDENTS IN THOSE FLOOD PRONE LOCATIONS NEED TO STAY              
TUNED.                                                                          
&&                                                                              
.CHS WATCHES/WARNINGS/ADVISORIES...                                             
GA...NONE.                                                                      
SC...NONE.                                                                      
MARINE...SMALL CRAFT ADVISORY FROM 7 AM FRIDAY TO 5 AM EST SATURDAY FOR         
     AMZ330.                                                                    
     SMALL CRAFT ADVISORY FROM 10 AM FRIDAY TO 5 AM EST SUNDAY FOR              
     AMZ352.                                                                    
     GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR               
     AMZ350.                                                                    
     SMALL CRAFT ADVISORY FROM 1 AM TO 9 AM EST FRIDAY FOR AMZ350.              
     SMALL CRAFT ADVISORY FROM 10 AM FRIDAY TO 11 PM EST MONDAY FOR             
     AMZ374.                                                                    
     SMALL CRAFT ADVISORY FROM 5 PM FRIDAY TO 5 AM EST SUNDAY FOR               
     AMZ354.                                                                    
&&                                                                              
$$                                                                              
ST                                                                              
</pre> ga                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE COLUMBIA SC                                            
336 PM EST WED DEC 19 2007                                                      
.SYNOPSIS...                                                                    
HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA TODAY THROUGH                   
THURSDAY. WEAKENING LOW PRESSURE WILL TRACK SOUTH OF THE AREA                   
THURSDAY NIGHT. THE LOW WILL BE OFF THE SOUTHEAST COAST FRIDAY.                 
&&                                                                              
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...                                     
THE GFS AND NAM TIME-HEIGHTS SHOW LINGERING LOW-LEVEL MOISTURE                  
OVERNIGHT BUT DRY HIGH PRESSURE BUILDING INTO THE AREA SHOULD BECOME            
MORE DOMINATE. PLAN TO FORECAST PARTLY CLOUDY SKIES. THE TEMPERATURE            
GUIDANCE IS CLOSE WITH LOWS IN THE MID TO UPPER 30S.                            
&&                                                                              
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...                     
THE RIDGE WILL MOVE OFF THE COAST THURSDAY. MOISTURE WILL INCREASE              
AHEAD OF A LEAD H5 SHORTWAVE TROUGH THURSDAY AFTERNOON BUT EXPECT               
THIS MOISTURE WILL REMAIN TOO SHALLOW FOR RAIN. ISENTROPIC LIFT ALSO            
APPEARS VERY WEAK THROUGH THE DAY. PLAN TO KEEP THE POP LESS THAN 20            
PERCENT. AGAIN THE TEMPERATURE GUIDANCE IS CLOSE WITH HIGHS NEAR                
60. THURSDAY NIGHT THE MOISTURE WILL BEGIN TO PUSH EAST OF THE                  
REGION WITH SOME REMAINING SHOWERS INTO THE DAY FRIDAY. ON FRIDAY               
THE WEDGE WILL BE IN PLACE OVER THE REGION SO HAVE INCREASED                    
CLOUDS AND LOWERED HIGH TEMPERATURES A FEW DEGREES. WEDGE WILL                  
REMAIN IN PLACE THROUGH FRIDAY NIGHT HOWEVER WITH THE UNCERTAINTY               
IN THE MODELS HAVE KEPT THE WEDGE PRECIPITATION FREE UNTIL                      
SATURDAY WHEN MOISTURE AHEAD OF THE NEXT SYSTEM BEGINS TO MOVE                  
INTO THE AREA.                                                                  
&&                                                                              
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...                                      
MODELS IN THE LONG TERM HAVE SIGNIFICANT DIFFERENCES WITH TIMING                
AND INTENSITY OF THE SYSTEM FOR THE WEEKEND AND THE BEGINNING OF                
THE WEEK. LOW PRESSURE WILL TRACK INTO THE GREAT LAKES REGION ON                
SATURDAY NIGHT...HOWEVER THE COLD FRONT TRACKING FOR SC WEAKENS                 
BEFORE ARRIVING SUNDAY. HAVE SLOWED THIS SYSTEM A BIT AS THE GFS                
SUGGESTS A SLOWING TREND. DIFFERENCES CONTINUE WITH THE FRONTAL                 
BOUNDARY AS THE GFS STALLS THE BOUNDARY OVER THE REGION AND OTHER               
MODELS PUSH THE FRONT OFFSHORE. HAVE KEPT WITH THE FRONT MOVING                 
OFFSHORE AND PRECIPITATION ENDING SUNDAY EVENING. MONDAY AND                    
TUESDAY THE GFS DEVELOPS A STRONG LOW PRESSURE SYSTEM ALONG THE                 
WESTERN GULF COAST AND MARCHES IT NORTHWARD INTO THE GREAT LAKES                
BY TUESDAY MORNING. OTHER MODELS SUGGEST A WEAK SYSTEM OVER THE                 
REGION MONDAY NIGHT AND TUESDAY...SO AGAIN HAVE KEPT WITH THE                   
DRIER SOLUTIONS AND INCREASED CLOUDS SLIGHTLY TO ACCOUNT FOR                    
UNCERTAINTY. EITHER OF THE SOLUTIONS CURRENTLY PROVE TOO WARM FOR               
ANY CHANCE OF SNOW FOR THE HOLIDAY.                                             
&&                                                                              
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...                                     
SATELLITE PLUS THE LATEST RUC TIME-HEIGHTS SHOW LINGERING LOW-                  
LEVEL MOISTURE AND SUPPORT KEEPING MAINLY VFR CEILINGS THROUGH THE              
AFTERNOON. EXPECT JUST SCATTERED CLOUDS TONIGHT AS DRY RIDGING                  
BECOMES MORE DOMINATE.                                                          
EXPECT IFR OR MVFR CEILINGS ASSOCIATED WITH LOW PRESSURE TRACKING               
SOUTH OF THE REGION THURSDAY NIGHT INTO FRIDAY...OTHERWISE NO                   
SIGNIFICANT AVIATION IMPACTS FORECAST DURING THE EXPECTED PERIOD.               
&&                                                                              
.CAE WATCHES/WARNINGS/ADVISORIES...                                             
SC...NONE.                                                                      
GA...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> ga                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE COLUMBIA SC                                            
943 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...                                                                    
AN UPPER-LEVEL DISTURBANCE WILL MOVE THROUGH THE FORECAST AREA                  
TODAY. SURFACE HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA                  
TODAY THROUGH THURSDAY. WEAKENING LOW PRESSURE WILL TRACK SOUTH                 
OF THE AREA THURSDAY NIGHT. THE LOW WILL BE OFF THE SOUTHEAST                   
COAST FRIDAY.                                                                   
&&                                                                              
.NEAR TERM /THROUGH TODAY/...                                                   
AN H5 SHORTWAVE TROUGH AND H85 WARM ADVECTION WERE SUPPORTS AREAS               
OF RAIN THIS MORNING. THE LIFT IS WEAK WITH LIMITED MOISTURE.                   
EXPECT COVERAGE WILL REMAIN SCATTERED WITH LIGHT AMOUNTS. SURFACE               
WET- BULB TEMPERATURES ARE ABOVE FREEZING AREAWIDE. THE MODELS                  
SHOW THE LIFT MOVING OUT OF THE FORECAST EARLY THIS AFTERNOON.                  
RADAR TRENDS SUPPORT THIS TIMING. MADE MINOR ADJUSTMENTS TO THE                 
GRIDS BASED ON CURRENT CONDITIONS.                                              
&&                                                                              
.SHORT TERM /TONIGHT THROUGH FRIDAY/...                                         
DRY RIDGING WILL DOMINATE TONIGHT AND THURSDAY. THE NEXT CHANCE FOR             
RAIN WILL OCCUR THURSDAY NIGHT INTO FRIDAY MORNING. MODELS HAVE                 
BEEN TRENDING SLOWER AND DRIER WITH THIS SYSTEM...AND PLAN ON                   
GOING WITH ONLY CHANCE POPS. SYSTEM WILL BE MOVING EAST OF THE                  
FORECAST AREA BY FRIDAY MORNING...SO POPS WILL ONCE AGAIN BECOME                
DRY BY THE AFTERNOON.                                                           
&&                                                                              
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...                                    
IN THE LONGER TERM...MODELS CONTINUE TO HAVE DIFFICULTY IN TIMING               
AND INTENSITY. THE NEXT SYSTEM APPEARS TO SLOW DOWN SLIGHTLY...AND WILL         
ARRIVE SATURDAY NIGHT WITH A COLD FRONT PUSHING ACROSS THE AREA                 
BY SUNDAY NIGHT. HAVE GONE MAINLY WITH THE GFS THIS RUN. WITH THE               
MODEL DIFFERENCES CONFIDENCE IN TIMING REMAINS LOW...HOWEVER THERE              
DOES APPEAR TO BE POTENTIAL FOR SIGNIFICANT RAINFALL AS THE COLD                
FRONT CROSSES THE AREA. HIGH PRESSURE WILL MOVE IN BEHIND THE                   
FRONT WITH SKIES CLEARING AND PRECIPITATION FREE CONDITIONS                     
THROUGH TUESDAY.                                                                
&&                                                                              
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...                                     
H85 WARM ADVECTION AND H5 SHORTWAVE TROUGH WERE SUPPORTING VFR                  
CEILINGS THIS MORNING. THERE WERE AREAS OF VERY LIGHT RAIN.                     
THE LOW-LEVEL DRY AIR IN PLACE AND JUST WEAK LIFT WERE HELPING TO               
KEEP THE CEILINGS FROM LOWERING INTO THE MVFR CATEGORY.                         
THE MODELS AND RADAR TRENDS SHOW THE SUPPORT FOR RAIN WILL END                  
EARLY THIS AFTERNOON. THE LATEST RUC TIME-HEIGHTS SHOW LINGERING                
LOW-LEVEL MOISTURE AND SUPPORT KEEPING VFR CEILINGS THROUGH THE                 
AFTERNOON. EXPECT JUST SCATTERED CLOUDS TONIGHT AS DRY RIDGING                  
BECOMES MORE DOMINATE.                                                          
EXPECT IFR OR MVFR CEILINGS ASSOCIATED WITH LOW PRESSURE TRACKING               
SOUTH OF THE REGION THURSDAY NIGHT INTO FRIDAY...OTHERWISE NO                   
SIGNIFICANT AVIATION IMPACTS FORECAST DURING THE EXPECTED PERIOD.               
&&                                                                              
.CAE WATCHES/WARNINGS/ADVISORIES...                                             
SC...NONE.                                                                      
GA...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> ga                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE NORTHERN INDIANA                                       
955 PM EST WED DEC 19 2007                                                      
.UPDATE...                                                                      
WILL BE SENDING AN UPDATE SHORTLY TO ACCOUNT FOR RADIATIONAL COOLING            
AND LOWER TEMPERATURES. SATELLITE SHOWS CIRRUS STREAMING OVER THE               
AREA BUT A LOOK OUTSIDE SUGGESTS THIS IS CURRENTLY QUITE THIN WITH              
MOST STARS AND MOON SHINING BRIGHTLY. LOW STRATUS DECK HAS SLOWED               
TO A CRAWL JUST EAST OF KSBN TO KFWA TO KDFI. HAVE LOWERED TEMPS A              
FEW DEGREES BELOW CURRENT READINGS IN THE WEST BUT SATELLITE SHOWS              
THICKER CIRRUS CANOPY OVER ILLINOIS MOVING THIS WAY. THEREFORE DROP             
SHOULD SLOW AND BECOME STEADY OR SLOWLY RISE LATER. MOS HAS NO CLUE             
AND MUCH TOO WARM AS IS LAMP GUIDANCE WHERE SKIES CLEARED. RUC40                
SURFACE TEMPS THE CLOSEST BUT THOSE LOOK TOO COLD. HAVE SLOWED THE              
INCREASE IN CLOUDS BY A FEW HOURS AS WELL BASED ON SATELLITE TRENDS.            
VISIBILITIES BETWEEN 1 AND 3 MILES WHERE LOW CLOUDS HAVE CLEARED.               
ADDED FREEZING FOG MENTION ALL AREAS WITH LOCALLY DENSE WORDING WEST            
WHERE SKIES ARE PARTIALLY CLEARED.                                              
&&                                                                              
.AVIATION                                                                       
FOG AND STRATUS REDEVELOPMENT THE CONCERN FOR AVIATION OVERNIGHT.               
SATELLITE SHOWS LOW CLOUD DECK JUST EXITING KFWA WHILE KSBN RIGHT ON            
BACK EDGE. NAM12 LOW LEVEL RH PROGS SUGGEST THIS CLEARING TO                    
CONTINUE WORKING NORTHEAST SO KSBN SHOULD SEE THE LOW CLOUDS CLEAR              
OUT VERY SHORTLY. WILL START TAFS THAT WAY GIVEN SATELLITE                      
OBSERVATIONS AND TRENDS. MEANWHILE...CROSSOVER TEMPS IN THE MID 20S             
AND CURRENT READINGS SUGGEST SITES ARE AT OR NEAR THESE VALUES.                 
MVFR AND EVEN IFR VIS ALREADY BEING REPORTED. COMPLICATING FACTOR IS            
INCREASING HIGH LEVEL CLOUDS OVERNIGHT THAT MAY INHIBIT DEEP                    
RADIATIONAL COOLING AND CONFINE VIS RESTRICTIONS TO THE HIGH END OF             
IFR. HAVE KEPT TAF SITES AT 2SM FOR OVERNIGHT AT THIS TIME AND WILL             
WATCH CLOSELY TO SEE HOW CONDITIONS BEHAVE THIS EVENING. CERTAINLY              
POSSIBLE FOR MUCH LOWER VIS WITH DENSE FOG GIVEN THE RECENT MELTING             
SNOWPACK COUPLED WITH HIGH PRESSURE AND LIGHT SURFACE WINDS WITH DRY            
AIR ALOFT.                                                                      
&&                                                                              
.SHORT TERM...                                                                  
TONIGHT AND THURSDAY.                                                           
FOCUS OF SHORT TERM WILL REVOLVE AROUND LOW LVL MSTR ACROSS THE                 
AREA.                                                                           
OTHER THAN FAR SW AREAS...CLOUDY SKIES HAVE PREVAILED UNDER A                   
STRONG INVERSION IN PLACE ACROSS THE REGION. AREA OF CLEARING TO                
THE SW HAS BEEN FINALLY WORKING NE ACROSS MAINLY SOUTHERN HALF TO               
2/3RDS OF THE CWA ALLOWING FOR WHAT WILL LIKELY BE A TEMPORARY                  
BREAK. NAM SOUNDINGS DID BEST JOB CAPTURING THE STRONG INVERSION                
AND APPROXIMATE HGT OF THE DECK. WILL TEND TO FOLLOW IT MORE SO                 
WITH SOUNDINGS AS DIURNAL SWING IN TEMPS WILL ALLOW FOR INVERSION               
TO STRENGTHEN FURTHER. ABUNDANT LL MSTR TO REMAIN FROM SLOWLY                   
DECREASING/SUBLIMATING SNOWPACK. HAVE TRIED TO CAPTURE CLEARING                 
TREND AND EVENTUAL FILLING BACK IN TOWARDS MIDNIGHT. WITH CLOUD                 
COVER IN PLACE AGAIN...HAVE INCREASED LOWS A FEW DEGREES...BUT NOT              
GOING TO INCREASE DRAMATICALLY AT THIS POINT UNTIL FULL MAGNITUDE               
OF CLOUD COVER IS VISIBLE. WILL ALSO BRING BACK IN WHAT SHOULD                  
JUST END UP BEING NUISANCE FOG AFTER MIDNIGHT.                                  
ON THURSDAY...INVERSION LOOKS TO STILL BE HOLDING ON WITH LOW LVL               
MSTR NOT QUICK TO GO ANYWHERE. WILL TRY TO REMAIN OPTIMISTIC AND                
KEEP WITH MOSTLY CLOUDY CONDITIONS FOR NOW...BUT THREAT FOR SOLID               
OVERCAST STILL THERE WITH NO OVERALL CHANGE IN FLOW. TEMPS WILL BE              
HIGHLY DEPENDANT ON THE CLOUD COVER. IF WE CAN CLEAR OUT IN MANY                
LOCATIONS...TEMPS COULD EASILY CLIMB INTO THE MID OR POSSIBLY                   
UPPER 30S DESPITE SNOWPACK. FOR NOW WILL STAY THE LOWER END AND                 
SEE HOW THINGS PAN OUT.                                                         
&&                                                                              
.LONG TERM...                                                                   
THURSDAY NIGHT THROUGH WEDNESDAY...                                             
FORECAST PERIOD BEGINS WITH SYSTEM MOVING ACROSS THE TENNESSEE                  
VALLEY IN SOUTHERN STREAM...MID LEVEL MOISTURE WILL SPREAD INTO THE             
AREA AS THIS SYSTEM PASSES TO OUR SOUTH. LITTLE IF ANY FORCING TO               
GENERATE ANY PRECIP...WOULD LEAN TOWARD DRY FCST BUT WILL SETTLE FOR            
BACKING DOWN TO PATCHY L/ZL- WITH NO MENTION OF POP. WAA ON FRIDAY              
AS SOUTHERLY FLOW DEVELOPS AHEAD OF NEXT SYSTEM. DESPITE SNOW COVER             
WE WERE ABLE TO GET TEMPS INTO THE MID-UPPER 30S YESTERDAY WITH                 
SIMILAR PATTERN SO WITH WARMER 850MB TEMPS FCST FOR FRIDAY EXPECT               
MOST OF THE CWA TO BE NEAR 40F...WITH PATCHY HAZE/FOG EXPECTED                  
DURING THE DAY FROM ADDED LOW LEVEL MOISTURE FROM SNOW MELT. WAA                
CONTINUES INTO FRIDAY NIGHT SO WILL KEEP MENTION OF AREAS FOG BUT NO            
SIGNAL FROM ANY OF THE MODELS FOR PRECIP SO WILL REMOVE SMALL CHANCE            
POPS. AS THE SYSTEM MOVES INTO THE AREA SATURDAY MODELS NOW FAVORING            
STRONG NORTHERN STREAM COMPONENT WHICH WOULD TAKE MAIN SFC LOW                  
ACROSS NORTHERN GREAT LAKES/SOUTHERN CANADA...ALTHOUGH OPERATIONAL              
GFS STILL HANGING ONTO SOME SOUTHERN STREAM ENERGY WITH FRONTAL WAVE            
MOVING INTO OHIO VALLEY BY 12Z SUNDAY. THIS WILL ALLOW FOR PLENTY OF            
WARM AIR TO BE IN PLACE AT THE ONSET OF PRECIP...SO RAIN CHANCES                
REMAIN FOR SATURDAY...SATURDAY NIGHT WILL SEE COLD FRONT PASS                   
THROUGH...NAM12 SUGGESTING PLENTY OF POST-FRONTAL MOISTURE AND WITH             
SHARPLY COLDER TEMPS BEHIND FRONT WILL SEE RAIN MIX WITH THEN CHANGE            
OVER TO SNOW BY 12Z SUNDAY. FCST SOUNDINGS SHOW ENTIRE COLUMN COOLS             
WITH FROPA SO NOT TOO CONCERNED WITH IP/ZR ATTM. LATEST MODEL RUNS              
ARE MORE AGGRESSIVE WITH MOVING SYSTEM EAST ON SUNDAY...BUT WILL                
HANG ONTO TO CHANCE OF SNOW SUNDAY AND TRIM BACK TO SMALL CHANCE OF             
LIGHT SNOW BY SUNDAY NIGHT. COULD STILL SEE SOME LINGERING LAKE                 
EFFECT SHSN IN NORTHERN TIER MONDAY SO WILL KEEP MENTION BUT TRIM               
AREA A LITTLE FARTHER NORTH. LATEST OPERATIONAL GFS HAS GONE FROM               
HIGH PRESSURE OVER THE AREA TUESDAY TO DEEP LOW OVER KY...NOT READY             
TO JUMP ON THAT XMAS SURPRISE...AS ENSEMBLES SHOW THIS IS THE                   
OUTLIER...STAYING WITH DRY FCST DAYS 6 AND 7.                                   
&&                                                                              
.IWX WATCHES/WARNINGS/ADVISORIES...                                             
IN...NONE.                                                                      
MI...NONE.                                                                      
OH...NONE.                                                                      
LM...NONE.                                                                      
&&                                                                              
$$                                                                              
UPDATE...LASHLEY                                                                
SHORT TERM/AVIATION...FISHER/LASHLEY                                            
LONG TERM...LOGSDON                                                             
</pre> in                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE DES MOINES IA                                          
1130 PM CST TUE DEC 18 2007                                                     
.UPDATE TO FORECAST AND AVIATION DISCUSSION...                                  
AREA OF LOW LEVEL STRATUS AND FOG SLIDING SOUTH QUICKLY OUT OF                  
MINNESOTA...LOOKS TO CLIP THE NORTHEASTERN CORNER OF THE CWA THROUGH            
EARLY WEDNESDAY MORNING. LATEST RUC ANALYSIS SHOWS MAJORITY OF LOW              
CLOUDS SLIDING JUST TO THE EAST OF THE CWA...SO HAVE UPDATED TO                 
INCREASE CLOUDS NEAR A KMCW TO KALO LINE THROUGH THE REMAINDER OF               
THE EVENING INTO THE OVERNIGHT HOURS. ALSO VISIBILITIES DROPPING TO             
1 TO 3 MILES BENEATH THE LOW CLOUDS...SO BEGAN ONSET OF FZFG MENTION            
THIS EVENING IN THE CLOUDY AREAS. OTHERWISE REMAINDER OF FORECAST ON            
TRACK.                                                                          
.SHORT TERM /TONIGHT/...                                                        
WEAK COLD FRONT OVR ERN IA AND ASSOCIATED WITH SFC LOW OVER                     
WISCONSIN WILL CONTINUE MOVING EAST TONIGHT. NOT A LOT OF AIRMASS               
CHANGE BEHIND THE FRONT AS TRUE ARCTIC BOUNDARY IS STALLED ACROSS               
NORTH CENTRAL MN AND NORTHWEST INTO SRN CANADA. A WEAK HIGH PRESSURE            
RIDGE WILL CRUISE OVER IOWA TONIGHT. SO WITH AN ESSENTIALLY CLEAR               
SKY AND LIGHT WINDS...EXPECT TEMPERATURES TO DROP TO AT OR BELOW                
COLDER GUIDANCE VALUES. ALSO EXPECT THAT WITH LOW LEVEL SATURATION              
OCCURRING AND STRONG INVERSION JUST ABOVE THE BOUNDARY LAYER...FOG              
WILL LIKELY DEVELOP LATE. THERE IS THE QUESTION OF LOW CLOUDS ALSO              
FORMING...BUT FOR NOW WILL JUST STICK WITH THE IDEA OF FOG SINCE I              
AM NOT CONVINCED LOW LEVEL MOISTURE WILL BE DEEP ENOUGH TO RESULT IN            
CLOUDS.                                                                         
.LONG TERM ...                                                                  
THERE IS PLENTY TO MULL OVER DURING THIS PERIOD...INCLUDING THE                 
POTENTIAL FOR SIGNIFICANT WINTER WEATHER FRIDAY NIGHT AND SATURDAY.             
FOR THE NEXT SEVERAL DAYS...MOS TEMPERATURE GUIDANCE CONTINUES TO               
HANDLE THE SNOW COVER POORLY...AND WILL CONTINUE TO KEEP THE                    
FORECAST AT OR BELOW THE COOLEST MOS WHICH HAS GENERALLY BEEN THE               
MAV OR MET. A COUPLE OF WEAK SHORT WAVES ARE EXPECTED TO TRAVERSE               
ACROSS THE STATE WEDNESDAY NIGHT AND THURSDAY. MOISTURE REMAINS                 
QUITE LIMITED AND WITH STRONG DOUBTS ABOUT GETTING ANY MEASURABLE               
PRECIPITATION...WILL KEEP POPS LIMITED TO SLIGHT CHANCE AT BEST.                
FREEZING DRIZZLE OR DRIZZLE STILL LOOKS TO BE THE DOMINATE WEATHER.             
LOOKING AHEAD TO THE WEEKEND SYSTEM...THE MODELS CONTINUE TO SHOW               
POOR CONSISTENCY AND HAVE PHASING ISSUES WITH NORTHERN AND SOUTHERN             
STREAM ENERGY. PREVIOUS RUNS OF THE EURO PHASED THE N/S UPPER LOWS              
AND WAS MUCH SLOWER AND STRONGER. THE PREVIOUS GFS HAD TAKEN THE SFC            
LOW AND PRECIPITATION FARTHER SE...BUT NOW HAS RETURNED TO LIFTING              
THE INITIAL SFC LOW THROUGH SE IOWA. BOTH 12Z RUNS ARE ACTUALLY                 
SIMILAR...BOTH MORE PROGRESSIVE WITH LESS QPF...AND LOOKING LESS                
OMINOUS FOR WARNING CRITERIA SNOWFALL AMOUNTS. BASED ON QPF AND                 
THERMAL PROFILES...THE GFS/ECMWF WOULD BOTH FAVOR THE NW 1/2 TO 2/3             
OF THE FORECAST AREA FOR THE HEAVIER SNOWS...BUT STILL BELOW 6 INCH             
WARNING CRITERIA...WITH A MIX AND LESS SNOW ACROSS THE SOUTHEAST.               
THE 12Z GEM ALSO PROVIDES SUPPORT FOR THIS SCENARIO. THIS IS SIMILAR            
TO THE MODEL CONSENSUS YESTERDAY AT THIS TIME...BUT CONFIDENCE IN               
PRECIP TYPE/AMOUNTS/PLACEMENT IS STILL VERY LOW DUE TO THE                      
INCONSISTENT SOLUTIONS. STILL FEEL THAT THIS SYSTEM MAY END UP BEING            
STRONGER AND LESS PROGRESSIVE IN LIFTING THE UPPER LOW OUT OF THE SW            
CONUS...SIMILAR TO WHAT THE EURO WAS SHOWING YESTERDAY. A NUMBER OF             
EVENTS IN THE RECENT AND MORE DISTANT PAST HAVE RESULTED IN THE                 
HEAVIER SNOW ENDING UP FARTHER NORTHWEST THAN INITIALLY                         
THOUGHT...AND TIME WILL TELL IF THAT WILL BE THE CASE WITH THIS                 
EVENT. POPS WERE INCREASED ANOTHER NOTCH...ESPECIALLY FOR FRIDAY                
NIGHT AND SATURDAY. THERE MAY BE SOME LINGERING LIGHT SNOW/FLURRIES             
NORTHEAST ON SUNDAY...OTHERWISE DRY FORECAST MAINTAINED MONDAY AND              
TUESDAY.                                                                        
&&                                                                              
.AVIATION...19/06Z                                                              
LOW STRATUS AND FOG MOSTLY SKIRTING THE NORTHWESTERN CWA...AND FOR              
THE MOST PART SHOULD REMAIN EAST OF THE KMCW AND KALO. HOWEVER HAVE             
INCLUDED A TEMPO GROUP FOR THE POSSIBILITY THAT THE IFR/LIFR                    
CEILINGS AND VSBYS MAKE IT INTO THOSE TERMINAL SITES. REMAINDER OF              
SITES WILL SEE MVFR/VFR CONDITIONS THROUGH THE NEXT FEW HOURS...WITH            
VSBYS EXPECTED TO DROP TO 1-3SM BY LATE NIGHT TOWARD SUNRISE. VFR               
CONDITIONS THEN EXPECTED FOR THE REMAINDER OF WED WITH INCREASING               
HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM PUSHING EAST OUT OF THE               
ROCKIES. LIGHT NORTHWEST WINDS TO SHIFT TO THE SOUTH TO SOUTHEAST               
WEDNESDAY INTO WEDNESDAY NIGHT.                                                 
&&                                                                              
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.                                        
&&                                                                              
$$                                                                              
SHORT TERM...MOYER                                                              
LONG TERM...KINNEY                                                              
AVIATION...ALBRECHT                                                             
</pre> ia                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE SHREVEPORT LA                                          
750 PM CST THU DEC 20 2007                                                      
.DISCUSSION...                                                                  
MUCH DRIER AIR HAS FILTERED IN BEHIND A COLD FRONT/DRY LINE WHICH               
ACCOMPANIED OUR UPPER LEVEL STORM SYSTEM EARLY THIS MORNING. THE                
BOUNDARY HAS JUST ABOUT PULLED UP STATIONARY ACROSS OUR EASTERN                 
ZONES THIS EVENING AND IS NOT EXPECTED TO MAKE MUCH MORE EASTWARD               
PROGRESS OVERNIGHT. WITH THE CLEAR SKIES AND HIGH DEWPOINTS ACROSS              
THE EAST NOT TO MENTION THE WET GROUND CONDITIONS FROM RAINFALL                 
THIS MORNING...ALREADY STARTING TO SEE VISIBILITIES CRATER AT                   
ELD...MLU AND AEX. FOR THIS REASON...HAVE DECIDED TO POST A DENSE               
FOG ADVISORY THROUGH 900 AM FRIDAY MORNING RUNNING IT GENERALLY                 
ALONG AND EAST OF A LINE FROM HOPE AND LEWISVILLE ARKANSAS TO                   
MINDEN...COUSHATTA AND NATCHITOCHES LOUISIANA. IF THE LATEST RUC13              
DATA IS TO BE BELIEVED...THEN WE COULD SEE THIS FOG ADVECT FURTHER              
WEST AFTER MIDNIGHT...ENCOMPASSING MUCH OF THE REGION PRIOR TO                  
DAYBREAK FRIDAY. OTHER SHORT TERM PROGS KEEPING ENOUGH DRY AIR OUT              
WEST TO PRECLUDE FOG DEVELOPMENT BUT WILL HEDGE ON THE SIDE OF                  
CAUTION AND JUST MENTION PATCHY FOG ACROSS NORTHEAST TEXAS AND                  
PATCHY DENSE FOG ACROSS EXTREME NORTHWEST LOUISIANA INTO THE                    
TEXARKANA AREA AND SOUTHEAST OKLAHOMA. WOULD NOT BE SURPRISED IF                
WE NEED TO EXPAND THE ADVISORY FURTHER WEST LATER TONIGHT BUT WILL              
CROSS THAT BRIDGE IF AND WHEN IT BECOMES NECESSARY.                             
FCST MIN TEMPERATURES AND ALL OTHER GRIDS IN LINE SO NO OTHER                   
CHANCES NECESSARY ATTM.                                                         
UPDATE AND ADVISORY OUT SHORTLY...13.                                           
&&                                                                              
.AVIATION...                                                                    
WATER VAPOR IMAGERY SHOWS TROUGH AXIS ON THE EASTERN SIDE OF THE MS             
VALLEY...W/00Z KSHV SOUNDING SHOWING A VERY DRY AMS IN PLACE.                   
HOWEVER...W/WET SOILS...DECOUPLING...AND ABUNDANT RADIATIONAL                   
COOLING...EXPECT DETERIORATING CEILINGS/VSBYS TO IFR/LIFR...W/KELD              
ALREADY IN THE SOUP AT 02Z.  LATEST RUC INDICATES SW AR AND LA MOST             
FAVORED FOR FOG.  EXPECT CONDITIONS TO QUICKLY IMPROVE TO VFR AFTER             
SUNRISE.  FORECAST SOUNDINGS INDICATE CONVECTIVE TEMPS FRIDAY                   
AFTERNOON IN THE TRIPLE DIGITS...SO NO CU FIELD EXPECTED.                       
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
SHV  46  73  53  68 /   0   0  20  50                                           
MLU  48  73  53  69 /   0   0  20  60                                           
DEQ  40  69  49  61 /   0   0  10  40                                           
TXK  47  71  53  63 /   0   0  10  50                                           
ELD  46  73  51  70 /   0   0  10  60                                           
TYR  42  75  54  64 /   0   0  20  30                                           
GGG  41  74  52  67 /   0   0  20  40                                           
LFK  41  76  52  72 /   0   0  30  50                                           
&&                                                                              
.SHV WATCHES/WARNINGS/ADVISORIES...                                             
AR...DENSE FOG ADVISORY UNTIL 9 AM FRIDAY FOR THE FOLLOWING ZONES:              
     COLUMBIA...HEMPSTEAD...LAFAYETTE...NEVADA...AND UNION AR.                  
LA...DENSE FOG ADVISORY UNTIL 9 AM FRIDAY FOR THE FOLLOWING ZONES:              
     BIENVILLE...CALDWELL...CLAIBORNE...GRANT...JACKSON...LA                    
     SALLE...LINCOLN...NATCHITOCHES...OUACHITA...RED                            
     RIVER...UNION LA...WEBSTER...AND WINN.                                     
OK...NONE.                                                                      
TX...NONE.                                                                      
&&                                                                              
$$                                                                              
13/44                                                                           
</pre> la                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE SHREVEPORT LA                                          
809 PM CST WED DEC 19 2007                                                      
.DISCUSSION...                                                                  
WARM FRONT AS OF 02Z HAS PULLED UP STATIONARY...ALONG THE AR/LA                 
BORDER SNAKING WESTWARD TO JUST NORTH OF MOUNT PLEASANT TEXAS.                  
FRONT HAS BEEN IN THIS POSITION FOR THE LAST FOUR HOURS AND AS A                
RESULT...TEMPERATURES HAVE FALLEN OFF QUICKLY ACROSS SOUTHWEST                  
ARKANSAS AND SOUTHEAST OKLAHOMA. HAVE LOWERED TEMPERATURES A                    
COUPLE OF CATEGORIES NORTH OF THIS BOUNDARY BUT THE THINKING IS                 
THAT THIS BOUNDARY MAY MOVE A LITTLE FURTHER NORTH TONIGHT BUT NOT              
MUCH PER 00Z RUC. HAVE ALSO ADDED PATCHY DENSE FOG WORDING ACROSS               
OUR NORTHERN ZONES WITH VISIBILITIES AS LOW AS 1/2 MILE AT ELD                  
ALREADY.                                                                        
CONCERNING CONVECTION...LOW LEVEL JET IS JUST NOW STARTING TO                   
CRANK OUT WEST OF THE REGION PER PALESTINE PROFILER SITE WITH                   
AROUND 30KTS AT 5K. THIS SHOULD CONTINUE TO INCREASE OVERNIGHT                  
WITH SHOWERS AND THUNDERSTORMS EXPECTED TO EXPAND IN COVERAGE AND               
INTENSITY ACROSS OUR WESTERN ZONES OVER THE NEXT FEW HOURS.                     
DESPITE MOST OF OUR CWA BEING SOUTH OF THE STALLED BOUNDARY...FEEL              
LIKE ACTIVITY WILL MOSTLY BE ELEVATED IN NATURE THUS SUPPORTIVE OF              
A HAIL THREAT LATER TONIGHT. MODIFIED MARITIME AIRMASS WILL TRY TO              
COME NORTHWARD INTO OUR SOUTHERN ZONES LATER TONIGHT AND THIS                   
COULD RESULT IN A WIND/ISOLATED TORNADO THREAT...BUT THIS ALL                   
DEPENDS ON IF THE ACTIVITY CAN BECOME ROOTED BELOW THE BOUNDARY                 
LAYER OR NOT.                                                                   
FOR NOW...HAVE BUMPED POPS TO LIKELY CATEGORY ACROSS OUR EXTREME                
NORTHWEST ZONES FOR LATER TONIGHT AS INITIAL ROUND OF CONVECTION                
WILL BE TOO CLOSE TO THIS REGION TO SPLIT HAIRS.                                
UPDATE OUT SHORTLY...13.                                                        
&&                                                                              
.AVIATION...                                                                    
LATEST SURFACE OBS SHOW WARM FRONT RUNNING RIGHT ALONG THE AR/LA                
BORDER...W/VSBYS APPROACHING VLIFR NORTH OF THE FRONT.  00Z SHV/LCH             
RAOBS SHOW STEEP MID-LEVEL LRS...BUT OTHERWISE UNIMPRESSIVE.                    
HOWEVER...KSHV VAD PROFILER SHOWS LLJ BEGINNING TO DEVELOP AHEAD OF             
TROUGH OVER THE TEXAS PANHANDLE...W/CONVECTION ALREADY FORMING WEST             
OF KLFK.  THUS...EXPECT LIFR/VLIFR CEILINGS/VSBYS ALL SITES BY 06Z              
OR SOONER.  AS TROUGH EXITS THURSDAY AFTERNOON...EXPECT SCOURING TO             
VFR BY 21Z ALL SITES EXCEPT KMLU/KELD.                                          
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
SHV  59  71  43  71 /  70  40  10  10                                           
MLU  58  71  45  70 /  70  60  10  10                                           
DEQ  48  67  35  68 /  70  30  10  10                                           
TXK  48  70  44  68 /  70  30  10  10                                           
ELD  48  71  41  70 /  70  30  10  10                                           
TYR  58  70  42  71 /  70  20  10  10                                           
GGG  58  70  42  71 /  70  20  10  10                                           
LFK  60  73  40  74 /  70  30  10  10                                           
&&                                                                              
.SHV WATCHES/WARNINGS/ADVISORIES...                                             
AR...NONE.                                                                      
LA...NONE.                                                                      
OK...NONE.                                                                      
TX...NONE.                                                                      
&&                                                                              
$$                                                                              
13/44                                                                           
</pre> la                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GRAY ME                                                
936 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...                                                                    
LOW PRESSURE WILL TRACK FROM THE GREAT LAKES TO NEAR CAPE COD                   
TONIGHT. MEANWHILE...A TROUGH OF LOW PRESSURE WILL EXTEND BACK                  
ACROSS NORTHERN NEW ENGLAND...SERVING AS A FOCUS FOR SNOWFALL                   
TONIGHT AND THURSDAY. THE LOW WILL MOVE EAST OUT TO SEA THURSDAY                
NIGHT...WITH HIGH PRESSURE RIDGING FROM THE NORTH FRIDAY AND                    
SATURDAY.                                                                       
&&                                                                              
.NEAR TERM /UNTIL 7 PM THIS EVENING/...                                         
FOR TODAY...THERE WILL BE TWO WAVES OF PRECIPITATION. THE                       
FIRST...WILL BE WITH THE WEAK WARM FRONT LIFTING ACROSS THE                     
REGION. THUS FAR THIS FRONT CAN BE SEEN ON THE IR SATELLITE WHERE               
MID-LEVEL WARM AIR ADVECTION HAS CAUSED A LINE OF LOW CLOUDS                    
EXTENDING INTO THE MOUNTAINS OF NEW HAMPSHIRE AND NORTHWESTERN                  
MAINE. EXPECT SOME LIGHT SNOW TO DEVELOP AS THIS FRONT LIFTS                    
NORTH...WITH SNOW ACCUMULATION ONLY A DUSTING WITH THIS WEAK FEATURE.           
CLOUDS WILL INCREASE IN ALL AREAS THIS AFTERNOON...WITH SNOW                    
BEGINNING IN CENTRAL MAINE AND SOUTHWESTERN NEW HAMPSHIRE...AND                 
QUICKLY SPREADING INTO ALL AREAS BY 00Z. EXPECT PRECIPITATION TO                
REMAIN ALL SNOW THROUGH 00Z...WITH SNOW ACCUMULATIONS AN INCH OR                
LESS THROUGH 00Z. STILL...COULD BE A SOMEWHAT MESSY EVENING                     
COMMUTE...ESPECIALLY IN AREAS WHERE SNOW BREAKS OUT FIRST.                      
UPDATE: IT APPEARS THE TROUGH AXIS IS BEGINNING TO SET UP AT                    
12Z...WITH NE WINDS AT MATINICUS ROCK AND PORTLAND LNB OF AROUND                
10 KTS. INLAND WINDS ARE GENERALLY NORTHERLY. ALOFT...12Z GYX                   
SOUNDING SHOWS SSW WINDS AT 10 KTS AT 950 MB...WITH SOUTHERLY                   
WINDS AT THE SURFACE AT CAPE COD. BASED ON THIS...LOOKS AS IF THE               
BOUNDARY GENERALLY RUNS FROM THE ISLES OF SHOALS BUOY...TO JUST                 
SOUTH OF MATINICUS ROCK. THE BOUNDARY WILL ROUGHLY SERVE AS A                   
RAIN/SNOW LINE...WITH THE BEST LIFT NORTH OF THE BOUNDARY. THIS                 
BOUNDARY IS BEST HANDLED BY BOTH THE 06Z NAM12 AND GFS40...AND IS               
FORECAST TO SLOWLY LIFT NORTH THIS AFTERNOON...STALLING RIGHT                   
ALONG THE SHORELINE THIS EVENING. FOLLOWING THIS...CURRENT                      
ADVISORIES AND SNOWFALL AMOUNTS STILL ON TRACK.                                 
&&                                                                              
.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM THURSDAY/...                        
UNUSUALLY GOOD MODEL AGREEMENT FOR THIS NORLUN-TROUGH EVENT.                    
NAM/GFS/GEM ALL SHOW SIGNIFICANT QPF FOOTHILLS SOUTHWARD. THE TROF              
AXIS IS EXPECTED TO SET UP ACROSS THE REGION...FOCUSING HEAVIEST                
SNOW ACROSS CENTRAL MAINE TONIGHT. THEN THE AXIS IS FORECAST TO                 
SHIFT SOUTH...WITH THE BAND SHIFTING SOUTHWARD AS WELL. GIVEN THE               
SUBTLE NATURE OF THIS EVENT...CONFIDENCE REMAINS LESS THAN A                    
LARGER SCALE EVENT. STILL...DYNAMICS OF A MODERATE LAPSE RATE IN                
THE LOWEST 5000 FT...AND A MOIST ONSHORE FLOW SUPPORT DECENT                    
(ALTHOUGH LESS THAN THE GFS) QPFS. GENERALLY USE A NAM/GFS BLEND                
FOR MOST PARAMETERS...BUT DO ADJUST FOR ANTICIPATED MESOSCALE                   
FEATURES. THE MAIN ONE IS THE COASTAL FRONT...WHICH IS LIKELY TO                
SET UP FROM EXETER...TO BIDDEFORD...TO JUST SOUTH OF PORTLAND...TO              
JUST SOUTH OF ROCKLAND. THUS...SOME BUFKIT SOUNDINGS ALONG THE                  
COAST ARE LIKELY TOO WARM IN THE BOUNDARY LAYER. MODELS SEEM TO FOCUS           
QPF BULLSEYE SOMEWHERE NEAR IZG...WITH THE SOUTHERN 2/3 OF THE CWA              
EXPECTED TO GET .50 OR GREATER OF QPF BY THE TIME ALL IS DONE.                  
WILL ISSUE A SNOW ADVISORY FOR THE ENTIRE CWA...                                
MAINE AND NEW HAMPSHIRE FOOTHILLS...6 TO 9 INCHES.                              
THE MOUNTAINS AND WESTERN NEW HAMPSHIRE...3 TO 6 INCHES.                        
MOST OF MAINE COASTLINE...4 TO 7 INCHES.                                        
SOUTHEASTERN NEW HAMPSHIRE...3 TO 6 INCHES.                                     
COASTAL YORK AND ROCKINGHAM...2 TO 5 INCHES.                                    
EXPECT THIS TO BE A LONG LASTING EVENT...TONIGHT THROUGH                        
THURSDAY...BUT THE BEST SNOW RATES WILL LIKELY BE FROM MIDNIGHT                 
TONIGHT THROUGH NOON THURSDAY. STILL...WITH THE EVENT SPREAD OUT                
OVER A 24 HOUR PERIOD...WILL USE 24 HOUR SNOWFALL CRITERIA. THE                 
TROF AXIS WILL FOCUS SNOWFALL...SO EXPECT SNOW TO VARY FROM LIGHT               
TO OCCASIONALLY HEAVY AT TIMES. ALSO...ANTICIPATE SOME AREAS MAY                
NEED TO BE UPGRADED TO WARNINGS...WITH 12 INCHES OF SNOW POSSIBLE               
WHERE FAVORABLE SNOW BANDS STALL. HOWEVER...LITTLE CONFIDENCE IN                
THE POSITION OF THESE BANDS...AND EXPECT AREAL COVERAGE OF THIS TO              
BE A SMALL PERCENTAGE OF THE CWA...SO DO NOT HAVE THE CONFIDENCE                
TO ISSUE WARNINGS AT THIS TIME.                                                 
&&                                                                              
.LONG TERM /THURSDAY THROUGH TUESDAY/...                                        
FOLLOWING SIMILAR THOUGHTS TO WED NIGHT FROM THE SHORT TERM                     
SECTION. WILL BE FOLLOWING THE HIER RESOLUTION...MESOSCALE MODEL                
TRENDS ON THURSDAY...NAM12/13KM DEV RUC/STONY BROOK MM5...FOR                   
THURSDAY...WHICH ARE IN TURN SUPPORTED ON A LARGER SCALE BY                     
GFS/GEM/HPC WINTER WX DESK. THIS SHIFTS AXIS OF HEAVIEST SNOW                   
FROM PWM-IZG AND POINTS EAST DURING THE MORNING...TO CON-SFM AND                
POINTS S BY AFTERNOON...AS FLOW TURNS FROM ESE-NNE. SO...HAVE                   
STARTED THE DAY WITH CAT POPS IN ALL BUT THE MTNS...BUT BACKED OFF              
ON POPS E OF THAT PWM-IZG LINE LATER IN THE DAY. AGAIN...SOME                   
DEVIATION IN HEAVIEST SNOW AXIS REMAINS A DISTINCT POSSIBILITY.                 
ALSO AS WINDS TURN MORE NE...COULD SEE COASTAL MAKE SOME INROADS                
TO THE SW...AND COULD SEE A CHANGE TO RA IN YORK AND ROCKINGHAM                 
COUNTIES...AND PERHAPS EVEN SERN CUMBERLAND COUNTY /CAPE                        
ELIZABETH-DOWNTOWN PORTLAND AREA/.                                              
BY THU EVENING...ACCUMULATION SNOW SHOULD HAVE ENDED IN ALL BUT                 
EXTREME SRN ZONES...AND THAT WILL WIND DOWN QUICKLY AS WELL AFTER               
SUNSET.                                                                         
AIR BEHIND THIS SYSTEM NOT QUITE AS COLD AS WE/VE SEEN IN THE LAST              
FEW WEEKS...AND MAX TEMPS FRI/SAT WILL RUN NEAR NORMAL...WITH LOWS              
SLIGHTLY BLO NORMALS...THANKS TO SNOW COVER.                                    
NEXT SYSTEM ARRIVES SAT NIGHT...AND GFS/EURO IN AGREEMENT ON A                  
TRACK WELL TO THE WEST...WHICH WOULD LIKELY LEAD TO EITHER A                    
SN/FZRA TO RA EVENT...OR JUST RAIN...FOR SAT NIGHT INTO SUN EVE.                
MAX TEMPS ON SUN RISE ABOVE NORMAL.                                             
SOME SEASONALLY COLD AIR WILL MOVE BACK IN ON MONDAY...WITH ONLY                
UPSLOPE SHSN EXPECTED MON-TUE.                                                  
&&                                                                              
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...                                     
EXPECT VFR CONDITIONS THROUGH 12Z THIS MORNING...WITH CLOUDS                    
SPREADING IN ABOVE 3000 FT. BETWEEN 12Z AND 18Z A BIT MORE                      
UNCERTAIN...AS FLOW BECOMES ONSHORE ARE MARGINALLY CONFIDENT THAT               
MVFR CIGS WILL MOVE INTO PWM-AUG. THEN SNOW WILL MOVE IN BETWEEN                
18Z - 00Z...WITH LOWERING CIGS AND VSBY AT ALL SITES. CONDITIONS                
WILL BE VARIABLE BEYOND THIS...WITH TAFS FORECAST IN THE MIDDLE OF              
THE VARIABLE CONDITIONS.                                                        
IFR/LIFR IN SN REMAINS POSSIBLE INTO THU EVE...WITH VFR EXPECTED                
FRI/SAT. ANOTHER SYSTEM...WHICH WILL LKLY PRODUCE MOSTLY                        
RAIN...COULD PRODUCE ANOTHER ROUND OF IFR SAT NIGHT AND SUN.                    
&&                                                                              
.MARINE...                                                                      
IN THE SHORT TERM...WILL LIKELY NEED A SMALL CRAFT ADVISORY FOR                 
LATE TONIGHT. NAM/GFS NOW AGREE ON LOW PRESSURE PASSING SOUTH                   
TONIGHT...WITH A TIGHTENING NE GRADIENT. GO A BIT ABOVE                         
GUIDANCE...BUT STILL EXPECT SCA CONDITIONS TO HOLD OFF UNTIL LATE               
TONIGHT...WHEN WINDS SHIFT MORE EASTERLY.                                       
UPDATED WINDS TO USE 06Z MODEL DATA...WHICH CAPTURES THE NE FLOW                
ACROSS MOST OF OUR WATERS.                                                      
EASTERLY WINDS WILL APPROACH GALES ON THU...AND SHIFT NE THU                    
NIGHT...BEFORE DIMINISHING BY FRI MORNING. GALES WILL AGAIN BE                  
POSSIBLE ON SUNDAY.                                                             
&&                                                                              
.GYX WATCHES/WARNINGS/ADVISORIES...                                             
ME...SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 5 PM EST THURSDAY                
     FOR MEZ007>009-012>014-018>028.                                            
NH...SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 5 PM EST THURSDAY                
     FOR NHZ001>010-013-014.                                                    
MARINE...NONE.                                                                  
&&                                                                              
$$                                                                              
</pre> me                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE MARQUETTE MI                                           
1235 AM EST WED DEC 19 2007                                                     
UPDATED AVIATION DISCUSSION                                                     
.SHORT TERM (TONIGHT THROUGH THU)...                                            
THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR                
PRECIPITATION SATURDAY THROUGH SUNDAY.                                          
WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW AND ASSOCIATED                 
TROUGH MOVING OVER EASTERN ONTARIO AND A RIDGE SHIFT INTO THE                   
WESTERN ONTARIO AND MINNESOTA. ANOTHER TROUGH IS DEVELOPING OVER                
MIDDLE HIGH PLAINS. SURFACE ANALYSIS DEPICTS A LOW OVER THE LOWER               
GREAT LAKES WITH A BROAD HIGH OVER THE OHIO RIVER VALLEY. A RIDGE               
RUNS FROM THE HIGH NORTH THROUGH WISCONSIN AND THE WEST PART OF THE             
FORECAST AREA. A STATIONARY FRONT STRETCHES FROM NEW ENGLAND THROUGH            
THE LOW TO THE ARROWHEAD OF MINNESOTA. A WARM FRONT RUNS FROM IOWA              
NORTHWEST TO SOUTHEAST SASKATCHEWAN THEN WEST TO CENTRAL BRITISH                
COLUMBIA. A LARGE HIGH BLANKETS THE ROCKIES.                                    
THE MID LEVEL RIDGE WILL SLIDE OVER THE FORECAST AREA OVERNIGHT                 
WHICH WILL CAUSE THE WINDS TO DROP OFF AND BACK SOUTH. THE TROUGH               
THAT IS DEVELOPING OVER THE HIGH PLAINS WILL SWEEP ACROSS THE                   
CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI RIVER VALLEY ON THURSDAY.            
THE WISCONSIN RIDGE WILL SHIFT OVER THE FORECAST AREA BY THIS                   
EVENING AND INTO EASTERN ONTARIO ON THURSDAY. 850MB TEMPERATURES OF             
AROUND -7C OVER EASTERN LAKE SUPERIOR AND NORTHWEST WINDS WILL                  
SUPPORT SOME LAKE EFFECT SNOW ENHANCEMENT OVER THE PART OF THE                  
EASTERN U.P. TONIGHT. THERE SHOULD BE SOME LIMITED CLEARING TONIGHT             
AND RADIATIONAL COOLING WILL BRING THE TEMPERATURES DOWN TO THE DEW             
POINT. SOUTHERLY WINDS WILL ALSO HELP PUSH THE TEMPERATURES UP TO               
AROUND FREEZING ON THURSDAY. SOUNDING DATA SHOWING DRY AIR AND AN               
INVERSION SETTLING DOWN TO 950MB OVER THE FORECAST WHICH TOGETHER               
COULD PRODUCE SOME PATCHY FOG TONIGHT THIS WILL BURN OFF ON THURSDAY            
WITH SURFACE WARMING. WEAK SHORTWAVE MOVING THROUGH WESTERN LAKE                
SUPERIOR ON THURSDAY COULD PRODUCE SOME LIGHT SNOW MAINLY OVER THE              
WESTERN.                                                                        
.LONG TERM (THU NIGHT THROUGH NEXT WED)...                                      
MAIN FORECAST CONCERN REMAINS ON POTENTIAL FOR HEAVY SNOW SAT NIGHT             
INTO SUN.                                                                       
THU NIGHT THROUGH SAT...SOUTHERLY WINDS WILL PREVAIL UNTIL A LOW                
PRESSURE TROUGH SWINGS ACROSS UPPER MI ON SAT (12Z ECMWF IS SLOWER              
THAN 12Z GFS). INCREASED HIGH TEMPS ON FRIDAY TO ACCOUNT FOR WAA OUT            
OF THE SSE. MAY NEED TO INCREASE HIGHS MORE IN FUTURE FORECASTS. AS             
FAR AS PCPN TYPE GOES...MAINLY KEPT WITH GOING FORECAST. IT LOOKS               
LIKE UPSLOPE AREAS WITH A SSE WIND (WESTERN AND CENTRAL U.P.) WILL              
SEE BETTER CHANCE OF FREEZING DRIZZLE...AND OTHER AREAS MAY SEE                 
DRIZZLE. FCST SOUNDINGS IN BUFKIT FOR IRON MOUNTAIN ON FRIDAY SHOW              
GREATER VALUES OF OMEGA AT LOW LEVELS THAN IN MQT AND HOUGHTON. THE             
TEMPS IN IRON MOUNTAIN REMAIN NEARLY ISOTHERMALLY AROUND 0C UP                  
THROUGH 850MB. THE MAIN SATURATED LAYER ALSO OCCURS AT TEMPS GREATER            
THAN -10C...SO DRIZZLE IS ALMOST CERTAIN. FOR MQT AND                           
HOUGHTON...POSITIVE OMEGA VALUES UP TO +5...MID-LEVEL DRY AIR...AND             
SFC TEMPS AROUND 0C LEAD TO UNCERTAINTY IN THE CHANCES OF FREEZING              
DRIZZLE VS. SNOW VS. NO PCPN AT ALL FOR FRI. CHANCES FOR PCPN                   
INCREASE ACROSS ALL OF THE U.P. BY SAT MORNING AS THE LOW PRESSURE              
SYSTEM APPROACHES THE REGION.                                                   
SAT NIGHT THROUGH WED...MODELS HAVE BECOME IN MUCH BETTER AGREEMENT             
WITH THE END OF THE WEEKEND SYSTEM...AND AT LEAST UP IN THE GREAT               
LAKES AREA...ARE IN PRETTY GOOD AGREEMENT THROUGH WED. AT 00Z                   
SUN...06Z MODELS PROG THE UPPER LOW OVER SASKATCHEWAN ON FRI TO DROP            
DOWN INTO NORTHERN MN ON SAT...WHILE A SHRTWV TROUGH MOVES FROM NEW             
MEXICO UP INTO SW MISSOURI. THERE STILL REMAINS ISSUES WHETHER OR               
NOT THE SHRTWV AND UPPER LOW WILL PHASE TOGETHER...AS NOTED BY THE              
06Z GFS KEEPING THEM UNPHASED. WILL CONTINUE TO SIDE WITH THE PHASED            
IDEA OF THE ECMWF/CANADIAN...WHICH PHASE THEM TOGETHER NEAR LAKE                
HURON ON SUNDAY. THIS RESULTS IN A 1007MB LOW OVER ILLINOIS SAT                 
EVENING TO LIFT N AND DEEPEN RAPIDLY...REACHING NORTHERN LAKE HURON             
AT 12Z SUN WITH A PRESSURE AROUND 990MB. THE LOW WILL THEN TRACK UP             
INTO NE ONTARIO LATER SUN AND INTO QUEBEC ON MONDAY. FOR UPPER                  
MI...THE TRACK IS FAVORABLE FOR HEAVY SYNOPTIC SNOW...WITH Q-VECTOR             
CONVERGENCE PROGS SUGGESTING FROM THE NORTHERN U.P. UP TO JAMES BAY.            
LOOKS LIKE TOO THAT AT LEAST AFTER 00Z SUN...MUCH OF THE PCPN WILL              
SWITCH OVER TO SNOW AS COLD AIR MOVES IN. THERE ARE TWO OTHER                   
ASPECTS OF THIS EVENT TOO. AS THE UPPER LOW APPROACHES SAT                      
NIGHT...850MB TEMPS PLUMMET COMPARED TO 12Z SAT...WITH READINGS                 
DROPPING TO -8C EAST TO -15C WEST BY 12Z SUN. THUS LAKE ENHANCEMENT             
LOOKS LIKE A PRETTY GOOD BET. GIVEN THE LOW TRACK...SURFACE AND                 
850MB WIND FIELDS SUGGEST RIGHT NOW THAT THE BEST ENHANCEMENT IS                
OVER NORTHWEST SNOW-BELTS. THE OTHER ASPECT TO THIS SYSTEM IS                   
WIND...WITH THE 00Z ECMWF SHOWING 850MB WINDS INCREASING TO 45-50 KT            
BY 00Z MON. THUS SOME BLOWING AND DRIFTING SNOW IS LIKELY...                    
BEGINNING SAT NIGHT. SYNOPTIC SNOW SHOULD CHANGE OVER TO A PURE LAKE            
EFFECT REGIME LATER SUN NIGHT AS THE UPPER AND SURFACE LOWS PULL                
AWAY...WHILE 850MB TEMPS SLOWLY WARM TO AROUND -10C BY 12Z MON. WILL            
DRY OUT CHRISTMAS EVE A BIT MORE NOW...SINCE MOST MODELS PROG UPPER             
AND SURFACE RIDGING TO MOVE INTO THE CWA. ONLY LAKE EFFECT CHANCES              
WILL REMAIN IN NW SNOWBELTS.                                                    
SHOULD THE SCENARIO OF THE UPPER LOW AND SHRTWV NOT PHASE TOGETHER              
AS SHOWN BY THE 06Z GFS...THE EVENT WILL TURN OUT WITH MORE PURE                
LAKE EFFECT SNOW FOR WEST AND NW SNOWBELTS...ALONG WITH BLOWING                 
SNOW. THUS...GIVEN THE DIFFERENCES BETWEEN THE ECMWF AND                        
GFS...ANYONE TRAVELING THIS WEEKEND SHOULD CONTINUE TO MONITOR LATER            
FORECASTS.                                                                      
FOR CHRISTMAS EVE NIGHT INTO CHRISTMAS DAY...THE WEATHER LOOKS                  
PRETTY TRANQUIL...WITH ONLY A WEAK SHRTWV TROUGH CROSSING CHRISTMAS             
EVE NIGHT. THE ECMWF AND GFS DEPICT LITTLE IF ANY PCPN FROM                     
THIS...AND THUS WILL NOT INCLUDE ANY IN THE FORECAST. ALSO...WITH SW            
FLOW DURING THIS PERIOD AND 850MB TEMPS CLIMBING TO -4 TO -6C BY 00Z            
WED...NO NEED FOR ANY LAKE EFFECT PCPN CHANCES. A NORTHERN STREAM               
SHRTWV TROUGH IS SHOWN BY THE GFS AND ECMWF TO APPROACH THE CWA TUE             
NIGHT AND WED. WILL BRING IN SOME SNOW CHANCES ON TUE NIGHT OVER                
WESTERN LAKE SUPERIOR...THEN ACROSS THE CWA ON WEDNESDAY AS THE                 
TROUGH MOVES THROUGH AND 850MB TEMPS DROP TO GENERATE LAKE EFFECT               
SNOW.                                                                           
&&                                                                              
.AVIATION (FOR THE 06Z TAF ISSUANCE)...                                         
LOOK FOR MVFR CIGS AT BOTH LOCATIONS TO LOWER TO IFR AS FLOW BECOMES            
SE (UPSLOPE AT BOTH LOCATIONS) AND DRYING/SUBSIDENCE ALOFT KEEPS                
MOISTURE TRAPPED AT LOW-LEVELS. MOIST UPSLOPE FLOW MAY ALSO                     
CONTRIBUTE TO TEMPORARY IFR VBSYS LATE TONIGHT AT KSAW. EXPECT SOME             
IMPROVEMENT AT KCMX BY LATE THU MORNING WHERE FLOW WILL SHIFT SSE               
WHICH IS NOT AS FAVORED AN UPSLOPE DIRECTION. SSE FLOW SHOULD                   
CONTINUE TO KEEP KSAW SOCKED IN UNDER MVFR CIGS.                                
&&                                                                              
.MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)...                       
THE PRESSURE GRADIENT UNDER A RIDGE THAT EXTENDS FROM FROM QUEBEC               
INTO NORTHERN LAKE SUPERIOR WAS PRODUCING LIGHT NE TO N WINDS. AS               
THE RIDGE MOVES OFF TO THE EAST ON THURSDAY...SOUTHERLY FLOW WILL               
INCREASE ON LAKE SUPERIOR WITH WINDS TO NEAR 30 KT BY THURSDAY NIGHT            
INTO EARLY FRIDAY. A STRONG SURFACE LOW IS EXPECTED TO MOVE TOWARDS             
THE UPPER GREAT LAKES ON SATURDAY. DEPENDING ON THE TRACK AND                   
TIMING...GALE FORCE WINDS COULD DEVELOP FROM LATE SATURDAY INTO                 
SUNDAY.                                                                         
&&                                                                              
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.                                        
&&                                                                              
$$                                                                              
SHORT TERM...DLG                                                                
LONG TERM...AJ/MRC                                                              
AVIATION...VOSS                                                                 
MARINE...DLG                                                                    
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
1152 PM EST WED DEC 19 2007                                                     
.AVIATION...LOW LEVEL MOISTURE REMAINING TRAPPED BELOW INVERSION                
LEADING TO WIDESPREAD MVFR STRATUS DECK ACROSS THE TAF SITES THIS               
MORNING...ESPECIALLY OVER KAPN AND KPLN. MIST FORMATION A LITTLE                
SLOW GETTING GOING THIS EVENING AND HAVE BACKED OFF THIS POSSIBILITY            
SOMEWHAT...ONLY SHOWING A SLIGHT DROP IN VISIBILITIES. HAVE GONE A              
LITTLE MORE OPTIMISTIC TOMORROW...HAVING SKIES SCATTER OUT DURING               
THE MORNING/EARLY AFTERNOON...LEADING TO VFR CONDITIONS. WINDS WILL             
REMAIN LIGHT AND VARIABLE TONIGHT...BECOMING LIGHT SOUTHEAST                    
THURSDAY.                                                                       
MSB                                                                             
&&                                                                              
.UPDATE...ISSUED 955 PM                                                         
PER 11U-3.9U SATELLITE IMAGERY...EXPANSIVE SUB 2KFT STRATUS DECK                
OVER THE NORTHERN LAKES REGION THIS EVENING AS REMNANT LOW LEVEL                
MOISTURE (WITH SOME ADDITIONAL NORTHWEST FLOW MOISTURE FLUX FROM THE            
BIG LAKES) REMAINS TRAPPED BELOW STRENGTHENING SUBSIDENCE INVERSION.            
JUST ENOUGH OVER WATER INSTABILITY TO PRODUCE SCATTERED FLURRIES                
OVER FAVORED NORTHWEST FLOW AREAS OF NORTHERN LOWER MICHIGAN.                   
HOWEVER...EXPECT THIS TO DIMINISH DURING THE NEXT SEVERAL HOURS AS              
WAA OVERSPREADS THE LAKES. EXPECT CLOUD SHIELD TO PRETTY MUCH REMAIN            
STATUS QUO OVER MUCH OF THE AREA...WITH THE EXCEPTION OF FAR SOUTH              
PARTS OF THE AREA WHERE MODEL PROGS SHOW JUST ENOUGH DRYING TO                  
POTENTIALLY SCOUR OUT SOME OF THE CLOUD DECK. NOCTURNAL TEMPERATURE             
RESPONSE RATHER SLOW ONCE AGAIN THIS EVENING...WITH TEMPERATURES                
SEVERAL DEGREES WARMER THAN INITIALLY PROGGED. GIVEN THIS SLOWER                
THAN ANTICIPATED DROP...WILL GO AHEAD AND BUMP TEMPERATURES UP A                
COUPLE DEGREES ACROSS THE BOARD. OTHERWISE...STILL EXPECTING                    
PATCHY/AREAS OF FOG DEVELOPMENT WITH FURTHER BOUNDARY LAYER COOLING.            
RECENT BELLAIRE OBSERVATION THAT TEMPORARY DROPPED TO A QUARTER MILE            
IN FOG ADDS CONFIDENCE TO THIS SCENARIO. BESIDES AFOREMENTIONED                 
TEMPERATURE ADJUSTMENT...REST OF FORECAST IN GREAT SHAPE WITH LITTLE            
CHANGES WARRANTED.                                                              
UPDATED GRIDS/NEARSHORES/ZONES OUT SHORTLY.                                     
MSB                                                                             
&&                                                                              
.DISCUSSION...ISSUED 400 PM                                                     
LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW SHORTWAVE                  
TROUGHING ACROSS THE GREAT LAKES WITH AN ASSOCIATED SURFACE LOW                 
MOVING ACROSS SE ONTARIO.  WEAK SURFACE TROUGH EMANATING FROM THIS              
LOW IS EXTENDING ACROSS THE STRAITS REGION...BUT APPEARS TO BE                  
LOOSING ITS INFLUENCE OVERALL ACROSS NORTHERN MICHIGAN.  CONVERGENCE            
ALONG THIS TROUGH AND GENERAL CYCLONIC FLOW HAS HELPED MAINTAIN IFR             
TO MVFR CLOUD DECK ACROSS THE AREA...BUT SHALLOW AND MARGINAL                   
OVER-LAKE INSTABILITY HAS NOT BEEN ENOUGH TO GENERATE LAKE EFFECT               
SNOW SHOWERS WITHIN NW FLOW REGIMES.  RADAR RETURNS ARE REALLY                  
SPOTTY AND LIGHT AT THIS HOUR WITH PERHAPS ONLY FLURRIES OR EVEN                
LIGHT DRIZZLE PRESENT AS SFC TEMPS HAVE WARMED ABOVE FREEZING THIS              
AFTERNOON.  SURFACE RIDGE AXIS UPSTREAM OVER WISCONSIN WILL HAVE ITS            
SIGHTS SET ON NORTHERN MICHIGAN OVERNIGHT...BUT STILL PLENTY OF LOW             
CLOUDS AND FOG RESIDE FROM NORTHERN MICHIGAN ON WEST TO THE RIDGE               
AXIS.  LOW LEVEL CLOUDS CLEAR OUT TO THE WEST OF THE RIDGE                      
AXIS...BUT MID-LEVEL WARM ADVECTION CLOUDS ALREADY PUSHING EAST INTO            
THE UPPER MIDWEST.  CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS             
TONIGHT.                                                                        
TONIGHT...SURFACE LOW WILL CONTINUE TO PUSH OFF TO THE EAST INTO                
THE NEW ENGLAND STATES WHILE THE LOW LEVEL RIDGE AXIS BUILDS IN                 
ACROSS NORTHERN MICHIGAN OVERNIGHT.  PRIOR TO THE ARRIVAL OF THE                
RIDGE AXIS...LIGHT NORTHWEST WINDS COMBINED WITH SHALLOW OVER-WATER             
INSTABILITY (LAKE-900MB TEMP DIFFERENCE AROUND -10C) WILL SPELL SCT             
LAKE EFFECT FLURRIES IN THE SNOWBELTS DURING THE EVENING.                       
OTHERWISE...INCREASING SHORTWAVE RIDGING ALOFT WILL PROMOTE DRYING              
IN THE MID-LEVELS AND DECREASING INVERSION HEIGHTS.  LOW LEVEL                  
MOISTURE REALLY DOES NOT HAVE ANYWHERE TO GO OVERNIGHT SINCE THE                
MOISTURE IS TRAPPED BENEATH THE INVERSION AND LOW LEVEL ADVECTIONS              
WILL BE RATHER LIGHT.  NAM12 925-850MB RH DETAILS SOME DRYING TAKING            
PLACE IN THE WESTERN ZONES...BUT THAT MAY BE A FUNCTION OF LOWERING             
INVERSION HEIGHTS AND NOT INDICATIVE OF THE ACTUAL AMOUNT OF LOW                
CLOUDS THAT ARE PRESENT.  PLENTY OF LOW CLOUDS UPSTREAM NEAR THE                
SURFACE RIDGE AXIS ACROSS WISCONSIN...IN ADDITION TO ONSHORE AND                
UPSLOPE FLOW WITH THE NW WINDS AND A LINGERING LOW LEVEL CONVERGENCE            
AXIS THAT SETS UP ACROSS NORTHEAST LOWER AND EASTERN UPPER...AND                
EVAPORATIVE COOLING AT THE TOP OF THE LOW LEVEL MOIST LAYER SUPPORTS            
GOING MOSTLY CLOUDY TO CLOUDY THE ENTIRE NIGHT...WITH LOWERING OF               
THE LOW LEVEL CLOUD BASE.  WITH COOLING OF THE BL AND ADDED MOISTURE            
TO THE BL FROM ABOVE FREEZING SURFACE TEMPS THE PAST TWO                        
AFTERNOONS...PATCHY FOG SHOULD DEVELOP POSSIBLY BECOMING MORE                   
WIDESPREAD ACROSS THE HIGHER TERRAIN DEPENDING UPON HOW MUCH CLOUD              
BASES LOWER. LOWS WILL RANGE FROM THE UPPER TEENS NEAR CAD AND HTL              
TO THE MID 20S ALONG THE GREAT LAKES SHORELINES.                                
MPC                                                                             
THURSDAY...WEAK CONVERGENCE AXIS ACROSS NRN LAKE HURON WILL WANE AS             
SFC RIDGE AXIS SLIDES EAST OF THE REGION IN THE MORNING. TRAPPED LOW            
CLOUDS ASSOCIATED WITH THIS TROUGH MAY BREAK APART FOR A BRIEF TIME             
IN THE MORNING...BUT AS WINDS TURN AROUND TO THE SOUTH WITH                     
CONTINUING SHALLOW OVERLAKE INSTABILITY...CLOUDS SHOULD FILL BACK IN            
ACROSS EASTERN UPPER. ELSEWHERE...SHALLOW/SUB 1500KFT MOISTURE WITH             
ADDED SFC MOISTURE FROM SNOWMELT...WILL KEEP AREAS OF FOG AND LOW               
CLOUD AROUND FOR A GOOD DEAL OF THE MORNING. WONDERING HOW MUCH OF              
THE LOW CLOUD AND FOG WILL ACTUALLY GET TRAPPED IN FOR MUCH OF THE              
DAY. THIS ONE IS A TOUGH CALL. THERE WILL BE 925 MB WARM ADVECTION              
THAT INCREASES THROUGH THE DAY...AND WILL LIKELY BRING SOME PARTLY              
CLOUDY SKIES TO THE SW CWA BY AFTERNOON. OVERALL...BELIEVE THAT A               
MOSTLY CLOUDY FORECAST WITH LINGERING AREAS OF FOG INTO THE EARLY               
AFTERNOON IS THE BEST CALL...ESPECIALLY WITH MID TO UPPER LEVEL                 
CLOUDS ADVANCING ITO THE CWA IN THE AFTERNOON. HIGHS AGAIN IN THE               
LOW TO MIDDLE 30S.                                                              
THURSDAY NIGHT...WITH THE CONTINUED MILD TEMPERATURES...MORE                    
SNOWMELT WILL CONTINUE TO CREATE QUITE THE SOUPY BL. WOULD NOT BE               
SURPRISED TO SEE AT LIGHT FOG NEVER REALLY ERODING FROM THURSDAY                
AFTERNOON...AND JUST CONTINUE INTO THURSDAY NIGHT. DIFFICULT TO                 
DISCERN HOW MUCH MID/UPPER CLOUD WILL BE AROUND. MID LEVEL WEAK WARM            
ADVECTION/ISENTROPIC UPGLIDE (290-295K) PERSISTS THROUGH THE                    
NIGHT...BUT WEAK MID LEVEL SHORTWAVE DEPARTS EAST BY 12Z WITH SOME              
MID LEVEL RIDGING. THIS COULD ALLOW FOR SOME DRIER AIR ALOFT TO                 
ARRIVE LATE...HELPING TO PROMOTE THICKENING FOG. EITHER WAY...FOG IN            
SOME FASHION WILL BE AROUND...AND WHETHER OR NOT AREAS OF/PATCHY IS             
USED CAN BE SAVED FOR TOMORROW`S FORECAST PACKAGE. AM NOT EXPECTING             
MUCH OF A TEMP FALL UNDER THE CLOUDS/WARM ADVECTION...LOWS GENERALLY            
IN THE MIDDLE 20S CAN BE EXPECTED.                                              
FRIDAY AND FRIDAY NIGHT...HEIGHTS CONTINUE TO RISE IN THE MID LEVELS            
AS SRN/NRN JET STREAM ENERGY RIPS INTO THE ROCKIES. THE SOUTHERLY               
FLOW ACROSS THE GREAT LAKES INCREASES RESULTING IN BETTER/STRONGER              
WARM AND MOIST AIR ADVECTION. WINDS OF DEEPER H8-H5 MOISTURE SWINGS             
THROUGH THE CWA FRIDAY. FORECAST SOUNDINGS NO INDICATIVE OF ANY                 
MEASURABLE PRECIPITATION...BUT RATHER LOW LEVEL MOISTURE THICKENING             
TO NEAR 750MB...ALL WARMER THAN -10C. THIS IS LOOKING MORE AND MORE             
LIKE A DRIZZLE SCENARIO...HINTED AT YESTERDAY. WILL BRING AREAS OF              
DRIZZLE INTO THE REGION STARTING FRIDAY AFTERNOON...THEN PROGRESSING            
THROUGH ALL OF THE CWA FRIDAY NIGHT. OF COURSE...FOG WILL ACCOMPANY             
THE DRIZZLE. AS FAR AS TEMPS...MID TO UPPER 30S FOR HIGHS ON FRIDAY             
WITH NEAR STEADY TEMPERATURES THROUGH THE NIGHT. FEEL AS IF ALL                 
AREAS WILL BE ABOVE 32F...SO NO NEED ATTM TO MENTION FREEZING                   
DRIZZLE.                                                                        
SATURDAY...THERE ARE SOME COMMONALITIES IN THE MODELS IN THIS TIME              
PERIOD. NRN AND SRN STREAM ENERGY WORK THEIR WAY NEAR THE                       
MISSISSIPPI VALLEY...REMAINING SEPARATE SYSTEMS WITH NO APPARENT                
PHASING (YET?). THE MORNING...IF TIMING IS CORRECT...WILL START OFF             
DRIZZLY AND FOGGY...BEFORE SFC LOW PRESSURE WORKS INTO THE WESTERN              
GREAT LAKES...ALONG WITH FORCING FROM SHORTWAVES. WILL KEEP THIS                
PERIOD SORT OF GENERAL. WILL GO WITH LIKELY RAIN FOR NRN LOWER AS               
AIR MASS LOOKS TO STAY WARM. LEFT A MIX IN FOR EASTERN UPPER...AND              
IN LINE WITH NEIGHBORING OFFICES. THESE DETAILS WILL BECOME CLEARER             
TOMORROW.                                                                       
SATURDAY NIGHT ONWARD...BOY...STILL LOOKING LIKE A COMMON SOLUTION              
BETWEEN THE MODELS IS JUST A LITTLE TOO FAR AWAY. OVERALL CONSENSUS             
IS TO STAY WITH THE ECMWF...AS THE GFS KEEPS THE TWO JET BRANCHES               
SEPARATE. THE 18Z NAM HAS NOW ALLOWED FOR THE TWO BRANCHES TO PHASE             
TOGETHER...SUCH AS THE 12Z ECMWF. THIS SCENARIO WOULD PULL THE                  
EXPECTED STRONG STORM SYSTEM FURTHER BACK TO THE NW...WHILE RAPIDLY             
DEEPENING THE SFC LOW. AREAS OF RAIN WOULD PERSIST ACROSS THE NE CWA            
INTO THE EVENING WHILE STRONG COLD ADVECTION BLOWS IN FROM THE SW.              
THERE ARE JUST TOO MANY UNCERTAINTIES STILL. FOR AT LEAST ONE MORE              
TIME...WILL GO WITH RAIN AND SNOW IN THE EVENING...MOST AREAS...THEN            
CHANGE TO ALL SNOW OVERNIGHT WITH WINDS BECOMING QUITE BRISK                    
SUNDAY/SUNDAY NIGHT). EXPECT CHANGES TO THIS FORECAST AS MORE                   
DETAILED TIMING/STRENGTH AND EVOLUTION OF THIS STORM WILL COME IN               
DUE TIME. DID INCREASE CHANCES FOR PRECIPITATION TO LIKELY. THAT                
LOOKS LIKE THE SAFEST BET. THE POTENTIAL FOR HAZARDOUS TRAVEL IS                
CERTAINLY STILL THERE OVER THE WEEKEND PRIOR TO THE CHRISTMAS                   
HOLIDAY...SO STAY TUNED FOR THE DETAILS TO ARRIVE IN LATER                      
FORECASTS. A RATHER BRIEF PERIOD OF LAKE EFFECT SNOWS ARE EXPECTED              
ON THE BACKSIDE OF THIS STORM SYSTEM AS IT PULLS EAST SUNDAY NIGHT              
INTO MONDAY. QUITE A BIT OF DRY AIR IS ACTUALLY FORECAST TO SPREAD              
IN BY MONDAY NIGHT.   SMD                                                       
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
624 PM EST WED DEC 19 2007                                                      
.AVIATION...WEAK NORTHWEST FLOW LAKE MICHIGAN MOISTURE FLUX TRAPPED             
BENEATH STRONG INVERSION LEADING TO EXTENSIVE MVFR CIGS/VISIBILITIES            
IN LOW CLOUDS AND MIST. EXPECT PRETTY MUCH STATUS QUO INTO THE                  
MORNING HOURS...WITH PERHAPS A LOWERING IN BOTH CIGS/VISIBILITIES               
OVERNIGHT AS INVERSION HEIGHT LOWERS AND BOUNDARY LAYER COOLS. MODEL            
MOISTURE PROGS SHOW GOOD POTENTIAL FOR MIXING OUT OF THE LOW CLOUD              
DECK THURSDAY MORNING/AFTERNOON OVER KPLN AND KTVC...WITH ABUNDANT              
LOW LEVEL MOISTURE LINGERING AT KAPN. WINDS WILL REMAIN LIGHT                   
THROUGH THE PERIOD.                                                             
MSB                                                                             
&&                                                                              
.DISCUSSION...ISSUED 400 PM                                                     
LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW SHORTWAVE                  
TROUGHING ACROSS THE GREAT LAKES WITH AN ASSOCIATED SURFACE LOW                 
MOVING ACROSS SE ONTARIO.  WEAK SURFACE TROUGH EMANATING FROM THIS              
LOW IS EXTENDING ACROSS THE STRAITS REGION...BUT APPEARS TO BE                  
LOOSING ITS INFLUENCE OVERALL ACROSS NORTHERN MICHIGAN.  CONVERGENCE            
ALONG THIS TROUGH AND GENERAL CYCLONIC FLOW HAS HELPED MAINTAIN IFR             
TO MVFR CLOUD DECK ACROSS THE AREA...BUT SHALLOW AND MARGINAL                   
OVER-LAKE INSTABILITY HAS NOT BEEN ENOUGH TO GENERATE LAKE EFFECT               
SNOW SHOWERS WITHIN NW FLOW REGIMES.  RADAR RETURNS ARE REALLY                  
SPOTTY AND LIGHT AT THIS HOUR WITH PERHAPS ONLY FLURRIES OR EVEN                
LIGHT DRIZZLE PRESENT AS SFC TEMPS HAVE WARMED ABOVE FREEZING THIS              
AFTERNOON.  SURFACE RIDGE AXIS UPSTREAM OVER WISCONSIN WILL HAVE ITS            
SIGHTS SET ON NORTHERN MICHIGAN OVERNIGHT...BUT STILL PLENTY OF LOW             
CLOUDS AND FOG RESIDE FROM NORTHERN MICHIGAN ON WEST TO THE RIDGE               
AXIS.  LOW LEVEL CLOUDS CLEAR OUT TO THE WEST OF THE RIDGE                      
AXIS...BUT MID-LEVEL WARM ADVECTION CLOUDS ALREADY PUSHING EAST INTO            
THE UPPER MIDWEST.  CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS             
TONIGHT.                                                                        
TONIGHT...SURFACE LOW WILL CONTINUE TO PUSH OFF TO THE EAST INTO                
THE NEW ENGLAND STATES WHILE THE LOW LEVEL RIDGE AXIS BUILDS IN                 
ACROSS NORTHERN MICHIGAN OVERNIGHT.  PRIOR TO THE ARRIVAL OF THE                
RIDGE AXIS...LIGHT NORTHWEST WINDS COMBINED WITH SHALLOW OVER-WATER             
INSTABILITY (LAKE-900MB TEMP DIFFERENCE AROUND -10C) WILL SPELL SCT             
LAKE EFFECT FLURRIES IN THE SNOWBELTS DURING THE EVENING.                       
OTHERWISE...INCREASING SHORTWAVE RIDGING ALOFT WILL PROMOTE DRYING              
IN THE MID-LEVELS AND DECREASING INVERSION HEIGHTS.  LOW LEVEL                  
MOISTURE REALLY DOES NOT HAVE ANYWHERE TO GO OVERNIGHT SINCE THE                
MOISTURE IS TRAPPED BENEATH THE INVERSION AND LOW LEVEL ADVECTIONS              
WILL BE RATHER LIGHT.  NAM12 925-850MB RH DETAILS SOME DRYING TAKING            
PLACE IN THE WESTERN ZONES...BUT THAT MAY BE A FUNCTION OF LOWERING             
INVERSION HEIGHTS AND NOT INDICATIVE OF THE ACTUAL AMOUNT OF LOW                
CLOUDS THAT ARE PRESENT.  PLENTY OF LOW CLOUDS UPSTREAM NEAR THE                
SURFACE RIDGE AXIS ACROSS WISCONSIN...IN ADDITION TO ONSHORE AND                
UPSLOPE FLOW WITH THE NW WINDS AND A LINGERING LOW LEVEL CONVERGENCE            
AXIS THAT SETS UP ACROSS NORTHEAST LOWER AND EASTERN UPPER...AND                
EVAPORATIVE COOLING AT THE TOP OF THE LOW LEVEL MOIST LAYER SUPPORTS            
GOING MOSTLY CLOUDY TO CLOUDY THE ENTIRE NIGHT...WITH LOWERING OF               
THE LOW LEVEL CLOUD BASE.  WITH COOLING OF THE BL AND ADDED MOISTURE            
TO THE BL FROM ABOVE FREEZING SURFACE TEMPS THE PAST TWO                        
AFTERNOONS...PATCHY FOG SHOULD DEVELOP POSSIBLY BECOMING MORE                   
WIDESPREAD ACROSS THE HIGHER TERRAIN DEPENDING UPON HOW MUCH CLOUD              
BASES LOWER. LOWS WILL RANGE FROM THE UPPER TEENS NEAR CAD AND HTL              
TO THE MID 20S ALONG THE GREAT LAKES SHORELINES.                                
MPC                                                                             
THURSDAY...WEAK CONVERGENCE AXIS ACROSS NRN LAKE HURON WILL WANE AS             
SFC RIDGE AXIS SLIDES EAST OF THE REGION IN THE MORNING. TRAPPED LOW            
CLOUDS ASSOCIATED WITH THIS TROUGH MAY BREAK APART FOR A BRIEF TIME             
IN THE MORNING...BUT AS WINDS TURN AROUND TO THE SOUTH WITH                     
CONTINUING SHALLOW OVERLAKE INSTABILITY...CLOUDS SHOULD FILL BACK IN            
ACROSS EASTERN UPPER. ELSEWHERE...SHALLOW/SUB 1500KFT MOISTURE WITH             
ADDED SFC MOISTURE FROM SNOWMELT...WILL KEEP AREAS OF FOG AND LOW               
CLOUD AROUND FOR A GOOD DEAL OF THE MORNING. WONDERING HOW MUCH OF              
THE LOW CLOUD AND FOG WILL ACTUALLY GET TRAPPED IN FOR MUCH OF THE              
DAY. THIS ONE IS A TOUGH CALL. THERE WILL BE 925 MB WARM ADVECTION              
THAT INCREASES THROUGH THE DAY...AND WILL LIKELY BRING SOME PARTLY              
CLOUDY SKIES TO THE SW CWA BY AFTERNOON. OVERALL...BELIEVE THAT A               
MOSTLY CLOUDY FORECAST WITH LINGERING AREAS OF FOG INTO THE EARLY               
AFTERNOON IS THE BEST CALL...ESPECIALLY WITH MID TO UPPER LEVEL                 
CLOUDS ADVANCING ITO THE CWA IN THE AFTERNOON. HIGHS AGAIN IN THE               
LOW TO MIDDLE 30S.                                                              
THURSDAY NIGHT...WITH THE CONTINUED MILD TEMPERATURES...MORE                    
SNOWMELT WILL CONTINUE TO CREATE QUITE THE SOUPY BL. WOULD NOT BE               
SURPRISED TO SEE AT LIGHT FOG NEVER REALLY ERODING FROM THURSDAY                
AFTERNOON...AND JUST CONTINUE INTO THURSDAY NIGHT. DIFFICULT TO                 
DISCERN HOW MUCH MID/UPPER CLOUD WILL BE AROUND. MID LEVEL WEAK WARM            
ADVECTION/ISENTROPIC UPGLIDE (290-295K) PERSISTS THROUGH THE                    
NIGHT...BUT WEAK MID LEVEL SHORTWAVE DEPARTS EAST BY 12Z WITH SOME              
MID LEVEL RIDGING. THIS COULD ALLOW FOR SOME DRIER AIR ALOFT TO                 
ARRIVE LATE...HELPING TO PROMOTE THICKENING FOG. EITHER WAY...FOG IN            
SOME FASHION WILL BE AROUND...AND WHETHER OR NOT AREAS OF/PATCHY IS             
USED CAN BE SAVED FOR TOMORROW`S FORECAST PACKAGE. AM NOT EXPECTING             
MUCH OF A TEMP FALL UNDER THE CLOUDS/WARM ADVECTION...LOWS GENERALLY            
IN THE MIDDLE 20S CAN BE EXPECTED.                                              
FRIDAY AND FRIDAY NIGHT...HEIGHTS CONTINUE TO RISE IN THE MID LEVELS            
AS SRN/NRN JET STREAM ENERGY RIPS INTO THE ROCKIES. THE SOUTHERLY               
FLOW ACROSS THE GREAT LAKES INCREASES RESULTING IN BETTER/STRONGER              
WARM AND MOIST AIR ADVECTION. WINDS OF DEEPER H8-H5 MOISTURE SWINGS             
THROUGH THE CWA FRIDAY. FORECAST SOUNDINGS NO INDICATIVE OF ANY                 
MEASURABLE PRECIPITATION...BUT RATHER LOW LEVEL MOISTURE THICKENING             
TO NEAR 750MB...ALL WARMER THAN -10C. THIS IS LOOKING MORE AND MORE             
LIKE A DRIZZLE SCENARIO...HINTED AT YESTERDAY. WILL BRING AREAS OF              
DRIZZLE INTO THE REGION STARTING FRIDAY AFTERNOON...THEN PROGRESSING            
THROUGH ALL OF THE CWA FRIDAY NIGHT. OF COURSE...FOG WILL ACCOMPANY             
THE DRIZZLE. AS FAR AS TEMPS...MID TO UPPER 30S FOR HIGHS ON FRIDAY             
WITH NEAR STEADY TEMPERATURES THROUGH THE NIGHT. FEEL AS IF ALL                 
AREAS WILL BE ABOVE 32F...SO NO NEED ATTM TO MENTION FREEZING                   
DRIZZLE.                                                                        
SATURDAY...THERE ARE SOME COMMONALITIES IN THE MODELS IN THIS TIME              
PERIOD. NRN AND SRN STREAM ENERGY WORK THEIR WAY NEAR THE                       
MISSISSIPPI VALLEY...REMAINING SEPARATE SYSTEMS WITH NO APPARENT                
PHASING (YET?). THE MORNING...IF TIMING IS CORRECT...WILL START OFF             
DRIZZLY AND FOGGY...BEFORE SFC LOW PRESSURE WORKS INTO THE WESTERN              
GREAT LAKES...ALONG WITH FORCING FROM SHORTWAVES. WILL KEEP THIS                
PERIOD SORT OF GENERAL. WILL GO WITH LIKELY RAIN FOR NRN LOWER AS               
AIR MASS LOOKS TO STAY WARM. LEFT A MIX IN FOR EASTERN UPPER...AND              
IN LINE WITH NEIGHBORING OFFICES. THESE DETAILS WILL BECOME CLEARER             
TOMORROW.                                                                       
SATURDAY NIGHT ONWARD...BOY...STILL LOOKING LIKE A COMMON SOLUTION              
BETWEEN THE MODELS IS JUST A LITTLE TOO FAR AWAY. OVERALL CONSENSUS             
IS TO STAY WITH THE ECMWF...AS THE GFS KEEPS THE TWO JET BRANCHES               
SEPARATE. THE 18Z NAM HAS NOW ALLOWED FOR THE TWO BRANCHES TO PHASE             
TOGETHER...SUCH AS THE 12Z ECMWF. THIS SCENARIO WOULD PULL THE                  
EXPECTED STRONG STORM SYSTEM FURTHER BACK TO THE NW...WHILE RAPIDLY             
DEEPENING THE SFC LOW. AREAS OF RAIN WOULD PERSIST ACROSS THE NE CWA            
INTO THE EVENING WHILE STRONG COLD ADVECTION BLOWS IN FROM THE SW.              
THERE ARE JUST TOO MANY UNCERTAINTIES STILL. FOR AT LEAST ONE MORE              
TIME...WILL GO WITH RAIN AND SNOW IN THE EVENING...MOST AREAS...THEN            
CHANGE TO ALL SNOW OVERNIGHT WITH WINDS BECOMING QUITE BRISK                    
SUNDAY/SUNDAY NIGHT). EXPECT CHANGES TO THIS FORECAST AS MORE                   
DETAILED TIMING/STRENGTH AND EVOLUTION OF THIS STORM WILL COME IN               
DUE TIME. DID INCREASE CHANCES FOR PRECIPITATION TO LIKELY. THAT                
LOOKS LIKE THE SAFEST BET. THE POTENTIAL FOR HAZARDOUS TRAVEL IS                
CERTAINLY STILL THERE OVER THE WEEKEND PRIOR TO THE CHRISTMAS                   
HOLIDAY...SO STAY TUNED FOR THE DETAILS TO ARRIVE IN LATER                      
FORECASTS. A RATHER BRIEF PERIOD OF LAKE EFFECT SNOWS ARE EXPECTED              
ON THE BACKSIDE OF THIS STORM SYSTEM AS IT PULLS EAST SUNDAY NIGHT              
INTO MONDAY. QUITE A BIT OF DRY AIR IS ACTUALLY FORECAST TO SPREAD              
IN BY MONDAY NIGHT.   SMD                                                       
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE MARQUETTE MI                                           
425 PM EST WED DEC 19 2007                                                      
.SHORT TERM (TONIGHT THROUGH THU)...                                            
THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR                
PRECIPITATION SATURDAY THROUGH SUNDAY.                                          
WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW AND ASSOCIATED                 
TROUGH MOVING OVER EASTERN ONTARIO AND A RIDGE SHIFT INTO THE                   
WESTERN ONTARIO AND MINNESOTA. ANOTHER TROUGH IS DEVELOPING OVER                
MIDDLE HIGH PLAINS. SURFACE ANALYSIS DEPICTS A LOW OVER THE LOWER               
GREAT LAKES WITH A BROAD HIGH OVER THE OHIO RIVER VALLEY. A RIDGE               
RUNS FROM THE HIGH NORTH THROUGH WISCONSIN AND THE WEST PART OF THE             
FORECAST AREA. A STATIONARY FRONT STRETCHES FROM NEW ENGLAND THROUGH            
THE LOW TO THE ARROWHEAD OF MINNESOTA. A WARM FRONT RUNS FROM IOWA              
NORTHWEST TO SOUTHEAST SASKATCHEWAN THEN WEST TO CENTRAL BRITISH                
COLUMBIA. A LARGE HIGH BLANKETS THE ROCKIES.                                    
THE MID LEVEL RIDGE WILL SLIDE OVER THE FORECAST AREA OVERNIGHT                 
WHICH WILL CAUSE THE WINDS TO DROP OFF AND BACK SOUTH. THE TROUGH               
THAT IS DEVELOPING OVER THE HIGH PLAINS WILL SWEEP ACROSS THE                   
CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI RIVER VALLEY ON THURSDAY.            
THE WISCONSIN RIDGE WILL SHIFT OVER THE FORECAST AREA BY THIS                   
EVENING AND INTO EASTERN ONTARIO ON THURSDAY. 850MB TEMPERATURES OF             
AROUND -7C OVER EASTERN LAKE SUPERIOR AND NORTHWEST WINDS WILL                  
SUPPORT SOME LAKE EFFECT SNOW ENHANCEMENT OVER THE PART OF THE                  
EASTERN U.P. TONIGHT. THERE SHOULD BE SOME LIMITED CLEARING TONIGHT             
AND RADIATIONAL COOLING WILL BRING THE TEMPERATURES DOWN TO THE DEW             
POINT. SOUTHERLY WINDS WILL ALSO HELP PUSH THE TEMPERATURES UP TO               
AROUND FREEZING ON THURSDAY. SOUNDING DATA SHOWING DRY AIR AND AN               
INVERSION SETTLING DOWN TO 950MB OVER THE FORECAST WHICH TOGETHER               
COULD PRODUCE SOME PATCHY FOG TONIGHT THIS WILL BURN OFF ON THURSDAY            
WITH SURFACE WARMING. WEAK SHORTWAVE MOVING THROUGH WESTERN LAKE                
SUPERIOR ON THURSDAY COULD PRODUCE SOME LIGHT SNOW MAINLY OVER THE              
WESTERN.                                                                        
.LONG TERM (THU NIGHT THROUGH NEXT WED)...                                      
MAIN FORECAST CONCERN REMAINS ON POTENTIAL FOR HEAVY SNOW SAT NIGHT             
INTO SUN.                                                                       
THU NIGHT THROUGH SAT...SOUTHERLY WINDS WILL PREVAIL UNTIL A LOW                
PRESSURE TROUGH SWINGS ACROSS UPPER MI ON SAT (12Z ECMWF IS SLOWER              
THAN 12Z GFS). INCREASED HIGH TEMPS ON FRIDAY TO ACCOUNT FOR WAA OUT            
OF THE SSE. MAY NEED TO INCREASE HIGHS MORE IN FUTURE FORECASTS. AS             
FAR AS PCPN TYPE GOES...MAINLY KEPT WITH GOING FORECAST. IT LOOKS               
LIKE UPSLOPE AREAS WITH A SSE WIND (WESTERN AND CENTRAL U.P.) WILL              
SEE BETTER CHANCE OF FREEZING DRIZZLE...AND OTHER AREAS MAY SEE                 
DRIZZLE. FCST SOUNDINGS IN BUFKIT FOR IRON MOUNTAIN ON FRIDAY SHOW              
GREATER VALUES OF OMEGA AT LOW LEVELS THAN IN MQT AND HOUGHTON. THE             
TEMPS IN IRON MOUNTAIN REMAIN NEARLY ISOTHERMALLY AROUND 0C UP                  
THROUGH 850MB. THE MAIN SATURATED LAYER ALSO OCCURS AT TEMPS GREATER            
THAN -10C...SO DRIZZLE IS ALMOST CERTAIN. FOR MQT AND                           
HOUGHTON...POSITIVE OMEGA VALUES UP TO +5...MID-LEVEL DRY AIR...AND             
SFC TEMPS AROUND 0C LEAD TO UNCERTAINTY IN THE CHANCES OF FREEZING              
DRIZZLE VS. SNOW VS. NO PCPN AT ALL FOR FRI. CHANCES FOR PCPN                   
INCREASE ACROSS ALL OF THE U.P. BY SAT MORNING AS THE LOW PRESSURE              
SYSTEM APPROACHES THE REGION.                                                   
SAT NIGHT THROUGH WED...MODELS HAVE BECOME IN MUCH BETTER AGREEMENT             
WITH THE END OF THE WEEKEND SYSTEM...AND AT LEAST UP IN THE GREAT               
LAKES AREA...ARE IN PRETTY GOOD AGREEMENT THROUGH WED. AT 00Z                   
SUN...06Z MODELS PROG THE UPPER LOW OVER SASKATCHEWAN ON FRI TO DROP            
DOWN INTO NORTHERN MN ON SAT...WHILE A SHRTWV TROUGH MOVES FROM NEW             
MEXICO UP INTO SW MISSOURI. THERE STILL REMAINS ISSUES WHETHER OR               
NOT THE SHRTWV AND UPPER LOW WILL PHASE TOGETHER...AS NOTED BY THE              
06Z GFS KEEPING THEM UNPHASED. WILL CONTINUE TO SIDE WITH THE PHASED            
IDEA OF THE ECMWF/CANADIAN...WHICH PHASE THEM TOGETHER NEAR LAKE                
HURON ON SUNDAY. THIS RESULTS IN A 1007MB LOW OVER ILLINOIS SAT                 
EVENING TO LIFT N AND DEEPEN RAPIDLY...REACHING NORTHERN LAKE HURON             
AT 12Z SUN WITH A PRESSURE AROUND 990MB. THE LOW WILL THEN TRACK UP             
INTO NE ONTARIO LATER SUN AND INTO QUEBEC ON MONDAY. FOR UPPER                  
MI...THE TRACK IS FAVORABLE FOR HEAVY SYNOPTIC SNOW...WITH Q-VECTOR             
CONVERGENCE PROGS SUGGESTING FROM THE NORTHERN U.P. UP TO JAMES BAY.            
LOOKS LIKE TOO THAT AT LEAST AFTER 00Z SUN...MUCH OF THE PCPN WILL              
SWITCH OVER TO SNOW AS COLD AIR MOVES IN. THERE ARE TWO OTHER                   
ASPECTS OF THIS EVENT TOO. AS THE UPPER LOW APPROACHES SAT                      
NIGHT...850MB TEMPS PLUMMET COMPARED TO 12Z SAT...WITH READINGS                 
DROPPING TO -8C EAST TO -15C WEST BY 12Z SUN. THUS LAKE ENHANCEMENT             
LOOKS LIKE A PRETTY GOOD BET. GIVEN THE LOW TRACK...SURFACE AND                 
850MB WIND FIELDS SUGGEST RIGHT NOW THAT THE BEST ENHANCEMENT IS                
OVER NORTHWEST SNOW-BELTS. THE OTHER ASPECT TO THIS SYSTEM IS                   
WIND...WITH THE 00Z ECMWF SHOWING 850MB WINDS INCREASING TO 45-50 KT            
BY 00Z MON. THUS SOME BLOWING AND DRIFTING SNOW IS LIKELY...                    
BEGINNING SAT NIGHT. SYNOPTIC SNOW SHOULD CHANGE OVER TO A PURE LAKE            
EFFECT REGIME LATER SUN NIGHT AS THE UPPER AND SURFACE LOWS PULL                
AWAY...WHILE 850MB TEMPS SLOWLY WARM TO AROUND -10C BY 12Z MON. WILL            
DRY OUT CHRISTMAS EVE A BIT MORE NOW...SINCE MOST MODELS PROG UPPER             
AND SURFACE RIDGING TO MOVE INTO THE CWA. ONLY LAKE EFFECT CHANCES              
WILL REMAIN IN NW SNOWBELTS.                                                    
SHOULD THE SCENARIO OF THE UPPER LOW AND SHRTWV NOT PHASE TOGETHER              
AS SHOWN BY THE 06Z GFS...THE EVENT WILL TURN OUT WITH MORE PURE                
LAKE EFFECT SNOW FOR WEST AND NW SNOWBELTS...ALONG WITH BLOWING                 
SNOW. THUS...GIVEN THE DIFFERENCES BETWEEN THE ECMWF AND                        
GFS...ANYONE TRAVELING THIS WEEKEND SHOULD CONTINUE TO MONITOR LATER            
FORECASTS.                                                                      
FOR CHRISTMAS EVE NIGHT INTO CHRISTMAS DAY...THE WEATHER LOOKS                  
PRETTY TRANQUIL...WITH ONLY A WEAK SHRTWV TROUGH CROSSING CHRISTMAS             
EVE NIGHT. THE ECMWF AND GFS DEPICT LITTLE IF ANY PCPN FROM                     
THIS...AND THUS WILL NOT INCLUDE ANY IN THE FORECAST. ALSO...WITH SW            
FLOW DURING THIS PERIOD AND 850MB TEMPS CLIMBING TO -4 TO -6C BY 00Z            
WED...NO NEED FOR ANY LAKE EFFECT PCPN CHANCES. A NORTHERN STREAM               
SHRTWV TROUGH IS SHOWN BY THE GFS AND ECMWF TO APPROACH THE CWA TUE             
NIGHT AND WED. WILL BRING IN SOME SNOW CHANCES ON TUE NIGHT OVER                
WESTERN LAKE SUPERIOR...THEN ACROSS THE CWA ON WEDNESDAY AS THE                 
TROUGH MOVES THROUGH AND 850MB TEMPS DROP TO GENERATE LAKE EFFECT               
SNOW.                                                                           
&&                                                                              
.AVIATION (FOR THE 18Z TAF ISSUANCE)...                                         
BOTH LOCATIONS ARE EXPECTED TO SEE A GRADUAL IMPROVEMENT LATE IN THE            
DAY AS A SFC RIDGE BUILDS INTO THE AREA. WITH LIGHT WINDS AND DRYING            
ABOVE THE MOIST BOUNDARY LAYER...EXPECT SOME FOG WILL DEVELOP                   
OVERNIGHT WITH VSBY INTO THE IFR RANGE. GUIDANCE SHOWING AN                     
INVERSION AND LESS SATURATED CONDITIONS AROUND 925MB A5 15Z ON                  
THURSDAY AT KSAW AND IMPROVED CONDITIONS AROUND 9Z AT KCMX.                     
&&                                                                              
.MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)...                       
THE PRESSURE GRADIENT UNDER A RIDGE THAT EXTENDS FROM FROM QUEBEC               
INTO NORTHERN LAKE SUPERIOR WAS PRODUCING LIGHT NE TO N WINDS. AS               
THE RIDGE MOVES OFF TO THE EAST ON THURSDAY...SOUTHERLY FLOW WILL               
INCREASE ON LAKE SUPERIOR WITH WINDS TO NEAR 30 KT BY THURSDAY NIGHT            
INTO EARLY FRIDAY. A STRONG SURFACE LOW IS EXPECTED TO MOVE TOWARDS             
THE UPPER GREAT LAKES ON SATURDAY. DEPENDING ON THE TRACK AND                   
TIMING...GALE FORCE WINDS COULD DEVELOP FROM LATE SATURDAY INTO                 
SUNDAY.                                                                         
&&                                                                              
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.                                        
&&                                                                              
$$                                                                              
SHORT TERM...DLG                                                                
LONG TERM...AJ/MRC                                                              
AVIATION/MARINE...DLG                                                           
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
400 PM EST WED DEC 19 2007                                                      
.DISCUSSION...LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW              
SHORTWAVE TROUGHING ACROSS THE GREAT LAKES WITH AN ASSOCIATED                   
SURFACE LOW MOVING ACROSS SE ONTARIO.  WEAK SURFACE TROUGH EMANATING            
FROM THIS LOW IS EXTENDING ACROSS THE STRAITS REGION...BUT APPEARS              
TO BE LOOSING ITS INFLUENCE OVERALL ACROSS NORTHERN MICHIGAN.                   
CONVERGENCE ALONG THIS TROUGH AND GENERAL CYCLONIC FLOW HAS HELPED              
MAINTAIN IFR TO MVFR CLOUD DECK ACROSS THE AREA...BUT SHALLOW AND               
MARGINAL OVER-LAKE INSTABILITY HAS NOT BEEN ENOUGH TO GENERATE LAKE             
EFFECT SNOW SHOWERS WITHIN NW FLOW REGIMES.  RADAR RETURNS ARE                  
REALLY SPOTTY AND LIGHT AT THIS HOUR WITH PERHAPS ONLY FLURRIES OR              
EVEN LIGHT DRIZZLE PRESENT AS SFC TEMPS HAVE WARMED ABOVE FREEZING              
THIS AFTERNOON.  SURFACE RIDGE AXIS UPSTREAM OVER WISCONSIN WILL                
HAVE ITS SIGHTS SET ON NORTHERN MICHIGAN OVERNIGHT...BUT STILL                  
PLENTY OF LOW CLOUDS AND FOG RESIDE FROM NORTHERN MICHIGAN ON WEST              
TO THE RIDGE AXIS.  LOW LEVEL CLOUDS CLEAR OUT TO THE WEST OF THE               
RIDGE AXIS...BUT MID-LEVEL WARM ADVECTION CLOUDS ALREADY PUSHING                
EAST INTO THE UPPER MIDWEST.  CLOUDS AND TEMPS ARE THE MAIN FORECAST            
CONCERNS TONIGHT.                                                               
TONIGHT...SURFACE LOW WILL CONTINUE TO PUSH OFF TO THE EAST INTO                
THE NEW ENGLAND STATES WHILE THE LOW LEVEL RIDGE AXIS BUILDS IN                 
ACROSS NORTHERN MICHIGAN OVERNIGHT.  PRIOR TO THE ARRIVAL OF THE                
RIDGE AXIS...LIGHT NORTHWEST WINDS COMBINED WITH SHALLOW OVER-WATER             
INSTABILITY (LAKE-900MB TEMP DIFFERENCE AROUND -10C) WILL SPELL SCT             
LAKE EFFECT FLURRIES IN THE SNOWBELTS DURING THE EVENING.                       
OTHERWISE...INCREASING SHORTWAVE RIDGING ALOFT WILL PROMOTE DRYING              
IN THE MID-LEVELS AND DECREASING INVERSION HEIGHTS.  LOW LEVEL                  
MOISTURE REALLY DOES NOT HAVE ANYWHERE TO GO OVERNIGHT SINCE THE                
MOISTURE IS TRAPPED BENEATH THE INVERSION AND LOW LEVEL ADVECTIONS              
WILL BE RATHER LIGHT.  NAM12 925-850MB RH DETAILS SOME DRYING TAKING            
PLACE IN THE WESTERN ZONES...BUT THAT MAY BE A FUNCTION OF LOWERING             
INVERSION HEIGHTS AND NOT INDICATIVE OF THE ACTUAL AMOUNT OF LOW                
CLOUDS THAT ARE PRESENT.  PLENTY OF LOW CLOUDS UPSTREAM NEAR THE                
SURFACE RIDGE AXIS ACROSS WISCONSIN...IN ADDITION TO ONSHORE AND                
UPSLOPE FLOW WITH THE NW WINDS AND A LINGERING LOW LEVEL CONVERGENCE            
AXIS THAT SETS UP ACROSS NORTHEAST LOWER AND EASTERN UPPER...AND                
EVAPORATIVE COOLING AT THE TOP OF THE LOW LEVEL MOIST LAYER SUPPORTS            
GOING MOSTLY CLOUDY TO CLOUDY THE ENTIRE NIGHT...WITH LOWERING OF               
THE LOW LEVEL CLOUD BASE.  WITH COOLING OF THE BL AND ADDED MOISTURE            
TO THE BL FROM ABOVE FREEZING SURFACE TEMPS THE PAST TWO                        
AFTERNOONS...PATCHY FOG SHOULD DEVELOP POSSIBLY BECOMING MORE                   
WIDESPREAD ACROSS THE HIGHER TERRAIN DEPENDING UPON HOW MUCH CLOUD              
BASES LOWER. LOWS WILL RANGE FROM THE UPPER TEENS NEAR CAD AND HTL              
TO THE MID 20S ALONG THE GREAT LAKES SHORELINES.                                
MPC                                                                             
THURSDAY...WEAK CONVERGENCE AXIS ACROSS NRN LAKE HURON WILL WANE AS             
SFC RIDGE AXIS SLIDES EAST OF THE REGION IN THE MORNING. TRAPPED LOW            
CLOUDS ASSOCIATED WITH THIS TROUGH MAY BREAK APART FOR A BRIEF TIME             
IN THE MORNING...BUT AS WINDS TURN AROUND TO THE SOUTH WITH                     
CONTINUING SHALLOW OVERLAKE INSTABILITY...CLOUDS SHOULD FILL BACK IN            
ACROSS EASTERN UPPER. ELSEWHERE...SHALLOW/SUB 1500KFT MOISTURE WITH             
ADDED SFC MOISTURE FROM SNOWMELT...WILL KEEP AREAS OF FOG AND LOW               
CLOUD AROUND FOR A GOOD DEAL OF THE MORNING. WONDERING HOW MUCH OF              
THE LOW CLOUD AND FOG WILL ACTUALLY GET TRAPPED IN FOR MUCH OF THE              
DAY. THIS ONE IS A TOUGH CALL. THERE WILL BE 925 MB WARM ADVECTION              
THAT INCREASES THROUGH THE DAY...AND WILL LIKELY BRING SOME PARTLY              
CLOUDY SKIES TO THE SW CWA BY AFTERNOON. OVERALL...BELIEVE THAT A               
MOSTLY CLOUDY FORECAST WITH LINGERING AREAS OF FOG INTO THE EARLY               
AFTERNOON IS THE BEST CALL...ESPECIALLY WITH MID TO UPPER LEVEL                 
CLOUDS ADVANCING ITO THE CWA IN THE AFTERNOON. HIGHS AGAIN IN THE               
LOW TO MIDDLE 30S.                                                              
THURSDAY NIGHT...WITH THE CONTINUED MILD TEMPERATURES...MORE                    
SNOWMELT WILL CONTINUE TO CREATE QUITE THE SOUPY BL. WOULD NOT BE               
SURPRISED TO SEE AT LIGHT FOG NEVER REALLY ERODING FROM THURSDAY                
AFTERNOON...AND JUST CONTINUE INTO THURSDAY NIGHT. DIFFICULT TO                 
DISCERN HOW MUCH MID/UPPER CLOUD WILL BE AROUND. MID LEVEL WEAK WARM            
ADVECTION/ISENTROPIC UPGLIDE (290-295K) PERSISTS THROUGH THE                    
NIGHT...BUT WEAK MID LEVEL SHORTWAVE DEPARTS EAST BY 12Z WITH SOME              
MID LEVEL RIDGING. THIS COULD ALLOW FOR SOME DRIER AIR ALOFT TO                 
ARRIVE LATE...HELPING TO PROMOTE THICKENING FOG. EITHER WAY...FOG IN            
SOME FASHION WILL BE AROUND...AND WHETHER OR NOT AREAS OF/PATCHY IS             
USED CAN BE SAVED FOR TOMORROW`S FORECAST PACKAGE. AM NOT EXPECTING             
MUCH OF A TEMP FALL UNDER THE CLOUDS/WARM ADVECTION...LOWS GENERALLY            
IN THE MIDDLE 20S CAN BE EXPECTED.                                              
FRIDAY AND FRIDAY NIGHT...HEIGHTS CONTINUE TO RISE IN THE MID LEVELS            
AS SRN/NRN JET STREAM ENERGY RIPS INTO THE ROCKIES. THE SOUTHERLY               
FLOW ACROSS THE GREAT LAKES INCREASES RESULTING IN BETTER/STRONGER              
WARM AND MOIST AIR ADVECTION. WINDS OF DEEPER H8-H5 MOISTURE SWINGS             
THROUGH THE CWA FRIDAY. FORECAST SOUNDINGS NO INDICATIVE OF ANY                 
MEASURABLE PRECIPITATION...BUT RATHER LOW LEVEL MOISTURE THICKENING             
TO NEAR 750MB...ALL WARMER THAN -10C. THIS IS LOOKING MORE AND MORE             
LIKE A DRIZZLE SCENARIO...HINTED AT YESTERDAY. WILL BRING AREAS OF              
DRIZZLE INTO THE REGION STARTING FRIDAY AFTERNOON...THEN PROGRESSING            
THROUGH ALL OF THE CWA FRIDAY NIGHT. OF COURSE...FOG WILL ACCOMPANY             
THE DRIZZLE. AS FAR AS TEMPS...MID TO UPPER 30S FOR HIGHS ON FRIDAY             
WITH NEAR STEADY TEMPERATURES THROUGH THE NIGHT. FEEL AS IF ALL                 
AREAS WILL BE ABOVE 32F...SO NO NEED ATTM TO MENTION FREEZING                   
DRIZZLE.                                                                        
SATURDAY...THERE ARE SOME COMMONALITIES IN THE MODELS IN THIS TIME              
PERIOD. NRN AND SRN STREAM ENERGY WORK THEIR WAY NEAR THE                       
MISSISSIPPI VALLEY...REMAINING SEPARATE SYSTEMS WITH NO APPARENT                
PHASING (YET?). THE MORNING...IF TIMING IS CORRECT...WILL START OFF             
DRIZZLY AND FOGGY...BEFORE SFC LOW PRESSURE WORKS INTO THE WESTERN              
GREAT LAKES...ALONG WITH FORCING FROM SHORTWAVES. WILL KEEP THIS                
PERIOD SORT OF GENERAL. WILL GO WITH LIKELY RAIN FOR NRN LOWER AS               
AIR MASS LOOKS TO STAY WARM. LEFT A MIX IN FOR EASTERN UPPER...AND              
IN LINE WITH NEIGHBORING OFFICES. THESE DETAILS WILL BECOME CLEARER             
TOMORROW.                                                                       
SATURDAY NIGHT ONWARD...BOY...STILL LOOKING LIKE A COMMON SOLUTION              
BETWEEN THE MODELS IS JUST A LITTLE TOO FAR AWAY. OVERALL CONSENSUS             
IS TO STAY WITH THE ECMWF...AS THE GFS KEEPS THE TWO JET BRANCHES               
SEPARATE. THE 18Z NAM HAS NOW ALLOWED FOR THE TWO BRANCHES TO PHASE             
TOGETHER...SUCH AS THE 12Z ECMWF. THIS SCENARIO WOULD PULL THE                  
EXPECTED STRONG STORM SYSTEM FURTHER BACK TO THE NW...WHILE RAPIDLY             
DEEPENING THE SFC LOW. AREAS OF RAIN WOULD PERSIST ACROSS THE NE CWA            
INTO THE EVENING WHILE STRONG COLD ADVECTION BLOWS IN FROM THE SW.              
THERE ARE JUST TOO MANY UNCERTAINTIES STILL. FOR AT LEAST ONE MORE              
TIME...WILL GO WITH RAIN AND SNOW IN THE EVENING...MOST AREAS...THEN            
CHANGE TO ALL SNOW OVERNIGHT WITH WINDS BECOMING QUITE BRISK                    
SUNDAY/SUNDAY NIGHT). EXPECT CHANGES TO THIS FORECAST AS MORE                   
DETAILED TIMING/STRENGTH AND EVOLUTION OF THIS STORM WILL COME IN               
DUE TIME. DID INCREASE CHANCES FOR PRECIPITATION TO LIKELY. THAT                
LOOKS LIKE THE SAFEST BET. THE POTENTIAL FOR HAZARDOUS TRAVEL IS                
CERTAINLY STILL THERE OVER THE WEEKEND PRIOR TO THE CHRISTMAS                   
HOLIDAY...SO STAY TUNED FOR THE DETAILS TO ARRIVE IN LATER                      
FORECASTS. A RATHER BRIEF PERIOD OF LAKE EFFECT SNOWS ARE EXPECTED              
ON THE BACKSIDE OF THIS STORM SYSTEM AS IT PULLS EAST SUNDAY NIGHT              
INTO MONDAY. QUITE A BIT OF DRY AIR IS ACTUALLY FORECAST TO SPREAD              
IN BY MONDAY NIGHT.   SMD                                                       
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION...UPDATED                                              
NATIONAL WEATHER SERVICE GAYLORD MI                                             
117 PM EST WED DEC 19 2007                                                      
.UPDATE...AREAS OF FREEZING DRIZZLE HAVE DISSIPATED EARLY THIS                  
AFTERNOON...WHILE TEMPERATURES HAVE WARMED AT OR ABOVE FREEZING.                
ALTHOUGH PATCHY FREEZING DRIZZLE MAY STILL EXIST PARTICULARLY                   
ACROSS THE HIGHER TERRAIN OF NORTHERN LOWER...WARMING TEMPERATURES              
THIS AFTERNOON WILL PREVENT MUCH IN THE WAY OF ACCUMULATIONS.                   
THEREFORE...HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR AREAS                
SOUTH OF M-32. ALSO MADE ONE OTHER CHANGE TO THIS AFTERNOONS                    
FORECAST. EARLY BATCH OF PRECIP OVER SOUTHERN LAKE SUPERIOR HAS                 
DISSIPATED OVER THE PAST COUPLE HOURS...AND IT APPEARS THAT                     
MARGINAL OVER-LAKE INSTABILITY IS NOT ENOUGH TO GENERATE ANY LAKE               
EFFECT SNOW SHOWERS. HAVE THUS CHANGED PRECIP TYPE TO FLURRIES FOR              
THE REMAINDER OF THE AFTERNOON.                                                 
NEW ZONES HAVE ALREADY BEEN SENT.                                               
MPC                                                                             
&&                                                                              
.AVIATION... /ISSUED 1203 PM EST WED DEC 19 2007/                               
AREAS OF LIGHT FREEZING DRIZZLE AND SNOW ASSOCIATED WITH A                      
SURFACE LOW MOVING EAST OVER LAKE HURON WILL COME TO AN END EARLY               
THIS AFTERNOON AT ALL TAF SITES. HOWEVER...MVFR VSBYS AND CIGS                  
LOOK TO PERSIST THROUGH TOMORROW MORNING BEFORE DRIER LOW LEVEL                 
AIR MAKES INTO NORTHERN MICHIGAN. SOME VERY LIGHT SNOW SHOWERS MAY              
MOVE ACROSS TVC/PLN...BUT NOT WORTH PUTTING PREDOMINATELY IN THE                
FORECAST.                                                                       
MPC                                                                             
&&                                                                              
.PREV UPDATE... /ISSUED 1030 AM EST WED DEC 19 2007/                            
UPDATE....12Z SURFACE/RAOB/RUC ANALYSIS AND IR/WV/RADAR IMAGERY                 
SHOW A SHORTWAVE AND ASSOCIATED SURFACE LOW MOVING ACROSS NE                    
LOWER...A COLD FRONT EXTENDING FROM THIS LOW SOUTH TOWARDS                      
LANSING...AND A SURFACE TROUGH EXTENDED NW TOWARDS MQT. LIGHT                   
RADAR RETURNS CONTINUE TO MOVE SE ON THE WESTERN FLANK OF THE                   
SURFACE LOW...ENHANCED A BIT BY THE AFOREMENTIONED SURFACE TROUGH.              
NUMEROUS LOCATIONS ARE STILL REPORTING LIGHT FREEZING                           
DRIZZLE...MIXED WITH FLURRIES OR LIGHT SNOW AT TIMES ACROSS                     
NORTHERN LOWER...AND THE 12Z APX SOUNDING SUGGESTS WHY WITH THE                 
MOISTURE DEPTH ONLY REACHING UP TO -11C. ACARS SOUNDING OUT OF                  
KINROSS SHOWS DEEPER MOISTURE UP TO -15C WHICH EXPLAINS ALL SNOW                
BEING REPORTED ACROSS EASTERN UPPER. NW WINDS BEHIND THE LOW ARE                
FUNNELING IN SLIGHTLY COOLER 850MB TEMPS THAN THE MODELS                        
PORTRAY...GIVING RISE TO POTENTIAL LAKE EFFECT PRECIP HEADING INTO              
THE AFTERNOON. BUT FIRST...HAVE TO DEAL WITH TIMING OF NUISANT                  
-FZDZ COMING TO AN END.                                                         
MAIN AREA OF -FZDZ MIXED WITH LIGHT SNOW WILL CONTINUE SOUTH ACROSS             
THE CWA THROUGH EARLY AFTERNOON.  EXIT TIMING BASED ON RADAR AND                
SATELLITE LOOPS IS AROUND 18Z ACROSS THE FAR SE CWA...BUT THERE MAY             
BE SOME LINGERING FZDZ BASED ON LOWER VSBYS ACROSS THE TIP OF THE               
MITT SO HAVE EXTENDED WINTER WEATHER ADVISORY THROUGH 19Z.  ALTHOUGH            
THE PRIMARY ROADS ARE PROBABLY OK BY NOW...UNTREATED SECONDARY ROADS            
MAY STILL BE A LITTLE ICY. THEREAFTER...NW FLOW BECOMES                         
ESTABLISHED (ALREADY TAKING SHAPE ACROSS LAKE SUPERIOR) WITH                    
MARGINAL DELTA T/S AROUND 13-14C AND EXPECT A TRANSITION TO LIGHT NW            
FLOW LAKE EFFECT FROM MID-AFTERNOON ONWARD.  INSTABILITY IS ONLY                
MARGINAL...SO ACCUMULATIONS SHOULD BE A HALF INCH OR LESS...WHICH               
THE CURRENT FORECAST DISPLAYS WELL.    CLOUD COVER WILL REMAIN                  
CLOUDY ALL DAY...AND TEMPERATURES THEREFORE WILL NOT INCREASE TOO               
MUCH.  SO HIGHS IN THE LOW-MID 30S LOOKS GOOD.                                  
MPC                                                                             
&&                                                                              
.PREVIOUS DISCUSSION...ISSUED 510 AM                                            
ON THE LATEST SURFACE WEATHER MAP...1009 MB LOW PRESSURE WAS                    
CENTERED ACROSS NORTHERN LAKE MICHIGAN. SATELLITE LOOPS AND SURFACE             
OBSERVATIONS INDICATED THAT A STRATOCU DECK HAD OVERSPREAD THE                  
REGION. APX RADAR CONTINUED TO SHOW 16-20 DBZ RETURNS FROM THE TIP              
OF THE MITT INTO EASTERN UPPER OF THE LAST FEW HOURS. MEANWHILE...A             
BROAD AREA OF 4-8 DBZ RETURNS DEVELOPED ACROSS SOUTHWEST AND SOUTH              
CENTRAL COUNTIES A COUPLE OF HOURS AGO WITH A SLOW PROGRESSION TO               
THE EAST. THE MAIN FORECAST CONCERNS REVOLVE AROUND EXTENT OF                   
FREEZING DRIZZLE AND POSSIBLE HEADLINES THIS MORNING...POPS THURSDAY            
NIGHT AND HOW MUCH TO TWEAK THE DETAILS OF THE POTENTIAL MAJOR STORM            
SYSTEM THIS WEEKEND.                                                            
CLIPPER AND ASSOCIATED AREA OF DIVQ WILL CONTINUE TO MOVE ACROSS FAR            
NORTHERN ZONES THIS MORNING. SO FAR ONLY LIGHT SNOW (NO FREEZING                
DRIZZLE) HAS BEEN REPORTED ACROSS THE TIP OF THE MITT AND EASTERN               
UPPER. MEANWHILE TO THE SOUTH LIGHT RETURNS CORRESPOND TO RECENT                
REPORTS OF FREEZING DRIZZLE AND DEVELOPING ICY CONDITIONS. MODEL                
SOUNDINGS/CROSS SECTIONS MOISTEN UP THE COLUMN THROUGH BETWEEN -12              
AND -14 C THIS MORNING WHICH WOULD MEAN THAT ANY PRECIPITATION THAT             
FALLS WOULD BE IN THE FORM OF SNOW. HOWEVER...WITH THE TRACK OF THE             
CLIPPER (ACROSS THE FAR NORTH) ITS HARD TO BELIEVE THAT IT WOULD                
MOISTEN UP  THIS MUCH SOUTH OF THE SURFACE LOW TRACK. THIS IS BORNE             
OUT WITH THE INCREASING NUMBER OF FREEZING DRIZZLE REPORTS.                     
THEREFORE WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS MORNING                 
ACROSS ALL ZONES IN NORTHERN LOWER WITH THE EXCEPTION OF THE COUNTIES           
IN THE TIPP OF THE MITT WHERE MAINLY LIGHT SNOW IS EXPECTED. AS FAR             
AS SNOW AMOUNTS ACROSS THE FAR NORTH...ONLY EXPECTING LESS THAN AN              
INCH OF ACCUMULATION. WINDS VEER INTO THE NORTHWEST THIS                        
AFTERNOON AND OVER LAKE INSTABILITY APPEARS TO BE MARGINALLY                    
SUFFICIENT TO SUPPORT LIGHT LAKE EFFECT SNOW SHOWERS (LAKE-850 MB               
DELTA TS INCREASE TO BETWEEN 13 TO 14) WITH 900-700 MB RH STILL 60              
TO 80 PERCENT AND. SO WILL ADD IN NUMEROUS LIGHT SNOW SHOWERS WITH              
AN INCH OR LESS OF ACCUMULATION INTO FAVORED NW FLOW AREAS. CLOUDS ARE          
EXPECTED TO HANG IN ALL DAY WITH MODEST COLD AIR ADVECTION.                     
TEMPERATURES SHOULD REMAIN NEARLY STEADY OR FALL BY A COUPLE OF                 
DEGREES (GENERALLY AROUND 30 TO THE LOWER 30S).                                 
TONIGHT...NAM LINGERS OVER LAKE INSTABILITY/MOISTURE WELL INTO THIS             
EVENING WHILE THE GFS HAS PRONOUNCED DRYING (MEAN 900-700 MB RH <40             
PERCENT) AND WARMING (850 TEMPS INCREASE BY A FEW DEGREES). AT THIS             
POINT WILL GO WITH A COMPROMISE SOLUTION WITH ONLY A CHANCE OF                  
LIGHT LAKE EFFECT SNOW SHOWERS IN NORTHWEST FLOW AREAS THROUGH                  
MIDNIGHT AS MEAN SURFACE-850 MB WINDS BARELY SUPPORT ORGANIZED LAKE             
EFFECT (10 KNOTS OR SO). INCREASING RIDGING/SUFFICIENT                          
WARMING/DRYING OVERNIGHT SHOULD PUT THE KABOSH ON ANY LINGERING                 
ACTIVITY. LOWS TONIGHT IN THE MIDDLE TEENS TO LOWER 20S.                        
THURSDAY...RIDGING AT THE SURFACE AND ALOFT FOR MUCH OF THE DAY. GFS            
IS FASTER THAN THE NAM WITH MOISTURE RETURN WITH DEVELOPING SOUTHERLY           
FLOW BUT THIS APPEARS TO BE A BIT QUICK. FOR NOW WILL CONTINUE WITH             
PARTLY CLOUDY AND MILD CONDITIONS WITH INCREASING CLOUDINESS LATE IN            
THE DAY. HIGHS IN THE MILD LOWER AND MIDDLE 30S.                                
THURSDAY NIGHT...WARM ADVECTION SHOULD INCREASE PER NAM/GFS LEADING             
TO THICKENING CLOUD DECK. MOISTURE DEPTH IS QUESTIONABLE FOR                    
PRECIPITATION PRODUCTION BUT WILL ADD IN A CHANCE OF FLURRIES                   
OVERNIGHT. THERE EVEN COULD BE SOME FREEZING DRIZZLE ONCE AGAIN BUT             
WILL LET THE DAYSHIFT TAKE A BETTER LOOK AT THAT SCENARIO DUE TO                
LIMITED TIME CONSTRAINT`S AT THE MOMENT. LOWS IN THE LOWER AND MIDDLE           
20S.                                                                            
FRIDAY...CONTINUED SOUTHERLY FLOW WITH DRY MID LEVELS SO A MOSTLY               
CLOUDY DAY IS EXPECTED WITH HIGHS GENERALLY IN THE MIDDLE 30S.                  
FRIDAY NIGHT THROUGH SUNDAY...COMPLEX WEATHER SITUATION SHAPING UP              
WITH ENERGY IN THE SOUTHERN JET STREAM MOVING NORTHEAST OUT OF THE              
DESERT SOUTHWEST WHILE ENERGY IN THE NORTHERN JET STREAM DROPS DOWN             
OUT OF CENTRAL CANADA. EXTENDED MODELS THIS RUN ARE IN BETTER                   
AGREEMENT THAT THE SOUTHERN ENERGY IMPACTS THE AREA FIRST WITH LOW              
PRESSURE MOVING BY TO OUR WEST WHICH WOULD LEAD TO MAINLY RAIN FOR              
SATURDAY. THE NORTHERN STREAM ENERGY IS SHOWN TO BE VERY IMPRESSIVE             
AND IT MERGES WITH THE SOUTHERN STREAM ENERGY SATURDAY NIGHT INTO               
SUNDAY WHICH WOULD LEAD TO FALLING TEMPERATURES...INCREASING WINDS              
AND RAIN CHANGING TO SNOW SATURDAY NIGHT AND CONTINUING INTO SUNDAY.            
MODELS HAVE BEEN WAVERING OVER THE DETAILS OVER THE LAST COUPLE OF              
DAYS BUT WILL MAKE A FEW ADJUSTMENTS TO CURRENT FORECAST WHICH LINE             
UP WITH SURROUNDING OFFICES...LIKE INCREASING POPS AND GOING WITH A             
CHANGEOVER TO ALL SNOW SATURDAY NIGHT INTO SUNDAY.                              
SULLIVAN                                                                        
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION...UPDATE                                               
NATIONAL WEATHER SERVICE MARQUETTE MI                                           
1245 PM EST WED DEC 19 2007                                                     
.SHORT TERM...                                                                  
.DISCUSSION...THE MAIN CONCERN WITH THIS UPDATE IS THE POTENTIAL FOR            
PRECIPITATION THIS AFTERNOON AND TONIGHT.                                       
WATER VAPOR IMAGERY AND RUC SHOWING A LOW OVER EAST CENTRAL ONTARIO             
AND A RIDGE OVER THE DAKOTAS AND MANITOBA. A SURFACE LOW IS OVER                
LAKE HURON WITH A STATIONARY FRONT RUNNING THROUGH IT FROM NORTHERN             
NEW YORK STATE TO WINNIPEG. CYCLONIC WINDS AROUND THE LOW ARE                   
KEEPING THE WINDS OUT OF THE NORTH ACROSS THE AREA. DRIER AIR IS                
ADVECTING INTO THE AREA FROM THE WEST CAUSING THE SNOW TO DIMINISH.             
A SURFACE LOW IS DEEPENING OVER ALBERTA WITH A WEAK TROUGH EXTENDING            
SOUTH INTO EASTERN COLORADO. COOLER AIR SETTLING OVER THE NORTHERN              
PLAINS AND THE UPPER MISSISSIPPI RIVER VALLEY IS PRODUCING                      
CONSIDERABLE AMOUNTS OF FOG OVER MINNESOTA AND WISCONSIN THIS                   
MORNING. LOW LEVEL MOISTURE AND TEMPERATURES ARE A LITTLE COOLER                
THAN ANY OF THE MODEL DEPICT AT THIS TIME. PRECIPITATION HAS ENDED              
OVER THE WEST HALF OF CWA AND WEAKEN CONSIDERABLY OVER THE EAST AS              
THE LOW MOVES EAST.                                                             
THE MID LEVEL LOW WILL BECOME MORE FOCUSED JUST NORTHEAST OF                    
GEORGIAN BAY TODAY AND SHIFT INTO EXTREME SOUTHEAST ONTARIO TONIGHT             
WHILE THE RIDGE OVER THE DAKOTAS WANDERS INTO MINNESOTA THIS                    
AFTERNOON AND INTO THE WESTERN U.P. TONIGHT. THE SNOW WILL CONTINUE             
TO END ACROSS THE U.P. AS THE SYSTEM MOVES EAST TODAY. THE                      
LAKE-850MB DELTA-T IS ONLY AROND 11C OVER THE CENTRAL AND EASTERN               
LAKE SUPERIOR. THIS SHOULD BE ENOUGH TO PRODUCE SOME LAKE                       
ENHANCEMENT IN THE FORECASTS ESPECIALLY OVER THE EAST. CLOUD COVER              
WILL HOLD TEMPERATURES DOWN TODAY. DRIER AIR WILL GIVE SOME CLEARING            
THIS EVENING WHICH WILL ALLOW TEMPERATURES TO FALL RAPIDLY                      
EARLY...THEN IT SHOULD TAPER OFF AS CLOUD COVER INCREASES. GUIDANCE             
LOOKS REASONABLE.                                                               
.LONG TERM...                                                                   
THURSDAY...THE RIDGE OVER THE DAKOTAS TODAY WILL SLIDE                          
OVERHEAD BY 12Z THURSDAY.  THE TROUGH OVER THE WESTERN STATES WILL              
HAVE MOVED TO THE VICINITY OF MINNESOTA AND IOWA...WEAKENING AS IT              
SLIDES OVER WESTERN LAKE SUPERIOR LATE THURSDAY AFTERNOON.  THE MAIN            
FEATURE OF INTEREST...THE WEEKEND SYSTEM...WILL BE COMING ONSHORE               
OVER THE WESTERN STATES THURSDAY MORNING.                                       
FRIDAY...THE MIDLEVEL HIGH WILL GET SHIFTED TO THE EAST OF THE CWA              
AS THE SINKING TROUGH FORMS A CUT-OFF LOW OVER ALBERTA BY 12Z FRIDAY.           
SATURDAY...MUCH OF THE ATTENTION WILL BE PLACED JUST TO OUR                     
WEST...AS THE MID LEVEL LOW OVER SOUTHERN MANITOBA AND THE DAKOTAS              
HEADS OUR WAY.  THE 00Z NAM HAS JUMPED TO THE SOUTH WHEN COMPARED TO            
ITS PREVIOUS 12Z RUN...WITH THE 500MB LOW CENTERED OVER CENTRAL                 
SOUTH DAKOTA AT 12Z.  THIS WAS MUCH FARTHER SOUTH THAN THE CONSENSUS            
OF THE REMAINING MODELS.  AS A RESULT...THE NAM WAS NOT UTILIZED IN             
THIS FORECAST BEYOND FRIDAY MORNING.  UP UNTIL THAT TIME THE MODELS             
ARE IN PRETTY GOOD AGREEMENT ACROSS UPPER MICHIGAN.                             
AS FOR SPECIFICS...IT LOOKS LIKE FREEZING DRIZZLE WILL BE A GOOD BET            
AT ERY UNTIL ABOUT 06-09Z SATURDAY WHEN SOUNDINGS OFF OF THE GFS                
WOULD SUGGEST RAIN.  850MB TEMPERATURES WILL RISE TO 0 TO 2C EAST               
FROM 00Z SATURDAY THROUGH 00Z SUNDAY...BEFORE COLD AIR SLIDES BACK              
IN.                                                                             
SUNDAY...BY 12Z SUNDAY THE MODELS ARE FAIRLY WELL LINED UP...SAYING             
THAT THE 500MB LOW WILL BE SOMEWHERE BETWEEN STANNARD ROCK AND LA               
CROSSE WISCONSIN.  THE 18Z GFS MORE IN LINE WITH THE NAM TREND WAS              
THE FARTHEST SOUTH AT THIS POINT...POSITIONED OVER CENTRAL IOWA.                
AT THE SURFACE AT 12Z SUNDAY...MODELS WERE IN GOOD AGREEMENT                    
POSITIONING THE SURFACE LOW JUST EAST OF LAKE SUPERIOR.  THIS WAS A             
CHANGE FROM PREVIOUS RUNS...QUICKER TO PUSH NORTHEASTWARD.  FOR                 
EXAMPLE...THE 18/00Z RUN OF THE GFS HAD THE LOW OVER                            
MILWAUKEE...ROUGHLY 350 MILES SSW OF THE LATEST ECMWF AND CANADIAN              
RUNS.  THE 19/00Z GFS HAS SLID A LITTLE MORE SOUTH OF                           
CONSENSUS...BUT IS STILL 320 MILES NE OF 2 RUNS AGO.                            
STEADY TO FALLING TEMPERATURES CAN BE EXPECTED SUNDAY.  PLENTY OF               
COLD AIR WILL ONCE AGAIN FILTER INTO THE REGION DURING THE DAY                  
SUNDAY.  IT LOOKS LIKE 850MB TEMPERATURES OF -18C TO -20C WILL BE               
SHORT LIVED DURING THE DAYLIGHT HOURS SUNDAY...WITH LAKE EFFECT SNOW            
SHOWERS LIKELY ACROSS COMMUNITIES FAVORED BY W TO NW WINDS THROUGH              
MONDAY NIGHT.                                                                   
OVERALL...QUICKER IS THE WAY TO GO...RESULTING IN COOLER                        
TEMPERATURES TO WRAP UP THE WORK WEEK AS WELL AS PLENTY OF                      
WEATHER/POP CHANGES.  WINDS WILL NEED TO BE FURTHER ADJUSTED BY                 
LATER SHIFTS.                                                                   
&&                                                                              
.AVIATION (FOR THE 18Z TAF ISSUANCE)...                                         
BOTH LOCATIONS ARE EXPECTED TO SEE A GRADUAL IMPROVEMENT LATE IN THE            
DAY AS A SFC RIDGE BUILDS INTO THE AREA. WITH LIGHT WINDS AND DRYING            
ABOVE THE MOIST BOUNDARY LAYER...EXPECT SOME FOG WILL DEVELOP                   
OVERNIGHT WITH VSBY INTO THE IFR RANGE. GUIDANCE SHOWING AN                     
INVERSION AND LESS SATURATED CONDITIONS AROUND 925MB A5 15Z ON                  
THURSDAY AT KSAW AND IMPROVED CONDITIONS AROUND 9Z AT KCMX.                     
&&                                                                              
.MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)...                       
THE PRESSURE GRADIENT OVER LAKE SUPERIOR BETWEEN LOW PRESSURE OVER              
NORTHERN LOWER MICHIGAN AND A RIDGE FROM QUEBEC INTO NORTHERN                   
ONTARIO WAS PRODUCING NE TO N WINDS INTO THE 15 TO 25 KT RANGE.                 
WINDS WILL DIMINISH TODAY AS THE LOW MOVES TO THE EAST AND A RIDGE              
BUILDS INTO THE AREA FROM MN. AS THE RIDGE MOVES OFF TO THE EAST ON             
THURSDAY...SOUTHERLY FLOW WILL INCREASE ON LAKE SUPERIOR WITH WINDS             
TO NEAR 30 KT BY THURSDAY NIGHT INTO EARLY FRIDAY. A STRONG SURFACE             
LOW IS EXPECTED TO MOVE TOWARDS THE UPPER GREAT LAKES ON SATURDAY.              
DEPENDING ON THE TRACK AND TIMING...GALE FORCE WINDS  COULD DEVELOP             
FROM LATE SATURDAY INTO SUNDAY.                                                 
&&                                                                              
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.                                        
&&                                                                              
$$                                                                              
SHORT TERM...DLG                                                                
LONG TERM...KF                                                                  
AVIATION/MARINE...JLB                                                           
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
1203 PM EST WED DEC 19 2007                                                     
.AVIATION...AREAS OF LIGHT FREEZING DRIZZLE AND SNOW ASSOCIATED                 
WITH A SURFACE LOW MOVING EAST OVER LAKE HURON WILL COME TO AN END              
EARLY THIS AFTERNOON AT ALL TAF SITES. HOWEVER...MVFR VSBYS AND                 
CIGS LOOK TO PERSIST THROUGH TOMORROW MORNING BEFORE DRIER LOW                  
LEVEL AIR MAKES INTO NORTHERN MICHIGAN. SOME VERY LIGHT SNOW                    
SHOWERS MAY MOVE ACROSS TVC/PLN...BUT NOT WORTH PUTTING                         
PREDOMINATELY IN THE FORECAST.                                                  
MPC                                                                             
&&                                                                              
.PREV DISCUSSION... /ISSUED 1030 AM EST WED DEC 19 2007/                        
UPDATE....12Z SURFACE/RAOB/RUC ANALYSIS AND IR/WV/RADAR IMAGERY                 
SHOW A SHORTWAVE AND ASSOCIATED SURFACE LOW MOVING ACROSS NE                    
LOWER...A COLD FRONT EXTENDING FROM THIS LOW SOUTH TOWARDS                      
LANSING...AND A SURFACE TROUGH EXTENDED NW TOWARDS MQT. LIGHT                   
RADAR RETURNS CONTINUE TO MOVE SE ON THE WESTERN FLANK OF THE                   
SURFACE LOW...ENHANCED A BIT BY THE AFOREMENTIONED SURFACE TROUGH.              
NUMEROUS LOCATIONS ARE STILL REPORTING LIGHT FREEZING                           
DRIZZLE...MIXED WITH FLURRIES OR LIGHT SNOW AT TIMES ACROSS                     
NORTHERN LOWER...AND THE 12Z APX SOUNDING SUGGESTS WHY WITH THE                 
MOISTURE DEPTH ONLY REACHING UP TO -11C. ACARS SOUNDING OUT OF                  
KINROSS SHOWS DEEPER MOISTURE UP TO -15C WHICH EXPLAINS ALL SNOW                
BEING REPORTED ACROSS EASTERN UPPER. NW WINDS BEHIND THE LOW ARE                
FUNNELING IN SLIGHTLY COOLER 850MB TEMPS THAN THE MODELS                        
PORTRAY...GIVING RISE TO POTENTIAL LAKE EFFECT PRECIP HEADING INTO              
THE AFTERNOON. BUT FIRST...HAVE TO DEAL WITH TIMING OF NUISANT                  
-FZDZ COMING TO AN END.                                                         
MAIN AREA OF -FZDZ MIXED WITH LIGHT SNOW WILL CONTINUE SOUTH ACROSS             
THE CWA THROUGH EARLY AFTERNOON.  EXIT TIMING BASED ON RADAR AND                
SATELLITE LOOPS IS AROUND 18Z ACROSS THE FAR SE CWA...BUT THERE MAY             
BE SOME LINGERING FZDZ BASED ON LOWER VSBYS ACROSS THE TIP OF THE               
MITT SO HAVE EXTENDED WINTER WEATHER ADVISORY THROUGH 19Z.  ALTHOUGH            
THE PRIMARY ROADS ARE PROBABLY OK BY NOW...UNTREATED SECONDARY ROADS            
MAY STILL BE A LITTLE ICY. THEREAFTER...NW FLOW BECOMES                         
ESTABLISHED (ALREADY TAKING SHAPE ACROSS LAKE SUPERIOR) WITH                    
MARGINAL DELTA T/S AROUND 13-14C AND EXPECT A TRANSITION TO LIGHT NW            
FLOW LAKE EFFECT FROM MID-AFTERNOON ONWARD.  INSTABILITY IS ONLY                
MARGINAL...SO ACCUMULATIONS SHOULD BE A HALF INCH OR LESS...WHICH               
THE CURRENT FORECAST DISPLAYS WELL.    CLOUD COVER WILL REMAIN                  
CLOUDY ALL DAY...AND TEMPERATURES THEREFORE WILL NOT INCREASE TOO               
MUCH.  SO HIGHS IN THE LOW-MID 30S LOOKS GOOD.                                  
MPC                                                                             
&&                                                                              
DISCUSSION...ISSUED 510 AM                                                      
ON THE LATEST SURFACE WEATHER MAP...1009 MB LOW PRESSURE WAS                    
CENTERED ACROSS NORTHERN LAKE MICHIGAN. SATELLITE LOOPS AND SURFACE             
OBSERVATIONS INDICATED THAT A STRATOCU DECK HAD OVERSPREAD THE                  
REGION. APX RADAR CONTINUED TO SHOW 16-20 DBZ RETURNS FROM THE TIP              
OF THE MITT INTO EASTERN UPPER OF THE LAST FEW HOURS. MEANWHILE...A             
BROAD AREA OF 4-8 DBZ RETURNS DEVELOPED ACROSS SOUTHWEST AND SOUTH              
CENTRAL COUNTIES A COUPLE OF HOURS AGO WITH A SLOW PROGRESSION TO               
THE EAST. THE MAIN FORECAST CONCERNS REVOLVE AROUND EXTENT OF                   
FREEZING DRIZZLE AND POSSIBLE HEADLINES THIS MORNING...POPS THURSDAY            
NIGHT AND HOW MUCH TO TWEAK THE DETAILS OF THE POTENTIAL MAJOR STORM            
SYSTEM THIS WEEKEND.                                                            
CLIPPER AND ASSOCIATED AREA OF DIVQ WILL CONTINUE TO MOVE ACROSS FAR            
NORTHERN ZONES THIS MORNING. SO FAR ONLY LIGHT SNOW (NO FREEZING                
DRIZZLE) HAS BEEN REPORTED ACROSS THE TIP OF THE MITT AND EASTERN               
UPPER. MEANWHILE TO THE SOUTH LIGHT RETURNS CORRESPOND TO RECENT                
REPORTS OF FREEZING DRIZZLE AND DEVELOPING ICY CONDITIONS. MODEL                
SOUNDINGS/CROSS SECTIONS MOISTEN UP THE COLUMN THROUGH BETWEEN -12              
AND -14 C THIS MORNING WHICH WOULD MEAN THAT ANY PRECIPITATION THAT             
FALLS WOULD BE IN THE FORM OF SNOW. HOWEVER...WITH THE TRACK OF THE             
CLIPPER (ACROSS THE FAR NORTH) ITS HARD TO BELIEVE THAT IT WOULD                
MOISTEN UP  THIS MUCH SOUTH OF THE SURFACE LOW TRACK. THIS IS BORNE             
OUT WITH THE INCREASING NUMBER OF FREEZING DRIZZLE REPORTS.                     
THEREFORE WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS MORNING                 
ACROSS ALL ZONES IN NORTHERN LOWER WITH THE EXCEPTION OF THE COUNTIES           
IN THE TIPP OF THE MITT WHERE MAINLY LIGHT SNOW IS EXPECTED. AS FAR             
AS SNOW AMOUNTS ACROSS THE FAR NORTH...ONLY EXPECTING LESS THAN AN              
INCH OF ACCUMULATION. WINDS VEER INTO THE NORTHWEST THIS                        
AFTERNOON AND OVER LAKE INSTABILITY APPEARS TO BE MARGINALLY                    
SUFFICIENT TO SUPPORT LIGHT LAKE EFFECT SNOW SHOWERS (LAKE-850 MB               
DELTA TS INCREASE TO BETWEEN 13 TO 14) WITH 900-700 MB RH STILL 60              
TO 80 PERCENT AND. SO WILL ADD IN NUMEROUS LIGHT SNOW SHOWERS WITH              
AN INCH OR LESS OF ACCUMULATION INTO FAVORED NW FLOW AREAS. CLOUDS ARE          
EXPECTED TO HANG IN ALL DAY WITH MODEST COLD AIR ADVECTION.                     
TEMPERATURES SHOULD REMAIN NEARLY STEADY OR FALL BY A COUPLE OF                 
DEGREES (GENERALLY AROUND 30 TO THE LOWER 30S).                                 
TONIGHT...NAM LINGERS OVER LAKE INSTABILITY/MOISTURE WELL INTO THIS             
EVENING WHILE THE GFS HAS PRONOUNCED DRYING (MEAN 900-700 MB RH <40             
PERCENT) AND WARMING (850 TEMPS INCREASE BY A FEW DEGREES). AT THIS             
POINT WILL GO WITH A COMPROMISE SOLUTION WITH ONLY A CHANCE OF                  
LIGHT LAKE EFFECT SNOW SHOWERS IN NORTHWEST FLOW AREAS THROUGH                  
MIDNIGHT AS MEAN SURFACE-850 MB WINDS BARELY SUPPORT ORGANIZED LAKE             
EFFECT (10 KNOTS OR SO). INCREASING RIDGING/SUFFICIENT                          
WARMING/DRYING OVERNIGHT SHOULD PUT THE KABOSH ON ANY LINGERING                 
ACTIVITY. LOWS TONIGHT IN THE MIDDLE TEENS TO LOWER 20S.                        
THURSDAY...RIDGING AT THE SURFACE AND ALOFT FOR MUCH OF THE DAY. GFS            
IS FASTER THAN THE NAM WITH MOISTURE RETURN WITH DEVELOPING SOUTHERLY           
FLOW BUT THIS APPEARS TO BE A BIT QUICK. FOR NOW WILL CONTINUE WITH             
PARTLY CLOUDY AND MILD CONDITIONS WITH INCREASING CLOUDINESS LATE IN            
THE DAY. HIGHS IN THE MILD LOWER AND MIDDLE 30S.                                
THURSDAY NIGHT...WARM ADVECTION SHOULD INCREASE PER NAM/GFS LEADING             
TO THICKENING CLOUD DECK. MOISTURE DEPTH IS QUESTIONABLE FOR                    
PRECIPITATION PRODUCTION BUT WILL ADD IN A CHANCE OF FLURRIES                   
OVERNIGHT. THERE EVEN COULD BE SOME FREEZING DRIZZLE ONCE AGAIN BUT             
WILL LET THE DAYSHIFT TAKE A BETTER LOOK AT THAT SCENARIO DUE TO                
LIMITED TIME CONSTRAINT`S AT THE MOMENT. LOWS IN THE LOWER AND MIDDLE           
20S.                                                                            
FRIDAY...CONTINUED SOUTHERLY FLOW WITH DRY MID LEVELS SO A MOSTLY               
CLOUDY DAY IS EXPECTED WITH HIGHS GENERALLY IN THE MIDDLE 30S.                  
FRIDAY NIGHT THROUGH SUNDAY...COMPLEX WEATHER SITUATION SHAPING UP              
WITH ENERGY IN THE SOUTHERN JET STREAM MOVING NORTHEAST OUT OF THE              
DESERT SOUTHWEST WHILE ENERGY IN THE NORTHERN JET STREAM DROPS DOWN             
OUT OF CENTRAL CANADA. EXTENDED MODELS THIS RUN ARE IN BETTER                   
AGREEMENT THAT THE SOUTHERN ENERGY IMPACTS THE AREA FIRST WITH LOW              
PRESSURE MOVING BY TO OUR WEST WHICH WOULD LEAD TO MAINLY RAIN FOR              
SATURDAY. THE NORTHERN STREAM ENERGY IS SHOWN TO BE VERY IMPRESSIVE             
AND IT MERGES WITH THE SOUTHERN STREAM ENERGY SATURDAY NIGHT INTO               
SUNDAY WHICH WOULD LEAD TO FALLING TEMPERATURES...INCREASING WINDS              
AND RAIN CHANGING TO SNOW SATURDAY NIGHT AND CONTINUING INTO SUNDAY.            
MODELS HAVE BEEN WAVERING OVER THE DETAILS OVER THE LAST COUPLE OF              
DAYS BUT WILL MAKE A FEW ADJUSTMENTS TO CURRENT FORECAST WHICH LINE             
UP WITH SURROUNDING OFFICES...LIKE INCREASING POPS AND GOING WITH A             
CHANGEOVER TO ALL SNOW SATURDAY NIGHT INTO SUNDAY.                              
SULLIVAN                                                                        
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR                  
     MIZ019>036-041-042.                                                        
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
1030 AM EST WED DEC 19 2007                                                     
.UPDATE....12Z SURFACE/RAOB/RUC ANALYSIS AND IR/WV/RADAR IMAGERY                
SHOW A SHORTWAVE AND ASSOCIATED SURFACE LOW MOVING ACROSS NE                    
LOWER...A COLD FRONT EXTENDING FROM THIS LOW SOUTH TOWARDS                      
LANSING...AND A SURFACE TROUGH EXTENDED NW TOWARDS MQT. LIGHT                   
RADAR RETURNS CONTINUE TO MOVE SE ON THE WESTERN FLANK OF THE                   
SURFACE LOW...ENHANCED A BIT BY THE AFOREMENTIONED SURFACE TROUGH.              
NUMEROUS LOCATIONS ARE STILL REPORTING LIGHT FREEZING                           
DRIZZLE...MIXED WITH FLURRIES OR LIGHT SNOW AT TIMES ACROSS                     
NORTHERN LOWER...AND THE 12Z APX SOUNDING SUGGESTS WHY WITH THE                 
MOISTURE DEPTH ONLY REACHING UP TO -11C. ACARS SOUNDING OUT OF                  
KINROSS SHOWS DEEPER MOISTURE UP TO -15C WHICH EXPLAINS ALL SNOW                
BEING REPORTED ACROSS EASTERN UPPER. NW WINDS BEHIND THE LOW ARE                
FUNNELING IN SLIGHTLY COOLER 850MB TEMPS THAN THE MODELS                        
PORTRAY...GIVING RISE TO POTENTIAL LAKE EFFECT PRECIP HEADING INTO              
THE AFTERNOON. BUT FIRST...HAVE TO DEAL WITH TIMING OF NUISANT                  
-FZDZ COMING TO AN END.                                                         
MAIN AREA OF -FZDZ MIXED WITH LIGHT SNOW WILL CONTINUE SOUTH ACROSS             
THE CWA THROUGH EARLY AFTERNOON.  EXIT TIMING BASED ON RADAR AND                
SATELLITE LOOPS IS AROUND 18Z ACROSS THE FAR SE CWA...BUT THERE MAY             
BE SOME LINGERING FZDZ BASED ON LOWER VSBYS ACROSS THE TIP OF THE               
MITT SO HAVE EXTENDED WINTER WEATHER ADVISORY THROUGH 19Z.  ALTHOUGH            
THE PRIMARY ROADS ARE PROBABLY OK BY NOW...UNTREATED SECONDARY ROADS            
MAY STILL BE A LITTLE ICY. THEREAFTER...NW FLOW BECOMES                         
ESTABLISHED (ALREADY TAKING SHAPE ACROSS LAKE SUPERIOR) WITH                    
MARGINAL DELTA T/S AROUND 13-14C AND EXPECT A TRANSITION TO LIGHT NW            
FLOW LAKE EFFECT FROM MID-AFTERNOON ONWARD.  INSTABILITY IS ONLY                
MARGINAL...SO ACCUMULATIONS SHOULD BE A HALF INCH OR LESS...WHICH               
THE CURRENT FORECAST DISPLAYS WELL.    CLOUD COVER WILL REMAIN                  
CLOUDY ALL DAY...AND TEMPERATURES THEREFORE WILL NOT INCREASE TOO               
MUCH.  SO HIGHS IN THE LOW-MID 30S LOOKS GOOD.                                  
MPC                                                                             
&&                                                                              
.AVIATION... /ISSUED 632 AM EST WED DEC 19 2007/                                
ABUNDANT LOW LEVEL MOISTURE ASSOCIATED WITH WEAK SURFACE                        
LOW PRESSURE MOVING ACROSS FAR NORTHERN LOWER MICHIGAN EARLY THIS               
MORNING IS RESULTING IN LOW END MVFR CIGS AND VISIBILITIES IN BR AND            
LIGHT FREEZING DRIZZLE AT TVC AND APN AND FREEZING DRIZZLE AND SNOW             
AT PLN. EXPECT THESE CONDITIONS TO PERSIST THROUGH MUCH OF THIS                 
MORNING UNTIL SLIGHTLY DRIER AIR FILTERING INTO THE REGION HELPS PUT            
AN END TO THE FREEZING DRIZZLE. HOWEVER...LIGHT LAKE EFFECT SNOW                
SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON...BUT MUCH OF THIS               
ACTIVITY WILL FALL BETWEEN TAF SITES. WINDS WILL PICK UP OUT OF THE             
NORTHWEST LATER THIS MORNING INTO THIS AFTERNOON BUT DIMINISH THIS              
EVENING.                                                                        
AJS                                                                             
&&                                                                              
DISCUSSION...ISSUED 510 AM                                                      
ON THE LATEST SURFACE WEATHER MAP...1009 MB LOW PRESSURE WAS                    
CENTERED ACROSS NORTHERN LAKE MICHIGAN. SATELLITE LOOPS AND SURFACE             
OBSERVATIONS INDICATED THAT A STRATOCU DECK HAD OVERSPREAD THE                  
REGION. APX RADAR CONTINUED TO SHOW 16-20 DBZ RETURNS FROM THE TIP              
OF THE MITT INTO EASTERN UPPER OF THE LAST FEW HOURS. MEANWHILE...A             
BROAD AREA OF 4-8 DBZ RETURNS DEVELOPED ACROSS SOUTHWEST AND SOUTH              
CENTRAL COUNTIES A COUPLE OF HOURS AGO WITH A SLOW PROGRESSION TO               
THE EAST. THE MAIN FORECAST CONCERNS REVOLVE AROUND EXTENT OF                   
FREEZING DRIZZLE AND POSSIBLE HEADLINES THIS MORNING...POPS THURSDAY            
NIGHT AND HOW MUCH TO TWEAK THE DETAILS OF THE POTENTIAL MAJOR STORM            
SYSTEM THIS WEEKEND.                                                            
CLIPPER AND ASSOCIATED AREA OF DIVQ WILL CONTINUE TO MOVE ACROSS FAR            
NORTHERN ZONES THIS MORNING. SO FAR ONLY LIGHT SNOW (NO FREEZING                
DRIZZLE) HAS BEEN REPORTED ACROSS THE TIP OF THE MITT AND EASTERN               
UPPER. MEANWHILE TO THE SOUTH LIGHT RETURNS CORRESPOND TO RECENT                
REPORTS OF FREEZING DRIZZLE AND DEVELOPING ICY CONDITIONS. MODEL                
SOUNDINGS/CROSS SECTIONS MOISTEN UP THE COLUMN THROUGH BETWEEN -12              
AND -14 C THIS MORNING WHICH WOULD MEAN THAT ANY PRECIPITATION THAT             
FALLS WOULD BE IN THE FORM OF SNOW. HOWEVER...WITH THE TRACK OF THE             
CLIPPER (ACROSS THE FAR NORTH) ITS HARD TO BELIEVE THAT IT WOULD                
MOISTEN UP  THIS MUCH SOUTH OF THE SURFACE LOW TRACK. THIS IS BORNE             
OUT WITH THE INCREASING NUMBER OF FREEZING DRIZZLE REPORTS.                     
THEREFORE WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS MORNING                 
ACROSS ALL ZONES IN NORTHERN LOWER WITH THE EXCEPTION OF THE COUNTIES           
IN THE TIPP OF THE MITT WHERE MAINLY LIGHT SNOW IS EXPECTED. AS FAR             
AS SNOW AMOUNTS ACROSS THE FAR NORTH...ONLY EXPECTING LESS THAN AN              
INCH OF ACCUMULATION. WINDS VEER INTO THE NORTHWEST THIS                        
AFTERNOON AND OVER LAKE INSTABILITY APPEARS TO BE MARGINALLY                    
SUFFICIENT TO SUPPORT LIGHT LAKE EFFECT SNOW SHOWERS (LAKE-850 MB               
DELTA TS INCREASE TO BETWEEN 13 TO 14) WITH 900-700 MB RH STILL 60              
TO 80 PERCENT AND. SO WILL ADD IN NUMEROUS LIGHT SNOW SHOWERS WITH              
AN INCH OR LESS OF ACCUMULATION INTO FAVORED NW FLOW AREAS. CLOUDS ARE          
EXPECTED TO HANG IN ALL DAY WITH MODEST COLD AIR ADVECTION.                     
TEMPERATURES SHOULD REMAIN NEARLY STEADY OR FALL BY A COUPLE OF                 
DEGREES (GENERALLY AROUND 30 TO THE LOWER 30S).                                 
TONIGHT...NAM LINGERS OVER LAKE INSTABILITY/MOISTURE WELL INTO THIS             
EVENING WHILE THE GFS HAS PRONOUNCED DRYING (MEAN 900-700 MB RH <40             
PERCENT) AND WARMING (850 TEMPS INCREASE BY A FEW DEGREES). AT THIS             
POINT WILL GO WITH A COMPROMISE SOLUTION WITH ONLY A CHANCE OF                  
LIGHT LAKE EFFECT SNOW SHOWERS IN NORTHWEST FLOW AREAS THROUGH                  
MIDNIGHT AS MEAN SURFACE-850 MB WINDS BARELY SUPPORT ORGANIZED LAKE             
EFFECT (10 KNOTS OR SO). INCREASING RIDGING/SUFFICIENT                          
WARMING/DRYING OVERNIGHT SHOULD PUT THE KABOSH ON ANY LINGERING                 
ACTIVITY. LOWS TONIGHT IN THE MIDDLE TEENS TO LOWER 20S.                        
THURSDAY...RIDGING AT THE SURFACE AND ALOFT FOR MUCH OF THE DAY. GFS            
IS FASTER THAN THE NAM WITH MOISTURE RETURN WITH DEVELOPING SOUTHERLY           
FLOW BUT THIS APPEARS TO BE A BIT QUICK. FOR NOW WILL CONTINUE WITH             
PARTLY CLOUDY AND MILD CONDITIONS WITH INCREASING CLOUDINESS LATE IN            
THE DAY. HIGHS IN THE MILD LOWER AND MIDDLE 30S.                                
THURSDAY NIGHT...WARM ADVECTION SHOULD INCREASE PER NAM/GFS LEADING             
TO THICKENING CLOUD DECK. MOISTURE DEPTH IS QUESTIONABLE FOR                    
PRECIPITATION PRODUCTION BUT WILL ADD IN A CHANCE OF FLURRIES                   
OVERNIGHT. THERE EVEN COULD BE SOME FREEZING DRIZZLE ONCE AGAIN BUT             
WILL LET THE DAYSHIFT TAKE A BETTER LOOK AT THAT SCENARIO DUE TO                
LIMITED TIME CONSTRAINT`S AT THE MOMENT. LOWS IN THE LOWER AND MIDDLE           
20S.                                                                            
FRIDAY...CONTINUED SOUTHERLY FLOW WITH DRY MID LEVELS SO A MOSTLY               
CLOUDY DAY IS EXPECTED WITH HIGHS GENERALLY IN THE MIDDLE 30S.                  
FRIDAY NIGHT THROUGH SUNDAY...COMPLEX WEATHER SITUATION SHAPING UP              
WITH ENERGY IN THE SOUTHERN JET STREAM MOVING NORTHEAST OUT OF THE              
DESERT SOUTHWEST WHILE ENERGY IN THE NORTHERN JET STREAM DROPS DOWN             
OUT OF CENTRAL CANADA. EXTENDED MODELS THIS RUN ARE IN BETTER                   
AGREEMENT THAT THE SOUTHERN ENERGY IMPACTS THE AREA FIRST WITH LOW              
PRESSURE MOVING BY TO OUR WEST WHICH WOULD LEAD TO MAINLY RAIN FOR              
SATURDAY. THE NORTHERN STREAM ENERGY IS SHOWN TO BE VERY IMPRESSIVE             
AND IT MERGES WITH THE SOUTHERN STREAM ENERGY SATURDAY NIGHT INTO               
SUNDAY WHICH WOULD LEAD TO FALLING TEMPERATURES...INCREASING WINDS              
AND RAIN CHANGING TO SNOW SATURDAY NIGHT AND CONTINUING INTO SUNDAY.            
MODELS HAVE BEEN WAVERING OVER THE DETAILS OVER THE LAST COUPLE OF              
DAYS BUT WILL MAKE A FEW ADJUSTMENTS TO CURRENT FORECAST WHICH LINE             
UP WITH SURROUNDING OFFICES...LIKE INCREASING POPS AND GOING WITH A             
CHANGEOVER TO ALL SNOW SATURDAY NIGHT INTO SUNDAY.                              
SULLIVAN                                                                        
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR                  
     MIZ019>036-041-042.                                                        
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION...UPDATED                                              
NATIONAL WEATHER SERVICE MARQUETTE MI                                           
1235 AM EST WED DEC 19 2007                                                     
UPDATED AVIATION DISCUSSION                                                     
.SHORT TERM...                                                                  
THE MAIN CONCERN WITH THE SHORT TERM PORTION OF THE FORECAST PACKAGE            
IS THE POTENTIAL FOR SNOW AND FREEZING DRIZZLE TONIGHT.                         
WATER VAPOR IMAGERY AND RUC SHOWING A WEAK TROUGH OVER MINNESOTA...A            
WEAK RIDGE OVER THE UPPER GREAT LAKES AND ANOTHER OVER THE NORTHERN             
HIGH PLAINS. ANOTHER TROUGH IS DIGGING OVER THE PACIFIC NORTHWEST.              
SURFACE ANALYSIS DEPICTS A LOW OVER CENTRAL WISCONSIN WITH A                    
STATIONARY FRONT EXTENDING EAST FROM THIS INTO NORTHERN LAKE                    
MICHIGAN...AND NORTHWEST THROUGH NORTHERN MINNESOTA. A WEAK SURFACE             
TROUGH EXTENDS SOUTH FROM THIS LOW THROUGH THE CENTRAL MISSISSIPPI              
RIVER VALLEY. A RIDGE BLANKETS MUCH OF CENTRAL AND SOUTHERN PLAINS.             
THE MID LEVEL TROUGH WILL REACH CENTRAL U.P. BY MIDNIGHT...NORTHERN             
LAKE HURON BY SUNRISE AND EASTERN ONTARIO BY LATE AFTERNOON.                    
THE SURFACE LOW WILL MOVE THROUGH SOUTHERN U.P. AND NORTHERN LAKE               
MICHIGAN...REACHING NORTHERN LAKE HURON BY SUNRISE. THE BEST                    
ISENTROPIC ASCENT AND DEEPER MOISTURE WITH THIS SYSTEM WILL BE THIS             
EVENING OVER THE U.P. THIS HEAVIEST PRECIPITATION WILL MOVE INTO                
EASTERN LAKE SUPERIOR LATE. A RIDGE WITH DRIER AIR WILL PUSH INTO               
THE WESTERN U.P. ON WEDNESDAY CAUSING THE SNOW TO DIMINISH.                     
.LONG TERM (WED NIGHT THROUGH NEXT TUE)...                                      
MAIN FORECAST CONCERN AND WILL CONTINUE FOR THE REST OF THE WEEK IS             
A WINTER STORM THAT COULD AFFECT THE CWA THIS WEEKEND. PEOPLE                   
TRAVELING THIS WEEKEND SHOULD MONITOR FORECASTS DAILY AS MODELS COME            
INTO BETTER AGREEMENT.                                                          
WED NIGHT THROUGH FRI...MUCH OF THIS PERIOD WILL GENERALLY BE QUIET             
WITH ONLY SOME LIGHT PCPN CHANCES FOR THU AND FRI. ON WED                       
NIGHT...UPPER RIDGING IS PROGGED OVER THE AREA WHILE A SHRTWV                   
APPROACHES DULUTH AROUND 12Z THU. SUBSIDENCE UNDER THE UPPER RIDGE              
SHOULD KEEP MUCH OF THE CWA DRY...AND APPEARS TO BE STRONG ENOUGH               
PER MODEL SOUNDINGS TO REMOVE ANY CLOUDS. GENERAL LIGHT WINDS IN THE            
EVENING ASSOCIATED WITH A SURFACE HIGH PRESSURE RIDGE...ALONG WITH              
PRECIPITABLE WATER VALUES BELOW 0.3 OF AN INCH...WILL ALLOW TEMPS TO            
DROP THROUGH THE DEWPOINTS AND PROMOTE SOME FOG DEVELOPMENT. GOING              
FORECAST LOW TEMPS SEEM REASONABLE. ON THU...THE SHRTWV NEAR DULUTH             
LIFTS NE INTO NORTHERN ONTARIO WHILE RIDGING REMAINS LOCKED IN OVER             
THE EASTERN CWA. THUS...HAVE RESTRICTED ANY PCPN CHANCES ASSOCIATED             
WITH DPVA FROM THE SHRTWV TO THE WEST HALF OF THE CWA. THESE PCPN               
CHANCES ARE SMALL...THOUGH...SINCE THE SHRTWV HAS LITTLE MOISTURE TO            
WORK WITH...PRIMARILY DUE TO THE LOW PRECIPITABLE WATER AIRMASS THAT            
MOVED IN WED NIGHT. AN INCREASE IN MID/HIGH CLOUDS IS LIKELY ACROSS             
THE CWA...THOUGH...WHICH SHOULD PREVENT TEMPS FROM CLIMBING TOO HIGH            
(STILL MAKING IT NEAR FREEZING). ANOTHER WEAK SHRTWV MAY MOVE ACROSS            
THE CWA THU NIGHT IN THE SW FLOW ALOFT BETWEEN TROUGHING OUT WEST               
AND RIDGING BUILDING IN THE EAST. EITHER THIS SHRTWV OR WARM                    
ADVECTION ASSOCIATED WITH THE RIDGE COULD TOUCH OFF SOME LIGHT                  
PCPN...PARTICULARLY IN THE WEST HALF WHERE MORE MOISTURE IS PRESENT.            
LOW CONFIDENCE IN FORCING MAINTAINS POPS AT 20. MUCH OF THE MOISTURE            
TOO IS SITUATED BELOW THE -10C ISOTHERM...AND THUS INCLUDE A MENTION            
OF FREEZING DRIZZLE. A MENTION OF FREEZING DRIZZLE WITH SLIGHT                  
CHANCE POPS FOR SNOW CONTINUES INTO FRIDAY WITH PLENTY OF LOW LEVEL             
MOISTURE AROUND...AND A WEAK WARM ADVECTION PATTERN. IF FREEZING                
DRIZZLE OCCURS...IT COULD SWITCH OVER TO JUST DRIZZLE AS                        
TEMPERATURES ARE EXPECTED TO CLIMB TO AROUND FREEZING.                          
FRI NIGHT THROUGH CHRISTMAS...                                                  
  MODEL DIFFERENCES..                                                           
THE BIG QUESTION THROUGH THIS TIME RANGE IS WHAT HAPPENS WITH THE               
SPLIT LONG WAVE TROUGH THAT STRETCHES FROM SASKATCHEWAN TO                      
ARIZONA/NEW MEXICO AT 00Z SAT. THIS LONG WAVE TROUGH CONSISTS OF AN             
UPPER LOW IN SOUTHERN SASKATCHEWAN AND A POTENT SHRTWV IN SOUTHERN              
ARIZONA/NEW MEXICO. WARM ADVECTION AHEAD OF THE LONG WAVE TROUGH                
SHOULD PRODUCE A FAIRLY STRONG RIDGE FROM THE GULF COAST NORTHWARD              
INTO MI BY FRI EVENING. THE STRENGTH OF THIS RIDGE WILL DETERMINE               
WHETHER THE TWO FEATURES IN THE LONG WAVE TROUGH PHASE TOGETHER...              
RESULTING IN A SLOWER AND DEEPER LOW HEADING TOWARDS UPPER MI...OR              
IF THEY STAY UNPHASED AND PRODUCE A MORE PROGRESSIVE AND WEAKER LOW             
THAT HEADS EAST OF THE AREA. THE 00Z CANADIAN/ECMWF FALL INTO THE               
SLOWER AND DEEPER CAMP...BRINGING A LOW NORTHWARD FROM NEAR                     
SPRINGFIELD MISSOURI AT 00Z SUN INTO CENTRAL UPPER MI AROUND 00Z                
MON. THE FASTER CAMP SUGGESTED BY THE 00Z/06Z GFS WOULD BRING A LOW             
UP FROM WESTERN KY AT 00Z SUN TO GEORGIAN BAY AT 00Z MON. THE 00Z               
UKMET CONSISTS OF PROPERTIES FROM BOTH CAMPS...BRINGING A LOW TO NE             
WI AT 00Z SUN AND THEN LIFTS INTO QUEBEC AT 00Z MON. GIVEN THE OTHER            
OPERATIONAL MODELS AND PREVIOUS RUNS...THE 00Z UKMET CAN BE THROWN              
OUT AS AN OUTLIER. HOWEVER...DECIDING WHETHER THE SLOWER OR FASTER              
CAMP IS THE CORRECT IDEA PROVES MUCH MORE DIFFICULT...AND FOR NOW               
WILL STICK WITH HPCS PLAN AND TO PRESERVE CONTINUITY BY FOLLOWING               
THE ECMWF. NOTE TOO THAT MODEL BIASES ARE USUALLY TOO FAST WITH                 
EJECTING LONG WAVE TROUGHS OUT OF THE WEST...WHICH MAY LEAD SOME                
CREDENCE TO THE SLOWER IDEA. BY THE WAY...THE MAIN SHRTWV                       
RESPONSIBLE FOR THE DEEP LOW IS STILL OUT AT THE WEST END OF THE                
ALEUTIANS...THUS LEAVING ROOM FOR OTHER POSSIBLE SOLUTIONS (SEE 12Z             
UKMET WHICH CUTS OFF THE SOUTHERN STREAM SHRTWV ENTIRELY).                      
  DETAILS..                                                                     
FOR FRI NIGHT...THE ECMWF SHOWS A SHRTWV MOVING INTO WESTERN WI BY              
12Z SAT WITH A NORTH/SOUTH SURFACE TROUGH ASSOCIATED WITH IT. DPVA              
AHEAD OF THIS SHRTWV COULD BRING SOME LIGHT PCPN INTO THE AREA.                 
925MB TEMPS AROUND 0C WOULD SUGGEST A BETTER LIKELIHOOD OF RAIN. ON             
SAT...THIS SURFACE TROUGH SHOULD MOVE INTO THE CWA AND STALL AS THE             
STRONG SYSTEM BEGINS DEVELOPS IN MISSOURI. MORE LIGHT PCPN COULD                
FALL ALONG THE TROUGH...WITH RAIN IN THE EAST AND A RAIN/SNOW MIX               
CENTRAL AND WEST. ON SAT NIGHT...THE SURFACE LOW IN MISSOURI WILL               
DEEPEN AS IT HEADS TOWARDS THE AREA IN RESPONSE TO THE SOUTHERN                 
FEATURE MERGING WITH THE UPPER LOW COMING OUT OF SASKATCHEWAN. THE              
PHASING OF THE UPPER FEATURES OCCURS OVER IOWA AT 12Z SUN WITH A LOW            
MOVING UP TO MILWAUKEE. THE PHASING SHOULD ALSO PRODUCE A LARGE                 
WIDESPREAD AREA OF PCPN FROM WI AND INTO UPPER MI LATER IN THE                  
NIGHT. 925MB TEMPS CONTINUE TO SHOW THAT BI-SECTION OF RAIN AND SNOW            
OVER THE AREA...WITH BEST CHANCE FOR RAIN EAST AND THE SNOW TO THE              
WEST. ON SUN...THE PHASED UPPER LOW HEADS UP TOWARD GREEN BAY AND               
CAUSES THE LOW NEAR MILWAUKEE TO BECOME OCCLUDED NEAR MNM. THIS                 
OCCLUSION SHOULD RESULT IN ENOUGH COOLING TO TO CHANGE ANY RAIN TO              
SNOW OVER THE CWA...ESPECIALLY OVER THE WEST AND CENTRAL. IF THE 00Z            
ECMWF/CANADIAN SOLUTION IS CORRECT...THERE IS A VERY BIG CONCERN                
THAT A WINTER STORM/BLIZZARD COULD OCCUR SUNDAY INTO SUNDAY NIGHT               
ACROSS THE WEST HALF OF UPPER MI...ESPECIALLY SINCE 850MB TEMPS COOL            
DRAMATICALLY IN THE WEST DURING THE DAY WHICH WOULD RESULT IN LAKE              
ENHANCEMENT. WINTER STORM CONDITIONS COULD ALSO OCCUR IN THE                    
EAST...PROBABLY SUNDAY AFTERNOON INTO SUNDAY NIGHT. NOTE THAT SINCE             
THE SYSTEM HAS A STRONG GULF OF MEXICO FEED...A HEAVY WET SNOW WOULD            
OCCUR. HOWEVER...DO NOT HAVE 100 PERCENT CONFIDENCE ON A BIG                    
SYNOPTIC SNOW GIVEN THE 12Z UKMET. AGAIN...STAY TUNED TO LATER                  
FORECASTS. AS THE UPPER LOW PULLS OUT CHRISTMAS EVE...EXPECT THE                
SYNOPTIC PCPN TO CHANGE OVER TO LAKE EFFECT WITH 850MB TEMPS ONLY               
RISING TO -10 TO -13C BY 00Z TUE. UPPER TROUGHING LINGERS OVER THE              
AREA ON CHRISTMAS...BUT 850MB TEMPS DO MANAGE TO RISE TO AROUND -8C             
AS HIGH PRESSURE BUILDS IN FROM THE WEST. THESE TEMPS ARE MARGINALLY            
COLD ENOUGH FOR LAKE EFFECT...BUT WILL LEAVE LAKE EFFECT CHANCES IN             
JUST IN CASE THE WEEKEND STORM IS SLOWER. IT COULD TURN OUT THAT                
CHRISTMAS IS DRY.                                                               
&&                                                                              
.AVIATION (FOR THE 06Z TAF ISSUANCE)...                                         
SFC LOW LOCATED OVER THE CENTRAL UPPER PENINSULA CONTINUES TO DRIFT             
E THIS AM. BACK EDGE OF WRAP AROUND SNOW MOVING THROUGH KCMX...WITH             
VSBY IMPROVING AS SNOW INTENSITY LESSENS. PRES GRADIENT TO ALSO                 
GRADUALLY SLACKENS AT KCMX BRINGING AN END TO GUSTY CONDITIONS                  
THERE. CIGS TO VARY BETWEEN MVFR AND IFR AS INVERSION STRENGTHENS               
OVERNIGHT WITH WEAK RIDGING MOVING IN BEHIND THE LOW. THERE REMAINS             
A POTENTIAL FOR FREEZING DRIZZLE AS BUFKIT SOUNDINGS SHOW LOW LEVELS            
REMAIN SATURATED UNDER THE INVERSION THROUGH THE REMAINDER OF THE               
MORNING AT KCMX AND KSAW. BOTH LOCATIONS TO SEE A GRADUALL                      
IMPROVEMENT LATE IN THE DAY AS THE SFC RIDGE PUSHES IN.                         
&&                                                                              
.MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)...                       
THE PRESSURE GRADIENT OVER LAKE SUPERIOR CAUSING NE WINDS INTO THE              
15 TO 25 KT RANGE BY THIS EVENING. WINDS SHOULD DIMINISH LATE                   
TONIGHT AND WED AS THE LOW MOVES AWAY FROM LAKE SUPERIOR AND A RIDGE            
OF HIGH PRESSURE BUILDS INTO THE REGION. AS THIS RIDGE MOVES OFF TO             
THE EAST ON THURSDAY...SOUTHERLY FLOW WILL INCREASE ON LAKE SUPERIOR            
WITH WINDS TO NEAR 30 KT BY THURSDAY NIGHT INTO EARLY FRIDAY. A                 
STRONG SURFACE LOW IS EXPECTED TO MOVE TOWARDS THE UPPER GREAT LAKES            
ON SATURDAY. DEPENDING ON THE TRACK AND TIMING...GALE FORCE WINDS               
CLOUD DEVELOP. RIGHT NOW THE BEST POSSIBILITY FOR GALES APPEARS                 
TO BE VERY LATE SATURDAY NIGHT AND INTO THE DAY ON SUNDAY AS THE LOW            
CROSSES WHITEFISH BAY SUNDAY MORNING.                                           
&&                                                                              
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.                                        
&&                                                                              
$$                                                                              
SHORT TERM...DLG                                                                
LONG TERM...AJ                                                                  
AVIATION...RJT                                                                  
MARINE...DLG                                                                    
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
1145 PM EST TUE DEC 18 2007                                                     
.AVIATION...ABUNDANT LOW LEVEL MOISTURE ASSOCIATED WITH WEAK SURFACE            
LOW PRESSURE APPROACHING FROM CENTRAL UPPER MICHIGAN WILL CONTINUE              
TO OVERSPREAD THE AREA TONIGHT...RESULTING IN LOW END MVFR CIGS AND             
VISIBILITIES IN BR AND LIGHT FREEZING DRIZZLE AND SNOW. EXPECT THESE            
CONDITIONS TO PERSIST THROUGH MUCH OF TOMORROW MORNING UNTIL                    
SLIGHTLY DRIER FILTERING INTO THE REGION HELPS SCOUR OUT SOME OF THE            
LOW LEVEL MOISTURE AND ACCOMPANYING LIGHT PRECIP. WINDS WILL REMAIN             
LIGHT THROUGH THE DURATION OF THE FORECAST PERIOD.                              
MSB                                                                             
&&                                                                              
.UPDATE...ISSUED 1020 PM                                                        
LATEST ANALYSIS SHOWS A 1010 MB LOW CENTERED NEAR MARQUETTE OUT                 
AHEAD OF LOW AMPLITUDE SHORTWAVE CUTTING EAST ACROSS NORTHERN                   
WISCONSIN. MODEST LOW AND MID LEVEL SOUTHWEST FLOW ISENTROPIC                   
UPGLIDE ALONG AND AHEAD OF THESE FEATURES AND NORTH OF A WARM FRONT             
EXTENDING FROM THE LOW INTO THE STRAITS REGION HELPING KICK A SHIELD            
OF LIGHT...TO OCCASIONALLY MODERATE...SNOW OVER CENTRAL AND WESTERN             
SECTIONS OF THE UPPER PENINSULA. SOUTH OF THIS SNOW SHIELD LIES AN              
EXTENSIVE 2KFT TO 3KFT LOW CLOUD DECK...WHICH EXTENDS ACROSS MUCH OF            
WISCONSIN AND HAS RECENTLY MADE INROADS INTO WESTERN SECTIONS OF OUR            
FORECAST AREA. AS ALWAYS...NOCTURNAL TEMPERATURE RESPONSE A PRODUCT             
OF CLOUD COVER...WITH TEMPERATURES RANGING FROM THE MID 30S NEAR                
FRANKFORT AND MANISTEE TO THE UPPER TEENS AND LOW 20S WHERE SKIES               
HAVE CLEARED OUT IN SOUTHEAST SECTIONS OF THE CWA. CURRENT TRENDS               
SUPPORT ONGOING FORECAST...WITH LIGHT SNOW AND POSSIBLE PATCHY                  
FREEZING DRIZZLE OVERSPREADING MUCH OF EASTERN UPPER MICHIGAN AND               
THE STRAITS REGION LATER THIS EVENING INTO THE MORNING HOURS AS                 
UPSTREAM LOW PRESSURE CUTS ALONG THE TIP OF THE MITT. SOUTH OF THIS             
AREA...LATEST MODEL SOUNDING GUIDANCE STILL SUPPORTING THE                      
DEVELOPMENT OF FREEZING DRIZZLE (ESPECIALLY OVER THE HIGHER TERRAIN             
AREAS WITH THE HELP OF LIGHT UPSLOPE FLOW) WITH SATURATED CONDITIONS            
FALLING SHORT OF THE FAVORABLE ICE NUCLEATION -10C TEMPERATURE. AS              
FOR A WINTER WEATHER ADVISORY...WILL HOLD OF FOR NOW...ESPECIALLY IN            
LIGHT OF LACK OF UPSTREAM OBS REPORTING FREEZING DRIZZLE AT THIS                
TIME. WHILE SLOW TO DEVELOP THIS EVENING...FOG FORMATION IS STILL               
EXPECTED AS SURFACE TEMPERATURE SLOWLY COOL. BASED OF CURRENT                   
TRENDS...BASICALLY ONLY COSMETIC CHANGES NEEDED ON GRIDS...WITH MAIN            
EMPHASIS ON MINOR TIMING ADJUSTMENTS AND OVERNIGHT TEMPERATURE                  
TRENDS.                                                                         
UPDATED GRIDS/ZONES/NEARSHORES OUT SHORTLY.                                     
MSB                                                                             
&&                                                                              
.DISCUSSION...ISSUED 351 PM                                                     
LATEST SURFACE/RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOW MORE OR LESS             
ZONAL FLOW ACROSS NORTH AMERICA WITH A SHORTWAVE NOTED OVER THE                 
PACIFIC NW AND WEAKER WAVES OVER MN AND LAKE WINNIPEG.  290-295K                
ISENTROPIC LIFT AHEAD OF THESE DUAL WAVES HAS LED TO A THINNING                 
MID-HIGH LEVEL CLOUD DECK THAT IS MOVING ACROSS THE CWA.  LINGERING             
LOW LEVEL MOISTURE BENEATH THE SUBSIDENCE INVERSION STILL IS                    
CONTRIBUTING TO A LOW END MVFR CLOUD DECK THAT HAS JUST ERODED                  
ACROSS CAD/HTL...WHILE MOISTURE FLUXES AND VERY SHALLOW OVER WATER              
INSTABILITY OFF LAKE MICHIGAN HAS KEPT THE CLOUDS NEAR MBL/FKS AND              
ACROSS EASTERN UPPER.  WITH THE THINNING CLOUD DECK...TEMPERATURES              
HAVE WARMED ABOVE FREEZING ACROSS MUCH OF NORTHERN MICHIGAN.                    
MEANWHILE...MVFR CLOUDS OVER NORTHERN WI HAVE BEEN BLOSSOMING THIS              
AFTERNOON AND MOVING EAST AHEAD OF A WEAK SURFACE LOW OVER WESTERN              
WI.  AS THIS SURFACE LOW MOVES ACROSS NORTHERN MICHIGAN TONIGHT AND             
LOW LEVEL MOISTURE INCREASES...MAIN FORECAST CONCERNS INCLUDE PRECIP            
CHANCES AND TYPE...WHICH THEN LASTS THROUGH TOMORROW.                           
TONIGHT...MN SHORTWAVE AND ASSOCIATED WEAK SURFACE LOW WILL APPROACH            
NORTHERN LAKE MICHIGAN THIS EVENING AND PASS ACROSS THE TIP OF THE              
MITT OVERNIGHT.  MOISTURE DEPTH WILL BE INITIALLY BELOW 900MB...TO              
START THE EVENING...THEN STEADILY INCREASE AS THE NIGHT WEARS ON.               
WATCHING TRENDS THIS AFTERNOON...THE 12KM NAM APPEARS TO HAVE A GOOD            
BEAD ON THINGS AND HAVE FOLLOWED ITS SOLUTION MORE CLOSELY.  THIS               
MOISTURE DEPTH DOES NOT APPROACH THE -10C ISOTHERM UNTIL AFTER ABOUT            
04Z AND THATS MOSTLY NORTH OF M-68.  AS MOISTURE INCREASES DURING               
THE EVENING...HAVE INTRODUCED PATCHY FOG AND FREEZING DRIZZLE ACROSS            
MOST OF NW LOWER AND EASTERN UPPER.  BELIEVE SOME PRECIP MAY JUST BE            
ALL LIQUID RIGHT ALONG THE LAKE MICHIGAN SHORELINE SINCE                        
TEMPERATURES THIS AFTERNOON HAVE RISEN TO 40F AT TVC.  AS                       
TEMPERATURES COOL BY MID TO LATE EVENING...ANY DRIZZLE SHOULD TURN              
INTO THE FREEZING VARIETY...WHILE INTRODUCED OCCASIONAL LIGHT SNOW              
FROM THE TIP OF THE MITT ON NORTH SINCE THE PROBABILITY OF ICE                  
NUCLEATION INCREASES BY THIS TIME.  THESE PRECIP TYPES THEN MAINTAIN            
CONTINUITY OVERNIGHT (OCCASIONAL LIGHT SNOW MIXED WITH PATCHY                   
FREEZING DRIZZLE AND FOG FROM THE TIP OF THE MITT ON NORTH...AREAS              
OF FREEZING DRIZZLE AND FOG FROM THE TIP OF THE MITT ON SOUTH). HAVE            
ALSO THROWN IN AREAS OF FOG SINCE VISIBILITIES TODAY HAVE BEEN                  
REALLY SLOW TO IMPROVE BEYOND 6SM AND VSBYS OVER WI ARE IN THE 3-5SM            
RANGE.  ADDED MOISTURE FROM LOCALIZED MELTING SNOW WILL ALSO HELP IN            
FOG FORMATION AS TEMPERATURES COOL TONIGHT.  WITH ANY WINTRY                    
PRECIP...THERE IS POTENTIAL FOR A HEADLINE LATER TONIGHT...BUT WILL             
HOLD OFF FOR NOW AND THE EVENING CREW CAN SEE HOW THE FORECAST                  
DEVELOPS.                                                                       
MPC                                                                             
WEDNESDAY...SFC LOW PRESSURE SCOOTING ACROSS NRN LAKE HURON IN                  
THE MORNING WITH WRAP AROUND DEEPER MOISTURE SWINGING ACROSS THE                
REGION IN ASSOCIATION WITH STRONG H7-H5 -DIVQ. THIS IS LIKELY TO                
BRING AT LEAST A PERIOD OF LIGHT SNOW TO NRN MICHIGAN NORTH OF                  
M-72. SOUTH OF THERE...THE MOISTURE OFF VARIOUS FORECAST SOUNDINGS              
NEVER TOUCHES THE MAGICAL -10C ISOTHERM. WILL GO WITH JUST AREAS                
OF FOG AND FREEZING DRIZZLE SOUTH OF M-72...AND WILL GO WITH                    
OCCASIONAL LIGHT SNOW/FLURRIES WITH AREAS OF FREEZING DRIZZLE                   
NORTH OF M-72. WITH SFC LOW OVERHEAD...AND RESULTANT CONVERGENCE                
AND DEEP LOW LEVEL MOISTURE ADVECTION...FEEL AS THOUGH THE DRIZZLE              
OCCURRENCE IS RATHER LIKELY. ANY POTENTIAL HEADLINES (FREEZING                  
RAIN ADVISORY) THAT MAY BE NEEDED BY EVENING CREW TONIGHT...WOULD               
BE NEEDED INTO WEDNESDAY MORNING. AS THIS SFC LOW DEPARTS FURTHER               
EAST IN THE AFTERNOON...MOISTURE REALLY BEGINS TO STRIP OUT. THE                
LOSS OF CONVERGENCE/WIND SHEAR IN THE SHALLOWING MOIST LAYER                    
CEASES...AND CHANCES FOR DRIZZLE ARE SEEMINGLY GONE. FEEL THAT                  
SKIES WILL JUST REMAIN RATHER CLOUDY BUT WILL INCLUDE A CHANCE FOR              
FLURRIES...AND REMAIN CONSISTENT WITH PREVIOUS FORECAST.                        
WEDNESDAY NIGHT...SFC RIDGE AXIS/COL REGION SLIPS IN OVERHEAD. MOST             
AREAS CONTINUE TO DRY...SHALLOW OUT THE LOW LEVEL MOISTURE. THERE IS            
SOME TRAPPED SHALLOW MOISTURE SEEN ON FORECAST SOUNDINGS...MAINLY               
ACROSS NE LOWER NEAR 925MB CONVERGENCE AXIS. FEEL THAT MOSTLY                   
CLOUDY/CLOUDY SKIES WILL RULE THIS REGION FOR MOST...IF NOT ALL OF              
THE NIGHT. A NE WIND ACROSS EASTERN UPPER...MAY HELP SKIES CLEAR OUT            
DUE TO DOWNSLOPING OUT OF ONTARIO...AND SHALLOW OVERLAKE INSTABILITY            
DOES NOT LOOK SUBSTANTIAL ENOUGH TO OFFSET THE AMOUNT OF DRYING                 
ACROSS NW LOWER. WILL GO WITH LOW END PARTLY CLOUDY FOR NOW. COULD              
SEE A WEAK LAND BREEZE DEVELOP OVERNIGHT IF WE CLEAR...AND TEMPS                
WILL FALL INTO THE TEENS IN SPOTS. THESE COLDER TEMPS WITH LIGHT                
WINDS FROM SFC RIDGE COULD HELP FOG DEVELOP TOO. RECENT WARMER                  
TEMPERATURES HAVE ALSO ADDED MOISTURE TO THE BL...WHICH COULD AID               
THE FOG DEVELOPMENT. WILL GO WITH PATCHY FOG FOR NOW IN THOSE AREAS             
EXPECTED TO CLEAR SOME.                                                         
THURSDAY THROUGH FRIDAY...SFC RIDGE AXIS SLIDES EAST WHILE STRONGER             
TROUGHING DEVELOPS OVER THE PAC NW. MID LEVEL HEIGHTS RISE OVER NRN             
MICHIGAN WHICH SPELLS MORE MODERATION OF THE TEMPERATURES. TEMPS                
THROUGH THE PERIOD WILL REACH THE LOWER AND MIDDLE 30S...AS DEEP                
SNOWPACK SHOULD KEEP TEMP RISES IN CHECK. A SOUTHERLY FLOW WILL                 
RESULT IN WARMING ALOFT THOUGH...AND A WEAKISH LOOKING WARM FRONT               
WILL IN FACT WORK ITS WAY THROUGH HERE THURSDAY NIGHT AND FRIDAY. A             
WING OF MOISTURE AHEAD OF THIS FEATURE WILL RESULT IN MID LEVEL                 
CLOUDINESS WHICH WILL LIKELY LOWER THROUGH FRIDAY AFTERNOON. LOWS               
THROUGH THURSDAY NIGHT WILL NOT GO FAR WITH INCREASING CLOUDINESS               
AND INCREASES SOUTH LOW LEVEL FLOW. WILL ONLY DIP READINGS INTO THE             
28-31F RANGE. THESE MILDER TEMPERATURES WILL KEEP ADDING MOISTURE TO            
THE BL...AND LIGHT FOG MAY BE PRESENT FOR A GOOD DEAL OF THE TIME.              
THERE MAY EVENTUALLY BE SOME LIGHT PRECIPITATION CONCERNS LATE                  
THURSDAY NIGHT AND FRIDAY...BUT WILL KEEP A PRECIP FREE FORECAST FOR            
NOW AS ANY AMOUNTS WOULD BE VERY LIGHT. THE BETTER CHANCES FOR                  
DEVELOPING PRECIPITATION WILL HOLD OFF UNTIL FRIDAY NIGHT ONWARD.               
FRIDAY NIGHT ONWARD...ISSUES IN THIS TIME FRAME REVOLVE AROUND                  
STRONG STORM SYSTEM FOR THE WEEKEND LIFTING OUT OF TEXAS. LONG RANGE            
MODELS SUGGEST THAT ECMWF REMAINS THE MODEL OF CHOICE. OVERALL                  
WEATHER DEVELOPMENT STILL HAS UNCERTAINTIES CONSIDERING THE                     
TIMEFRAME IS QUESTION (5-6 DAYS OUT). THERE IS NOT MUCH CHANGE IN               
WHAT IS EXPECTED AT THIS POINT...FRIDAY NIGHT WEATHER COULD HAVE A              
PLETHORA OF WEATHER TYPES DUE TO SFC TEMPERATURES HOLDING AROUND 32F            
AS MOISTURE INCREASES FROM ABOVE AND BELOW THE COLUMN. THIS WOULD               
SUGGEST DRIZZLE OR FREEZING DRIZZLE...OR JUST FLAT OUT RAIN. TRENDS             
KEEP RAIN IN THE FORECAST...BUT A COLDER SCENARIO WOULD SUPPORT SNOW            
AS WELL...AND WE JUST DO NOT KNOW THOSE SPECIFICS YET. WILL KEEP                
RAIN AND SNOW IN THE FORECAST ONE MORE TIME...THROUGH SUNDAY MORNING            
THEN FOLLOW CLOSER TO THE ECMWF. THIS WOULD THEN SUGGEST STRONG COLD            
ADVECTION (UNDER SOUTHERLY WINDS)...WITH SNOW ENTERING THE PICTURE              
FOR THE AFTERNOON. SNOW SHOWERS WILL THEN BE LIKELY THROUGH SUNDAY              
NIGHT. SCATTERED SNOW SHOWERS IN NW FLOW REGIMES MONDAY INTO                    
TUESDAY...BUT WITH MODERATING H8 TEMPS WARMER THAN -10C BY TUESDAY.             
SMD                                                                             
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...NONE.                                                                      
LH...NONE.                                                                      
LS...NONE.                                                                      
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO                           
850 PM CST THU DEC 20 2007                                                      
.DISCUSSION...                                                                  
DENSE FOG CONTINUES TO SPREAD TO THE WEST UNDER INFLUENCE OF A VERY             
WEAK SURFACE FLOW AROUND LOW PRESSURE TROUGH IN EASTERN MISSOURI AT             
THIS TIME. MODELS SHOW THIS TROUGH BREAKING DOWN AS STRONGER                    
TROUGHING IN HIGH PLAINS STARTS TO TAKE SHAPE OVERNIGHT WITH LOW                
LEVEL FLOW BECOMING SOUTHEAST. THIS SHOULD SLOW THE WESTWARD                    
PROGRESSION AFTER MIDNIGHT BUT MAY SPREAD IT MORE INTO NORTHWEST                
MISSOURI...WHICH IS ALREADY EXPERIENCING PATCHY DENSE FOG UNDER THE             
CLEAR SKIES AND LIGHT WINDS. BOTH NAM AND RUC 950 MB DEPICTIONS OF              
THIS MOISTURE WOULD SUGGEST IT MAKING TO NEAR THE MISSOURI KANSAS               
BORDER IN NORTHWEST MISSOURI OVERNIGHT AND INTO EASTERN PORTIONS OF             
THE KANSAS CITY METRO AREA.  FOR NOW...WILL GO AHEAD AND EXPAND THE             
ADVISORY TO INCLUDE AREAS THAT ARE SEEING THE WIDESPREAD DENSE FOG              
SPREADING IN AT THIS TIME...AND KEEP AN EYE ON THE TRENDS...ADDING              
COUNTIES AS NEEDED.                                                             
PC                                                                              
&&                                                                              
.PREV DISCUSSION...                                                             
/720 PM CST THU DEC 20 2007/                                                    
HAVE MADE SEVERAL PHONE CALLS TO AREAS JUST WEST OF WHERE WE HAD FOG            
ADVISORY IN EFFECT...AND THEY ARE VERIFYING THE SATELLITE TREND OF              
THE LOWER VISIBILITIES SPREADING BACK TO THE WEST. WILL EXPAND THE              
DENSE FOG ADVISORY FURTHER TO THE WEST TO COVER.  ESPECIALLY                    
CONCERNED FOR THE INTERSTATES INCLUDING I70 FROM CONCORDIA EASTWARD             
AND I35 IN HARRISON COUNTY.                                                     
PC                                                                              
/414 PM CST THU DEC 20 2007/                                                    
FORECAST CONCERNS FOR THE FIRST HALF OF THE FORECAST ARE TWO FOLD.              
TONIGHT WE ARE LOOKING AT CONTINUED DENSE FOG ACROSS AREAS FROM                 
NORTH CENTRAL AND NORTH EAST MISSOURI SOUTH THROUGH CENTRAL                     
MISSOURI. THE SECOND FORECAST CONCERN IS THE WINTER STORM EXPECTED              
THIS WEEKEND.                                                                   
MOISTURE TRAPPED IN THE BOUNDARY LAYER...AND LIGHT WINDS ASSOCIATED             
WITH A SURFACE TROUGH...HAVE CONSPIRED TODAY TO KEEP THE EASTERN                
THIRD OF THE FORECAST AREA UNDER DENSE FOG. CONDITIONS ARE NOT                  
EXPECTED TO CHANGE ACROSS THAT AREA OVERNIGHT. SURFACE TROUGH WILL              
SLIDE EAST A LITTLE...BUT ONLY ENOUGH TO ALLOW SURFACE WINDS TO                 
SWITCH TO THE SOUTHEAST...ADVECTING MORE MOISTURE IN AT THE SURFACE.            
HAVE GONE WITH A DENSE FOG ADVISORY FOR THE REST OF THE AFTERNOON               
THROUGH 10 AM FRIDAY MORNING AS A RESULT. FARTHER WEST SKIES CLEARED            
TODAY AND THE FOG THAT SET IN DISSIPATED RATHER QUICKLY. TONIGHT                
WILL SEE THE INVERSION TRAP ABUNDANT MOISTURE AT THE SURFACE                    
AGAIN...BUT WINDS JUST ABOVE THE INVERSION WILL STAY A LITTLE HIGHER            
IN RESPONSE TO THE DEEPENING TROUGH IN THE WESTERN CONUS. EXPECT                
THIS SLIGHTLY HIGHER WIND ABOVE THE INVERSION TO INDUCE ENOUGH                  
MIXING OVERNIGHT TO PREVENT THE FOG FROM BECOMING AS DENSE ACROSS               
THE WESTERN TWO THIRDS OF THE FORECAST AREA. IN FACT...HAVE KEPT FOG            
OUT OF THE FORECAST FOR AREAS FROM THE KANSAS CITY METRO ON SOUTH AS            
MODEL SOUNDINGS SHOW THE SURFACE MOISTURE TO BE PARTICULARLY                    
SHALLOW. THIS WILL NEED TO BE WATCHED OVERNIGHT THOUGH IN CASE                  
RADIATION FOG BEGIN TO DEVELOP UNDER THE CLEAR SKIES.                           
ATTENTION THEN TURNS TOWARDS FRIDAY NIGHT AND SATURDAY AS THE                   
DEEPENING WEST CONUS TROUGH SWEEPS EAST THROUGH THE PLAINS. GFS AND             
ECMWF HAVE CONTINUED TO CONVERGE TOWARDS ONE SOLUTION FOR THIS                  
WEEKENDS SYSTEM...AND THE NAM-WRF SEEMS TO BE MOVING IN THE SAME                
DIRECTION. THE EARLY WEEKEND SHORTWAVE TROUGH WILL ACTUALLY CONSIST             
OF A NORTHERN AND SOUTHERN STREAM WAVES PHASING AS THEY THEY MOVE               
THROUGH MISSOURI. THERE IS A STRONG SHOT OF COLD AIR THAT WILL                  
QUICKLY SPREAD ACROSS THE FORECAST AREA SATURDAY. THIS SYSTEM WILL              
BE BRINGING THE BULK OF ITS MOISTURE FROM THE PACIFIC...SO THE                  
EXPECTATION IS THAT MUCH OF THE PRECIPITATION WILL BE POST                      
FRONTAL...IN THE DEFORMATION ZONE BEHIND THE SURFACE LOW.                       
WITH THE SOLUTIONS FROM THE GFS/ECMWF/AND NAM-WRF ALL CONVERGING I              
HAVE NOT HAD TO MAKE MANY ADJUSTMENTS TO THE GOING FORECAST FOR                 
FRIDAY NIGHT INTO SATURDAY. DID KEEP SOME LIKELY POPS ACROSS THE                
EASTERN HALF OF THE FORECAST AREA FOR SATURDAY EVENING AS THE WEIGHT            
OF THE CONSENSUS SLOWS THE SYSTEM A LITTLE. OTHERWISE...EXPECT MUCH             
OF THE PRECIPITATION FALLING FROM THE SKY TO BE SNOW BY THE                     
AFTERNOON HOURS. FREEZING RAIN AND SLEET ARE GOING TO BE MINOR AS               
THE SPEED WITH WHICH THE COLD AIR RUSHES IN SHOULD PRECLUDE MUCH                
OPPORTUNITY FOR MIXED PRECIP. CURRENT SNOWFALL TOTALS STILL LOOK                
RANGE BETWEEN 1 TO 4 INCHES OF ACCUMULATION...IN PART DUE TO THE                
PROGRESSIVE NATURE OF THE SYSTEM. ALSO...WIND BEHIND THE FRONT LOOKS            
TO BE SUSTAINED AS HIGH AS 20 TO 30 MPH WITH HIGHER GUSTS.                      
THEREFORE...ADDED BLOWING SNOW TO THE FORECAST WEATHER FOR THE DAY              
SATURDAY AND SATURDAY NIGHT.                                                    
CUTTER                                                                          
EXTENDED...(SUNDAY-THURSDAY)                                                    
THE NORTHERN AND SOUTHERN SHORTWAVE BRANCHES WILL CONTINUE TO PHASE             
AT THE START OF THE EXTENDED FORECAST ON SUNDAY. THE PHASING SYSTEM             
WILL QUICKLY DEPART TO THE NORTHEAST...WITH SHORTWAVE                           
RIDGING/SURFACE HIGH PRESSURE SPREADING EAST IN ITS WAKE.                       
A SERIES OF PACIFIC SHORTWAVE TROUGHS WILL CONTINUE TO HEAD EAST                
THROUGH THE MEAN FLOW ACROSS THE CONUS NEXT WEEK. MODEL AGREEMENT               
DIMINISHES QUICKLY BY EARLY NEXT WEEK WITH REGARD TO THESE SHORTWAVE            
FEATURES. AS SUCH...THERE IS LOW CONFIDENCE FOR PRECIPITATION                   
CHANCES. IF ONE MODEL WERE TO BE CHOSEN OVER ANOTHER...WOULD HAVE TO            
SIDE WITH THE MORE CONSISTENT ECMWF. THE ECMWF STILL BRINGS A                   
CLIPPER SYSTEM FURTHER SOUTH THAN THE GFS ON MONDAY...BUT WITH                  
LITTLE MOISTURE TO WORK WITH MEASURABLE PRECIPITATION IS NOT                    
EXPECTED FOR OUR NECK OF THE WOODS. THE NEXT IN THE SERIES OF                   
PROGRESSIVE SHORTWAVES IS PROGGED TO AFFECT THE REGION TOWARD                   
WEDNESDAY.                                                                      
STOFLET                                                                         
&&                                                                              
.AVIATION...                                                                    
/535 PM CST THU DEC 20 2007/                                                    
FOR THE 00Z TAF CYCLE...SOUNDINGS SHOW ANOTHER INVERSION SETTING UP             
ACROSS THE KANSAS/MISSOURI BORDER REGION TONIGHT...WITH A MODEST AND            
MOIST SOUTHEAST SURFACE FLOW. HOWEVER...THE WIND JUST OFF THE                   
SURFACE IS EXPECTED TO REMAIN A LITTLE STRONGER EARLY FRIDAY MORNING            
THAN IT WAS THIS MORNING. THOUGHTS ARE THAT THIS WILL KEEP THE                  
SURFACE LAYER MIXED A LITTLE MORE WITH THE DRY LAYER ABOVE                      
PREVENTING A DRASTIC DECREASE IN VISIBILITIES IN THE MORNING.                   
BIGGEST CONCERN WILL BE AT KSTJ WITH ITS SLIGHTLY LOWER ELEVATION               
ISOLATING IT A BIT MORE FROM THE EFFECTS OF DRIER AIR MIXING IN                 
OVER TOP.  WILL GO WITH A TEMPO CATEGORY FOR IFR CONDITIONS LATE                
TONIGHT AT THAT SITE.                                                           
PC                                                                              
&&                                                                              
.EAX WATCHES/WARNINGS/ADVISORIES...                                             
MO...DENSE FOG ADVISORY UNTIL 10 AM FRIDAY FOR MOZ003-MOZ004-                   
     MOZ005-MOZ006-MOZ007-MOZ008-MOZ013-MOZ014-MOZ015-MOZ016-                   
     MOZ017-MOZ022-MOZ023-MOZ024-MOZ025-MOZ030-MOZ031-MOZ032-                   
     MOZ033-MOZ038-MOZ039-MOZ040-MOZ044-MOZ045-MOZ046-MOZ054.                   
KS...NONE.                                                                      
$$                                                                              
</pre> mo                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE WILMINGTON NC                                          
925 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...                                                                    
A WEAK TROUGH OF LOW PRESSURE WILL CONTINUE TO LINGER WHILE                     
WEAKENING JUST OFF THE COAST TODAY. A FAST MOVING SYSTEM WILL                   
BRING A CHANCE OF SHOWERS LATE THURSDAY AND EARLY FRIDAY. A RIDGE               
OF HIGH PRESSURE WILL SPREAD INTO THE CAROLINAS FROM THE NORTH ON               
SATURDAY WITH THE POSSIBLE DEVELOPMENT OF ANOTHER COASTAL TROUGH.               
FINALLY...A STRONG COLD FRONT WILL MOVE ACROSS THE REGION LATE                  
SUNDAY...QUICKLY FOLLOWED BY ANOTHER SYSTEM ON CHRISTMAS DAY.                   
&&                                                                              
.NEAR TERM /THROUGH TONIGHT/...                                                 
AS OF 3 AM WEDNESDAY..HIGH PRESSURE AXIS OVER EASTERN NORTH                     
CAROLINA AT 06 UTC WITH ONLY MID LEVEL CLOUDINESS. THE LATEST RUC               
SHOWS THE COASTAL TROUGH SITUATED JUST TO THE SOUTH OF THE AREA.                
THE 00 UTC RUNS OF THE GFS AND NAM ALONG WITH THE 21 UTC SREF ALL               
ARE PROJECTING A COASTAL TROUGH TO CONTINUE TO DEVELOP NORTHWARD                
BUT REMAIN OFFSHORE AND MINIMAL IMPACT EXPECTED. THE SREF                       
PRECIPITATION PROBABILITY FIELDS SHOW ALL PRECIPITATION STAYS EAST              
OF THE FORECAST AREA. SO EXPECT AREA TO REMAIN DRY WITH THE                     
LIMITED MOISTURE SEEN IN THE VERTICAL PROFILES. FOR TEMPERATURES                
WENT WITH A CONSENSUS FORECAST OF THE STATISTICAL GUIDANCE                      
PRODUCTS.                                                                       
&&                                                                              
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...                                
AS OF 3 AM WEDNESDAY...THE MAIN QUESTION IS THE SENSIBLE WX                     
EFFECT OF A PROGRESSIVE SOUTHERN STREAM SYSTEM...WHICH IS EXPECTED              
TO MOVE EAST ACROSS THE CAROLINAS THU NIGHT.                                    
MOISTURE FEED AHEAD OF THIS SYSTEM IS SLOW TO DEVELOP...AND THE                 
RUN-TO-RUN TREND IS A BIT SLOWER YET.  THE OTHER TRICKY FACTOR WILL             
BE THE DRY NNE FLOW AND HOW MUCH EVAPORATION WILL OCCUR.  BEST SHOT             
FOR PRECIP WILL BE 06-12Z FRI...WITH THE MAIN ENERGY STAYING FAR                
ENOUGH SOUTH TO WARRANT A GRADIENT FROM LOW CHANCE IN THE NORTH...TO            
HIGH CHANCE IN THE SOUTH.  MOISTURE IS SLOW TO EXIT ON FRIDAY SO                
WILL TAPER POPS DOWN THRU THE DAY.                                              
TEMPS ARE HIGHLY DEPENDENT ON CLOUD COVER IN THIS PERIOD.  FORECAST             
HIGHS IN THE UPPER 50S ON THU REPRESENT THE BEST-CASE SCENARIO AND              
AN EARLIER ARRIVAL OF CLOUDINESS WILL REALLY HOLD TEMPS BACK.                   
MODELS ARE HINTING THAT FRIDAY TEMPS WILL ALSO BE LIMITED BY LOW                
CLOUDS...BUT CONFIDENCE IS STILL QUITE LOW AT THIS POINT.                       
&&                                                                              
.LONG TERM /FRIDAY THROUGH TUESDAY/...                                          
AS OF 3 AM WEDNESDAY...PATTERN REMAINS FAIRLY PROGRESSIVE BUT THE               
MAIN COMPLICATION IS THAT EXTENDED GFS MOS IS QUITE BULLISH WITH                
PRECIP CHANCES...ADVERTISING POPS WELL ABOVE CLIMO AND SOLIDLY IN               
THE CHANCE CATEGORY THROUGH MOST OF THE PERIOD. FOR NOW AM NOT                  
BUYING WHAT THE GFS IS SELLING...ESPECIALLY IN THE ONGOING                      
DROUGHT. HAVE FOCUSED INSTEAD ON PERIODS THAT SEEM TO HAVE A LEGIT              
CHANCE OF PRECIP...THUS CARRYING 30-40 POPS SAT NIGHT THROUGH SUN               
NIGHT AS A STRONG COLD FRONT CROSSES THE AREA.                                  
TEMPS ABOVE CLIMO FOR THE WEEKEND AND INTO MONDAY UNDER FLAT UPPER              
RIDGING...THEN WE GET KNOCKED BACK TO NEAR OR BELOW CLIMO NUMBERS               
BEHIND THE COLD FRONT.                                                          
&&                                                                              
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...                                     
MID LEVEL CLOUDINESS IS APPROACHING THE TAF SITES THIS MORNING. THE             
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE STILL OVER THE FORECAST             
AREA WITH COASTAL TROUGH FORMED JUST SOUTH OF THE MYR AND CRE TAF               
SITS. 06 UTC GFS... 06 UTC NAM AND 03 UTC SREF ALL ARE STILL IN                 
AGREEMENT ON DEVELOPING TROUGH FARTHER NORTH AND OFF THE COAST.                 
LATEST 11-3.9 MICRON SATELLITE IMAGERY IS SHOWING MID LEVEL                     
CLOUDINESS MOVING TOWARDS THE COAST AND LATEST BUFR SOUNDING                    
CONTINUE TO SHOW MOISTURE BUILDING FROM 10K TO 5K FT. WINDS WILL BE             
LIGHT AND VARIABLE OVER THE NEXT 9 HOURS WITH SOUTHWEST WINDS                   
EXPECTED AFTER 15 UTC AS RIDGE SHIFTS EASTWARD.                                 
LOW PRESSURE MOVES ALONG THE SOUTHEASTERN STATES THURSDAY NIGHT INTO            
FRIDAY...WITH POSSIBLE LOW CEILINGS AND PRECIP.                                 
&&                                                                              
.MARINE...                                                                      
NEAR TERM /THROUGH 7 AM THURSDAY/...                                            
AS OF 900 AM WEDNESDAY...COASTAL TROUGH SITUATED WITHIN A BROAD                 
RIDGE BARELY DISTINGUISHABLE OFFSHORE BASED ON SURFACE AND BUOY                 
OBS AND SATELLITE PICS. GRADIENT VERY SLACK WITH WINDS ESSENTIALLY              
LIGHT AND VARIABLE OVER THE COASTAL ZONES. SEAS CURRENTLY 2 FT OR               
LESS. WINDS WILL PICK UP A BIT FROM THE SW THIS AFTERNOON AS A                  
COLD FRONT IN FORMATION APPROACHES...SHIFTING NW TONIGHT AFTER                  
FROPA...BECOMING N BY DAYBREAK.                                                 
SHORT TERM /THURSDAY 7 AM THROUGH FRIDAY/...                                    
AS OF 3 AM WEDNESDAY...NE GRADIENT WILL GRADUALLY TIGHTEN UP THRU               
THE PERIOD. WIND SPEEDS REMAIN FAIRLY LIGHT MOST OF THURSDAY...BUT              
INCREASE INTO THE 15-20 KT RANGE...WHERE SMALL TWEAKS IN DIRECTION              
BECOME CRITICAL TO SEA GROWTH. THE CURRENTLY ADVERTISED 040-050                 
DIRECTION SHOULD BE EXPOSED ENOUGH TO BUILD SEAS TO 5 FT AWAY FROM              
SHORE ON FRIDAY...BUT IF THE GRADIENT REMAINS MORE NORTHERLY THE                
NEAR-SHORE ALLOWANCES WILL NEED TO BE LARGER.                                   
LONG TERM/FRIDAY NIGHT THROUGH SUNDAY/...                                       
AS OF 3 AM WEDNESDAY...NE FLOW WILL SHIFT TO THE SOUTH ON SATURDAY              
AS MODELS ARE HINTING AT A WEAKENING COASTAL TROF OR WARM FRONT.                
EVEN IF THE NE FLOW HANGS ON INTO SAT NIGHT...WILL SEE THE SW FLOW              
AHEAD OF THE FRONT BECOME DOMINANT BY SUNDAY EITHER WAY. SCA WINDS              
AND SEAS ARE LIKELY ON SUNDAY AHEAD OF THE FRONT...BUT WE ARE                   
STILL TALKING 5 DAYS OUT.                                                       
&&                                                                              
.ILM WATCHES/WARNINGS/ADVISORIES...                                             
SC...NONE.                                                                      
NC...NONE.                                                                      
MARINE...NONE.                                                                  
&&                                                                              
$$                                                                              
SYNOPSIS...REK                                                                  
NEAR TERM...REK                                                                 
</pre> nc                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE RALEIGH NC                                             
735 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA                     
TODAY...FOLLOWED BY ANOTHER DRY HIGH PRESSURE SYSTEM BUILDING OVER              
THE AREA ON THURSDAY. A LOW PRESSURE SYSTEM IS EXPECTED TO TRACK                
ACROSS THE DEEP SOUTH THURSDAY AND THURSDAY NIGHT.                              
&&                                                                              
.NEAR TERM /THROUGH TODAY/...                                                   
AS OF 730 AM... A QUICK UPDATE HAS BEEN SENT FOR THE BAND OF                    
PRECIPITATION CURRENTLY MOVING THROUGH THE FAR WESTERN PIEDMONT.                
THIS LOOKS TO BE SUPPORTED BY UPPER DIVERGENCE ASSOCIATED WITH A                
DIVING 110+ KT JET AND MID LEVEL DIFFERENTIAL POSITIVE VORTICITY                
ADVECTION WITH THE SHORTWAVE TROUGH NOW DROPPING INTO THE MOUNTAINS.            
THE WET BULB PROFILE ON THE 12Z GSO SOUNDING IS ALMOST ENTIRELY                 
BELOW ZERO BUT WITH MARGINAL MOISTURE... HOWEVER THE 12Z RNK                    
SOUNDING SHOWS SUFFICIENT SATURATION IN THE -10 TO -15C LAYER FOR               
THE POSSIBILITY OF A LIGHT MIXTURE OF SNOW AND RAIN THROUGH THE                 
MORNING. TEMPS MAY STRUGGLE TO CLIMB THROUGH THE 40S TODAY.-GIH                 
AS OF 230 AM WEDNESDAY...SFC ANALYSIS THIS MORNING SHOWS 1029 MB                
HIGH PRESSURE OFF THE MID-ATLANTIC COAST...WITH SFC RIDGING                     
EXTENDING SOUTHWEST THROUGH NC INTO GA/AL/FL. A 1009 MB SURFACE                 
LOW WAS LOCATED OVER LAKE MICHIGAN. A WEAKER SURFACE LOW WAS                    
LOCATED NEAR THE LA/TX/AR BORDER. A RELATIVELY WARM/MOIST AIRMASS               
(TEMPS IN THE 50S TO LOWER 60S AND DEWPOINTS IN THE 40S AND 50S)                
AHEAD OF THE SFC LOW WAS BEGINNING TO SPREAD NORTH FROM THE GULF                
OF MEXICO INTO THE DEEP SOUTH AS FAR NORTH AS WESTERN TN.                       
ALOFT...00Z RAOB ANALYSIS AND CURRENT WV IMAGERY SHOW SEVERAL                   
SHORTWAVES EMBEDDED IN THE FLOW UPSTREAM OF THE AREA...THE                      
STRONGEST OF WHICH WAS LOCATED IN SOUTHERN IL/MO. A WEAKER                      
SHORTWAVE WAS LOCATED IN EASTERN TN/KY. THE 00Z GSO SOUNDING HAD A              
PWAT OF 0.24".                                                                  
CURRENT REGIONAL RADAR IMAGERY SHOWS AN AREA OF SHOWERS ASSOC/W AN              
UPPER LEVEL SHORTWAVE AND ISENTROPIC LIFT APPROACHING THE SOUTHERN              
APPALACHIANS. THESE SHOWERS ARE REACHING THE GROUND WEST OF THE                 
MOUNTAINS...FALLING OUT OF BKN/OVC 5-8 KFT CEILINGS. NEITHER THE 00Z            
GFS NOR THE NAM SEEM TO HAVE PICKED UP ON THE CORRECT TIMING OR                 
LOCATION OF THIS PRECIP...WITH THE 00-06Z QPF FROM BOTH MODELS TOO              
FAR WEST OF WHERE THE CURRENT ACTIVITY IS LOCATED. THE ATMOSPHERE               
ACROSS CENTRAL NC IS VERY DRY THIS MORNING...WITH PWAT VALUES AROUND            
A QUARTER OF AN INCH AND SFC DEWPOINTS IN THE TEENS TO 20S. THE                 
LIKELIHOOD OF ANY SHOWER ACTIVITY REACHING THE GROUND IN THE DRY                
ATMOSPHERE EAST OF THE MOUNTAINS THIS MORNING IS VERY SLIM.                     
HOWEVER...GIVEN THAT CURRENT WETBULB TEMPERATURES ARE BELOW FREEZING            
(27-31F)...AND SHOULD REMAIN SO THROUGH SUNRISE...ANY PRECIP THAT               
DOES REACH THE GROUND EAST OF THE MOUNTAINS...EVEN A TRACE...COULD              
POTENTIALLY BE A PROBLEM IF IT FALLS AS FZRA. FCST SOUNDINGS FOR                
THIS MORNING SHOW ABOVE FREEZING TEMPS IN THE LOWEST 5-7 KFT...WITH             
A 40F WARM NOSE PROGGED AT AROUND 1 KFT AGL. GIVEN THE AMOUNT OF DRY            
AIR IN THE LOWER LEVELS...ANY EVAPORATIVE COOLING ASSOC/W FALLING               
PRECIP COULD ALTER THE THERMAL STRUCTURE TO ONE MORE FAVORABLE FOR              
FROZEN PRECIP. THE 0637Z SFC OB IN ATLANTA THIS MORNING WAS                     
REPORTING SLEET AND RAIN WITH A TEMP OF 39 AND A DEWPOINT OF 28.                
THE SHORTWAVE THAT IS AIDING SHOWER ACTIVITY APPROACHING THE                    
MOUNTAINS IS LOCATED IN EASTERN TN/KY BASED ON WATER VAPOR IMAGERY              
AND RUC H5 HEIGHT/VORT FIELDS. EXTRAPOLATION OF THE MOVEMENT OF THIS            
FEATURE SHOW THE SHORTWAVE ALONG THE NC/VA BORDER NEAR DANVILLE BY              
12Z. NAM/GFS ISENTROPIC ANALYSIS SHOWS ISENTROPIC LIFT INCREASING               
ACROSS THE AREA TOWARD SUNRISE AS WELL. AT THIS TIME PREFER TO LEAVE            
OUT ANY POPS THIS MORNING GIVEN THE VERY DRY ATMOSPHERE ACROSS THE              
AREA...HOWEVER...THIS WILL BE VERY CLOSELY MONITORED OVER THE NEXT              
FEW HOURS GIVEN THE BELOW FREEZING WETBULB TEMPERATURES. EXPECT                 
MOSTLY CLOUDY SKIES DEVELOPING ACROSS THE AREA FROM WEST TO EAST BY             
OR SHORTLY AFTER SUNRISE.                                                       
THE SURFACE BOUNDARY ASSOC/W THE LOW PRESSURE SYSTEM OVER THE GREAT             
LAKES IS PROGGED TO CROSS CENTRAL NC DURING THE AFTERNOON HOURS. THE            
STRONGER SHORTWAVE CURRENTLY OVER MO/IL IS PROGGED TO DROP ESE INTO             
THE AREA THIS AFTERNOON IN CONCERT WITH THE WEAK SFC TROUGH /                   
BOUNDARY. GFS/NAM FCST SOUNDINGS SHOW CEILINGS BETWEEN 5-12 KFT                 
TODAY WITH A DRY SUB-CLOUD LAYER. NEITHER MODEL PRODUCES MEASURABLE             
PRECIP ACROSS THE AREA THIS AFTERNOON...AND PROBABILITIES OF                    
MEASURABLE PRECIP OFF THE SREF REMAIN LESS THAN 25%. ALTHOUGH AN                
ISOLATED SPRINKLE OR LIGHT SHOWER CANNOT BE RULED OUT THIS                      
AFTERNOON...AT THIS TIME PROBABILITIES APPEAR TOO LOW TO INTRODUCE              
PRECIP INTO THE FORECAST.                                                       
WILL KNOCK DOWN HIGH TEMPS AT LEAST SEVERAL DEGREES TODAY GIVEN 12Z             
THICKNESSES BETWEEN 1310-1320 METERS...00Z THICKNESSES PROGGED                  
BETWEEN 1320-1330 METERS...AND A GOOD DEAL OF CLOUD COVER EXPECTED              
INTO AT LEAST EARLY/MID AFTERNOON...ALL OF WHICH ARGUE FOR HIGH                 
TEMPS IN THE MID TO UPPER 40S IN MOST LOCATIONS...LOWER 50S                     
PERHAPS IN THE FAR SOUTHERN PORTIONS OF THE AREA. THIS IS AT THE                
LOW END OR BELOW THE LATEST 00Z MAV/MET MOS GUIDANCE. -VINCENT                  
&&                                                                              
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...                                   
AS OF 300 AM WEDNESDAY...SFC HIGH PRESSURE OVER THE MIDWEST                     
STATES MOVES EAST INTO THE MID-ATLANTIC TONIGHT...REMAINING OVER                
THE AREA DURING THE DAY ON THURSDAY. A VIGOROUS SOUTHERN STREAM                 
TROUGH...CURRENTLY OVER SOUTHERN CALIFORNIA...WILL TRAVERSE THE                 
COUNTRY AND INITIATE CYCLOGENESIS IN THE LEE OF THE ROCKIES                     
TONIGHT...WITH THE UPPER LEVEL TROUGH AND ASSOC SFC LOW                         
APPROACHING THE DEEP SOUTH DURING THE DAY THURSDAY. ACROSS CENTRAL              
NC...WITH HIGH PRESSURE IN CONTROL... EXPECT MOSTLY CLEAR SKIES AT              
THE BEGINNING OF THE DAY...WITH INCREASING CLOUD COVER LATER IN                 
THE AFTERNOON/EVENING IN ADVANCE OF THE APPROACHING SHORTWAVE AND               
SFC LOW. ALTHOUGH THICKNESSES ON THURSDAY ARE PROGGED TO BE ONLY                
SLIGHTLY WARMER THAN TODAY...CLEAR OR MOSTLY CLEAR SKIES ARE                    
EXPECTED THROUGH THE MORNING AND MOST OF THE AFTERNOON...AND THIS               
SHOULD ALLOW TEMPS TO REACH THE MID 50S ACROSS THE AREA.                        
DIFFICULT FORECAST ON TAP FOR THURSDAY NIGHT AND FRIDAY. BOTH THE               
GFS/NAM CONTINUE TO TAKE THE SOUTHERN STREAM WAVE AND SURFACE LOW               
SOUTH OF THE AREA. SFC RIDGING IS PROGGED TO DEVELOP IN ADVANCE OF              
THIS SYSTEM ACROSS THE CAROLINAS ON THURSDAY...WITH THE SOUTHERN                
PORTION OF THE WEDGE OVER GA/SC/NC FURTHER STRENGTHENING THU NIGHT              
AS ISENTROPIC LIFT BEGINS TO INCREASE AND PRECIP ADVANCES TOWARD THE            
AREA FROM THE SOUTHWEST. BOTH THE GFS/NAM SHOW A MILLER TYPE-B                  
SCENARIO WHERE THE INLAND SFC LOW OVER NORTHERN AL OR SOUTHERN TN               
JUMPS EAST OF THE WEDGE TO THE GA/FL COAST OR EVEN OFFSHORE FRIDAY              
MORNING. AT THIS TIME THE BEST LIFT REMAINS SOUTH OF THE AREA...AND             
LITTLE IF ANY PRECIP IS EXPECTED ACROSS CENTRAL NC. THE 00Z GFS                 
SHOWS 0.05 TO 0.10" FALLING ALONG/SOUTH OF HIGHWAY 64 BETWEEN 06-12Z            
FRIDAY MORNING...WHILE THE 00Z NAM DOES NOT GENERATE ANY MEASURABLE             
PRECIP ACROSS CENTRAL NC IN ASSOC/W THIS SYSTEM. THE SREF SHOWS LESS            
THAN 25% PROBABILITIES OF MEASURABLE PRECIP ACROSS MOST OF CENTRAL              
NC...EXCEPT ALONG THE NC/SC BORDER AND IN THE FAR WESTERN PIEDMONT              
WHERE PROBABILITIES ARE AS HIGH AS 45%.                                         
AT THIS TIME THE BEST CHANCE FOR PRECIP APPEARS TO BE ALONG THE                 
NC/SC BORDER BETWEEN 06-17Z FRIDAY...AND WILL THEREFORE CONFINE A               
LOW CHANCE (30%) OF SHOWERS TO THOSE LOCATIONS DURING THAT TIME                 
PERIOD...WITH A SLIGHT CHANCE EXTENDING NORTH TO HIGHWAY 64 AND INTO            
THE TRIAD. THE LATEST FCST SOUNDINGS SHOW THERMAL PROFILES                      
SUPPORTIVE OF ALL LIQUID PRECIP...HOWEVER...IF PRECIP ASSOC/W THE               
SYSTEM IS HEAVIER AND SPREADS FURTHER NORTH THAN ANTICIPATED...OR IF            
THE ANTECEDENT SFC RIDGING/WEDGE IS STRONGER THAN EXPECTED...P-TYPE             
PROBLEMS WOULD BE POSSIBLE...AND THIS WILL NEED TO BE MONITORED                 
CLOSELY OVER THE NEXT 24-36 HOURS. DIFFICULT LOW TEMP FORECAST                  
FRIDAY MORNING...SINCE THIS WILL DEPEND ON THE AMOUNT OF CLOUD                  
COVER...THE STRENGTH OF THE ANTECEDENT SFC RIDGING AND WHETHER OR               
NOT PRECIP IS FALLING INTO COOL/DRY AIR AT THE SURFACE. AT THIS TIME            
WILL ADVERTISE LOWER/MID 30S NORTH TO UPPER 30S SOUTH.                          
THICKNESSES ON FRIDAY ARE EXPECTED TO RANGE BETWEEN 1305-1330                   
METERS...SIMILAR TO TODAY/THU. WITH FULL SUN TEMPERATURES WOULD BE              
SIMILAR TO WHAT IS EXPECTED THURSDAY...ALTHOUGH WITH SIGNIFICANT                
CLOUD COVER TEMPERATURES WOULD BE MORE SIMILAR TO WHAT IS EXPECTED              
TODAY. AT THIS TIME...WILL TREND CLOSE TO MOS GUIDANCE...WITH HIGHS             
RANGING FROM THE MID 40S NORTH TO LOWER 50S SOUTH. LOW TEMPS FRIDAY             
NIGHT IN THE MID 30S NORTH TO LOWER 40S SOUTH. -VINCENT                         
&&                                                                              
.LONG TERM /SATURDAY THROUGH TUESDAY/...                                        
AS OF 300 AM EST... THE WEEKEND LOOKS TO BE CLOUDY AND WET. ON                  
SATURDAY BOTH THE 00Z/19 GFS AND 00Z/19 ECMWF SHOW HIGH PRESSURE                
LOCATED OVER THE EASTERN PORTION OF MAINE EXTENDING INTO THE                    
AREA. WEAK ISENTROPIC LIFT DEPICTED BY THE MODELS MAY PRODUCE SOME              
LIGHT PRECIP ON SATURDAY AND SATURDAY NIGHT. THUS...WILL CARRY A                
SLIGHT CHANCE FOR RAIN ON SATURDAY AND INCREASE THE POPS TO CHANCE              
DURING THE OVERNIGHT HOURS FROM WEST TO EAST. HIGHS SATURDAY WILL               
BE CATEGORY ABOVE NORMAL. LOWS SUNDAY MORNING WILL RUN 10 TO 15                 
DEGREES ABOVE NORMAL...AS THE HIGH PRESSURE RIDGE BEGINS TO                     
RETREAT AND WINDS BECOME SOUTHERLY IN ADVANCE OF THE FRONT.                     
A FAIRLY IMPRESSIVE UPPER LEVEL TROUGH WILL APPROACH THE AREA FROM              
THE WEST ON SUNDAY WITH A SURFACE COLD FRONT CROSSING THE AREA                  
SUNDAY AFTERNOON INTO THE EVENING. TIMING FOR THE SURFACE FRONT IS              
LOOKING BETTER AS THE THE 00Z/19 GFS AND ECMWF ARE COMING INTO                  
BETTER AGREEMENT... WITH BOTH SHOWING THE FRONT CROSSING THE AREA               
DURING THE AFTERNOON INTO THE EVENING ON SUNDAY. BOTH THE GFS AND               
ECMWF DEPICT A FAIRLY STRONG UPPER LEVEL JET ASSOCIATED WITH THIS               
SYSTEM. AT THIS TIME WE APPEAR TO BE IN THE FAVORED RIGHT ENTRANCE              
REGION OF THE JET... WHICH WOULD INCREASE LIFT AND COUPLED WITH GOOD            
SOUTHERLY FLOW IN ADVANCE OF THE SURFACE FRONT SHOULD INCREASE THE              
LIKELIHOOD OF A MORE SUBSTANTIAL RAIN EVENT. THUS...WILL INCREASE               
POPS TO 50% FOR SUNDAY AFTERNOON INTO THE EARLY EVENING ACROSS THE              
CWA. WILL LIKELY NEED TO UP POPS IN LATER FORECASTS IF THE SYSTEM               
CONTINUES TO SHOW CONSISTENCY IN THE MODELS FROM RUN TO RUN. HIGHS              
SUNDAY WILL BE WELL ABOVE AVERAGE WITH TEMPS RANGING FROM THE                   
UPPER 50S NORTHWEST TO THE UPPER 60S IN THE SOUTHEAST. LOWS MONDAY              
WILL RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S IN THE EAST.               
MONDAY WILL BE NOTICEABLY COOLER AS HIGH PRESSURE BUILDS INTO THE               
REGION AT THE SURFACE. HOWEVER...HIGH TEMPS WILL STILL BE NEAR                  
NORMAL FOR THIS TIME OF YEAR.                                                   
MODELS BEGIN TO DIVERGE IN THEIR SOLUTIONS BEYOND MONDAY...AS THE               
00Z/19 GFS BRINGS A UPPER LEVEL SHORTWAVE ACROSS THE REGION ON                  
TUESDAY...WHILE THE 00Z/19 ECMWF DEVELOPS A CUT OFF UPPER LEVEL                 
LOW OVER NORTHERN PORTIONS OF THE GULF COAST STATES. THUS...WITH                
MODEL DIFFERENCES AT THIS TIME WILL STICK CLOSE TO CLIMATOLOGY AND              
KEEP ANY MENTION OF PRECIP OUT OF THE FORECAST FOR NOW. -BSD                    
&&                                                                              
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...                                     
AS OF 630 AM WEDNESDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF            
PERIOD. A WEAK SHORTWAVE WILL CROSS CENTRAL NORTH CAROLINA TODAY                
UNDER FAST ZONAL FLOW ALOFT. THIS SHORTWAVE IS IS PRODUCING BKN/OVC             
DECK OF CLOUDS AT 6 TO 8 KFT AT ALL SITE AS OF 1130Z... EXCEPT                  
KRWI... WHERE THESE CLOUDS SHOULD MOVE IN BETWEEN 13-14Z THIS                   
MORNING. THIS DECK SHOULD BEGIN TO SCATTER OUT IN THE AFTERNOON...              
WITH SKIES BECOMING MOSTLY CLEAR IN THE EVENING. IN ADDITION... AN              
ISOLATED SHOWER OR TWO WILL BE POSSIBLE THIS MORNING AS WELL.                   
MVFR TO IFR CONDITIONS ARE POSSIBLE WITH A STORM SYSTEM PASSING JUST            
SOUTH OF THE AREA THURSDAY NIGHT...PRIMARILY AT FAY WITH THE BEST               
MOISTURE STAYING SOUTH OF GSO/INT/RDU/RWI. ISENTROPIC LIFT WILL                 
INCREASE BY SATURDAY MORNING AS LOW LEVEL RIDGING MOVES OFFSHORE IN             
ADVANCE OF A STRENGTHENING STORM SYSTEM OVER THE CENTRAL U.S. MVFR              
TO IFR CONDITIONS WILL BE POSSIBLE DURING THIS TIME. THIS STORM                 
SYSTEM WILL PUSH A COLD FRONT THROUGH CENTRAL NORTH ON                          
SUNDAY...RESULTING IN A GOOD LIKELIHOOD OF SHOWERS ALONG WITH                   
OCCASIONALLY MVFR TO IFR CONDITIONS. -BSD                                       
&&                                                                              
.RAH WATCHES/WARNINGS/ADVISORIES...                                             
NONE.                                                                           
&&                                                                              
$$                                                                              
SYNOPSIS...VINCENT                                                              
NEAR TERM...HARTFIELD/VINCENT                                                   
SHORT TERM...VINCENT                                                            
LONG TERM...BSD                                                                 
AVIATION...BSD                                                                  
</pre> nc                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE WILMINGTON NC                                          
605 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...                                                                    
A WEAK COASTAL TROUGH WILL CONTINUE TO DEVELOP OFF THE COAST AND                
MOVE AWAY FROM THE AREA TONIGHT. ANOTHER FAST MOVING SYSTEM JUST                
TO THE SOUTH OF THE REGION WILL BRING A CHANCE OF SHOWERS LATE                  
THURSDAY AND EARLY FRIDAY. HIGH PRESSURE WILL PREVAIL ON                        
SATURDAY...FOLLOWED BY A STRONG COLD FRONT LATE SUNDAY.                         
&&                                                                              
.NEAR TERM /THROUGH 7 AM THURSDAY/...                                           
AS OF 3 AM WEDNESDAY..HIGH PRESSURE AXIS OVER EASTERN NORTH                     
CAROLINA AT 06 UTC WITH ONLY MID LEVEL CLOUDINESS. THE LATEST RUC               
SHOWS THE COASTAL TROUGH SITUATED JUST TO THE SOUTH OF THE AREA.                
THE 00 UTC RUNS OF THE GFS AND NAM ALONG WITH THE 21 UTC SREF ALL               
ARE PROJECTING A COASTAL TROUGH TO CONTINUE TO DEVELOP NORTHWARD                
BUT REMAIN OFFSHORE AND MINIMAL IMPACT EXPECTED. THE SREF                       
PRECIPITATION PROBABILITY FIELDS SHOW ALL PRECIPITATION STAYS EAST              
OF THE FORECAST AREA. SO EXPECT AREA TO REMAIN DRY WITH THE                     
LIMITED MOISTURE SEEN IN THE VERTICAL PROFILES. FOR TEMPERATURES                
WENT WITH A CONSENSUS FORECAST OF THE STATISTICAL GUIDANCE                      
PRODUCTS.                                                                       
&&                                                                              
.SHORT TERM /THURSDAY 7 AM THROUGH FRIDAY/...                                   
AS OF 3 AM WEDNESDAY...THE MAIN QUESTION IS THE SENSIBLE WX                     
EFFECT OF A PROGRESSIVE SOUTHERN STREAM SYSTEM...WHICH IS EXPECTED              
TO MOVE EAST ACROSS THE CAROLINAS THU NIGHT.                                    
MOISTURE FEED AHEAD OF THIS SYSTEM IS SLOW TO DEVELOP...AND THE                 
RUN-TO-RUN TREND IS A BIT SLOWER YET.  THE OTHER TRICKY FACTOR WILL             
BE THE DRY NNE FLOW AND HOW MUCH EVAPORATION WILL OCCUR.  BEST SHOT             
FOR PRECIP WILL BE 06-12Z FRI...WITH THE MAIN ENERGY STAYING FAR                
ENOUGH SOUTH TO WARRANT A GRADIENT FROM LOW CHANCE IN THE NORTH...TO            
HIGH CHANCE IN THE SOUTH.  MOISTURE IS SLOW TO EXIT ON FRIDAY SO                
WILL TAPER POPS DOWN THRU THE DAY.                                              
TEMPS ARE HIGHLY DEPENDENT ON CLOUD COVER IN THIS PERIOD.  FORECAST             
HIGHS IN THE UPPER 50S ON THU REPRESENT THE BEST-CASE SCENARIO AND              
AN EARLIER ARRIVAL OF CLOUDINESS WILL REALLY HOLD TEMPS BACK.                   
MODELS ARE HINTING THAT FRIDAY TEMPS WILL ALSO BE LIMITED BY LOW                
CLOUDS...BUT CONFIDENCE IS STILL QUITE LOW AT THIS POINT.                       
&&                                                                              
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...                                    
AS OF 3 AM WEDNESDAY...PATTERN REMAINS FAIRLY PROGRESSIVE BUT THE               
MAIN COMPLICATION IS THAT EXTENDED GFS MOS IS QUITE BULLISH WITH                
PRECIP CHANCES...ADVERTISING POPS WELL ABOVE CLIMO AND SOLIDLY IN               
THE CHANCE CATEGORY THROUGH MOST OF THE PERIOD. FOR NOW AM NOT                  
BUYING WHAT THE GFS IS SELLING...ESPECIALLY IN THE ONGOING                      
DROUGHT. HAVE FOCUSED INSTEAD ON PERIODS THAT SEEM TO HAVE A LEGIT              
CHANCE OF PRECIP...THUS CARRYING 30-40 POPS SAT NIGHT THROUGH SUN               
NIGHT AS A STRONG COLD FRONT CROSSES THE AREA.                                  
TEMPS ABOVE CLIMO FOR THE WEEKEND AND INTO MONDAY UNDER FLAT UPPER              
RIDGING...THEN WE GET KNOCKED BACK TO NEAR OR BELOW CLIMO NUMBERS               
BEHIND THE COLD FRONT.                                                          
&&                                                                              
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...                                     
MID LEVEL CLOUDINESS IS APPROACHING THE TAF SITES THIS MORNING. THE             
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE STILL OVER THE FORECAST             
AREA WITH COASTAL TROUGH FORMED JUST SOUTH OF THE MYR AND CRE TAF               
SITS. 06 UTC GFS... 06 UTC NAM AND 03 UTC SREF ALL ARE STILL IN                 
AGREEMENT ON DEVELOPING TROUGH FARTHER NORTH AND OFF THE COAST.                 
LATEST 11-3.9 MICRON SATELLITE IMAGERY IS SHOWING MID LEVEL                     
CLOUDINESS MOVING TOWARDS THE COAST AND LATEST BUFR SOUNDING                    
CONTINUE TO SHOW MOISTURE BUILDING FROM 10K TO 5K FT. WINDS WILL BE             
LIGHT AND VARIABLE OVER THE NEXT 9 HOURS WITH SOUTHWEST WINDS                   
EXPECTED AFTER 15 UTC AS RIDGE SHIFTS EASTWARD.                                 
LOW PRESSURE MOVES ALONG THE SOUTHEASTERN STATES THURSDAY NIGHT INTO            
FRIDAY...WITH POSSIBLE LOW CEILINGS AND PRECIP.                                 
&&                                                                              
.MARINE...                                                                      
NEAR TERM /THROUGH 7 AM THURSDAY/...                                            
AS OF 300 AM WEDNESDAY...SURFACE ANALYSIS AND RUC MODEL SHOW COASTAL            
TROUGH DEVELOPING JUST SOUTH OF THE WATER AT THIS TIME. TROUGH                  
SHOULD BUILD NORTHWARD AND JUST EAST OF THE COASTAL WATERS                      
THROUGHOUT THE DAY. WINDS ARE VARIABLE AT THIS TIME WITH WINDS                  
SPEEDS LESS THAN 10 KNOTS. WINDS ARE EXPECTED TO SHIFT TO THE                   
SOUTHWEST THIS AFTERNOON AND NORTHWESTERLY TONIGHT. WINDS SPEED ARE             
ONLY EXPECTED TO INCREASE TO 15 KNOTS TONIGHT. LATEST WAVEWATCH III             
AND REEFCAST ALL ARE SHOWING SEAS 1 TO 2 FEET THROUGH TODAY WITH A              
SLIGHT INCREASE IN SEAS OFFSHORE WITH THE INCREASED NORTHWESTERLY               
WINDS TONIGHT.                                                                  
SHORT TERM /THURSDAY 7 AM THROUGH FRIDAY/...                                    
AS OF 3 AM WEDNESDAY...NE GRADIENT WILL GRADUALLY TIGHTEN UP THRU               
THE PERIOD. WIND SPEEDS REMAIN FAIRLY LIGHT MOST OF THURSDAY...BUT              
INCREASE INTO THE 15-20 KT RANGE...WHERE SMALL TWEAKS IN DIRECTION              
BECOME CRITICAL TO SEA GROWTH. THE CURRENTLY ADVERTISED 040-050                 
DIRECTION SHOULD BE EXPOSED ENOUGH TO BUILD SEAS TO 5 FT AWAY FROM              
SHORE ON FRIDAY...BUT IF THE GRADIENT REMAINS MORE NORTHERLY THE                
NEAR-SHORE ALLOWANCES WILL NEED TO BE LARGER.                                   
LONG TERM/FRIDAY NIGHT THROUGH SUNDAY/...                                       
AS OF 3 AM WEDNESDAY...NE FLOW WILL SHIFT TO THE SOUTH ON SATURDAY              
AS MODELS ARE HINTING AT A WEAKENING COASTAL TROF OR WARM FRONT.                
EVEN IF THE NE FLOW HANGS ON INTO SAT NIGHT...WILL SEE THE SW FLOW              
AHEAD OF THE FRONT BECOME DOMINANT BY SUNDAY EITHER WAY. SCA WINDS              
AND SEAS ARE LIKELY ON SUNDAY AHEAD OF THE FRONT...BUT WE ARE                   
STILL TALKING 5 DAYS OUT.                                                       
&&                                                                              
.ILM WATCHES/WARNINGS/ADVISORIES...                                             
SC...NONE.                                                                      
NC...NONE.                                                                      
MARINE...NONE.                                                                  
&&                                                                              
$$                                                                              
SYNOPSIS...DRH                                                                  
NEAR TERM...DRH                                                                 
SHORT TERM...RAS                                                                
LONG TERM...RAS                                                                 
AVIATION...DRH                                                                  
</pre> nc                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE RALEIGH NC                                             
325 AM EST WED DEC 19 2007                                                      
.SYNOPSIS...HIGH PRESSURE CENTERED JUST OFF THE VIRGINIA                        
COAST WILL CONTINUE TO EXTEND SOUTHWESTWARD THROUGH THE CAROLINAS               
TONIGHT. A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA ON                     
WEDNESDAY...FOLLOWED BY ANOTHER DRY HIGH PRESSURE SYSTEM BUILDING               
OVER THE AREA ON THURSDAY. A LOW PRESSURE SYSTEM IS EXPECTED TO                 
TRACK ACROSS THE DEEP SOUTH THURSDAY AND THURSDAY NIGHT.                        
&&                                                                              
.NEAR TERM /THROUGH TODAY/...                                                   
AS OF 230 AM WEDNESDAY...SFC ANALYSIS THIS MORNING SHOWS 1029 MB                
HIGH PRESSURE OFF THE MID-ATLANTIC COAST...WITH SFC RIDGING                     
EXTENDING SOUTHWEST THROUGH NC INTO GA/AL/FL. A 1009 MB SURFACE                 
LOW WAS LOCATED OVER LAKE MICHIGAN. A WEAKER SURFACE LOW WAS                    
LOCATED NEAR THE LA/TX/AR BORDER. A RELATIVELY WARM/MOIST AIRMASS               
(TEMPS IN THE 50S TO LOWER 60S AND DEWPOINTS IN THE 40S AND 50S)                
AHEAD OF THE SFC LOW WAS BEGINNING TO SPREAD NORTH FROM THE GULF                
OF MEXICO INTO THE DEEP SOUTH AS FAR NORTH AS WESTERN TN.                       
ALOFT...00Z RAOB ANALYSIS AND CURRENT WV IMAGERY SHOW SEVERAL                   
SHORTWAVES EMBEDDED IN THE FLOW UPSTREAM OF THE AREA...THE                      
STRONGEST OF WHICH WAS LOCATED IN SOUTHERN IL/MO. A WEAKER                      
SHORTWAVE WAS LOCATED IN EASTERN TN/KY. THE 00Z GSO SOUNDING HAD A              
PWAT OF 0.24".                                                                  
CURRENT REGIONAL RADAR IMAGERY SHOWS AN AREA OF SHOWERS ASSOC/W AN              
UPPER LEVEL SHORTWAVE AND ISENTROPIC LIFT APPROACHING THE SOUTHERN              
APPALACHIANS. THESE SHOWERS ARE REACHING THE GROUND WEST OF THE                 
MOUNTAINS...FALLING OUT OF BKN/OVC 5-8 KFT CEILINGS. NEITHER THE 00Z            
GFS NOR THE NAM SEEM TO HAVE PICKED UP ON THE CORRECT TIMING OR                 
LOCATION OF THIS PRECIP...WITH THE 00-06Z QPF FROM BOTH MODELS TOO              
FAR WEST OF WHERE THE CURRENT ACTIVITY IS LOCATED. THE ATMOSPHERE               
ACROSS CENTRAL NC IS VERY DRY THIS MORNING...WITH PWAT VALUES AROUND            
A QUARTER OF AN INCH AND SFC DEWPOINTS IN THE TEENS TO 20S. THE                 
LIKELIHOOD OF ANY SHOWER ACTIVITY REACHING THE GROUND IN THE DRY                
ATMOSPHERE EAST OF THE MOUNTAINS THIS MORNING IS VERY SLIM.                     
HOWEVER...GIVEN THAT CURRENT WETBULB TEMPERATURES ARE BELOW FREEZING            
(27-31F)...AND SHOULD REMAIN SO THROUGH SUNRISE...ANY PRECIP THAT               
DOES REACH THE GROUND EAST OF THE MOUNTAINS...EVEN A TRACE...COULD              
POTENTIALLY BE A PROBLEM IF IT FALLS AS FZRA. FCST SOUNDINGS FOR                
THIS MORNING SHOW ABOVE FREEZING TEMPS IN THE LOWEST 5-7 KFT...WITH             
A 40F WARM NOSE PROGGED AT AROUND 1 KFT AGL. GIVEN THE AMOUNT OF DRY            
AIR IN THE LOWER LEVELS...ANY EVAPORATIVE COOLING ASSOC/W FALLING               
PRECIP COULD ALTER THE THERMAL STRUCTURE TO ONE MORE FAVORABLE FOR              
FROZEN PRECIP. THE 0637Z SFC OB IN ATLANTA THIS MORNING WAS                     
REPORTING SLEET AND RAIN WITH A TEMP OF 39 AND A DEWPOINT OF 28.                
THE SHORTWAVE THAT IS AIDING SHOWER ACTIVITY APPROACHING THE                    
MOUNTAINS IS LOCATED IN EASTERN TN/KY BASED ON WATER VAPOR IMAGERY              
AND RUC H5 HEIGHT/VORT FIELDS. EXTRAPOLATION OF THE MOVEMENT OF THIS            
FEATURE SHOW THE SHORTWAVE ALONG THE NC/VA BORDER NEAR DANVILLE BY              
12Z. NAM/GFS ISENTROPIC ANALYSIS SHOWS ISENTROPIC LIFT INCREASING               
ACROSS THE AREA TOWARD SUNRISE AS WELL. AT THIS TIME PREFER TO LEAVE            
OUT ANY POPS THIS MORNING GIVEN THE VERY DRY ATMOSPHERE ACROSS THE              
AREA...HOWEVER...THIS WILL BE VERY CLOSELY MONITORED OVER THE NEXT              
FEW HOURS GIVEN THE BELOW FREEZING WETBULB TEMPERATURES. EXPECT                 
MOSTLY CLOUDY SKIES DEVELOPING ACROSS THE AREA FROM WEST TO EAST BY             
OR SHORTLY AFTER SUNRISE.                                                       
THE SURFACE BOUNDARY ASSOC/W THE LOW PRESSURE SYSTEM OVER THE GREAT             
LAKES IS PROGGED TO CROSS CENTRAL NC DURING THE AFTERNOON HOURS. THE            
STRONGER SHORTWAVE CURRENTLY OVER MO/IL IS PROGGED TO DROP ESE INTO             
THE AREA THIS AFTERNOON IN CONCERT WITH THE WEAK SFC TROUGH /                   
BOUNDARY. GFS/NAM FCST SOUNDINGS SHOW CEILINGS BETWEEN 5-12 KFT                 
TODAY WITH A DRY SUB-CLOUD LAYER. NEITHER MODEL PRODUCES MEASURABLE             
PRECIP ACROSS THE AREA THIS AFTERNOON...AND PROBABILITIES OF                    
MEASURABLE PRECIP OFF THE SREF REMAIN LESS THAN 25%. ALTHOUGH AN                
ISOLATED SPRINKLE OR LIGHT SHOWER CANNOT BE RULED OUT THIS                      
AFTERNOON...AT THIS TIME PROBABILITIES APPEAR TOO LOW TO INTRODUCE              
PRECIP INTO THE FORECAST.                                                       
WILL KNOCK DOWN HIGH TEMPS AT LEAST SEVERAL DEGREES TODAY GIVEN 12Z             
THICKNESSES BETWEEN 1310-1320 METERS...00Z THICKNESSES PROGGED                  
BETWEEN 1320-1330 METERS...AND A GOOD DEAL OF CLOUD COVER EXPECTED              
INTO AT LEAST EARLY/MID AFTERNOON...ALL OF WHICH ARGUE FOR HIGH                 
TEMPS IN THE MID TO UPPER 40S IN MOST LOCATIONS...LOWER 50S                     
PERHAPS IN THE FAR SOUTHERN PORTIONS OF THE AREA. THIS IS AT THE                
LOW END OR BELOW THE LATEST 00Z MAV/MET MOS GUIDANCE. -VINCENT                  
&&                                                                              
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...                                   
AS OF 300 AM WEDNESDAY...SFC HIGH PRESSURE OVER THE MIDWEST                     
STATES MOVES EAST INTO THE MID-ATLANTIC TONIGHT...REMAINING OVER                
THE AREA DURING THE DAY ON THURSDAY. A VIGOROUS SOUTHERN STREAM                 
TROUGH...CURRENTLY OVER SOUTHERN CALIFORNIA...WILL TRAVERSE THE                 
COUNTRY AND INITIATE CYCLOGENESIS IN THE LEE OF THE ROCKIES                     
TONIGHT...WITH THE UPPER LEVEL TROUGH AND ASSOC SFC LOW                         
APPROACHING THE DEEP SOUTH DURING THE DAY THURSDAY. ACROSS CENTRAL              
NC...WITH HIGH PRESSURE IN CONTROL... EXPECT MOSTLY CLEAR SKIES AT              
THE BEGINNING OF THE DAY...WITH INCREASING CLOUD COVER LATER IN                 
THE AFTERNOON/EVENING IN ADVANCE OF THE APPROACHING SHORTWAVE AND               
SFC LOW. ALTHOUGH THICKNESSES ON THURSDAY ARE PROGGED TO BE ONLY                
SLIGHTLY WARMER THAN TODAY...CLEAR OR MOSTLY CLEAR SKIES ARE                    
EXPECTED THROUGH THE MORNING AND MOST OF THE AFTERNOON...AND THIS               
SHOULD ALLOW TEMPS TO REACH THE MID 50S ACROSS THE AREA.                        
DIFFICULT FORECAST ON TAP FOR THURSDAY NIGHT AND FRIDAY. BOTH THE               
GFS/NAM CONTINUE TO TAKE THE SOUTHERN STREAM WAVE AND SURFACE LOW               
SOUTH OF THE AREA. SFC RIDGING IS PROGGED TO DEVELOP IN ADVANCE OF              
THIS SYSTEM ACROSS THE CAROLINAS ON THURSDAY...WITH THE SOUTHERN                
PORTION OF THE WEDGE OVER GA/SC/NC FURTHER STRENGTHENING THU NIGHT              
AS ISENTROPIC LIFT BEGINS TO INCREASE AND PRECIP ADVANCES TOWARD THE            
AREA FROM THE SOUTHWEST. BOTH THE GFS/NAM SHOW A MILLER TYPE-B                  
SCENARIO WHERE THE INLAND SFC LOW OVER NORTHERN AL OR SOUTHERN TN               
JUMPS EAST OF THE WEDGE TO THE GA/FL COAST OR EVEN OFFSHORE FRIDAY              
MORNING. AT THIS TIME THE BEST LIFT REMAINS SOUTH OF THE AREA...AND             
LITTLE IF ANY PRECIP IS EXPECTED ACROSS CENTRAL NC. THE 00Z GFS                 
SHOWS 0.05 TO 0.10" FALLING ALONG/SOUTH OF HIGHWAY 64 BETWEEN 06-12Z            
FRIDAY MORNING...WHILE THE 00Z NAM DOES NOT GENERATE ANY MEASURABLE             
PRECIP ACROSS CENTRAL NC IN ASSOC/W THIS SYSTEM. THE SREF SHOWS LESS            
THAN 25% PROBABILITIES OF MEASURABLE PRECIP ACROSS MOST OF CENTRAL              
NC...EXCEPT ALONG THE NC/SC BORDER AND IN THE FAR WESTERN PIEDMONT              
WHERE PROBABILITIES ARE AS HIGH AS 45%.                                         
AT THIS TIME THE BEST CHANCE FOR PRECIP APPEARS TO BE ALONG THE                 
NC/SC BORDER BETWEEN 06-17Z FRIDAY...AND WILL THEREFORE CONFINE A               
LOW CHANCE (30%) OF SHOWERS TO THOSE LOCATIONS DURING THAT TIME                 
PERIOD...WITH A SLIGHT CHANCE EXTENDING NORTH TO HIGHWAY 64 AND INTO            
THE TRIAD. THE LATEST FCST SOUNDINGS SHOW THERMAL PROFILES                      
SUPPORTIVE OF ALL LIQUID PRECIP...HOWEVER...IF PRECIP ASSOC/W THE               
SYSTEM IS HEAVIER AND SPREADS FURTHER NORTH THAN ANTICIPATED...OR IF            
THE ANTECEDENT SFC RIDGING/WEDGE IS STRONGER THAN EXPECTED...P-TYPE             
PROBLEMS WOULD BE POSSIBLE...AND THIS WILL NEED TO BE MONITORED                 
CLOSELY OVER THE NEXT 24-36 HOURS. DIFFICULT LOW TEMP FORECAST                  
FRIDAY MORNING...SINCE THIS WILL DEPEND ON THE AMOUNT OF CLOUD                  
COVER...THE STRENGTH OF THE ANTECEDENT SFC RIDGING AND WHETHER OR               
NOT PRECIP IS FALLING INTO COOL/DRY AIR AT THE SURFACE. AT THIS TIME            
WILL ADVERTISE LOWER/MID 30S NORTH TO UPPER 30S SOUTH.                          
THICKNESSES ON FRIDAY ARE EXPECTED TO RANGE BETWEEN 1305-1330                   
METERS...SIMILAR TO TODAY/THU. WITH FULL SUN TEMPERATURES WOULD BE              
SIMILAR TO WHAT IS EXPECTED THURSDAY...ALTHOUGH WITH SIGNIFICANT                
CLOUD COVER TEMPERATURES WOULD BE MORE SIMILAR TO WHAT IS EXPECTED              
TODAY. AT THIS TIME...WILL TREND CLOSE TO MOS GUIDANCE...WITH HIGHS             
RANGING FROM THE MID 40S NORTH TO LOWER 50S SOUTH. LOW TEMPS FRIDAY             
NIGHT IN THE MID 30S NORTH TO LOWER 40S SOUTH. -VINCENT                         
&&                                                                              
.LONG TERM /SATURDAY THROUGH TUESDAY/...                                        
AS OF 300 AM EST... THE WEEKEND LOOKS TO BE CLOUDY AND WET. ON                  
SATURDAY BOTH THE 00Z/19 GFS AND 00Z/19 ECMWF SHOW HIGH PRESSURE                
LOCATED OVER THE EASTERN PORTION OF MAINE EXTENDING INTO THE                    
AREA. WEAK ISENTROPIC LIFT DEPICTED BY THE MODELS MAY PRODUCE SOME              
LIGHT PRECIP ON SATURDAY AND SATURDAY NIGHT. THUS...WILL CARRY A                
SLIGHT CHANCE FOR RAIN ON SATURDAY AND INCREASE THE POPS TO CHANCE              
DURING THE OVERNIGHT HOURS FROM WEST TO EAST. HIGHS SATURDAY WILL               
BE CATEGORY ABOVE NORMAL. LOWS SUNDAY MORNING WILL RUN 10 TO 15                 
DEGREES ABOVE NORMAL...AS THE HIGH PRESSURE RIDGE BEGINS TO                     
RETREAT AND WINDS BECOME SOUTHERLY IN ADVANCE OF THE FRONT.                     
A FAIRLY IMPRESSIVE UPPER LEVEL TROUGH WILL APPROACH THE AREA FROM              
THE WEST ON SUNDAY WITH A SURFACE COLD FRONT CROSSING THE AREA                  
SUNDAY AFTERNOON INTO THE EVENING. TIMING FOR THE SURFACE FRONT IS              
LOOKING BETTER AS THE THE 00Z/19 GFS AND ECMWF ARE COMING INTO                  
BETTER AGREEMENT... WITH BOTH SHOWING THE FRONT CROSSING THE AREA               
DURING THE AFTERNOON INTO THE EVENING ON SUNDAY. BOTH THE GFS AND               
ECMWF DEPICT A FAIRLY STRONG UPPER LEVEL JET ASSOCIATED WITH THIS               
SYSTEM. AT THIS TIME WE APPEAR TO BE IN THE FAVORED RIGHT ENTRANCE              
REGION OF THE JET... WHICH WOULD INCREASE LIFT AND COUPLED WITH GOOD            
SOUTHERLY FLOW IN ADVANCE OF THE SURFACE FRONT SHOULD INCREASE THE              
LIKELIHOOD OF A MORE SUBSTANTIAL RAIN EVENT. THUS...WILL INCREASE               
POPS TO 50% FOR SUNDAY AFTERNOON INTO THE EARLY EVENING ACROSS THE              
CWA. WILL LIKELY NEED TO UP POPS IN LATER FORECASTS IF THE SYSTEM               
CONTINUES TO SHOW CONSISTENCY IN THE MODELS FROM RUN TO RUN. HIGHS              
SUNDAY WILL BE WELL ABOVE AVERAGE WITH TEMPS RANGING FROM THE                   
UPPER 50S NORTHWEST TO THE UPPER 60S IN THE SOUTHEAST. LOWS MONDAY              
WILL RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S IN THE EAST.               
MONDAY WILL BE NOTICEABLY COOLER AS HIGH PRESSURE BUILDS INTO THE               
REGION AT THE SURFACE. HOWEVER...HIGH TEMPS WILL STILL BE NEAR                  
NORMAL FOR THIS TIME OF YEAR.                                                   
MODELS BEGIN TO DIVERGE IN THEIR SOLUTIONS BEYOND MONDAY...AS THE               
00Z/19 GFS BRINGS A UPPER LEVEL SHORTWAVE ACROSS THE REGION ON                  
TUESDAY...WHILE THE 00Z/19 ECMWF DEVELOPS A CUT OFF UPPER LEVEL                 
LOW OVER NORTHERN PORTIONS OF THE GULF COAST STATES. THUS...WITH                
MODEL DIFFERENCES AT THIS TIME WILL STICK CLOSE TO CLIMATOLOGY AND              
KEEP ANY MENTION OF PRECIP OUT OF THE FORECAST FOR NOW. -BSD                    
&&                                                                              
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...                                     
AS OF 1230 AM WEDNESDAY...VFR CONDITIONS ARE EXPECTED THROUGH THE               
TAF PERIOD. A WEAK SHORTWAVE WILL APPROACH CENTRAL NORTH CAROLINA               
THIS MORNING UNDER FAST ZONAL FLOW ALOFT. THIS SHORTWAVE IS                     
ALREADY PRODUCING A DECK OF CLOUDS WITH BASES BETWEEN 4-5 KFT                   
ACROSS TN/AL/MS/GA. THIS MOISTURE WILL SPREAD ACROSS THE REGION                 
LATER THIS MORNING...WITH SKIES LIKELY GOING BROKEN AT GSO/INT                  
BETWEEN 12-13Z...AND A FEW HOURS LATER AT RDU/FAY/RWI. CEILINGS                 
SHOULD STAY VFR...AVERAGING 5 KFT. THIS DECK SHOULD BEGIN TO                    
SCATTER OUT IN THE AFTERNOON...WITH SKIES BECOMING MOSTLY CLEAR IN              
THE EVENING.                                                                    
MVFR TO IFR CONDITIONS ARE POSSIBLE WITH A STORM SYSTEM PASSING JUST            
SOUTH OF THE AREA THURSDAY NIGHT...PRIMARILY AT FAY WITH THE BEST               
MOISTURE STAYING SOUTH OF GSO/INT/RDU/RWI. ISENTROPIC LIFT WILL                 
INCREASE BY SATURDAY MORNING AS LOW LEVEL RIDGING MOVES OFFSHORE IN             
ADVANCE OF A STRENGTHENING STORM SYSTEM OVER THE CENTRAL U.S. MVFR              
TO IFR CONDITIONS WILL BE POSSIBLE DURING THIS TIME. THIS STORM                 
SYSTEM WILL PUSH A COLD FRONT THROUGH CENTRAL NORTH ON                          
SUNDAY...RESULTING IN A GOOD LIKELIHOOD OF SHOWERS ALONG WITH                   
OCCASIONALLY MVFR TO IFR CONDITIONS. -BSD                                       
&&                                                                              
.RAH WATCHES/WARNINGS/ADVISORIES...                                             
NONE.                                                                           
&&                                                                              
$$                                                                              
SYNOPSIS...VINCENT                                                              
NEAR TERM...VINCENT                                                             
SHORT TERM...VINCENT                                                            
LONG TERM...BSD                                                                 
AVIATION...BSD                                                                  
</pre> nc                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GRAND FORKS ND                                         
930 AM CST THU DEC 20 2007                                                      
.SHORT TERM...                                                                  
ONCE AGAIN TEMPERATURES AND FOG CONTINUE BE FORECAST CHALLENGES FOR             
REMAINDER OF DAY. PATCHY BR...LOCALLY DENSE...PERSISTS FROM RED                 
RIVER VALLEY INTO NW MN. ASSOCIATED STRATUS DECK LOOKS TO BE                    
EXPANDING ACROSS NW MN AND BEING TRAPPED UNDER SHARP INVERSION MAY              
BE TOUGH TO ERODE. WILL AGAIN EXTEND BR THROUGH AM HOURS AND HOPE               
INCREASING MIXING WILL DISSIPATE MOST FOG. REMAINDER OF FA SHOULD               
SEE FAIR AMOUNT OF SOLAR WITH ONLY UPSTREAM SCT-BKN CI/AC.                      
TEMPERATURES WILL ALSO POSE CHALLENGES.  COLDEST READINGS THIS AM               
WEST OF VALLEY WHERE SKIES WERE CLEAR. WEAK WARM ADVECTION CONTINUES            
TODAY WITH RUC INDICATING AN INCREASE IN MIXING AS SURFACE GRADIENT             
TIGHTENS A BIT. WITH WARM COLUMN AND SOLAR WESTERN AREAS SHOULD NOT             
HAVE ANY PROBLEM REACHING FORECAST HIGHS. MAX TEMPERATURES OVER                 
REMAINDER OF FA UNDER BR AND STRATUS WILL HINGE ON MIXING/SOLAR.                
BEING PESSIMISTIC AREAS ADJACENT TO VALLEY IN NW/WEST CENTRAL MN MAY            
SEE LIMITED RECOVERY WITH FAR EAST ALREADY CLOSE TO EXPECTED HIGHS              
BUT NOT LIKELY TO SEE MUCH IMPROVEMENT IN LOW CIGS. WILL LOWER MAX              
TEMPERATURES SLIGHTLY ACROSS MN ADJACENT TO VALLEY AND LEAVE                    
REMAINDER AS IS.                                                                
&&                                                                              
.AVIATION...                                                                    
IFR/MVFR CIGS/VSBY FROM VALLEY EAST. MODELS SUGGEST INCREASED MIXING            
WHICH MAY IMPROVE VSBYS IN BR LATE AM INTO EARLY AFTERNOON. NOT                 
QUITE AS CONFIDENT IN LOSING LOWER CIGS OVER MN. MOISTURE REMAINS               
TRAPPED BLO SHARP INVERSION AND CONFIDENCE NOT REAL HIGH ON CIGS                
ERODING.                                                                        
&&                                                                              
.FGF WATCHES/WARNINGS/ADVISORIES...                                             
ND...NONE.                                                                      
MN...NONE.                                                                      
&&                                                                              
$$                                                                              
VOELKER                                                                         
</pre> nd                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE WILMINGTON OH                                          
1019 AM EST WED DEC 19 2007                                                     
.SYNOPSIS...                                                                    
A WEAK COLD FRONT WILL PASS ACROSS THE REGION TODAY...WASHING OUT               
SOUTH OF THE OHIO RIVER THIS EVENING. HIGH PRESSURE WILL THEN BUILD             
INTO THE AREA THROUGH THURSDAY MORNING...FOLLOWED BY A WEAK UPPER               
LEVEL SHORTWAVE WHICH WILL PASS SOUTH OF THE REGION THURSDAY                    
NIGHT.                                                                          
&&                                                                              
.NEAR TERM /UNTIL 6 PM THIS EVENING/...                                         
COMPLICATED NEAR TERM FORECAST. A WEAK COLD FRONT WILL CONTINUE TO              
PASS ACROSS THE REGION THROUGH THIS AFTERNOON. AS IT DOES...SFC                 
TEMPS WILL ACTUALLY WARM SOME ACRS THE SE CWFA...BUT COOL OR                    
REMAIN STEADY ACRS THE REMAINDER OF THE REGION. WILL USED A BLEND               
OF THE LATEST RUC AND NAM-WRF FOR TEMPERATURES THROUGH THIS                     
EVENING. SKIES SHOULD REMAIN MOSTLY CLOUDY. ZONES/GRIDS WILL BE                 
ISSUED SOON.                                                                    
&&                                                                              
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...                         
AS THERMAL TROUGH PUSHES OFF TO THE EAST OVERNIGHT...SHOULD                     
SEE AT LEAST SOME PARTIAL CLEARING WORK ITS WAY ACROSS OUR AREA FROM            
THE WEST.                                                                       
SFC HIGH WILL SHIFT EAST OF THE REGION THURSDAY MORNING WHICH                   
BRINGS RETURN FLOW AND A WARM UP...ESPECIALLY ACROSS THE SRN HALF               
OF THE CWA. WEAK H5 SHORTWAVE STILL PROGGED TO PASS SOUTH OF THE                
REGION THURS NIGHT. BEST FORCING AND PRECIP CHANCES WILL REMAIN                 
WELL SOUTH OF THE CWA. BUT WITH A LITTLE BIT OF H8 MOISTURE                     
SKIRTING THE SOUTHERN TIER OF COUNTIES IN WEAK WAA REGIME...A FEW               
STRAY SHRA OR SPRINKLES MAY MAKE IT INTO FAR SRN PORTIONS OF THE                
CWA. OTHERWISE...EXPECT DRY WEATHER AND A CONTINUED WARMING TREND               
TO CONTINUE INTO FRI AND FRI NIGHT AS UPPER RIDGE BUILDS                        
OVERHEAD...AND RETURN SRLY FLOW CONTINUES AHEAD OF WEEKEND SYSTEM.              
&&                                                                              
.LONG TERM /SATURDAY THROUGH TUESDAY/...                                        
MAIN FOCUS THIS PERIOD IS A STRENGTHENING STORM SYSTEM FORECAST TO              
PASS THROUGH THE REGION SATURDAY NIGHT. MODELS SLOWLY TRENDING                  
TOWARD A CONSENSUS...KEEPING THE UPPER WAVE MORE AMPLIFIED ACROSS               
THE WRN US BEFORE IT PHASES WITH NRN STREAM ENERGY OVER THE GREAT               
LAKES LATE ON SATURDAY. THIS BRINGS THE SFC LOW TRACK A BIT                     
FURTHER SOUTH AND EAST...BUT STILL KEEPS OUR CWA WARM SECTORED                  
UNTIL FRONTAL PASSAGE SAT NIGHT WHICH MEANS A RAIN EVENT AREAWIDE.              
GIVEN GOOD RUN TO RUN CONTINUITY...BELIEVE LIKELY POPS ARE                      
WARRANTED ALONG AND AHEAD OF THE FRONT. GFS FORECAST SOUNDINGS                  
INDICATE SEASONABLY STRONG ELEVATED INSTABILITY (NR 1000 J/KG) SO               
THUNDER IS A POSSIBILITY SAT NIGHT. HOWEVER...WILL WAIT FOR BETTER              
RUN TO RUN CONSISTENCY BEFORE INTRODUCING LATE DECEMBER                         
THUNDERSTORMS. THOUGH MOST PRECIP SHOULD BE PRE-FRONTAL...ANY                   
LINGERING MOISTURE WOULD MIX WITH AND CHANGE TO SNOW HEADING INTO               
SUN MORNING. LITTLE IF ANY SNOW ACCUM. TEMPS SHOULD BE SLOW                     
TO WARM ON SUNDAY WITH STRONG CAA BEHIND THE FRONT.                             
NO OTHER MAJOR SYSTEMS EXPECTED TO IMPACT THE REGION THROUGH                    
CHRISTMAS DAY SO FORECAST IS DRY INTO EARLY NEXT WEEK. LARGE SCALE              
TROUGHING ACROSS THE EASTERN HALF OF THE COUNTRY SHOULD KEEP TEMPS              
BELOW AVG.                                                                      
&&                                                                              
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...                                     
CLOUD DECK HAS DROPPED TO MVFR ACROSS MUCH OF THE AREA THIS                     
MORNING AND CLOUDS HAVE BEEN SLOWLY FILLING IN BACK TO OUR WEST                 
ACROSS EASTERN INDIANA. COMBINATION OF THIS AND THE FACT THAT THE               
925-850 MB THERMAL TROUGH WILL BE PIVOTING ACROSS THE AREA                      
THROUGH EARLY AFTERNOON...SHOULD KEEP MVFR CIGS THROUGH MUCH OF                 
THE AFTERNOON AND INTO EARLY EVENING. AS THERMAL TROUGH PUSHES OFF              
TO THE EAST AND LOW LEVEL FLOW BEGINS TO BACK...EXPECT CLOUDS TO                
ERODE FROM SOUTHWEST TO NORTHEAST ACROSS OUR AREA TONIGHT.                      
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE SATURDAY                      
AFTERNOON INTO SUNDAY.                                                          
&&                                                                              
.ILN WATCHES/WARNINGS/ADVISORIES...                                             
OH...NONE.                                                                      
KY...NONE.                                                                      
IN...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...HICKMAN                                                              
NEAR TERM...HICKMAN                                                             
SHORT TERM...HAWBLITZEL/JGL                                                     
LONG TERM...HAWBLITZEL                                                          
AVIATION...JGL                                                                  
</pre> oh                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC                              
1010 PM EST THU DEC 20 2007                                                     
.SYNOPSIS...                                                                    
WEAK HIGH PRESSURE WILL GIVE WAY TO AN AREA OF LOW PRESSURE TONIGHT.            
COOL AND UNSETTLED NORTHEAST FLOW WILL REMAIN INTO THE WEEKEND AS A             
WEDGE OF HIGH PRESSURE LINGERS. A COLD FRONT IS EXPECTED TO CROSS               
THE AREA ON SUNDAY.                                                             
&&                                                                              
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...                                       
MOST OF THE SIGNIFICANT PRECIPITATION DURING THE REMAINDER OF THE               
OVERNIGHT PERIOD WILL REMAIN WELL TO THE SOUTH OF THE CWA IN THE                
VICINITY OF THE SURFACE LOW PRESSURE SYSTEM MOVING EASTWARD ALONG               
THE GULF COAST TOWARD NORTHERN FL.  RUC DEPICTS SOME LIGHT RAIN                 
SPREADING ACROSS EXTREME NORTHEAST GA AND WESTERN CAROLINAS BETWEEN             
05Z AND 08Z AS SHORT WAVE TROUGH APPROACHES AND ISENTROPIC LIFT                 
STRENGTHENS A LITTLE OVER SOUTHERN PERIPHERY OF HIGH PRESSURE SYSTEM            
EXTENDING SOUTHWARD FROM EASTERN CANADA AND NEW ENGLAND.  OVERNIGHT             
FORCING IS RATHER WEAK AND CURRENT RADAR DEPICTION SHOWS THAT                   
EXISTING PRECIPITATION IS NOT EXTENSIVE IN COVERAGE.  SO... HAVE                
LOWERED POPS SOMEWHAT FROM PREVIOUS FORECAST BUT MOST OF CWA WILL               
STILL HAVE LIKELY OR CATEGORICAL.                                               
&&                                                                              
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...                     
AS OF 200 PM THURSDAY...PRECIPITATION FROM SOUTHERN STREAM SHORT WAVE           
AND ATTENDANT SURFACE LOW WILL BE AFFECTING THE FORECAST AREA FRIDAY            
MORNING. HOWEVER...EXPECT RAINFALL TO BE ON THE LIGHT SIDE AS BEST              
FORCING WILL BE TO THE SOUTH. ALSO...EXPECT THAT CONVECTION TO THE              
SOUTH WILL ROB MOISTURE INFLUX. NEVERTHELESS...IT LOOKS LIKE                    
WIDESPREAD LIGHT RAIN (CATEGORICAL POPS) WILL BE OVER THE SOUTHERN              
PIEDMONTS EARLY FRIDAY...BUT WILL TAPER POPS OFF RAPIDLY TO THE                 
NORTH. THIS SYNOPTIC SCALE PRECIP WILL MOVE OUT THE REGION BY MIDDAY            
AS SHORT WAVE MOVES OFF THE SE COAST. HOWEVER...NO CLEARING IS                  
EXPECTED AS COLD HIGH OVER NEW ENGLAND WEDGES SOUTHWARD ALONG AND               
EAST OF THE APPALACHIANS. MODELS INDICATE THAT CAD WILL PERSIST                 
THROUGH SAT ALONG WITH WEAK UPSLOPE COMPONENT IN THE MOUNTAINS..                
HENCE...EXPECT CLOUDY CONDITIONS TO PREVAIL THROUGH SAT. AREAS OF               
LIGHT RAIN/DRIZZLE ARE A GOOD BEST ALONG THE ESCARPMENT THROUGH SAT.            
PATCHY DRIZZLE A GOOD BET ELSEWHERE FRI NIGHT. BETTER UPSLOPE                   
COMPONENT AND MOISTURE TRANSPORT WILL SUPPORT INCREASING CHANCES OF             
RAIN...ESPECIALLY OVER THE MOUNTAINS SAT NIGHT. APPROACHING COLD                
FRONT LATE SAT NIGHT WILL ALSO BOOST PRECIP CHANCES IN THE                      
MOUNTAINS. WILL STAY ON THE LOW END OF GUIDANCE FOR MAX TEMPS BOTH              
FRI AND SAT. TEMPS WILL PROBABLY SHOW A NON-DIURNAL TREND SAT NIGHT             
AS CAD ERODES AND WARM ADVECTION KICKS IN. USED 3 HOURLY GMOS TO                
POPULATE TEMPERATURE GRIDS WHICH KEEPS SAT NIGHT LOWS ESSENTIALLY               
IN THE UPPER 40S EAST OF THE MOUNTAINS AND LOW TO MID 40S IN                    
MOUNTAINS.                                                                      
&&                                                                              
.LONG TERM /SUNDAY THROUGH THURSDAY/...                                         
AS OF 230 PM THURSDAY...NAM/GFS IN GOOD AGREEMENT THAT COLD FRONT               
WILL CROSS THE FORECAST AREA ON SUNDAY. HIGHEST POPS WILL BE IN THE             
MOUNTAINS (LIKELY FOR NOW) WITH CHANCE POPS TO THE EAST. THERE MAY              
BE ENOUGH FORCING FOR WIDESPREAD SHOWERS EVERYWHERE...BUT FOR NOW WILL          
JUST SHOW CHANCE TYPE POPS TO EAST OF THE MOUNTAINS AS FLOW DOES                
VEER TO THE SW WHICH MAY TEND TO DIMINISH SHOWER CHANCES E OF                   
MOUNTAINS. EXPECT RAPID CLEARING BEHIND THE FRONT BY SUN EVENING.               
HIGH PRESSURE WILL BUILD OVER THE REGION ON MONDAY WHICH SHOULD                 
PRODUCE A VERY NICE DAY. SUNDAY AND MONDAY LOOK TO BE MILD WITH                 
TEMPS ONE TO TWO CATEGORIES ABOVE NORMAL. THINGS GET MURKY RATHER               
QUICKLY AFTER MONDAY AS THE MEDIUM RANGE GUIDANCE CONTINUES TO BE IN            
FLUX. THE ECWMF AND GFS SOLUTIONS ARE QUITE DIFFERENT FOR CHRISTMAS             
ONWARD. AFTER CONSULTATION WITH NEIGHBORING OFFICES...IT WAS                    
DETERMINED THAT HPC GUIDANCE WOULD BE UTILIZED WHICH LEANS HEAVILY              
ON THE ECWMF SOLUTION. THIS SOLUTION BRINGS A SHORT WAVE ACROSS THE             
AREA ON TUE WITH CYCLOGNESIS ALONG THE COAST. THIS WOULD SPARE THE              
SOUTHERN APPALACHIANS FROM MUCH IN THE WAY OF SIGNIFICANT PRECIP.               
MAYBE JUST SOME WIDELY SCATTERED/SCATTERED SHOWERS (POSSIBLY MIXED              
WITH SNOW AT HIGHER ELEVATIONS IN MOUNTAINS). THEN A DRY DAY                    
WEDNESDAY. THE BEST THREAT FOR PRECIP THEN BECOMES THURSDAY AS A                
COLD FRONT APPROACHES FROM THE W.                                               
GFS ON THE OTHER HAND DEVELOPS A SWATH OF OVERRUNNUNG PRECIP OVER               
THE FORECAST AREA BY LATE TUE USING THE OLD BOUNDARY TO THE S. IT               
KEEPS THIS SWATH OF MOISTURE/PRECIP ACROSS THE REGION INTO THU ALONG            
THE STATIONARY FRONT...WITH A SOUTHERN STREAM LOW THEN EJECTING NE              
DURING THU TO THE W OF APPALACHIANS. HOPEFULLY WE WILL GET BETTER               
AGREEMENT AS WE DRAW CLOSER.                                                    
&&                                                                              
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...                                       
CEILINGS WILL LOWER INTO MVFR RANGE AS WARM ADVECTION/ISENTROPIC                
LIFT OVER SOUTHERN PERIPHERY OF DAMMING HIGH STRENGTHENS THROUGH THE            
NIGHT.  THERMAL ADVECTION AND LIFT... PLUS A LITTLE HELP FROM WEAK              
UPSLOPE WIND COMPONENT... APPEAR TO BE PROMOTING DEVELOPMENT OF RAIN            
AREA FROM UPSTATE SC INTO WESTERN NC.  HOWEVER... PRIMARY AREA OF               
PRECIPITATION OVERNIGHT LIKELY TO REMAIN WELL TO OUR SOUTH NEAR                 
SURFACE LOW THAT WILL MOVE STEADILY EASTWARD.  BY 06Z TO 08Z...                 
EXPECT SOME IFR CEILINGS AND VISIBILITIES TO APPEAR AS ISENTROPIC               
LIFT NEARS ITS MAXIMUM... BUT PRECIPITATION SHOULD REMAIN RATHER                
LIGHT.  IFR AND LOW MVFR CEILING AND VISIBILITY WILL IMPROVE                    
SOMEWHAT BETWEEN 15Z AND 18Z AS STRONGEST FORCING FOR PRECIPITATION             
EXITS THE REGION... BUT MVFR CEILING WILL CONTINUE.                             
AVIATION OUTLOOK...CIG AND VSBY RESTRICTIONS ARE EXPECTED THROUGH               
SUNDAY AS MOISTURE LINGERS IN THE PERSISTENT COLD AIR DAMMING                   
REGION. A COLD FRONTAL PASSAGE SHOULD SCOUR THE COLD WEDGE BY MON               
WITH COOL HIGH PRESSURE BUILDING IN BEHIND IT.                                  
&&                                                                              
.GSP WATCHES/WARNINGS/ADVISORIES...                                             
GA...NONE.                                                                      
NC...NONE.                                                                      
SC...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...BSH                                                                  
NEAR TERM...LGL                                                                 
SHORT TERM...LG                                                                 
LONG TERM...LG                                                                  
AVIATION...LGL                                                                  
</pre> sc                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ABERDEEN SD                                            
817 PM CST WED DEC 19 2007                                                      
.UPDATE...                                                                      
LATEST RUC SOUNDINGS...COMBINED WITH NAM12 925MB COND PRES DEF                  
PLOTS...SHOW THAT FOG IS A POSSIBILITY TONIGHT ACROSS THE CWA. BY               
0215UTC...KETH IS AT 5SM BR...WITH KABR AT 4SM BR. HAVE UPDATED WX              
GRIDS TO REFLECT FOG THROUGH 14Z. BASED ON DWPTS...CURRENT LOWS                 
LOOK OK...ALTHO MAY BE A TAD TO LOW IN THE JAMES RIVER                          
VALLEY...BUT WILL LEAVE AS IS FOR NOW. UPDATED ZONES HAVE BEEN                  
SENT.                                                                           
UPDATED AVIATION DISCUSSION BELOW.                                              
&&                                                                              
.PREV DISCUSSION...                                                             
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT                                    
MAIN CHALLENGE IN THE SHORT TERM IS TEMPERATURES. A WEAK UPPER                  
LEVEL TROUGH WILL SLIDE ACROSS THE PLAINS TONIGHT. THE UPPER FLOW               
BECOMES NEARLY ZONAL ON THURSDAY...THEN SHIFTS TO SOUTHWESTERLY AS              
A STRONG TROUGH DIGS DOWN THE WEST SIDE OF THE ROCKIES. AT THE                  
SURFACE...A TROUGH/WARM FRONT ASSOCIATED WITH LOW PRESSURE OVER                 
SOUTHWEST CANADA SLIDES ACROSS THE CWA TONIGHT. GFS HINTING AT SOME             
FLURRIES POSSIBLE ACROSS THE NORTHEASTERN CWA...BUT CLOUD BASES                 
WILL BE PRETTY HIGH AND HAVE OPTED TO NOT MENTION THEM. THE                     
SOUTHWEST CANADA LOW TRACKS TO SOUTHERN SASK ON THURSDAY...THEN                 
ELONGATES OVER THE NORTHERN AND CENTRAL PLAINS THURSDAY NIGHT WITH              
A COLD FRONT JUST APPROACHING THE WESTERN CWA BY FRIDAY MORNING.                
EXPECT A PERIOD OF MOSTLY CLEAR SKIES TONIGHT...THEN WILL SEE MORE              
MID TO HIGH CLOUDS PUSH IN THURSDAY AHEAD OF THE APPROACHING LOW                
PRESSURE SYSTEM. NO SIGNIFICANT ENERGY OR MOISTURE AROUND...SO                  
WILL LEAVE THE SHORT TERM DRY.                                                  
MILD TEMPERATURES WILL CONTINUE WITH H85 TEMPS STAYING ABOVE ZERO               
THROUGH LATE THURSDAY NIGHT. EXPECT LOWS TONIGHT AND THURSDAY TO                
BE IN THE TEENS WITH THURSDAY HIGHS A GOOD CATEGORY OR TWO ABOVE                
NORMAL.                                                                         
.LONG TERM...FRIDAY MORNING THROUGH THURSDAY                                    
LOTS TO DISCUSS CONCERNING PROGRESSION OF WEATHER DURING THE                    
WEEKEND AND THE FIRST HALF OF NEXT WEEK. WILL BEGIN WITH A WINTER               
STORM...FOLLOWED BY A RAPID TEMPERATURE DROP IN THE WAKE OF THE                 
SYSTEM...A RETURN TO WARMER TEMPERATURES...AND END WITH A WEAK                  
WEATHER SYSTEM LATE IN THE PERIOD.                                              
UPPER TROUGH SET UP ACROSS THE FRONT RANGE WITH AN INTENSE UPPER                
LOW DROPPING SOUTHWARD ACROSS THE NORTHERN CWA SATURDAY AM. THIS                
DEVELOPS STRONG BAROCLINIC FLOW ACROSS THE SOUTHEASTERN CWA. DECENT             
CONTINUITY EXISTS BETWEEN GFS/GFS ENSEMBLE AND ECMWF RUNS IN                    
TIMING OF SYSTEM THOUGH EARLY SATURDAY. SOLUTIONS DIVERGE LATE                  
SATURDAY...WITH ECMWF SLOWER THAN GFS/GFS ENSEMBLES. AS FOR POP                 
TOTALS...ENSEMBLES DEPICT MAJORITY OF LIQUID IS IN THE NORTHEAST                
AND SOUTH CENTRAL CWA...ACCUMULATING AFTER FRIDAY AFTERNOON. WITH SLOWER        
ECMWF SOLUTION WOUND NOT BE SURPRISED TO SEE LINGERING SNOW                     
SHOWERS THROUGH EARLY SATURDAY. SNOW ACCUMLATIONS BETWEEN 1 TO 3                
INCHES THE MOST LIKELY OUTCOME.                                                 
WILL CONTINUE TREND FOR ANOMALOUSLY WARM TEMPERATURES WITH H925                 
LAYER ABOVE FREEZING FOR THE START OF THE PERIOD. CAA REGIME                    
DEVELOPS WELL BEHIND PASSAGE OF WEAK TROUGH FRIDAY...AND PERSIST                
INTO SUNDAY AM. ONCE COLD BUBBLE AT H925 DRIFTS INTO                            
MINNESOTA...WILL SEE WEAK WAA DEVELOP BY SUNDAY AM. NOT EXPECTING               
THIS TO ALLOW FOR DRASTIC WARM UP IN THE JAMES VALLEY WITH WEAK                 
GRADIENT AND SOUTHERLY FLOW NEAR THE SURFACE...ALONG WITH ADDED                 
SNOWFALL FROM THE WEEKEND. THE WESTERN CWA WILL SET UP FOR WARMER               
TEMPERATURES AS SNOW COVER IS EXPECTED TO REMAIN THIN AND WITH A                
SOUTHWESTERLY FLOW.                                                             
CONCERNING A MID WEEK WEATHER SYSTEM. NORMALLY WOULD NOT EVEN                   
INCLUDE SAVE FOR THE CONTINUITY BETWEEN GFS AND ECMWF                           
DETERMINISTIC RUNS AS WELL AS GFS ENSEMBLE MEMBERS BRINGING A SHORTWAVE         
THOUGH THE CWA. WILL LIMIT MENTION TO SLIGHT CHANCE OF                          
PRECIPITATION FOR NOW.                                                          
&&                                                                              
.AVIATION...                                                                    
MVFR CIGS/VSBYS POSSIBLE FROM 03Z TO 14Z FOR KABR AND KATY TAF                  
SITES AS FOG IS EXPECTED TO DEVELOP AND/OR IS CURRENTLY                         
DEVELOPING. P6SM/SKC CONDS EXPECTED THROUGH 18Z FOR KPIR AND KMBG               
TAF LOCATIONS.                                                                  
&&                                                                              
.ABR WATCHES/WARNINGS/ADVISORIES...                                             
SD...NONE.                                                                      
MN...NONE.                                                                      
&&                                                                              
$$                                                                              
UPDATE...HINTZ                                                                  
SHORT TERM...PARKIN                                                             
LONG TERM...CONNELLY                                                            
AVIATION...HINTZ                                                                
WEATHER.GOV/ABERDEEN                                                            
</pre> sd                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX                                      
826 PM CST THU DEC 20 2007                                                      
.UPDATE...THE NAM/GFS DETERMINISTIC SOLNS PROGD 00Z FRI SFC DEW                 
POINTS 5-10C DEGRESS GREATER THAN METAR VALUES. THE LOCAL MM5                   
PROGD THE LOWEST 00Z FRI SFC DEW POINTS OVR THE NERN CWFA...                    
INCONSISTENT WITH THE 00Z FRI OBSERVATIONS. YET...THE RUC SOLN                  
PERFORMED MUCH BETTER IN THIS RESPECT...AND THUS MORE CONFIDENT IN              
THIS SOLN. HWR...ALTHOUGH THE RUC PROGS 12Z FRI SFC TEMPS HIGHER                
THAN THE CURRENT FCST...WL DEFER TO THE CURRENT FCST. ANTICIPATE                
THAT LIGHT WIND/EXTREMELY DRY CONDITIONS/DECOUPLING CONDITIONS WL               
ALLOW FOR SFC TEMPS TO MOVE CLOSER TO THE SFC DEW POINTS. THUS...               
WL RETAIN THE CURRENT TEMP FCST. CAVEAT...THE NAM/GFS PROG WEAK                 
ONSHORE WIND AFT 09Z FRI...WHICH COULD RESULT IN HIGHER MIN TEMPS               
OVR THE COASTAL COUNTIES.                                                       
&&                                                                              
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD.                       
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
CORPUS CHRISTI    83  45  80  63  77  /   0   0   0  10  10                     
VICTORIA          81  43  78  58  72  /   0   0   0  20  20                     
LAREDO            82  45  84  56  75  /   0   0   0   0  10                     
ALICE             84  43  83  59  77  /   0   0   0  10  10                     
ROCKPORT          82  49  76  63  75  /   0   0   0  20  20                     
COTULLA           81  41  81  53  72  /   0   0   0   0  10                     
KINGSVILLE        84  43  82  61  79  /   0   0   0  10  10                     
NAVY CORPUS       82  50  78  65  76  /   0   0   0  10  10                     
&&                                                                              
.CRP WATCHES/WARNINGS/ADVISORIES...                                             
TX...NONE.                                                                      
GM...NONE.                                                                      
&&                                                                              
$$                                                                              
WC/87...SHORT TERM                                                              
JR/19...AVIATION                                                                
</pre> tx                                                                       

AREA FORECAST DISCUSSION...UPDATED                                              
NATIONAL WEATHER SERVICE LA CROSSE WI                                           
927 PM CST THU DEC 20 2007                                                      
.UPDATE...                                                                      
LATEST RUC SOUNDINGS INDICATE LOW LEVEL MOISTURE DEPTH TO DECREASE              
FROM WEST TO EAST TONIGHT ACROSS THE AREA. SO GREATEST THREAT FOR               
FZDZ LOOKS TO REMAIN TO THE EAST OF THE MISSISSIPPI RIVER. RADAR                
RETURNS OVER THE PAST HOUR HAVE BEEN DIMINISHING ACROSS THE EASTERN             
COUNTIES...BUT CALLS STILL INDICATE VERY LIGHT RAIN/DRIZZLE/FREEZING            
DRIZZLE STILL OCCURRING WITH MOST OF THE SUB-FREEZING TEMPERATURES              
FOUND NORTH OF HIGHWAY 29. VISIBILITIES HAVE HELD UP IN THE ONE                 
HALF TO ONE MILE RANGE ACROSS THE NORTHERN HALF OF THE DENSE FOG                
ADVISORY AREA FOR MOST OF THE EVENING. BUT ACROSS NORTHEAST IOWA ONE            
QUARTER OR LESS IS BEING REPORTED. WITH CONTINUED SOUTHEAST FLOW                
STILL EXPECT WIDESPREAD DENSE FOG ACROSS THE WESTERN ZONES                      
OVERNIGHT AND INTO FRIDAY MORNING. ALL IN ALL GRIDS LOOKS TO BE IN              
GOOD SHAPE AND PLAN NO MAJOR CHANGES TO ONGOING FORECAST.                       
&&                                                                              
JLR                                                                             
.PREV DISCUSSION...                                                             
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT                                      
FORECAST CONCERNS THIS PACKAGE...DENSE FOG/DZ/FZDZ TONIGHT...                   
POTENTIAL WINTER STORM CENTERED ON SAT/SAT NIGHT.                               
DATA ANALYSIS AT 18Z HAD ONE LOW PRESSURE CENTERED OVER ALB AND                 
A WEAKER ONE OVER THE LA/AR AREA. BROAD SOUTH/SOUTHEAST FLOW AHEAD              
OF THESE LOWS WAS PUSHING WARM/MORE MOIST AIR NORTH INTO THE REGION.            
DEW POINTS INTO THE UPPER 20S/LOW 30S ACROSS MUCH OF IA/SOUTHERN                
WI/NORTHERN IL. FOG-PRODUCT/VIS IMAGERY/SFC OBS SHOWING LOW STRATUS             
DECK ADVECTING/EXPANDING NORTH ACROSS AREA ALONG AND EAST OF I-35.              
VSBYS ALREADY LESS THAN 2SM IN FOG OVER THE WEST HALF OF THE                    
FORECAST AREA AS THE INCREASING MOIST AIRMASS IS ADVECTED NORTH OVER            
THE SNOW COVERED LANDSCAPE. EARLY AFTERNOON TEMPS IN THE LOW/MID                
30S...ADDING TO THE BOUNDARY LAYER MOISTURE WITH SOME MELTING SNOW.             
NO MAJOR ERRORS NOTED WITH 20/12Z NAM/GFS INITIALIZATIONS...WITH                
SOLUTIONS MORE SIMILAR TO EACH OTHER THAN THEIR RUNS OF 12 AND 24HRS            
AGO. GFS TRENDING TOWARD THE STRONGER...MORE PHASED ECMWF/UKMET/NAM             
SOLUTIONS WITH THE TROUGH AS IT LIFTS THRU THE UPPER MIDWEST SAT/               
SUN. NAM STILL THE STRONGEST...WITH GFS/ECMWF/UKMET OFFERING A                  
RATHER GOOD CONSENSUS AT THE SFC/500MB AT 12Z SUN. DPROG/DT OF 500MB            
HGTS AT 20/12Z SHOWED NAM/GFS RUNS OF 18/12Z AND 19/12Z VERIFIED                
REASONABLY WELL ACROSS NOAM/EASTERN PAC. MODELS HAVE TRENDED TOWARD             
THE STRONGER LOOK OF NAM WITH THE ENERGY OFF THE CA COAST WHILE                 
TRENDING TOWARD THE GFS WITH THE NORTHERN STREAM ENERGY OVER BC.                
THRU 36HRS...NAM SHOWS THE BETTER RUN-TO-RUN CONSISTENCY WIT THE                
SOUTHERN STREAM ENERGY INTO AZ/NM WHILE GFS SHOWS THE BETTER                    
CONSISTENCY WITH THE NORTHERN STREAM ENERGY INTO MT/SASKAT. FOR 36-             
84HRS MODELS HAVE CONVERGED ON A COMMON SOLUTION WITH THE SOUTHERN              
STREAM ENERGY LIFTING TO MO/AR WHILE CONSIDERABLE DIFFERENCE STILL              
REMAIN WITH THE NORTHERN STREAM/DEVELOPING UPPER LOW OVER THE                   
NORTHERN PLAINS/WESTERN GREAT LAKES. TREND IS TOWARD ECMWF IN THIS              
TIME-FRAME...WITH 20/00Z ECMWF OFFERING A REASONABLE COMPROMISE OF              
LATEST NAM/GFS SOLUTIONS AT 60/72HRS AS NORTHERN/SOUTHERN STREAM                
PHASE. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED NAM/GFS REASONABLE             
WITH THE SFC MASS FIELDS ACROSS CENTRAL NOAM. PER WV IMAGERY...                 
MODELS LOOK TO HAVE GOOD DEPICTIONS OF THE SHORTWAVE FEATURES OVER              
NOAM/EASTERN PAC...WITH A MODEL COMPROMISE PERHAPS A BIT BETTER                 
THAN EITHER NAM/GFS ALONE. GOOD DARKENING SEEN IN WV IMAGERY WITH               
THE SHORTWAVE COMING ON THE CA COAST. WITH ALL THE MODEL VARIABILITY            
OF LATE AND 18Z DATA TENDING TO SUPPORT A MODEL COMPROMISE...PREFER             
THAT SOLUTION THIS CYCLE. GIVEN DEPENDENCE OF FORECAST ON NUANCES               
OF NORTHERN/SOUTHERN STREAM PHASING...SHORT-TERM FORECAST CONFIDENCE            
AVERAGE AT BEST.                                                                
FOR THE SHORT TERM...SOUTH/SOUTHEAST WINDS TONIGHT WILL CONTINUE TO             
ADVECT MOISTURE NORTHWARD ACROSS THE AREA...OVER THE SNOW PACK AND              
UNDER AN INVERSION NEAR 850MB. WITH VSBYS ALREADY LOW AND THE                   
CONTINUED LOADING OF THE SUB-INVERSION LAYER WITH MOISTURE...WILL               
ISSUE A DENSE FOG ADVISORY FOR TONIGHT INTO FRI MORNING FOR AREAS               
WEST OF THE MS RIVER. LOW CLOUD/FOG BLANKET AND CONTINUED LOW LEVEL             
WARM ADVECTION...TEMPS TO BE NEARLY STEADY TONIGHT NEAR THE                     
FREEZING MARK. WITH WEAK CONVERGENCE/LIFT IN THE MOIST SFC-850MB                
LAYER...PATCHY DZ/FZDZ STILL LOOKS REASONABLE TONIGHT. AS DEPTH OF              
MOISTURE DECREASES FROM WEST TO EAST LATER TONIGHT...THREAT OF                  
DZ/FZDZ WILL DIMINISH AS WELL...AND THIS ALREADY DEPICTED IN GRIDS.             
WITH CONTINUED MOIST SOUTH WINDS OVER THE SNOW COVER FRI...FOG WILL             
PERSIST THRU MUCH OF THE DAY AND ADVISORY MAY NEED TO BE EXTENDED               
INTO THE EARLY AFTERNOON...MUCH LIKE WED.                                       
ATTENTION QUICKLY TURNS TO WEEKEND SYSTEM AND POTENTIAL FOR                     
SIGNIFICANT SNOW FOLLOWED BY STRONG WEST/NORTHWEST WINDS. LATEST                
MODEL SUITE/ENSEMBLES HAVE TRENDED STRONGER/MORE PHASED WITH THE                
NORTHERN/SOUTHERN STREAMS AS THE SHORTWAVES CROSS THE MID MS                    
VALLEY AND UPPER MIDWEST. THIS MORE PHASED SOLUTION BRINGS DEEPER               
MOISTURE /4-5 G/KG/ AND DEEPER/STRONGER 850-500MB FN/QG CONVERGENCE             
NORTHWARD INTO THE FORECAST AREA CENTERED ON 00Z SUN. THIS COUPLED              
WITH STRONGER PV ADVECTION AND 300MB AGEOSTROPHIC FLOW/DIVERGENCE               
ALOFT. SOUNDINGS INITIALLY SUPPORT PRECIP AS SNOW OVER THE NORTHWEST            
HALF OF THE FORECAST AREA SAT MORNING...TO RAIN OVER THE SOUTHEAST              
END. APPEARS TO BE ONLY SMALL CHANCES OF MIXED/FREEZING PRECIP TYPES            
WITH THIS SYSTEM AS SOUNDINGS SHOW AIRMASS WARMER THAN 0C MIXED TO              
THE SFC. DEEP DYNAMIC LIFT/COOLING OF THE AIRMASS AHEAD OF THE                  
EJECTING SOUTHERN STREAM SHORTWAVE THEN LOOKS TO QUICKLY COOL                   
THE COLUMN FROM THE TOP DOWN AND CHANGE AND RA/SN MIX TO ALL SNOW               
LATE SAT MORNING/AFTN. GIVEN VERY DYNAMIC TREND OF THIS SYSTEM /SFC             
LOW DEEPENS ABOUT 14MB FROM 00Z SUN TO 12Z SUN/...THE TREND TOWARD A            
STRONGER MORE PHASED SOLUTION...AND POTENTIAL IMPACT ON A MAJOR                 
HOLIDAY TRAVEL WEEKEND...ISSUED A WINTER STORM WATCH FOR THE                    
SOUTHERN THIRD OF THE FORECAST AREA FOR SAT AFTERNOON/NIGHT AS A                
START. AS DETAILS BECOME CLEARER...POTENTIAL FOR THE WATCH TO BE                
EXPANDED NORTH/EAST WITH LATER ISSUANCES. WITH THE RAPIDLY DEEPENING            
LOW SAT NIGHT PRESSURE GRADIENT OVER THE AREA INCREASES BY 12Z SUN              
WITH STRONG/GUSTY WEST/NORTHWEST WINDS IN THE WAKE OF THE LOW FOR               
LATE SAT NIGHT/MUCH OF SUNDAY. MAY NEED TO EXPEND WATCH OR ANY LATER            
HEADLINES INTO SUNDAY DUE TO STRONG WINDS CREATING BLOWING/DRIFTING             
SNOW. WITH A BETTER CONSENSUS FOR THE STRONGER SYSTEM...RAISED POPS             
FOR MUCH THE SAT/SAT NIGHT PERIOD INTO LIKELY/CATEGORICAL RANGES.               
POTENTIAL FOR WRAP-AROUND DEFORMATION BAND OF -SN TO REMAIN OVER THE            
AREA ON SUN AND RAISED -SN CHANCES ON SUN AS WELL.                              
WITH CLOUD/FOG BLANKET...FAVORED WARMER OF GUIDANCE LOWS TONIGHT                
WITH NEAR STEADY TEMPS. WITH CLOUDS/FOG FRI...TRENDED TOWARD COOLER             
OF GUIDANCE HIGHS. FAVORED A BLEND OF GUIDANCE LOWS/HIGHS FRI                   
NIGHT/SAT...WITH FALLING TEMPS DURING THE DAY SAT. TRENDED TOWARD               
COLDER OF GUIDANCE LOWS SAT NIGHT AS COLD AIR POURS IN AND THE                  
UPPER LOW DROPS ACROSS THE REGION. PREFERRED A BLEND OF GFS MEX/                
ENSEMBLE MOS AND HPC GUIDANCE FOR HIGHS/LOWS SUN/SUN NIGHT.                     
.LONG TERM...MONDAY THROUGH THURSDAY                                            
20/00Z MEDIUM RANGE MODELS/ENSEMBLE MEAN OFFER A MODEST CONSENSUS               
WITH EACH OTHER FOR MON-THU...BUT DIFFERENCES IN TIMING/STRENGTH OF             
THE SHORTWAVE TROUGHS INCREASES THRU THE PERIOD. RUN-TO-RUN                     
CONSISTENCY OF TIMING/STRENGTH DETAILS BY TUE AND BEYOND IS QUITE               
LOW. THIS NOT UNEXPECTED GIVEN MODELS STILL STRUGGLING WITH THE                 
NORTHERN/SOUTHERN STREAM BALANCE OF ENERGY WITH THE SYSTEM THIS                 
WEEKEND AND NUMEROUS STRONGER SHORTWAVE TROUGHS ACROSS THE CONUS FOR            
NEXT WEEK. THUS...FORECAST CONFIDENCE IN THE LONG TERM ON THE LOW               
SIDE THIS CYCLE. GFS ENSEMBLE MEAN DOES TREND TOWARD A MODEL BLEND/             
COMPROMISE OF THE GFS/ECMWF/UKMET RUNS...AT LEAST WITH TIMING OF                
FEATURES. WHAT MODEL CONSENSUS THERE IS INDICATES A RATHER ACTIVE               
FLOW PATTERN ACROSS NOAM THRU NEXT WEEK...ESPECIALLY THE SOUTHERN               
STREAM. UPPER MIDWEST LOOKS TO BE CAUGHT UNDER SPLIT FLOW MON/TUE               
WITH A COLD SFC HIGH PRESSURE RIDGE SLIDING ACROSS THE REGION...FOR             
DRY...QUIET WEATHER. FOR WED/THU ECMWF AND TO A LESSER DEGREE GFS               
ENSEMBLE MEAN TRENDING TOWARD SOME PHASING OF THE NORTHERN/SOUTHERN             
STREAMS AND A SIGNIFICANT TROUGH LIFTING NORTHEAST ACROSS THE                   
CENTRAL CONUS. UKMET/CAN GEM/20/06Z GFS RUN LOOK TO MAINTAIN MORE OF            
A SPLIT FLOW AND BULK OF THE ACTIVE WEATHER SOUTH OF THE AREA. HPC              
TRENDED TOWARD A MODEL COMPROMISE WEIGHTED TOWARD THE USUALLY BETTER            
ECMWF AND ENSEMBLES FOR WED/THU. SMALL SNOW CHANCES WED INTO THU                
LOOKS REASONABLE FOR NOW GIVEN RANGE MODEL SOLUTIONS AND LOWER                  
FORECAST CONFIDENCE BY DAYS 6/7 FOR ANY ONE PARTICULAR OUTCOME.                 
FAVORED A BLEND OF GFS MEX/ENSEMBLE MOS AND HPC GUIDANCE MAXES/MINS             
THRU THE PERIOD.                                                                
&&                                                                              
.AVIATION...TONIGHT AND FRIDAY                                                  
LOW CLOUDS AND/OR FOG EXPECTED TO PERSIST ACROSS THE AREA THROUGH               
TONIGHT AND INTO FRIDAY. THIS BASED ON EXPANSE OF STRATUS CONTINUING            
TO MOVE NORTHWARD FROM IOWA AND ILLINOIS. IN FACT...BASED ON CURRENT            
CONDITIONS AND LOCAL STUDY OF DENSE FOG EVENTS...FORECAST CONFIDENCE            
WAS HIGH FOR KRST TAF SITE TO HAVE VISIBILITY NEAR 1/4 MILE DURING              
LARGE PORTIONS OF 18Z 20DEC07 TAF VALID TIME. SOME IMPROVEMENT                  
SHOULD OCCUR AFTER 16Z 21DEC07. LOOKING AHEAD...POTENTIAL FOR WINTRY            
PRECIPITATION EVENT TO IMPACT BOTH KRST AND KLSE TAF SITES AND IN               
FACT MOST OF THE AIRPORTS IN THE FORECAST AREA THIS WEEKEND.                    
&&                                                                              
.ARX WATCHES/WARNINGS/ADVISORIES...                                             
WI...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE                    
     SATURDAY NIGHT FOR WIZ053-WIZ054-WIZ055-WIZ061.                            
MN...DENSE FOG ADVISORY UNTIL 10 AM CST FRIDAY FOR MNZ079-MNZ086-               
     MNZ087-MNZ088-MNZ094-MNZ095-MNZ096.                                        
IA...DENSE FOG ADVISORY UNTIL 10 AM CST FRIDAY FOR IAZ008-IAZ009-               
     IAZ010-IAZ011-IAZ018-IAZ019-IAZ029-IAZ030.                                 
     WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE                    
     SATURDAY NIGHT FOR IAZ008-IAZ009-IAZ010-IAZ011-IAZ018-                     
     IAZ019-IAZ029-IAZ030.                                                      
&&                                                                              
$$                                                                              
SHORT/LONG TERM...RRS                                                           
AVIATION..........THOMPSON                                                      
</pre> wi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE LA CROSSE WI                                           
1026 AM CST THU DEC 20 2007                                                     
.UPDATE...PRIMARY CONCERN WAS WITH DENSE FOG ACROSS PARTS OF                    
SOUTHEAST MINNESOTA AND NORTHEAST IOWA TODAY. SATELLITE IMAGERY                 
INDICATED STRATUS EXPANDING STEADILY NORTHWARD INTO FORECAST AREA               
THIS MORNING. VISIBILITY LOWERS TO AS LOW AS 1/4 MILE PER 16Z                   
OBSERVATION AT KOLZ.                                                            
LATEST RUC AND 12Z 20DEC07 NAM/WRF SUPPORTED LOW CLOUDS AND FOG TO              
CONTINUE PUSHING NORTHWARD TODAY ACROSS THE ENTIRE FORECAST AREA.               
BASED ON CURRENT OBSERVATIONS...INCLUDED FOG ACROSS PARTS OF                    
SOUTHEAST MINNESOTA AND NORTHEAST IOWA REST OF TODAY.                           
WILL CONTINUE TO MONITOR VISIBILITY TRENDS IN CASE WIDESPREAD 1/4               
MILE SCENARIO DEVELOPS. FOR NOW...HAVE UPDATED CURRENT DATA BASE                
AND WILL UPDATE ZONE FORECASTS FOR LATEST TRENDS.                               
&&                                                                              
THOMPSON                                                                        
.PREV DISCUSSION... /ISSUED 340 AM CST THU DEC 20 2007/                         
SHORT TERM...TODAY THROUGH SATURDAY NIGHT                                       
FORECAST FOCUS IN THE SHORT-TERM CENTERS ON THE PCPN CHANCES FOR                
TODAY...AND THEN WHAT THE WEEKEND SYSTEM WILL DO.                               
TODAY...A RELATIVE WEAK AND PROGRESSIVE 500 MB SHORTWAVE TROUGH WILL            
TRACK EAST ACROSS THE REGION. DESPITE ITS NON-DESCRIPT                          
APPEARANCE...THIS FEATURE WILL BRING SOME QG CONVERGENCE THROUGH THE            
LAYERS WITH IT...ALONG WITH SOME BROAD LOW LEVEL WARMING ON THE                 
925:700 MB SFCS. SOME ISENTROPIC UPGLIDE IS ALSO INDICATED AHEAD OF             
THE SHORTWAVE TROUGH...IN THE 285:300 K SFCS. THE THERMODYNAMIC LIFT            
PEAKS THIS AFTERNOON ALONG AND EAST OF THE MISSISSIPPI                          
RIVER...GENERALLY EXITING EAST BETWEEN 00-06Z. SO...THERE IS SOME               
LIFT TO WORK WITH...AND POTENTIALLY SOME PCPN...ALL DEPENDING ON HOW            
MUCH SATURATION THERE WILL BE. A WEST-EAST RUNNING X-SECTION HAS THE            
CURRENT HIGH/MID LEVEL SATURATION PUSHING EAST BY THIS                          
AFTERNOON...WITH AN INCREASE IN THE LOW LEVEL MOISTURE //800MB TO               
THE SFC// THIS AFTERNOON. THE MOISTURE ISN/T DEEP ENOUGH TO SUPPORT             
ANY SIGNIFICANT PCPN PROCESSES...BUT IT IS FOR DRIZZLE/FREEZING                 
DRIZZLE. SO...WITH SOME BROADSCALE LIFT THROUGH THE TOP OF THIS                 
LAYER...PATCHY DRIZZLE/FREEZING DRIZZLE WILL BE POSSIBLE...MOSTLY               
THIS AFTERNOON AND EARLY EVENING...AND MOSTLY ALONG AND EAST OF THE             
MISSISSIPPI RIVER.                                                              
NOW...ON TO THE MUCH TALKED ABOUT STORM SYSTEM FOR THE WEEKEND. THE             
MODELS HAVE CERTAINLY HAD THEIR FUN WITH US...WHILE CONTINUING TO               
BRING THE REGION SOME PCPN...WHAT AND WHERE HAS VARIED ALMOST ON A              
DAY TO DAY...RUN TO RUN BASIS. NOW THAT THE SYSTEM HAS MOVED INTO               
THE SHORT-TERM...VARIANCES CONTINUE. I CERTAINLY DIDN/T ASK SANTA               
FOR THIS. ANYWAY...THE MODELS DO SEEM TO BE SETTLING MORE ON A SPLIT            
500 MB FLOW TYPE SYSTEM...THAT MERGES TOGETHER AS IT PASSES INTO THE            
GREAT LAKES...STRENGTHENING FOR ITS TREK ACROSS THE NEW ENGLAND                 
STATES. HOWEVER...THE DEVELOPMENT OF THEIR SFC LOWS ARE                         
DIFFERENT...AND SO IS THEIR RESULTING QPF. THE NAM AND EC WOULD                 
DEVELOP A SINGLE LOW CENTER...OVER WI/ILL BY 00Z SUN. THE GFS KEEPS             
THIS SYSTEM SPLIT YET...WITH LOW CENTERS OVER SOUTHERN CANADA AND               
ARK. EVENTUALLY THESE SOLUTION COME TOGETHER AS THE STORM MOVES                 
EAST. THE 21Z SREF IS SIMILAR TO THE GFS WITH PLACEMENT OF ITS LOW              
CENTERS. THE GFS HAS BEEN FAIRLY CONSISTENT WITH A TWO-HEADED SYSTEM            
AS IT MOVES THROUGH THE GREAT LAKE STATES...ALTHOUGH A BIT SLOWER               
OVER ITS PAST FEW RUNS. THE EC HAS BEEN VARIABLE...BUT HAS MOVED                
FROM TWO LOWS TO ONE AS IT MOVES ACROSS THE REGION...WHILE THE NAM              
HAS HAD ONE LOW...JUST MOVED IT FARTHER SOUTH. IT WOULD SEEM THAT               
THE GFS HAS BEEN MORE CONSISTENT...AND IS FAVORED BY THE ENSEMBLES.             
THE DIFFERENCES ARE SIGNIFICANT IN THAT THE NAM/EC WOULD BRING                  
STRONGER FORCING ACROSS THE FORECAST AREA...ALONG WITH THE                      
DEFORMATION PCPN BAND WEST/NORTH OF THE SFC LOW. AS A RESULT...MORE             
QPF AND MORE SNOW POTENTIAL. THE GFS...CONVERSELY...IS MUCH LESS IN             
ITS QPF. WITH THE NAM...COBB OUTPUT WOULD PUT 3-5 INCHES ACROSS MUCH            
OF THE AREA. THE GFS IS LESS THAN AN INCH. THE SREF WOULD SUGGEST               
1-2 INCHES...AND THE EC 2-4. DON/T THINK GOING TOWARD THE HIGH                  
END...OR THE LOW END...IS THE WAY TO GO. WITH SUCH VARIABILITY IN               
THE MODEL SOLUTIONS...WILL OPT WITH SOMETHING IN THE MIDDLE...AND               
ALLOW LATER FORECASTS TO ADJUST UP OR DOWN...AS THE CASE MAY BE. ONE            
THING THE MODELS DO AGREE ON IS THAT SATURDAY/SAT EVENING WILL BE               
THE BEST TIME FOR SOME ACCUMULATING PCPN.                                       
BEFORE GETTING TO SNOW AMOUNTS...OR LACK THERE OFF...PRECIPITATION              
TYPE NEEDS TO BE QUESTIONED. AS THEY HAVE BEEN DOING...THE MODELS               
CONTINUE TO PULL CONSIDERABLE WARM AIR NORTHWARD AHEAD OF THE                   
SYSTEM...AND THEN A QUICK COOL DOWN BEHIND THE ASSOCIATED COLD                  
FRONT. LOOKING AT A NORTHWEST-SOUTHEAST RUNNING X-SECTION...THE NAM             
IS BY FAR THE WARMEST MODEL...SURGING +4 C AIR IN THE 900:850 MB                
LAYER NORTH OF RST AT 00Z SAT...WITH THE EC/GFS CLOSER TO +1. THE               
MODELS COOL THIS LAYER DOWN AS THE SYSTEM TRANSITIONS EAST...                   
BUT THE NAM STILL STAYS FAIRLY WARM...WITH A DEEP //800 MB TO THE               
SFC// ABOVE ZERO LAYER FROM LSE TO THE SOUTHEAST AT 18Z SAT. BY 00Z             
ALL MODELS ARE COOL. THINK THE NAM MIGHT BE TOO AGGRESSIVE WITH THIS            
WARMING...AND WILL LEAN TOWARD THE EC/GFS IN THIS STEAD. STILL...THE            
TEMP PROFILES POINT TO SOME RAIN...OR RAIN/SNOW FOR PARTS OF                    
NORTHEAST IOWA/SOUTHWEST WISCONSIN AS THIS SYSTEM MOVES                         
IN...GRADUALLY CHANGING OVER TO SNOW BY SAT AFTERNOON. THIS TREND IS            
SHOWN WELL IN THE 21Z SREF DOMINANT PCPN TYPE DEPICTION. AS HAS BEEN            
THE CASE OVER THE PAST SEVERAL DAYS...THESE TEMP PROFILES SUPPORT               
EITHER RAIN OR SNOW...AND NOT SLEET OR FREEZING RAIN.                           
AS FOR SNOW TOTALS...THE GREATER TOTALS WILL COME WHERE                         
THE BEST FORCING COMES TOGETHER WITH THE COLDER AIR. SEEING AS THE              
FORECAST AREA WILL LIKELY LIE IN THIS TRANSITION ZONE ADDS FURTHER              
DIFFICULTLY IN TRYING TO PINPOINT TOTALS. AS MENTIONED                          
PREVIOUSLY...SAT/SAT EVENING APPEARS TO BE THE BEST TIME FOR                    
ACCUMULATIONS...AND WILL TAKE A MIDDLE OF THE ROAD APPROACH FOR                 
AMOUNTS FOR NOW. 2 TO 4 INCHES SEEMS TO BE A REASONABLE PLACE TO                
START. LATEST HPC GUIDANCE IS FOLLOWING THE EC...WHICH WOULD PUT THE            
BETTER ACCUMS OVER CENTRAL/EASTERN WI INTO EASTERN IA. IF THE NAM               
HAS ITS WAY...IT WOULD BE OVER NORTHWEST WI INTO CENTRAL IA. TOUGH              
CALL...AND HATE TO BE WISHY WASHY...BUT MODEL CONFIDENCE DOES NOT               
LEND ITSELF TO ANYTHING TOO SPECIFIC AT THIS MOMENT.                            
SO...CONFIDENCE REMAINS HIGH THAT THE REGION WILL RECEIVE SOME                  
PRECIPITATION WITH THIS SYSTEM...CONFIDENCE ON AMOUNTS ARE NOT. A               
SNOW OR SNOW/RAIN OR EVEN JUST RAIN FOR AWHILE ALSO APPEARS QUITE               
LIKELY. JUST HOW FAR WEST AND NORTH THIS MIX OR RAIN WILL EXTEND IS             
NOT AS CLEAR. IT CERTAINLY HAS BEEN A VERY INTERESTING...BUT                    
FRUSTRATING...SYSTEM TO TRY TO FORECAST.                                        
LONG TERM...SUNDAY THROUGH WEDNESDAY                                            
THE STORM SYSTEM CONTINUES TO PULL OFF TO THE EAST ON SUNDAY. SOME              
LIGHT SNOW/FLURRIES WILL BE POSSIBLE POST THE SYSTEM...IN THE WRAP              
AROUND REGION OF THE LOW...BUT MOSTLY TO THE NORTH AND EAST OF THE              
LOCAL AREA. HIGH PRESSURE THEN LOOKS TO BUILD IN FOR XMAS                       
EVE/XMAS...AND SHOULD BRING SOME QUIET AND MOSTLY CLEAR CONDITIONS              
FOR THE HOLIDAY. FOR WED...A 500 MB TROUGH WILL START TO APPROACH               
THE REGION...HOWEVER CURRENT INDICATIONS BY THE GFS/EC IS TO TAKE               
THE BULK OF THE ASSOCIATED SHORTWAVE ENERGY EITHER NORTH OR SOUTH OF            
THE LOCAL AREA.                                                                 
AVIATION...                                                                     
A WEAK SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA THIS AFTERNOON               
AND EVENING. ENOUGH FORCING WILL OCCUR FROM THIS WAVE TO POSSIBLY               
PRODUCE SOME LIGHT PRECIPITATION. FORECAST SOUNDINGS INDICATE THAT              
MVFR CEILINGS SHOULD DEVELOP THIS AFTERNOON AS THE WAVE APPROACHES.             
THE CLOUD LAYER DOES NOT LOOK TO RESIDE IN COLD ENOUGH TEMPERATURES             
TO HAVE ICE IN IT...SO ANY PRECIPITATION THAT DEVELOPS WILL EITHER              
BE DRIZZLE OR FREEZING DRIZZLE DEPENDING ON SURFACE TEMPERATURES.               
SOUTH TO SOUTHEAST WINDS WILL PUMP WARMER AND MOIST AIR INTO THE                
AREA OVERNIGHT WHICH IS EXPECTED TO RESULT IN IFR CEILINGS                      
DEVELOPING. VISIBILITIES SHOULD REMAIN EITHER IFR OR MVFR THROUGH               
TODAY AND TONIGHT.                                                              
04                                                                              
&&                                                                              
.ARX WATCHES/WARNINGS/ADVISORIES...                                             
WI...NONE.                                                                      
MN...NONE.                                                                      
IA...NONE.                                                                      
&&                                                                              
$$                                                                              
RIECK                                                                           
</pre> wi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ALBANY NY                                              
1225 AM EST FRI DEC 21 2007                                                     
.SYNOPSIS...                                                                    
HIGH PRESSURE OVER QUEBEC WILL BUILD SOUTH INTO NEW ENGLAND AND NEW             
YORK TODAY. SATURDAY IT WILL SLIDE OFFSHORE AND A SOUTHERLY FLOW                
OF MILDER AIR WILL BECOME ESTABLISHED OVER THE EASTERN SEABOARD. A              
STORM WILL ORGANIZE IN THE MID MISSISSIPPI VALLEY SATURDAY AFTERNOON            
AND INTENSIFY AS IT MOVES THROUGH THE GREAT LAKES REGION TO HUDSON`S            
BAY SUNDAY. AHEAD OF IT INCREASING MOISTURE WILL BRING A WINTRY MIX             
OF PRECIPITATION AT FIRST...BUT IT WILL WARM ENOUGH TO CHANGE THE               
PRECIPITATION TO RAIN...WHICH WILL BE HEAVY AT TIMES SUNDAY                     
AFTERNOON. THE STORMS COLD FRONT WILL SWEEP TROUGH THE REGION SUNDAY            
NIGHT...AND IT WILL TURN MUCH COLDER. CHRISTMAS EVE AN UPPER LEVEL              
DISTURBANCE WILL PASS ACROSS THE REGION AND IN THE CHILLY NORTHWEST             
FLOW WILL TRIGGER SCATTERED SNOW SHOWERS. HIGH PRESSURE WILL BUILD              
INTO THE REGION FROM ONTARIO CHRISTMAS DAY.                                     
&&                                                                              
.NEAR TERM /UNTIL 6 AM FRIDAY/...                                               
IT SEEMS A NARROW YET PERSIST/INTERMITTENT  BAND OF LIGHT SNOW                  
CONTINUES TO IMPACT WESTERN NEW ENGLAND AND ATTEMPTING TO CROSS INTO            
EASTERN NEW YORK (NORTH OF THE MID HUDSON VALLEY).  LATEST RUN OF               
THE RUC13 AND 00Z NAM/WRF INDICATE THIS IS RESPONSE TO LOW LEVEL                
CONVERGENCE AND DEFORMATION WHICH IS EXPECTED TO BE INTERMITTENT                
THROUGH TONIGHT.  WILL UPDATE POPS ACCORDINGLY BUT KEEP IT IN THE               
SLIGHT CHANCE CATEGORY.  WHERE IT HAS SNOWED...VISIBILITIES HAVE                
DROPPED BACK 1-3 MILES...MAINLY ACROSS THE HIGHER ELEVATIONS. THE               
OTHER CONCERN IS THE TEMPERATURES OVERNIGHT.  WITH PERSISTENT CLOUD             
COVER AND LACK OF ADVECTION...WILL RAISE OVERNIGHT LOWS SEVERAL                 
DEGREES WHICH CORRESPONDS WELL WITH THE 00Z RUN OF THE GFS LAMP.                
&&                                                                              
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...                                        
THE SURFACE HIGH WILL BE CENTERED TO OUR EAST AND WILL SHIFT OFF                
THE NEW ENGLAND COAST FRIDAY NIGHT. IT WILL KEEP US DRY WITH A                  
DEVELOPING SOUTHEAST FLOW. LOW LEVEL CLOUDS WILL LIFT FRIDAY BUT                
HIGH LEVEL CLOUDS WELL IN ADVANCE OFF OF THE SYSTEM FOR THE WEEKEND             
WILL BE STREAMING IN...SO NOT MUCH SUN EXPECTED. TEMPERATURES WILL              
BE SEASONABLE.                                                                  
&&                                                                              
.LONG TERM /SATURDAY THROUGH THURSDAY/...                                       
HIGH PRESSURE SLIDES OFF THE ATLC COAST SATURDAY...AND SOUTHERNLY               
FLOW INCREASES THROUGH THE DAY.  500HPA RIDGE OVER THE EASTERN                  
SEABOARD. CLOUDS WILL BE VARIABLE AS WAA PRODUCES MID AND HI                    
CLOUDS. MEANWHILE THE LOW LEVEL SOUTHEAST FLOW WILL ALSO BRING                  
MOISTURE INTO THE REGION AND CONSIDERABLE LOW LEVEL MOISTURE                    
REMAINS THAT HAS LINGERED SINCE THURSDAY. SO ALOT OF CLOUDS AND BY              
SAT AFTN AND EVENING SPOTTY LIGHT DRIZZLE...FREEZING DRIZZLE AND                
FLURRIES.  TEMPERATURES MAY FALL A BIT DURING THE EVENING...BUT                 
INCREASING SOUTHERLY FLOW WILL RESULT IN STEADY OR SLOWLY RISING                
TEMPS OVERNIGHT. TEMPS WILL STILL BE AROUND OR BLO FREEZING IN                  
MANY AREAS AND PTYPE LIKELY TO BE ZR...BUT AMOUNTS WILL BE LIGHT.               
RAPIDLY DEEPENING SURFACE LOW IN THE GREAT LAKES SUNDAY WILL PUSH               
A CDFNT INTO NYS SUN AFTERNOON...WHICH SWEEPS EAST ACROSS REGION                
BY EVENING. WITH RAPIDLY INCREASE SOUTHERNLY INFLOW AHEAD OF THE                
SYSTEM TEMPS WILL RISE INTO THE 40S...AND KATAFRONT TYPE DYNAMICS               
OF SHOWERY/SQUALLY RAINS WILL DEVELOP ALONG AND AHEAD OF CDFNT.                 
ENSEMBLE QPF AMOUNTS FM PLUMES OF 1 TO 2 INCHES LIKELY IN 6 TO 9                
HOUR PERIOD. SIGNIFICANT SNOWMELT AND RUNOFF LIKELY. SEE HYDRO                  
SECTION FOR PARTICULARS. THE 500HPA CUTOFF...FOLLOWS ACROSS THE                 
REGION SUNDAY NIGHT AS VERY STRONG CAA FLASH FREEZES ANY REMAINING              
LIQUID...AND MELTED SNOW. ALSO THE PASSAGE OF THE CUT OFF WILL BE               
ACCOMPANIED BY SECONDARY ARCTIC CDFNT CHRISTMAS EVE WITH SCT -SHSN              
IN CAA...WITH STRONG UPPER DYNAMICS...BUT NOT IDEAL SETUP FOR LAKE              
EFFECT IN FCA. FINALLY SURFACE HIGH AND 500HPA RIDGE BUILD ACROSS               
THE REGION CHRISTMAS DAY...AND SEASONABLE TEMPS AND MAINLY CLEAR                
SKIES THE RESULT. BEYOND THEN THE SURFACE HIGH PASSES OFFSHORE...AND            
THE MODELS DIVERGE ON A VARIETY OF PASSING WEATHER SYSTEMS. WITH                
CUT OFF LOW ORGANIZING OVER GRTLKS REGION..ONE SFC LOW PASSES WELL              
SOUTH OF REGION OR THROUGH REGION THURSDAY OR FRIDAY. FOR NOW WENT              
WITH GFS MOS GUIDANCE AND SCT -SHSN AND CHC SNOW AT END OF EFP.                 
AFTER ALL THE 1.5 PVU ANOMALY THAT WILL ORGANIZE THIS SYSTEM IS                 
CURRENTLY NEAR TOKYO JAPAN.                                                     
&&                                                                              
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...                                       
AN EAST/NORTHEASTERLY FLOW AT LOW LEVELS IS RESULTING IN WIDE                   
SPREAD MVFR TO IFR CEILINGS OVER THE REGION WITH BROKEN TO                      
OVERCAST STRATUS 600 TO 2000 FEET AGL AT MANY OF THE METAR                      
SITES...WITH WIDESPREAD IFR/LIFR CEILINGS AND OBSCURATIONS                      
OVER HIGHER TERRAIN. A CONTINUED FLOW OF VERY MOIST AIR OFF                     
THE ATLANTIC WILL RESULT IN IMPROVEMENT BEING SLOW TO OCCUR.                    
WINDS WILL BE LIGHT FROM THE NORTH AND EAST IN THE EARLY                        
MORNING HOURS...AND EASTERLY AROUND 5 KNOTS DURING THE DAY                      
TODAY.                                                                          
OUTLOOK...                                                                      
TONIGHT...MVFR/IFR DUE TO LOW CLOUDS AND/OR FOG.                                
SAT...VFR...NO SIGNIFICANT WEATHER EXPECTED.                                    
SUN...IFR MIXED PCPN...STRONG S-SE WINDS.                                       
MON...VFR...EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS DOWNWIND                
      OF LAKE ONTARIO                                                           
TUE...VFR...NO SIGNIFICANT WEATHER EXPECTED.                                    
&&                                                                              
.HYDROLOGY...                                                                   
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH SATURDAY. A STRONG STORM              
SYSTEM WILL IMPACT THE REGION ON SUNDAY. STRONG SOUTHERLY WINDS ARE             
EXPECTED TO DEVELOP ACROSS THE AREA ON SUNDAY. THIS WILL BRING A                
WARM SURGE OVER A SNOW PACK THAT CONTAINS 1 TO 3 INCHES OF WATER                
EQUIVALENT FROM ALBANY SOUTH AND 2 TO 4 INCHES OF WATER EQUIVALENT              
OVER NORTHERN AREAS. A COLD FRONT WILL CROSS THE AREA SUNDAY                    
EVENING. MODELS HAVE TRENDED WETTER BRINGING AROUND AN INCH OF RAIN             
TO ALL AREAS IN A 6 HOUR PERIOD SUNDAY AFTERNOON OR EVENING. THE                
UPPER MOHAWK...MOOSE...UPPER HUDSON AND VERMONT BASINS ARE EXPECTED             
TO SEE A 6 TO 12 HOUR WARM PERIOD LATE SUNDAY...WHICH WILL PROBABLY             
NOT BE ENOUGH TO RIPEN THE SNOW. NORTHERN SNOW COVER SHOULD ABSORB              
THE RAIN WITH MINIMAL RUNOFF BEFORE REFREEZING. HOWEVER...SOUTHERN              
AREAS MAY SEE 18 TO 24 HOURS OF ABOVE FREEZING TEMPERATURES. THE                
QUESTION IS HOW MUCH SNOW MELTS. LOCAL RIVER MODELS SHOW THAT                   
STREAMS CAN HANDLE AS MUCH AS TWO INCHES OF COMBINED MELT AND RAIN              
WITH MINIMAL FLOODING. 3 INCHES OR MORE OF MELT AND RAIN WOULD CAUSE            
SIGNIFICANT FLOODING. THE GROUND HERE AT ALBANY IS FROZEN TO A DEPTH            
OF 5 INCHES. FROZEN GROUND ENHANCES THE CHANCES THAT FLOODING...AND             
POSSIBLY FLASH FLOODING...MAY OCCUR. RIVER ICE COVER IS NOT THICK               
ENOUGH TO CAUSE ICE JAM PROBLEMS. THE HIGHEST CONFIDENCE IS FOR                 
TIDAL FLOODING LATE SUNDAY ALONG THE MID HUDSON RIVER NEAR KINGSTON             
AND POUGHKEEPSIE DUE TO STRONG SOUTHERLY WINDS. OTHER BASINS AT RISK            
FOR FLOODING INCLUDES THE SCHOHARIE...THE LOWER MOHAWK...THE                    
ESOPUS...THE BATTEN KILL...THE HOOSIC...WAPPINGERS CREEK AND THE                
HOUSATONIC AND ITS TRIBUTARIES FROM FALLS VILLAGE DOWN STREAM.                  
FREEZING TEMPERATURES ARE EXPECTED ACROSS THE ENTIRE AREA BY MONDAY             
MORNING WHICH WILL END THE RUNOFF. IF FLOODING WERE TO OCCUR IT                 
WOULD MOST LIKELY BEGIN SUNDAY AFTERNOON AND LINGER INTO MONDAY.                
&&                                                                              
.ALY WATCHES/WARNINGS/ADVISORIES...                                             
CT...NONE.                                                                      
NY...NONE.                                                                      
MA...NONE.                                                                      
VT...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...SNYDER                                                               
NEAR TERM...BGM                                                                 
SHORT TERM...IAA                                                                
LONG TERM...SNYDER                                                              
AVIATION...RCK                                                                  
HYDROLOGY...DIRIENZO                                                            
WWW.WEATHER.GOV/ALBANY                                                          
</pre> ct                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO                           
1142 PM CST THU DEC 20 2007                                                     
.DISCUSSION...                                                                  
/1042 PM CST THU DEC 20 2007/                                                   
WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR REST OF FORECAST               
AREA EXCEPT FOR THE KANSAS COUNTIES AND CASS AND BATES COUNTIES IN              
MISSOURI.  WILL START THE ADDITIONAL COUNTIES AS OF MIDNIGHT.                   
CURRENT FOG CONTINUES TO SPREAD WESTWARD AT AROUND 5 KTS. DEEPER                
MOISTURE CAN BE SEEN ON SATELLITE SPREADING INTO NORTHWEST                      
MISSOURI...WHILE FOG IS SHALLOWER BUT STILL STILL PRODUCING LOW                 
VSBYS IN SOUTHWEST MISSOURI. THINK THE SLIGHT INCREASE IN THE LOW               
LEVEL WINDS LATER TONIGHT WILL HAVE THE MOST IMPACT ON THIS                     
SHALLOWER MOISTURE SO WILL LEAVE SOUTHWEST COUNTIES OUT OF THE                  
ADVISORY AT THIS POINT.                                                         
PC                                                                              
&&                                                                              
.PREV DISCUSSION...                                                             
/850 PM CST THU DEC 20 2007/                                                    
DENSE FOG CONTINUES TO SPREAD TO THE WEST UNDER INFLUENCE OF A VERY             
WEAK SURFACE FLOW AROUND LOW PRESSURE TROUGH IN EASTERN MISSOURI AT             
THIS TIME. MODELS SHOW THIS TROUGH BREAKING DOWN AS STRONGER                    
TROUGHING IN HIGH PLAINS STARTS TO TAKE SHAPE OVERNIGHT WITH LOW                
LEVEL FLOW BECOMING SOUTHEAST. THIS SHOULD SLOW THE WESTWARD                    
PROGRESSION AFTER MIDNIGHT BUT MAY SPREAD IT MORE INTO NORTHWEST                
MISSOURI...WHICH IS ALREADY EXPERIENCING PATCHY DENSE FOG UNDER THE             
CLEAR SKIES AND LIGHT WINDS. BOTH NAM AND RUC 950 MB DEPICTIONS OF              
THIS MOISTURE WOULD SUGGEST IT MAKING TO NEAR THE MISSOURI KANSAS               
BORDER IN NORTHWEST MISSOURI OVERNIGHT AND INTO EASTERN PORTIONS OF             
THE KANSAS CITY METRO AREA.  FOR NOW...WILL GO AHEAD AND EXPAND THE             
ADVISORY TO INCLUDE AREAS THAT ARE SEEING THE WIDESPREAD DENSE FOG              
SPREADING IN AT THIS TIME...AND KEEP AN EYE ON THE TRENDS...ADDING              
COUNTIES AS NEEDED.                                                             
PC                                                                              
/720 PM CST THU DEC 20 2007/                                                    
HAVE MADE SEVERAL PHONE CALLS TO AREAS JUST WEST OF WHERE WE HAD FOG            
ADVISORY IN EFFECT...AND THEY ARE VERIFYING THE SATELLITE TREND OF              
THE LOWER VISIBILITIES SPREADING BACK TO THE WEST. WILL EXPAND THE              
DENSE FOG ADVISORY FURTHER TO THE WEST TO COVER.  ESPECIALLY                    
CONCERNED FOR THE INTERSTATES INCLUDING I70 FROM CONCORDIA EASTWARD             
AND I35 IN HARRISON COUNTY.                                                     
PC                                                                              
/414 PM CST THU DEC 20 2007/                                                    
FORECAST CONCERNS FOR THE FIRST HALF OF THE FORECAST ARE TWO FOLD.              
TONIGHT WE ARE LOOKING AT CONTINUED DENSE FOG ACROSS AREAS FROM                 
NORTH CENTRAL AND NORTH EAST MISSOURI SOUTH THROUGH CENTRAL                     
MISSOURI. THE SECOND FORECAST CONCERN IS THE WINTER STORM EXPECTED              
THIS WEEKEND.                                                                   
MOISTURE TRAPPED IN THE BOUNDARY LAYER...AND LIGHT WINDS ASSOCIATED             
WITH A SURFACE TROUGH...HAVE CONSPIRED TODAY TO KEEP THE EASTERN                
THIRD OF THE FORECAST AREA UNDER DENSE FOG. CONDITIONS ARE NOT                  
EXPECTED TO CHANGE ACROSS THAT AREA OVERNIGHT. SURFACE TROUGH WILL              
SLIDE EAST A LITTLE...BUT ONLY ENOUGH TO ALLOW SURFACE WINDS TO                 
SWITCH TO THE SOUTHEAST...ADVECTING MORE MOISTURE IN AT THE SURFACE.            
HAVE GONE WITH A DENSE FOG ADVISORY FOR THE REST OF THE AFTERNOON               
THROUGH 10 AM FRIDAY MORNING AS A RESULT. FARTHER WEST SKIES CLEARED            
TODAY AND THE FOG THAT SET IN DISSIPATED RATHER QUICKLY. TONIGHT                
WILL SEE THE INVERSION TRAP ABUNDANT MOISTURE AT THE SURFACE                    
AGAIN...BUT WINDS JUST ABOVE THE INVERSION WILL STAY A LITTLE HIGHER            
IN RESPONSE TO THE DEEPENING TROUGH IN THE WESTERN CONUS. EXPECT                
THIS SLIGHTLY HIGHER WIND ABOVE THE INVERSION TO INDUCE ENOUGH                  
MIXING OVERNIGHT TO PREVENT THE FOG FROM BECOMING AS DENSE ACROSS               
THE WESTERN TWO THIRDS OF THE FORECAST AREA. IN FACT...HAVE KEPT FOG            
OUT OF THE FORECAST FOR AREAS FROM THE KANSAS CITY METRO ON SOUTH AS            
MODEL SOUNDINGS SHOW THE SURFACE MOISTURE TO BE PARTICULARLY                    
SHALLOW. THIS WILL NEED TO BE WATCHED OVERNIGHT THOUGH IN CASE                  
RADIATION FOG BEGIN TO DEVELOP UNDER THE CLEAR SKIES.                           
ATTENTION THEN TURNS TOWARDS FRIDAY NIGHT AND SATURDAY AS THE                   
DEEPENING WEST CONUS TROUGH SWEEPS EAST THROUGH THE PLAINS. GFS AND             
ECMWF HAVE CONTINUED TO CONVERGE TOWARDS ONE SOLUTION FOR THIS                  
WEEKENDS SYSTEM...AND THE NAM-WRF SEEMS TO BE MOVING IN THE SAME                
DIRECTION. THE EARLY WEEKEND SHORTWAVE TROUGH WILL ACTUALLY CONSIST             
OF A NORTHERN AND SOUTHERN STREAM WAVES PHASING AS THEY THEY MOVE               
THROUGH MISSOURI. THERE IS A STRONG SHOT OF COLD AIR THAT WILL                  
QUICKLY SPREAD ACROSS THE FORECAST AREA SATURDAY. THIS SYSTEM WILL              
BE BRINGING THE BULK OF ITS MOISTURE FROM THE PACIFIC...SO THE                  
EXPECTATION IS THAT MUCH OF THE PRECIPITATION WILL BE POST                      
FRONTAL...IN THE DEFORMATION ZONE BEHIND THE SURFACE LOW.                       
WITH THE SOLUTIONS FROM THE GFS/ECMWF/AND NAM-WRF ALL CONVERGING I              
HAVE NOT HAD TO MAKE MANY ADJUSTMENTS TO THE GOING FORECAST FOR                 
FRIDAY NIGHT INTO SATURDAY. DID KEEP SOME LIKELY POPS ACROSS THE                
EASTERN HALF OF THE FORECAST AREA FOR SATURDAY EVENING AS THE WEIGHT            
OF THE CONSENSUS SLOWS THE SYSTEM A LITTLE. OTHERWISE...EXPECT MUCH             
OF THE PRECIPITATION FALLING FROM THE SKY TO BE SNOW BY THE                     
AFTERNOON HOURS. FREEZING RAIN AND SLEET ARE GOING TO BE MINOR AS               
THE SPEED WITH WHICH THE COLD AIR RUSHES IN SHOULD PRECLUDE MUCH                
OPPORTUNITY FOR MIXED PRECIP. CURRENT SNOWFALL TOTALS STILL LOOK                
RANGE BETWEEN 1 TO 4 INCHES OF ACCUMULATION...IN PART DUE TO THE                
PROGRESSIVE NATURE OF THE SYSTEM. ALSO...WIND BEHIND THE FRONT LOOKS            
TO BE SUSTAINED AS HIGH AS 20 TO 30 MPH WITH HIGHER GUSTS.                      
THEREFORE...ADDED BLOWING SNOW TO THE FORECAST WEATHER FOR THE DAY              
SATURDAY AND SATURDAY NIGHT.                                                    
CUTTER                                                                          
EXTENDED...(SUNDAY-THURSDAY)                                                    
THE NORTHERN AND SOUTHERN SHORTWAVE BRANCHES WILL CONTINUE TO PHASE             
AT THE START OF THE EXTENDED FORECAST ON SUNDAY. THE PHASING SYSTEM             
WILL QUICKLY DEPART TO THE NORTHEAST...WITH SHORTWAVE                           
RIDGING/SURFACE HIGH PRESSURE SPREADING EAST IN ITS WAKE.                       
A SERIES OF PACIFIC SHORTWAVE TROUGHS WILL CONTINUE TO HEAD EAST                
THROUGH THE MEAN FLOW ACROSS THE CONUS NEXT WEEK. MODEL AGREEMENT               
DIMINISHES QUICKLY BY EARLY NEXT WEEK WITH REGARD TO THESE SHORTWAVE            
FEATURES. AS SUCH...THERE IS LOW CONFIDENCE FOR PRECIPITATION                   
CHANCES. IF ONE MODEL WERE TO BE CHOSEN OVER ANOTHER...WOULD HAVE TO            
SIDE WITH THE MORE CONSISTENT ECMWF. THE ECMWF STILL BRINGS A                   
CLIPPER SYSTEM FURTHER SOUTH THAN THE GFS ON MONDAY...BUT WITH                  
LITTLE MOISTURE TO WORK WITH MEASURABLE PRECIPITATION IS NOT                    
EXPECTED FOR OUR NECK OF THE WOODS. THE NEXT IN THE SERIES OF                   
PROGRESSIVE SHORTWAVES IS PROGGED TO AFFECT THE REGION TOWARD                   
WEDNESDAY.                                                                      
STOFLET                                                                         
&&                                                                              
.AVIATION...                                                                    
FOR THE 06Z TAFS...WILL BRING IN THE DENSER FOG AT 10Z IN THE KANSAS            
CITY AREA. COULD BE AS EARLY AS 09Z...BUT AM SEEING SOME SIGNS OF               
THE WESTWARD PROGRESSION SLOWING INTO THE METRO AREA. FOR                       
KSTJ...VSBYS MAY BOUNCE AROUND FOR A WHILE UNTIL THE DENSE FOG AREA             
CAN MOVE IN. WILL JUST TEMPO THE QUARTER MILE VISIBILITIES AT THIS              
POINT...AND LET MIDNIGHT SHIFT FINE TUNE AS TIMING IS MORE CERTAIN.             
PC                                                                              
&&                                                                              
.EAX WATCHES/WARNINGS/ADVISORIES...                                             
MO...DENSE FOG ADVISORY UNTIL 10 AM FRIDAY FOR MOZ003-MOZ004-MOZ005-            
     MOZ006-MOZ007-MOZ008-MOZ013-MOZ014-MOZ015-MOZ016-MOZ017-                   
     MOZ022-MOZ023-MOZ024-MOZ025-MOZ030-MOZ031-MOZ032-MOZ033-                   
     MOZ038-MOZ039-MOZ040-MOZ044-MOZ045-MOZ046-MOZ054.                          
     DENSE FOG ADVISORY UNTIL 10 AM FRIDAY FOR MOZ001-MOZ002-MOZ011-            
     MOZ012-MOZ020-MOZ021-MOZ028-MOZ029-MOZ037.                                 
KS...NONE.                                                                      
$$                                                                              
</pre> mo                                                                       

AREA FORECAST DISCUSSION...CORRECTION                                           
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO                           
1042 PM CST THU DEC 20 2007                                                     
.DISCUSSION...                                                                  
WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR REST OF FORECAST               
AREA EXCEPT FOR MIAMI AND LINN COUNTIES IN KANSAS AND CASS AND BATES            
COUNTIES IN MISSOURI.  WILL START THE ADDITIONAL COUNTIES AS OF                 
MIDNIGHT. CURRENT FOG CONTINUES TO SPREAD WESTWARD AT AROUND 5 KTS.             
DEEPER MOISTURE CAN BE SEEN ON SATELLITE SPREADING INTO NORTHWEST               
MISSOURI...WHILE FOG IS SHALLOWER BUT STILL STILL PRODUCING LOW                 
VSBYS IN SOUTHWEST MISSOURI. THINK THE SLIGHT INCREASE IN THE LOW               
LEVEL WINDS LATER TONIGHT WILL HAVE THE MOST IMPACT ON THIS                     
SHALLOWER MOISTURE SO WILL LEAVE EXTREME SOUTHWEST COUNTIES OUT OF              
THE ADVISORY AT THIS POINT.                                                     
PC                                                                              
&&                                                                              
.PREV DISCUSSION...                                                             
/850 PM CST THU DEC 20 2007/                                                    
DENSE FOG CONTINUES TO SPREAD TO THE WEST UNDER INFLUENCE OF A VERY             
WEAK SURFACE FLOW AROUND LOW PRESSURE TROUGH IN EASTERN MISSOURI AT             
THIS TIME. MODELS SHOW THIS TROUGH BREAKING DOWN AS STRONGER                    
TROUGHING IN HIGH PLAINS STARTS TO TAKE SHAPE OVERNIGHT WITH LOW                
LEVEL FLOW BECOMING SOUTHEAST. THIS SHOULD SLOW THE WESTWARD                    
PROGRESSION AFTER MIDNIGHT BUT MAY SPREAD IT MORE INTO NORTHWEST                
MISSOURI...WHICH IS ALREADY EXPERIENCING PATCHY DENSE FOG UNDER THE             
CLEAR SKIES AND LIGHT WINDS. BOTH NAM AND RUC 950 MB DEPICTIONS OF              
THIS MOISTURE WOULD SUGGEST IT MAKING TO NEAR THE MISSOURI KANSAS               
BORDER IN NORTHWEST MISSOURI OVERNIGHT AND INTO EASTERN PORTIONS OF             
THE KANSAS CITY METRO AREA.  FOR NOW...WILL GO AHEAD AND EXPAND THE             
ADVISORY TO INCLUDE AREAS THAT ARE SEEING THE WIDESPREAD DENSE FOG              
SPREADING IN AT THIS TIME...AND KEEP AN EYE ON THE TRENDS...ADDING              
COUNTIES AS NEEDED.                                                             
PC                                                                              
/720 PM CST THU DEC 20 2007/                                                    
HAVE MADE SEVERAL PHONE CALLS TO AREAS JUST WEST OF WHERE WE HAD FOG            
ADVISORY IN EFFECT...AND THEY ARE VERIFYING THE SATELLITE TREND OF              
THE LOWER VISIBILITIES SPREADING BACK TO THE WEST. WILL EXPAND THE              
DENSE FOG ADVISORY FURTHER TO THE WEST TO COVER.  ESPECIALLY                    
CONCERNED FOR THE INTERSTATES INCLUDING I70 FROM CONCORDIA EASTWARD             
AND I35 IN HARRISON COUNTY.                                                     
PC                                                                              
/414 PM CST THU DEC 20 2007/                                                    
FORECAST CONCERNS FOR THE FIRST HALF OF THE FORECAST ARE TWO FOLD.              
TONIGHT WE ARE LOOKING AT CONTINUED DENSE FOG ACROSS AREAS FROM                 
NORTH CENTRAL AND NORTH EAST MISSOURI SOUTH THROUGH CENTRAL                     
MISSOURI. THE SECOND FORECAST CONCERN IS THE WINTER STORM EXPECTED              
THIS WEEKEND.                                                                   
MOISTURE TRAPPED IN THE BOUNDARY LAYER...AND LIGHT WINDS ASSOCIATED             
WITH A SURFACE TROUGH...HAVE CONSPIRED TODAY TO KEEP THE EASTERN                
THIRD OF THE FORECAST AREA UNDER DENSE FOG. CONDITIONS ARE NOT                  
EXPECTED TO CHANGE ACROSS THAT AREA OVERNIGHT. SURFACE TROUGH WILL              
SLIDE EAST A LITTLE...BUT ONLY ENOUGH TO ALLOW SURFACE WINDS TO                 
SWITCH TO THE SOUTHEAST...ADVECTING MORE MOISTURE IN AT THE SURFACE.            
HAVE GONE WITH A DENSE FOG ADVISORY FOR THE REST OF THE AFTERNOON               
THROUGH 10 AM FRIDAY MORNING AS A RESULT. FARTHER WEST SKIES CLEARED            
TODAY AND THE FOG THAT SET IN DISSIPATED RATHER QUICKLY. TONIGHT                
WILL SEE THE INVERSION TRAP ABUNDANT MOISTURE AT THE SURFACE                    
AGAIN...BUT WINDS JUST ABOVE THE INVERSION WILL STAY A LITTLE HIGHER            
IN RESPONSE TO THE DEEPENING TROUGH IN THE WESTERN CONUS. EXPECT                
THIS SLIGHTLY HIGHER WIND ABOVE THE INVERSION TO INDUCE ENOUGH                  
MIXING OVERNIGHT TO PREVENT THE FOG FROM BECOMING AS DENSE ACROSS               
THE WESTERN TWO THIRDS OF THE FORECAST AREA. IN FACT...HAVE KEPT FOG            
OUT OF THE FORECAST FOR AREAS FROM THE KANSAS CITY METRO ON SOUTH AS            
MODEL SOUNDINGS SHOW THE SURFACE MOISTURE TO BE PARTICULARLY                    
SHALLOW. THIS WILL NEED TO BE WATCHED OVERNIGHT THOUGH IN CASE                  
RADIATION FOG BEGIN TO DEVELOP UNDER THE CLEAR SKIES.                           
ATTENTION THEN TURNS TOWARDS FRIDAY NIGHT AND SATURDAY AS THE                   
DEEPENING WEST CONUS TROUGH SWEEPS EAST THROUGH THE PLAINS. GFS AND             
ECMWF HAVE CONTINUED TO CONVERGE TOWARDS ONE SOLUTION FOR THIS                  
WEEKENDS SYSTEM...AND THE NAM-WRF SEEMS TO BE MOVING IN THE SAME                
DIRECTION. THE EARLY WEEKEND SHORTWAVE TROUGH WILL ACTUALLY CONSIST             
OF A NORTHERN AND SOUTHERN STREAM WAVES PHASING AS THEY THEY MOVE               
THROUGH MISSOURI. THERE IS A STRONG SHOT OF COLD AIR THAT WILL                  
QUICKLY SPREAD ACROSS THE FORECAST AREA SATURDAY. THIS SYSTEM WILL              
BE BRINGING THE BULK OF ITS MOISTURE FROM THE PACIFIC...SO THE                  
EXPECTATION IS THAT MUCH OF THE PRECIPITATION WILL BE POST                      
FRONTAL...IN THE DEFORMATION ZONE BEHIND THE SURFACE LOW.                       
WITH THE SOLUTIONS FROM THE GFS/ECMWF/AND NAM-WRF ALL CONVERGING I              
HAVE NOT HAD TO MAKE MANY ADJUSTMENTS TO THE GOING FORECAST FOR                 
FRIDAY NIGHT INTO SATURDAY. DID KEEP SOME LIKELY POPS ACROSS THE                
EASTERN HALF OF THE FORECAST AREA FOR SATURDAY EVENING AS THE WEIGHT            
OF THE CONSENSUS SLOWS THE SYSTEM A LITTLE. OTHERWISE...EXPECT MUCH             
OF THE PRECIPITATION FALLING FROM THE SKY TO BE SNOW BY THE                     
AFTERNOON HOURS. FREEZING RAIN AND SLEET ARE GOING TO BE MINOR AS               
THE SPEED WITH WHICH THE COLD AIR RUSHES IN SHOULD PRECLUDE MUCH                
OPPORTUNITY FOR MIXED PRECIP. CURRENT SNOWFALL TOTALS STILL LOOK                
RANGE BETWEEN 1 TO 4 INCHES OF ACCUMULATION...IN PART DUE TO THE                
PROGRESSIVE NATURE OF THE SYSTEM. ALSO...WIND BEHIND THE FRONT LOOKS            
TO BE SUSTAINED AS HIGH AS 20 TO 30 MPH WITH HIGHER GUSTS.                      
THEREFORE...ADDED BLOWING SNOW TO THE FORECAST WEATHER FOR THE DAY              
SATURDAY AND SATURDAY NIGHT.                                                    
CUTTER                                                                          
EXTENDED...(SUNDAY-THURSDAY)                                                    
THE NORTHERN AND SOUTHERN SHORTWAVE BRANCHES WILL CONTINUE TO PHASE             
AT THE START OF THE EXTENDED FORECAST ON SUNDAY. THE PHASING SYSTEM             
WILL QUICKLY DEPART TO THE NORTHEAST...WITH SHORTWAVE                           
RIDGING/SURFACE HIGH PRESSURE SPREADING EAST IN ITS WAKE.                       
A SERIES OF PACIFIC SHORTWAVE TROUGHS WILL CONTINUE TO HEAD EAST                
THROUGH THE MEAN FLOW ACROSS THE CONUS NEXT WEEK. MODEL AGREEMENT               
DIMINISHES QUICKLY BY EARLY NEXT WEEK WITH REGARD TO THESE SHORTWAVE            
FEATURES. AS SUCH...THERE IS LOW CONFIDENCE FOR PRECIPITATION                   
CHANCES. IF ONE MODEL WERE TO BE CHOSEN OVER ANOTHER...WOULD HAVE TO            
SIDE WITH THE MORE CONSISTENT ECMWF. THE ECMWF STILL BRINGS A                   
CLIPPER SYSTEM FURTHER SOUTH THAN THE GFS ON MONDAY...BUT WITH                  
LITTLE MOISTURE TO WORK WITH MEASURABLE PRECIPITATION IS NOT                    
EXPECTED FOR OUR NECK OF THE WOODS. THE NEXT IN THE SERIES OF                   
PROGRESSIVE SHORTWAVES IS PROGGED TO AFFECT THE REGION TOWARD                   
WEDNESDAY.                                                                      
STOFLET                                                                         
&&                                                                              
.AVIATION...                                                                    
/535 PM CST THU DEC 20 2007/                                                    
FOR THE 00Z TAF CYCLE...SOUNDINGS SHOW ANOTHER INVERSION SETTING UP             
ACROSS THE KANSAS/MISSOURI BORDER REGION TONIGHT...WITH A MODEST AND            
MOIST SOUTHEAST SURFACE FLOW. HOWEVER...THE WIND JUST OFF THE                   
SURFACE IS EXPECTED TO REMAIN A LITTLE STRONGER EARLY FRIDAY MORNING            
THAN IT WAS THIS MORNING. THOUGHTS ARE THAT THIS WILL KEEP THE                  
SURFACE LAYER MIXED A LITTLE MORE WITH THE DRY LAYER ABOVE                      
PREVENTING A DRASTIC DECREASE IN VISIBILITIES IN THE MORNING.                   
BIGGEST CONCERN WILL BE AT KSTJ WITH ITS SLIGHTLY LOWER ELEVATION               
ISOLATING IT A BIT MORE FROM THE EFFECTS OF DRIER AIR MIXING IN                 
OVER TOP.  WILL GO WITH A TEMPO CATEGORY FOR IFR CONDITIONS LATE                
TONIGHT AT THAT SITE.                                                           
PC                                                                              
&&                                                                              
.EAX WATCHES/WARNINGS/ADVISORIES...                                             
MO...DENSE FOG ADVISORY UNTIL 10 AM FRIDAY FOR MOZ003-MOZ004-MOZ005-            
     MOZ006-MOZ007-MOZ008-MOZ013-MOZ014-MOZ015-MOZ016-MOZ017-                   
     MOZ022-MOZ023-MOZ024-MOZ025-MOZ030-MOZ031-MOZ032-MOZ033-                   
     MOZ038-MOZ039-MOZ040-MOZ044-MOZ045-MOZ046-MOZ054.                          
     DENSE FOG ADVISORY UNTIL 10 AM FRIDAY FOR MOZ001-MOZ002-MOZ011-            
     MOZ012-MOZ020-MOZ021-MOZ028-MOZ029-MOZ037.                                 
KS...NONE.                                                                      
$$                                                                              
</pre> mo                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE PUEBLO CO                                              
408 AM MST FRI DEC 21 2007                                                      
.SHORT TERM...                                                                  
(TODAY AND TONIGHT)                                                             
...SNOW WILL FLY LATER TODAY INTO TONIGHT MOST AREAS...                         
...RUSH HOUR ACROSS COS AREA WILL BE AFFECTED THIS AFTERNOON...                 
CURRENTLY...WESTERLY SFC WINDS HAVE KEPT TEMPS UP THIS MORNING AS               
REASDING MOST AREAS ARE IN THE 30S AND 40S. CLOUDS OVER THE SAN LUIS            
VALLEY (SLV) HAVE EVEN KEPT TEMPS IN THE TEENS (VS NEGATIVE VALUES              
OF THE LAST WEEK OR SO). COMPOSITE RADAR ACROSS THE STATE INDICATS              
SNOW IS ALREADY FALLING OVER NW CO AND ECHOES ARE BEGINNING TO SHOW             
UP OVER NEW MEXICO. SFC CHART/3H P CHANGE SHOWS FRONT STILL UP IN               
THE C WY AREA. WATER VAPOR/RUC ANALYSIS FIEDLS SHOW TROUGH AXIS                 
EXTENDING FROM SALT LAKE SSW ACROSS S CALIF.                                    
MET DISCUSSION...THE "XMAS HOLIDAY WEEK ACTIVE WX PATTERN" WHICH HAS            
BEEN ADVERTISED BY THIS WFO THE LAST FEW DAYS WILL BEGIN TODAY.                 
FIRST IN A SERIES OF SYSTEMS STILL ON TRACK TO BRING SNOW TO THE                
REGION TODAY AND TONIGHT. COMBINATION OF STRONG FRONTOGENETICAL                 
FORCING S  OF HIWAY 50 AND STRONG NNE WINDS AT 700 MB SHOULB BRING              
THE HEAVIEST SNOW ACCUMS ACROSS THE WETS/SANGRE MTN RANGES THEN E               
TOWARDS THE KS BORDER S OF HIWAY 50. SNOW AND BLOWING SNOW WILL ALSO            
OCCUR ACROSS THE PALMER DIVIDE...BUT WIND MAY BE THE BIGGEST CONCERN            
OVER THIS REGION.                                                               
TODAY (THROUGH 18Z)...TWEAKED POPS A BIT HERE. KEPT VERY HITH POPS              
ALONG CONTDVD REGION BUT CUT BACK ALL OTEHR AREAS AS I DO NOT THINK             
WE WILL SEE ANY SIGNIF PRECIP E OF THE CONTDVD UNTIL AFTER 18Z.                 
ALSO...WARMED TEMPS UP A BIT THIS MORNING AS FRONT WILL LIKELY NOT              
CROSS THE PALMER UNTIL AT LEAST NOONISH.                                        
LATER TODAY (AFTER 18Z)...AFTER FRONT CROSSES THE PALMER DVD BELIEVE            
WINDS WILL PICK UP FROM THE N AND BECOME QUITE GUSTY AND TEMPS WILL             
BEGIN THERE DOWNWARD TREND. PRECIP WILL LIKELY BEGIN ACROSS TELLER              
COUNTY BY EARLY AFTERNOON AND REACH DOWN ACROSS N EL PASO BY MID TO             
LATE AFTERNOON. I DO BELIEVE RUSH HOUR WILL BE AFFECTED BY BLOWING              
SNOW ACROSS THE GREATER COS AREA...AND HAVE INTRODUCED A SNOW AND               
BLOWING SNOW ADVISORY FOR TELLER/N EL PASO STARTING A 21Z. ATTM...I             
AM MORE CONCERNED ABOUT THE BLOWING SNOW THAN THE ACCUMULATING SNOW             
AS WINDS BY LATER THIS AFTERNOON COULD BE IN THE 20-30 MPH RANGE AS             
LATEST GUIDANCE IS SHOWING 700 MB WINDS IN THE 40-50 KNOT RANGE. AS             
FOR THE MTNS...SNOWS WILL BE FLYING ACROSS THE CONTDVD WHERE 3-6" OF            
NEW SNOW SHOULD FALL BY 00Z.                                                    
TONIGHT...WINTER STORM WARNINGS ARE IN EFFECT FOR THE WETS AND S                
SANGRE MTN RANGES. S/BS ADVISORIES ARE IN EFFECT FOR THE PLAINS                 
GENERALLY S OF US HIWAY 50. ADVISORIRES ARE ALSO IN EFFECT FOR THE              
WET MTN VALLEY AND THE N SANGRES. ADVISORIES ARE ONGOING ACROSS N EL            
PASO/TELLER. THE HEAVIEST SNOW WITH THIS SYSTEM WILL FALL ACROSS THE            
E FACING SLOPES OF THE WETS AND S SANGRES. THESE AREAS SHOULD SEE               
8-12" OF NEW SNOW BY 12Z TOMORROW. OVER THE PLAINS...THE HEAVIEST               
SNOWS WILL FALL GENERALLY ALONG THE RATON MESA ALONG THE CO/NM                  
BORDER. SOME OF THESE SNOW TOTAL REACHED INTO THE WARNING CATEGORY              
BUT DECIDED TO GO WITH A S/BS ADVISORY AS MOST OF THE REGION SHOULD             
SEE TOTALS IN THE 3-6 RANGE. WINDS WILL ALSO BE A CONCERN ACROSS                
THIS AREA TONIGHT AND TRAVEL WILL BE DIFFICULT ACROSS RATON PASS AND            
ALONG HIWAY S OF KLAA. AS ALWAYS WITH THESE NE WIND EVENTS...PUEBLO             
COUNTY WILL BE PROBLEMATIC. I AM CONFIDENT THAT THE S SXNS OF THE               
COUNTY WILL SEE S/BS CRITERIA BUT THE N PART OF THE COUNTY                      
(INCLUDING PUB) WILL NOT SEE MUCH. PLAN TO MENTION THIS IN DETAIL IN            
THE HILITE PACKAGE THAT WILL BE ISSUED SHORTLY. SNOW ACROSS THE                 
PALMER DVD SHOULD START TO WIND DOWN AFTER MIDNIGHT...AND ACROSS THE            
RATON MESA TOWARDS SUNRISE. /HODANISH                                           
.LONG TERM...                                                                   
(SATURDAY THROUGH THURSDAY)                                                     
...UNSETTLED WEATHER PROBABLE THROUGH THURSDAY...                               
FORECAST MODELS INDICATE THAT A STRING OF FAST MOVING UPPER LEVEL               
SYSTEMS WILL BE LINED UP TO AFFECT THE REGION THROUGH THURSDAY.                 
MAXIMUM TEMPERATURES ARE EXPECTED TO REMAIN IN THE 20S AND 30S EACH             
DAY...THEN DROP INTO THE SINGLE DIGITS TO TEENS EACH NIGHT. THE                 
EXCEPTION WILL BE THE SAN LUIS VALLEY...WHERE LOW TEMPS WILL MOST               
LIKELY DIP WELL BELOW ZERO EACH NIGHT.                                          
SATURDAY...THE FIRST UPPER TROUGH WILL BE EXITING THE REGION SAT                
MORNING...MAKING FOR AN INITIALLY COLD AND BLUSTERY START ACROSS THE            
FAR E PLAINS. NW FLOW SETTLES IN...WITH LINGERING POTENTIAL FOR                 
ISOLATED SNOW OVER THE CENTRAL MTS WHILE THE PLAINS CLEAR OUT DURING            
THE AFTN.                                                                       
SUNDAY AND MONDAY...NEXT SYSTEM DROPS DOWN ACROSS THE N                         
ROCKIES...PRODUCING ISOLATED TO SCATTERED SNOW FOR THE CONTDVD                  
THROUGH THE DAY...THEN SPREADING TO THE ENTIRE CWA BY THE EVENING.              
BY MON MORNING THIS LOW SHOULD BE MOVING OUT...WITH PCPN TAPERING               
OFF ACROSS THE SE CORNER. A BREAK IN THE ACTIVE PATTERN IS FORECAST             
FOR THE REST OF MONDAY...BEFORE THE NEXT SYSTEM DROPS DOWN FOR THE              
NIGHT.                                                                          
MONDAY NIGHT THROUGH TUESDAY NIGHT...LONG RANGE MODELS ARE                      
INDICATING THAT THE NEXT STORM SYSTEM WILL DROP A BIT FURTHER SOUTH             
THAN PREVIOUS DISTURBANCES. THIS TRANSLATES TO A GREATER CHANCE OF              
SNOW FOR THE CONTDVD CHRISTMAS EVE...THEN ALL OF THE FORECAST AREA              
THROUGH CHRISTMAS DAY.                                                          
WEDNESDAY AND THURSDAY...LOOKS TO BE A REPEAT OF MONDAY AND TUESDAY.            
ALL OF THESE SYSTEMS DO NOT LOOK TOO IMPRESSIVE WHEN TALKING ABOUT              
SNOW AMOUNTS...BUT THE RAPID SUCCESSION INCREASES THE POTENTIAL OF              
IT FEELING LIKE THE HOLIDAY SEASON THROUGH NEXT WEEK. MOORE                     
&&                                                                              
.AVIATION...                                                                    
ALL TAF SITES WILL BE IMPACTED BY THIS WX SYSTEM. FRONT SHOULD CROSS            
KCOS AROUND 18Z AND KPUB BY 19Z. WINDS WILL SHIFT TO THE N AND                  
BECOME QUITE GUSTY...WITH N WINDS 20-30 MPH. ACROSS THE KCOS                    
REGION...SNOW SHOULD BECOME A CONCERN BY LATE IN THE AFTERNOON AND              
LASTING INTO THE EVENING. ACCUMS SHOULD NOT BE A MAIN CONCERN                   
(1-2")...BUT WINDS WILL BE THE MAIN ISSUE. BY LATER THIS                        
EVENING...NORTHERLY WINDS COULD BE APPROACHING 35 KNOTS. THE SNOW               
AND WINDS SHOULD BEGIN TO DECREASE AFTER MIDNIGHT. WITH N                       
WINDS...CIGS SHOULD NOT BE A MAJOR CONCERN AND SNOW SHOULD NOT BE               
HEAVY...EXPECT MAINLY MVFR CONDITIONS THROUGH THE WORST OF IT.                  
HOWEVER..IF SNOWS ACCUM A BIT MORE THAN EXPECTED...AND THINGS START             
BLOWING THEN VIS COULD BE SEVERELY RESTRICTED THIS EVENING DUE TO               
THE BLOWING SNOW.                                                               
KPUB...WINDS AND SNOW WILL BE LESS ACROSS KPUB. MAIN ACTIVITY WILL              
BE THIS EVENING WITH CIGS MAINLY IN THE BKN020-030 RANGE AND VIS                
RESTRICTIONS 2-3SM.                                                             
KALS...EXPECT PERIODS OF SNOW IN THE VALLEL DURING THE EVENING                  
PERIOD. BRIEF HEAVY SNOW COULD CAUSE IFR CONDITIONS AT TIMES.                   
&&                                                                              
.PUB WATCHES/WARNINGS/ADVISORIES...                                             
SNOW AND BLOWING SNOW ADVISORY FROM 6 PM THIS EVENING TO 5 AM                   
MST SATURDAY FOR COZ072-073-078-086>088-093-094-097>099.                        
SNOW AND BLOWING SNOW ADVISORY UNTIL 8 PM MST THIS EVENING FOR                  
COZ058>061-066-068.                                                             
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 5 AM MST SATURDAY                
FOR COZ074-075-079-080.                                                         
SNOW AND BLOWING SNOW ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM                 
MST SATURDAY FOR COZ081-082-084.                                                
&&                                                                              
$$                                                                              
34/27                                                                           
</pre> co                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE CHARLESTON SC                                          
859 AM EST FRI DEC 21 2007                                                      
.SYNOPSIS...                                                                    
A STRONG UPPER-LEVEL DISTURBANCE WHICH WILL PASS THROUGH THE                    
REGION AND MOVE OFF THE COAST TODAY. THIS WILL ENHANCE A WEDGE                  
PATTERN OVER THE CAROLINAS THAT SHOULD HOLD UNTIL BREAKING DOWN ON              
SUN AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL MOVE OFF              
THE COAST BY EARLY MON...BUT UNSETTLED WEATHER COULD RETURN BY                  
CHRISTMAS DAY AS ANOTHER UPPER LEVEL DISTURBANCE IS POSSIBLE.                   
&&                                                                              
.NEAR TERM /UNTIL 6 PM THIS EVENING/...                                         
06Z GFS/RUC HAVE CONVERGED ON A SIMILAR SOLUTION WHICH PUTS                     
A SFC LOW NEAR THE W WALL OF THE GULF STREAM SE OF CHARLESTON THIS              
AFTN. ALMOST A 12 MB PRES GRAD FORECAST INDICATES A WINDY SETUP.                
NAM SHOWS 60 KT H925 WINDS THIS AFTN...LIKELY OVERDONE BUT WORRISOME.           
IMPRESSIVE DEFORMATION AXIS ALONG AND JUST W OF I-95 HAS FUELED A               
ZONE OF 3-6 INCH RNFL AMOUNTS FROM HARDEEVILLE AND PORT WENTWORTH               
SW TO LONG AND TATTNALL COUNTIES. A FLOOD ADVISORY FOR MINOR                    
FLOODING IS IN EFFECT THROUGH MID MORNING FOR QUITE A FEW OF OUR                
COUNTIES. ZONES HAVE BEEN UPDATED THIS MORNING TO REFLECT HEAVY                 
RAIN AND INCREASE QPF. RADAR AND GROUND OBSERVATION RECENTLY                    
INDICATED OVER 5 INCHES OF RAIN HAS ALREADY FALLEN AT THE SAVANNAH              
AIRPORT. THIS RNFL MAX EXTENDS NWD TO AROUND HARDEEVILLE.                       
RAIN ALONG THE NW SIDE OF THE LOW LEVEL WARM FRONT MAY BE A BIT                 
SLOWER TO PULL OUT OF THE ERN PART OF THE FA TODAY.                             
THE EJECTING SFC LOW OFF THE GEORGIA COAST THIS MORNING SHOULD                  
ENHANCE A CLASSIC WEDGE SETUP TODAY. WE INDICATED HIGH TEMPS IN OUR             
NW TIER WILL OCCUR DURING THIS MORNING...FALLING AFTERNOON. VERY                
LITTLE CHANGE TO OVERALL TEMPERATURE SCHEME OVERALL. WINDS SHOULD               
INCREASE THIS AFTERNOON. WILL NEED TO WATCH FOR WIND ADVISORY                   
CRITERIA POSSIBILITIES ALONG THE IMMEDIATE CHARLESTON COUNTY COAST              
AT SOME POINT LATER TODAY.                                                      
THE COMBINATION OF STRONG PINCHING...DEEPENING LOW OVER THE ATLC                
AND RAPID PRES RISES IN ITS WAKE WILL RESULT IN STRONG AND GUSTY                
WINDS OVER THE COASTAL COUNTIES TODAY. HIGHEST WINDS WILL BE NEAR               
THE COAST...AND MOST NOTABLY ACROSS CHARLESTON COUNTY. WE HAVE                  
THUS INITIATED A HIGH WIND ADVISORY.                                            
&&                                                                              
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...                        
HEAVIER PRECIP SHOULD HAVE TAPERED OFF BY TONIGHT EXCEPT FOR A FEW              
CONVECTIVE SHOWERS POSSIBLE OVER FAR NE PORTIONS. HOWEVER...                    
CONTINUED WEDGE PATTERN WITH WEAK ISENTROPIC LIFT COULD RESULT IN               
SOME DRIZZLE THROUGH THE NIGHT IN MANY AREAS. EXTENSIVE CLOUD COVER             
AND A RATHER CONTIGUOUS AIRMASS IN PLACE SHOULD KEEP TEMPERATURES               
FAIRLY STEADY THROUGH THE NIGHT OR SLIGHTLY FALLING. GUIDANCE TEMPS             
FOR SAT SEEM MUCH TOO HIGH OVER THE NORTHERN HALF OF THE AREA. MID              
TO UPPER 60S IS PRETTY MUCH OUT OF THE QUESTION ASSUMING THE WEDGE              
OF HIGH PRES REMAINS FIRMLY PLANTED ACROSS THE EASTERN SEABOARD. WE             
SHOULD HAVE A LARGE TEMP GRADIENT ACROSS THE AREA WITH UPPER 60S FAR            
S TO UPPER 50S N. DECREASED POPS TO SLIGHT CHANCE OVER SE SC WHERE              
BEST CHANCE OF SOME ISENTROPIC ALONG THE COASTAL TROUGH WILL EXIST.             
&&                                                                              
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...                                 
WHILE MODEL SOLUTIONS REMAIN SPLIT FOR MOST OF THE EXTENDED...                  
CONFIDENCE THAT THE GUIDANCE IS RUNNING TOO WARM IS QUITE HIGH. MUCH            
OF THE LONG-TERM PERIOD WILL BE DOMINATED BY A WEDGE PATTERN WITH               
HIGH PRES OVER THE NE STATES. AS USUAL WITH PERSISTENT WEDGE                    
PATTERNS IN THIS PART OF THE COUNTRY...THE GFS MOS TEMPS ARE ABOUT              
TEN DEGREES TOO WARM ON AVERAGE. THIS STILL SEEMS TO BE THE CASE                
WITH THE 00Z RUN. INHERITED GRIDS SEEM QUITE REASONABLE AND ARE WELL            
COLLABORATED ON THE WHOLE...THUS DID NOT MAKE SIGNIFICANT CHANGES TO            
THESE PERIODS.                                                                  
&&                                                                              
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...                                       
SFC LOW AT 11Z WAS CLOSE TO MOVING OFF THE GEORGIA COAST S OF KSAV              
AND WINDS WERE ALREADY BACKING IN NRN CHATHAM COUNTY INDICATING THE             
LOW IS SLIPPING OF THE SSE. HEAVY RNFL IS PINNED DOWN AROUND THE                
SAVANNAH AIRPORT AND VSBYS AND CIGS SHOULD CONTINUE TO BOUNCE WITH              
THE PRECIP LOADING. STRONG LOW LEVEL CONVERGENCE IS INCREASING                  
FURTHER UP THE COAST AND HEAVY RAINS MAY ALSO BECOME PINNED ALONG               
THE CHARLESTON COUNTY LATER THIS MORNING. IN EITHER CASE...IFR/MVFR             
CONDITIONS SHOULD BECOME LIFR BY THIS AFTERNOON AS THE WEDGE                    
INVERSION LOWERS AND STRENGTHENS. LIFR CIGS TONIGHT...VERY LOW                  
CONFIDENCE ON VSBYS IN THE WEDGE.                                               
AT BOTH TAF SITES...N TO NE WINDS SHOULD BE GUSTY FROM THIS AFTN                
THROUGH THIS EVENING...HIGHEST AT KCHS. THIS IS DEPENDANT ON THE                
EVOLUTION OF A VERY COMPLEX SYNOPTIC REGIME.                                    
EXTENDED AVIATION OUTLOOK...LIFR OR LOWER CIGS AND REDUCED VSBYS                
IN FOG SAT MORNING...LIFTING TO MVFR CIGS SAT AFTN. LOW CIGS MAY                
REDEVELOP SAT NIGHT. THERE SHOULD BE SOME IMPROVEMENT BY SUNDAY                 
NIGHT AND MONDAY...BUT ANOTHER ROUND OF LOW CIGS IS POSSIBLE                    
TUESDAY AND TUESDAY NIGHT.                                                      
&&                                                                              
.MARINE...                                                                      
KJAX SOUNDING SHOWS 35-40 KT BELOW 2K FT THIS MORNING AND STRONG                
PINCHING IS DEVELOPING AND WILL STRENGTHEN FURTHER AS LOW DEEPENS               
AS IT REACHES THE GULF STREAM. WITH STRONG PRES RISES IN WAKE OF                
THE LOW WILL GO AHEAD AND RAISE A GALE WARNING FOR AMZ352-354-374.              
THUS ALL WATERS ARE NOW UNDER A GALE WARNING. HAVE RAISED                       
SEAS/WAVES ACCORDINGLY. HAVE ALSO ADDED TSTMS TO THE SC WATERS AND              
LOWERED COVERAGE OVER PRECIP ON THE SE GA WATERS.                               
STRONG GRAD PINCHING IS LIKELY TODAY THROUGH EARLY TONIGHT GIVEN                
THE DYNAMICS AND THERMAL GRADIENT/DIABATIC EFFECT. WHILE THE NAM                
MODEL SEEMS A BIT QUESTIONABLE WITH THE TRACK OF THE SFC LOW TODAY...           
THE GFS REMAINS ON TRACK...ALBEIT WEAK WITH THE WIND SPEEDS GIVEN               
THE TILTING WEDGE SCENARIO. WE HAVE UPGRADED GALE WATCH TO A WARNING            
OFF THE CHARLESTON COUNTY COAST AND INCLUDED THE HARBOR FOR TODAY               
INTO TONIGHT. N WINDS SHOULD TRAP-DOOR DOWN THE BACKSIDE OF THE                 
EJECTING LOW THIS AFTN...SPEEDS AND SEAS INCREASING GEORGIA LEGS.               
SCA ALL WATERS OUTSIDE OF THE GALE WARNINGS. SEAS COULD BUILD AS                
HIGH AS 9-10 FT 15-30 NM OFF THE NRN CHARLESTON COUNTY BY 00Z/22.               
WINDS SHOULD BE ON THE DECREASE TONIGHT AND SAT OVER THE WATERS BUT             
SEAS WILL REMAIN ELEVATED THROUGH TUE. SMALL CRAFT ADVISORIES                   
CONTINUE THROUGH SAT NIGHT IN THE NEARSHORE WATERS AND THROUGH MON              
EVENING OVER THE OFFSHORE.                                                      
LAKE WINDS...RECENT OBSERVATION FROM EADYTOWN AND TIGHTENING OF THE             
PRES GRAD HAS PROMPTED AN ISSUANCE OF A LAKE WIND ADVISORY FOR                  
LAKE MOULTRIE. WE RAN THE ADVISORY THROUGH TONIGHT AS THE GRAD                  
REMAINS QUITE STRONG.                                                           
&&                                                                              
.TIDES/COASTAL FLOODING...                                                      
HIGH TIDE AROUND 5-6 AM THIS MORNING FELL BELOW COASTAL FLOOD ADVISORY          
CRITERIA BUT RAIN LIKELY EXACERBATED SOME MINOR FLOODING.                       
HIGH ASTRONOMICAL TIDES EXPECTED SAT THROUGH TUE MORNINGS. THE                  
QUESTION IS WHEN WE EXPECT METEOROLOGICAL FACTORS TO RESULT IN                  
ENOUGH POSITIVE ANOMALY TO PUSH TIDES ABOVE CRITICAL THRESHOLDS FOR             
SHALLOW COASTAL FLOODING. SAT MORNING HOLDS A CONSIDERABLE CHANCE               
ALONG THE SC COAST GIVEN CONTINUED NE WINDS AND SOME SWELL WAVE. SUN            
AND MON WILL BE CLOSE BUT WINDS WILL EITHER BE DUE S OR DUE                     
N...NEITHER OF WHICH NORMALLY RESULTS IN MUCH OF A RESIDUAL. TUE                
MORNING WE COULD AGAIN BE PUSHING 7 FT AT CHS IF NE FLOW SETS UP AS             
FORECAST.                                                                       
&&                                                                              
.EQUIPMENT...                                                                   
THERE WAS NO BE NO 12Z UPPER AIR FLIGHT THIS MORNING DUE TO HEAVY               
PCPN AND GROUND EQUIPMENT ISSUES.                                               
&&                                                                              
.CHS WATCHES/WARNINGS/ADVISORIES...                                             
GA...WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR GAZ119.                    
SC...LAKE WIND ADVISORY UNTIL 5 AM EST SATURDAY FOR SCZ045.                     
     WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR SCZ048>051.                
MARINE...GALE WARNING UNTIL 11 PM EST THIS EVENING FOR AMZ352-354.              
     GALE WARNING UNTIL 5 AM EST SATURDAY FOR AMZ330-350-374.                   
&&                                                                              
$$                                                                              
33/RVT/JRL                                                                      
</pre> ga                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE DES MOINES IA                                          
530 AM CST FRI DEC 21 2007                                                      
.UPDATED FOR THE AVIATION FORECAST...                                           
.SYNOPSIS...                                                                    
LOW LAYERS SATURATED THIS MORNING WITH LIFR CIGS/VSBYS ALONG AND                
EAST OF AXA-BNW-LWD LINE AT 09Z.  SYS IN QUESTION FOR WEEKEND                   
PUSHING THROUGH WRN CONUS.  WEAK SHRT WVS NOTED OVER SD AND UPR MS              
RIVER VALLEY WITH PATCHY MID/HIGH CLOUDS ABOVE...BUT LITTLE OTHER               
FORCING IN PLACE FOR THE TIME BEING.                                            
&&                                                                              
.DISCUSSION...                                                                  
IMMEDIATE CONCERN WILL BE FATE OF DENSE FOG ADVY.  WILL LEAVE IT                
GOING FCST AREA WIDE THROUGH 15Z.  VSBYS NOT TOO LOW IN WRN                     
SECTIONS AT 09Z...BUT WITH WEAK SELY FLOW AND DIMINISHING MID/HIGH              
CLOUDS FEEL POTENTIAL IS CERTAINLY THERE FOR DENSE FOG DEVELOPMENT              
OVER ENTIRE AREA.  WITH PLENTY OF STRATUS UPSTREAM OVER MO...CANNOT             
SEE ANY REASON WHY LOW VSBYS WILL NOT CONTINUE ERN SECTIONS SO HAVE             
ADVY GOING THERE TOO TIL 18Z.                                                   
ATTENTION THEN TURNS TO SIGNIFICANT WEEKEND SYS.  NAM/GFS BOTH KEEP             
AREA LOCKED INTO STRATUS TONIGHT WITH COLUMN NOT REALLY TRYING TO               
SATURATE UNTIL 09Z AND AFTER.  HAVE LOWERED MEASURABLE POPS THROUGH             
AT LEAST MIDNIGHT WITH FOG AND TRACE MENTIONS OF EITHER DRZL OR FRZG            
DRZL DEPENDING ON SFC TEMPS WHICH GENERALLY FOLLOWED A BLEND OF                 
AVAILABLE GUIDANCE AND LOW LEVEL TEMPS.  TRANSITIONED TO HIGHER POPS            
BEFORE DAYBREAK AND RAIN OR SNOW WORDING.  FORECAST INTO SAT WAS                
BASICALLY A BLEND OF 00Z GFS/12Z ECMWF.  AIRMASS SATURATES WITH ALL             
SNOW NWRN HALF AND RAIN CHANGING TO SNOW SERN HALF.  SFC AND WARM               
LAYER TEMPS FALL AT GENERALLY THE SAME TIME SO ALTHOUGH THERE COULD             
BE A BRIEF PERIOD OF SLEET AS WARM LAYERS DIPS TO 1-3C...DO NOT FEEL            
IT WILL BE LONG ENOUGH OR SIGNIFICANT ENOUGH TO MENTION.  DID PUSH              
START OF WATCH BACK TO 18Z HOWEVER AS BEST UVM DOES NOT ARRIVE UNTIL            
THAT TIME...AND STILL HAVE RAIN MENTION SE.                                     
DENDRITIC LAYER FORCING INCREASES DURING THE AFTERNOON IN 300K ISENT            
SFC AND H5/H6 PRES LAYER.  EXPECT RELATIVELY NARROW SW-NE RIBBON OF             
SNOW TO DEVELOP INTO CENTRAL IA...THEN MORE WIDESPREAD AND INTENSE              
UVM CLIPPING SERN PORTIONS AS PRIMARY SHRT WV EJECTS INTO MID MS                
VALLEY.  SNOWFALL INTENSITIES REALLY INCREASE AS FORCING MOVES INTO             
DVN AREA DURING THE EARLY EVENING.  MOISTURE                                    
TRANSPORT...FRONTOGENETICAL FORCING AND LOWERING STATIC STABILITIES             
ALL COME TOGETHER DURING THIS TIME FRAME.  CONSIDERING THIS AMOUNT              
OF FORCING IN DENDRITIC LAYER...HAVE SNOW AMOUNTS IN HIGH END OF                
COBB OUTPUT WITH AMOUNTS RANGING FROM 1 FAR NW TO 6 FAR SE WHERE UVM            
IS BEST.  QUICK LOOK AT 00Z ECMWF QPF IS NOW HIGHER...BUT LATER                 
SWITCH TO SNOW MAY DIMINISH AMOUNTS SOMEWHAT SE SO PRETTY MUCH STUCK            
WITH AFOREMENTIONED THINKING FOR THE TIME BEING ALTHOUGH THIS TREND             
WILL HAVE TO BE WATCHED.                                                        
THESE AMOUNTS DO NOT JUSTIFY WATCH BY THEMSELVES...BUT WITH BLOWING             
SNOW CONSIDERED WILL LEAVE HEADLINE GOING AS IS.  SOMEWHAT LOW                  
CONFIDENCE ON WRN EDGES...BUT WITH BLOWING SNOW POTENTIAL DID NOT               
CHANGE ANYTHING AT THE MOMENT BESIDES ALTERATION OF START TIME AND              
EXTENSION TIL 12Z SUN.  ALTHOUGH CONFIDENCE NOT HIGH ENOUGH TO BOOST            
INTO BLIZZARD WATCH YET...WILL MENTION NEAR BLIZZARD CONDITIONS IN              
TEXT OF WSW.  AS SYS MATURES AROUND 00Z...VSBYS COULD DROP TO 1/4MI             
WITH WINDS GUSTING TO NEAR 35 MPH.  SNOW WILL QUICKLY DIMINISH IN               
OUR AREA DURING THE EVENING...BUT BLOWING SNOW POTENTIAL CONTINUES              
OVERNIGHT HENCE WATCH EXTENSION.  WINDS SHOULD GUST WELL THROUGH THE            
20S FOR AN EXTENDED PERIOD.                                                     
RAW MODEL AND SREF TEMPS SUGGEST GUIDANCE IS TOO WARM TODAY AND COOL            
TONIGHT WITH BLANKET OF STRATUS SO HAVE GONE BELOW AND ABOVE MOS                
TODAY AND TONIGHT RESPECTIVELY.  WENT ABOVE SAT MORNING BEFORE TEMPS            
START CRASHING WITH QUICK SURGE OF WAA.  EXPECT LITTLE REBOUND SUN              
WITH WRAP AROUND STRATUS SO HAVE UNDERCUT GUIDANCE SUN.                         
&&                                                                              
.AVIATION...21/12Z                                                              
LIFR CONDITIONS TO CONTINUE THROUGH 15Z AT ALL TERMINAL SITES...WITH            
THE EASTERN TERMINALS STILL SEEING LIFR CONDITIONS THROUGH 18Z.                 
VSBYS MAY IMPROVE THROUGHOUT THE AFTERNOON INTO THE IFR/MVFR                    
RANGE...HOWEVER CEILINGS ARE STILL EXPECTED TO REMAIN LOW. ALL                  
MODELS INDICATING A DECENT LAYER OF SATURATION THAT PERSISTS                    
THROUGHOUT THE LOWER LEVELS THROUGH THE DAY. HAVE TRENDED TOWARD A              
SLIGHTLY INCREASING VSBYS/CIGS IN THE AFTERNOON...AS RUC HINTS A                
BRIEF TIME PERIOD OF SOME DRIER AIR PUSHING INTO THE                            
WESTERN/SOUTHERN TAF SITES. HOWEVER AM SOMEWHAT SKEPTICAL...AND ALL             
AREAS MAY REMAIN SOCKED IN WITH FOG/LOW STRATUS THROUGH THE DAY WITH            
SOUTHEAST FLOW CONTINUING TO ADVECT MOISTURE FROM MISSOURI/FOG AREA             
INTO THE CWA.                                                                   
&&                                                                              
DMX WATCHES/WARNINGS/ADVISORIES...                                              
DENSE FOG ADVY ENTIRE AREA THROUGH 15Z...AND ALONG AND EAST OF                  
ALGONA-WEBSTER CITY-DES MOINES-CORYDON LINE TIL 18Z.                            
WINTER STORM WATCH 18Z SAT-12Z SUN ALONG AND EAST OF FOREST                     
CITY-WEBSTER CITY-WINTERSET-CHARITON-CORYDON LINE.                              
&&                                                                              
$$                                                                              
SMALL/ALBRECHT                                                                  
</pre> ia                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE LAKE CHARLES LA                                        
955 AM CST FRI DEC 21 2007                                                      
.UPDATE...DENSE FOG BURN OUT DELAYED ON THE LONGEST NIGHT OF THE                
YEAR. SHOULD BE SEEING RAPID IMPROVEMENT OVER THE EASTERN ZONES                 
VERY SHORTLY. WILL ISSUE UPDATED ZONES REMOVING PATCHY FOG ACCORDINGLY.         
OTHERWISE, LOWERED TEMPS TODAY DUE TO BOTH DELAYED BURNOFF AND                  
WEAK SUN USING LATEST UPDATED RUC.                                              
&&                                                                              
.PREV DISCUSSION... /ISSUED 610 AM CST FRI DEC 21 2007/                         
DISCUSSION...SHARP MOISTURE GRADIENT ACROSS EXTREME EASTER PARTS                
OF THE REGION...WHERE DEWPOINTS GO FROM 47 AT KLFT TO 59 AT KBTR.               
NOT COINCIDENTALLY...THIS ALSO SERVES AS THE DEMARCATION LINE FOR               
AREAS OF DENSE FOG...WHICH IS PRIMARILY OVER EASTERN PARTS OF                   
LOUISIANA INTO MISSISSIPPI. WILL MENTION AREAS OF FOG WITH DENSE                
SPOTS OVER THE EXTREME EASTERN TIER OF PARISHES...BUT FOREGO AN                 
ADVISORY WITH VISIBILITY BOUNCING AROUND A BIT...WORSENING A                    
LITTLE JUST WEST OF THE ATCHAFALAYA WHILE IMPROVING EAST OF IT.                 
SUNNY AND WARM CONDITIONS ON TAP FOR TODAY WITH HIGH PRESSURE AT                
THE SURFACE GRADUALLY SHIFTING EAST WHILE SHORTWAVE RIDGING ALOFT               
MOVES OVERHEAD. WILL START TO SEE MOISTURE RETURNING TO THE AREA                
LATE THIS AFTERNOON AND IN EARNEST LATE TONIGHT INTO EARLY                      
SATURDAY ONCE THE SFC HIGH SHIFTS EAST OF THE AREA AND 30-40 LLJ                
DEVELOPS.                                                                       
THERE ARE DIFFERENCES AMONG THE NAM AND GFS THAT HAVE IMPORTANT                 
IMPLICATIONS ON JUST HOW ACTIVE SATURDAY WILL OR WILL NOT BE.                   
WITHOUT DELVING INTO THE GORY DETAILS...SUFFICE IT TO SAY IN                    
SUMMARY THAT THE GFS OFFERS THE BETTER SEVERE POTENTIAL FROM A                  
TIMING...KINEMATIC...AND THERMODYNAMIC PERSPECTIVE...THOUGH IN                  
BOTH CASES INSTABILITY WILL BE A LIMITING FACTOR. TO THAT                       
END...SPC HAS A "SEE TEXT" DENOTED FOR THE AREA...AND CONCUR WITH               
THAT ASSESSMENT GIVEN THE PRESENT UNCERTAINTY.                                  
WHAT DOES SEEM MORE CERTAIN IS STRONG SOUTHERLY WINDS AHEAD OF THE              
FRONT...FOLLOWED BY EVEN STRONGER NORTH WINDS BEHIND IT. A LAKE                 
WIND ADVISORY IS POSSIBLE FOR PARTS OF THE AREA ON BOTH                         
SIDES...PARTICULARLY ALONG THE COAST. SHOWERS AND THUNDERSTORMS                 
EXPECTED TO COME TO AN END BY SATURDAY EVENING...WITH SUNDAY                    
DOMINATED BY COLD AIR ADVECTION.                                                
FOR THE MEDIUM TO EXTENDED RANGE...HAVE CONTINUED TO LEAN ON THE                
ECMWF...WITH THE GFS COMING MORE IN LINE WITH ITS SOLUTIONS. IT                 
WOULD SEEM THAT THIS SATURDAY FRONT WILL BE THE END OF THE 70                   
PLUS DEGREE DAYS FOR A WHILE...WITH THE TRAIN OF SHORTWAVES AMID                
THE PROGRESSIVE FLOW COMING FAST AND FURIOUS. LOOKS LIKE ABOVE                  
NORMAL RAIN CHANCES ABOUT EVERY TWO DAYS OR SO...WITH THE FIRST                 
SHOT AFTER THIS FRONT COMING MONDAY INTO...YEP...CHRISTMAS. THE                 
HIGHEST POPS FALL ON CHRISTMAS EVE...WITH THINGS HOPEFULLY                      
WINDING DOWN CHRISTMAS DAY AS THE UPPER TROF LIFTS OUT TOWARD THE               
MID ATLANTIC. ANOTHER WILL BE ON ITS HEELS...HOWEVER...AND                      
WEDNESDAY LOOKS TO BE THE NEXT DECENT CHANCE.                                   
AVIATION...EASTERN TERMINALS...KARA...KLFT...AND KAEX...FLIRTING                
WITH EXPANSIVE AREA OF FOG PRIMARILY OVER SOUTHEAST AND NORTHEAST               
LOUISIANA THIS MORNING. THERE HAS BEEN SOME WESTWARD EXPANSION                  
OVER THE PAST COUPLE OF HOURS...BUT ANY RESTRICTIONS WILL BE SHORT              
LIVED AND OCCUR GENERALLY PRIOR TO 13Z.                                         
MARINE...SOME PATCHY FOG THIS MORNING OVER THE 0-20NM ZONE FROM                 
INTRACOASTAL CITY TO THE LOWER ATCHAFALAYA. OTHERWISE...LIGHT                   
NORTH WINDS THIS MORNING WILL GRADUALLY BECOME EAST AND FINALLY                 
SOUTH BY THIS AFTERNOON AS HIGH PRESSURE SHIFTS EAST OF THE AREA.               
SOUTHERLY FLOW WILL STRENGTHEN TONIGHT IN ADVANCE OF A COLD FRONT THAT          
IS FORECAST TO MOVE THROUGH THE COASTAL WATERS SATURDAY AFTERNOON               
INTO SATURDAY NIGHT. AN SCEC HEADLINE MAY BE WARRANTED TONIGHT                  
AFTER MIDNIGHT AND SATURDAY PRIOR TO THE FRONT. SHOWERS AND                     
THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THE FRONT...WITH STRONG                
NORTHERLY WINDS AND BUILDING SEAS EXPECTED ONCE IT PASSES THROUGH.              
AN SCA SEEMS LIKELY FOR THESE CONDITIONS BEHIND THE FRONT.                      
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
KLCH  72  57  73  42 /   0  20  40  20                                          
KBPT  73  58  72  41 /   0  20  30  10                                          
KAEX  70  54  73  40 /   0  20  50  20                                          
KLFT  72  58  76  43 /   0  20  40  30                                          
&&                                                                              
.LCH WATCHES/WARNINGS/ADVISORIES...                                             
LA...NONE.                                                                      
TX...NONE.                                                                      
GM...NONE.                                                                      
&&                                                                              
$$                                                                              
11                                                                              
</pre> la                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
1117 AM EST FRI DEC 21 2007                                                     
.UPDATE...LITTLE TO NONE OF THE RETURNS ON THE RADAR ARE MAKING IT              
TO THE GROUND. SO HAVE SLASHED THE POPS FOR THE REST OF THE                     
DAYTIME AS MID LEVEL DRY AIR CONTINUES OVER THE REGION. SO FAR,                 
THE NAM AND RUC HAVE THE BETTER HANDLE ON THE 850 MB MOISTURE                   
MOVING IN WHICH LOOKS THE BEST. SO HAVE SCT SPRINKLES IN THE                    
FORECAST FOR THE AFTERNOON. BASED ON THE LOWER CLOUDS (AROUND 1500              
FEET) AT ANJ, AS WELL AS BELOW FREEZING TEMPERATURES, PUT PATCHY                
ZL- IN FOR E UPPER WITH IT CHANGING TO SCT SPRINKLES FOR THE                    
AFTERNOON AS THE TEMEPERATURES WARM AND THE DRY AIR PUSHES THE                  
LOWER CLOUDS OUT. OTHERWISE, TEMPERATURES AND WINDS LOOK GOOD.                  
LUTZ                                                                            
&&                                                                              
.PREV DISCUSSION... /ISSUED 738 AM EST FRI DEC 21 2007/                         
AVIATION...BKN MVFR CIGS ANTICIPATED ACROSS PORTIONS OF NRN LOWER               
MICHIGAN THIS MORNING...PARTICULARLY AT PLN/APN WITH SE FLOW OFF                
LAKE HURON PUSHING LOW CLOUD COVER INTO THOSE AREAS. OTHERWISE...               
SPOTTY ELEVATED SHOWER ACTIVITY WILL BE FOUND ACROSS THE REGION                 
TODAY ALONG ADVANCING NOSE OF WARM AIR AND MOISTURE ALOFT. LOWERING             
CIGS/VSBYS ALONG WITH AREAS OF DRIZZLE ANTICIPATED TONIGHT LEADING              
TO MVFR AND EVENTUALLY IFV CONDITIONS AT ALL THREE TAF LOCATIONS.               
ADAM                                                                            
DISCUSSION...ISSUED AT 509 AM.                                                  
LONGWAVE TROUGH PATTERN PREVALENT ACROSS NORTH AMERICA WITH A MYRIAD            
OF AMPLIFYING SHORTWAVES MOVING THROUGH THE FLOW. MOST SIGNIFICANT              
OF THESE WAVES...AND WHAT WILL BE THE MAIN FOCUS IN THE FORECAST FOR            
THE WEEKEND...BEGINNING TO TRAVERSE THE EXPANSE OF THE ROCKIES. ONE             
PIECE OF ENERGY NOW DIGGING INTO THE SW STATES WHILE ANOTHER WAVE IN            
WESTERN CANADA. OPERATIONAL NAM/GFS SOLUTIONS AS WELL AS THE GFS                
ENSEMBLES AND ECMWF SOLUTION ALL STILL DEPICTING A TROUGH MERGER                
BETWEEN THESE TWO SYSTEMS OVER THE UPPER MIDWEST... LATE SATURDAY               
THROUGH SUNDAY...AND ASSOCIATED RAPID SPIN-UP OF A DEEP SFC LOW OVER            
NRN MICHIGAN. IN THE MEANTIME...STILL PLENTY TO THINK ABOUT IN THE              
SHORT TERM. BUILDING MID LEVEL RIDGING DOWNSTREAM OF THIS SYSTEM AND            
INCREASING LOW LEVEL WARM/MOISTURE ADVECTION INTO THE WESTERN GREAT             
LAKES EXPECTED TO DOMINATE TODAY THROUGH MUCH OF SATURDAY...WITH                
CHANCES FOR LIGHT SHOWER AND DRIZZLE/FREEZING DRIZZLE ACTIVITY THE              
MAIN FORECAST ISSUES.                                                           
TODAY AND TONIGHT...MID CLOUD COVER AND ELEVATED RADAR RETURNS ALONG            
ADVANCING MID LEVEL MOISTURE GRADIENT CONTINUE TO PRESS INTO THE                
REGION FROM THE WEST-SOUTHWEST. HOWEVER...MORE WIDESPREAD LOW CLOUD             
COVER AND DRIZZLE ACTIVITY STILL WAY BACK ACROSS CENTRAL WISCONSIN              
INTO WESTERN UPPER MICHIGAN...ALTHOUGH SOME STRATUS HAS DEVELOPED/              
EXPANDED ACROSS THE HIGHER TERRAIN OF NE LOWER MICHIGAN OVERNIGHT.              
THUS FAR...RADAR RETURNS LOOK CONVECTIVE IN NATURE AS AXIS OF                   
STEEPER MID LEVEL LAPSE RATES PRESSES OUT OF WISCONSIN. BUT OUTSIDE             
OF A COUPLE OBS IN SW LOWER MICHIGAN SHOWING PRECIP OVERNIGHT...                
NOTHING REALLY GETTING TO THE GROUND THUS FAR. HOWEVER...RADAR                  
RETURNS HAVE INCREASED IN COVERAGE OVER THE LAST HOUR OR SO AND                 
PROBABLY NEED TO CARRY SOME SORT OF PRECIP THIS MORNING AS THE                  
MOISTURE AXIS AND STEEPER LAPSE RATES LIFT UP THROUGH THE REGION.               
QUESTION IS...WHAT WILL IT BE? FORECAST NAM SOUNDINGS FOR THIS                  
MORNING DEPICT ABOVE FREEZING LAYER ALOFT NOSING INTO THE REGION.               
BUT GIVEN THE DRY LOW LEVEL AIR STILL IN PLACE AND CONVECTIVE NATURE            
TO THE PRECIP...THINK ANYTHING THAT DOES REACH THE GROUND WILL BE OF            
THE FROZEN VARIETY. TIME WILL TELL OF COURSE BUT FOR NOW WILL CARRY             
CHANCY SNOW SHOWER WORDING THROUGH MIDDAY.                                      
THEN BY LATER THIS AFTERNOON THROUGH SATURDAY...LOW LEVEL                       
MOISTURE FINALLY GETS SHOVED INTO THE REGION LATER THIS AFTERNOON               
AND ESPECIALLY THIS EVENING...SETTING THE STAGE FOR AREAS OF FOG AND            
DRIZZLE TO DEVELOP. HAVE NOT CHANGED MUCH TO THE GOING FORECAST IN              
THIS REGARD OTHER THAN SLOWING DOWN THE DEVELOPMENT OF WIDESPREAD               
FOG AND DRIZZLE UNTIL LATER IN THE EVENING...AND ADDING FREEZING                
DRIZZLE TO SOME OF THE HIGHER TERRAIN AREAS WHERE TEMPS WILL LIKELY             
HOVER AROUND FREEZING. SOUPY CONDITIONS THEN EXPECTED TO PERSIST                
THROUGH SATURDAY ALTHOUGH CONTINUING WARM ADVECTION/MOISTENING ALOFT            
MAY BRING BETTER CHANCES FOR MEASURABLE PRECIP INTO THE REGION. IN              
ANY EVENT...A DREARY...DAMP COOL DAY LOOKS ON TAP FOR NRN MICHIGAN              
WITH TEMPS SLOWLY REACHING THE 35 TO 40 DEGREE MARK.                            
SATURDAY NIGHT THROUGH SUNDAY...TROUGH MERGER SLATED TO TAKE SHAPE              
OVER THE UPPER MIDWEST BRINGING ABOUT A RAPID SPIN UP OF A DEEP SFC             
LOW NEARLY OVER THE STATE...TRACKING UP ACROSS EASTERN LAKE SUPERIOR            
ON SUNDAY. VERY STRONG DYNAMICS COME INTO PLAY IN THIS SCENARIO AND             
AT THIS POINT CATEGORICAL POPS ARE JUSTIFIED SATURDAY NIGHT INTO                
SUNDAY WITH A GOOD SWATH OF PRECIP RUNNING UP THROUGH THE REGION.               
ALSO AT THIS POINT...MAINLY RAIN ANTICIPATED SATURDAY NIGHT WITH THE            
LOW DEEPENING JUST WEST OF THE REGION AND +4C OR BETTER H8 AIR                  
GETTING SHOVED UP THROUGH EASTERN UPPER MICHIGAN. A RAPID CHANGEOVER            
TO SNOW AS WELL AS SOUTHWEST-WEST LAKE EFFECT/ENHANCED SNOW SHOWERS             
EXPECTED TO FOLLOW SUNDAY AS CORE OF -14C OR COLDER H8 AIR ROTATES              
AROUND INTO LOWER MICHIGAN. A LOT OF WIND AND THE POTENTIAL FOR                 
HEAVY SNOW/NEAR BLIZZARD CONDITIONS WITH THIS SYSTEM SUNDAY AND                 
SUNDAY NIGHT WILL LIKELY WARRANT HEADLINES IN THE NEXT 1 TO 2                   
FORECAST CYCLES.                                                                
TBA                                                                             
CHRISTMAS EVE AND CHRISTMAS...LAKE AGGREGATE TROUGHING WILL CONTINUE            
ACROSS THE GREAT LAKES THROUGH THE DAY ON MONDAY...BEFORE 850MB                 
TEMPERATURES WARM TO AROUND -5C BY 00Z MONDAY. WITH SURFACE TROUGH              
ROTATING ACROSS NORTHERN MICHIGAN EARLY MONDAY MORNING...EXPECT TO              
SEE FAIRLY WIDESPREAD SNOW SHOWERS AND BLOWING SNOW. DURING THE DAY             
ON MONDAY...DEEPER MOISTURE STARTS TO PULL OUT AND PRECIPITATION                
SLOWLY BECOMES PURELY LAKE EFFECT. FINALLY...AS THE BOUNDARY LAYER              
WARMS...LAKE EFFECT WILL END MONDAY EVENING. HIGH PRESSURE WILL                 
BECOME ESTABLISHED OVER THE GREAT LAKES BY CHRISTMAS DAY...PROVIDING            
A FAIRLY PLEASANT DAY WITH HIGHS WARMING INTO THE LOWER 30S UNDER               
PARTLY SUNNY SKIES AFTER STARTING THE DAY IN THE TEENS.                         
KAS                                                                             
AVIATION... /ISSUED 1154 PM EST THU DEC 20 2007/                                
MID/HIGH CLOUDS ACROSS NORTHERN MI OVERNIGHT...SOME ST OVER                     
LAKE HURON MAY IMPACT APN THIS EVENING. CLOUD COVER AND PERSISTENT              
SOUTHEAST FLOW MAY IMPACT FOG POTENTIAL AT TERMINAL SITES OVERNIGHT.            
CEILINGS WILL LOWER DURING THE DAY FRIDAY...PREVAILING MVFR                     
CONDITIONS EXPECTED. SOME DRIZZLE OR LIGHT RAIN POSSIBLE DURING THE             
AFTERNOON.                                                                      
JPB                                                                             
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LMZ341.             
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LHZ346.             
LS...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LSZ321.             
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE ST LOUIS MO                                            
615 AM CST FRI DEC 21 2007                                                      
.DISCUSSION...                                                                  
LOTS OF WX CONCERNS FOR THE NXT 48 HRS. PRIMARY ISSUE FOR TDA...AT              
LEAST FOR THIS MRNG...IS DENSE FOG THAT CURRENTLY BLANKETS ENTR                 
FCST AREA. WITH ONLY A MODEST INCR IN MIXING DURG THE DAY...AND                 
WITH SFC/LO LVL TRAJECTORIES CONTINUING TO PUSH HIER DWPT AIR INTO              
REGION...THINK IMPROVEMENT WILL BE FAIRLY SLOW. PREVIOUSLY ISSUED               
DENSE FOG ADVISORY RUNS UNTIL 16Z AND HAVE OPTED TO NOT EXTEND IT               
ATTM AS CLIMO FAVORS SM INCR IN VSBYS...ALBEIT MODEST...IN THE                  
15-16Z TIME FRAME.                                                              
IF ST HOLDS ENTR DAY AS SUGGESTED BY INVERSION ON FCST                          
SNDGS...TEMPS ARE GOING TO STRUGGLE TO WRM. BASED ON YSTDAS                     
DIURNAL RECOVERY HV GIVEN MOST AREAS A MAX TEMP ABT 10 DEGREES ABV              
GOING READINGS.                                                                 
ATTENTION THEN TURNS TO SYSTEM MOVING THROUGH AREA SAT AND SAT                  
NGT. SPEED AND INTENSITY OF SYS CONTS TO VARY A BIT FROM MODEL TO               
MODEL AND FROM RUN TO RUN. HWVR...IT APRS THAT GFS IS TOO SLOW                  
WITH THE SYSTEM...AND MODEL CONSENSUS OF                                        
WRF/NAM...ECMWF...SREF...AND CANADIAN ALL SEEMS TO SUGGEST LEANING              
TWD A MORE PROGRESSIVE SOLN. FCST FROM 18Z SAT-12Z SUN GENLY                    
FOLLOWS A SREF/WRF-NAM BLEND FOR MOST ELEMENTS.                                 
ALTHO INITIALLY ON SAT MRNG MSTR WILL BE LIMITED...INCRG S FLOW                 
AHD OF TROF SHUD RAPIDLY MOISTEN THE AMS AOB 500 MB...AND PCPN                  
SHUD BGN TO BLOSSOM AS UVV ASSOC WITH TROF WORKS INTO MSVLY.                    
COLDER AIR WILL THEN WORK EWD...CHGG RAIN TO SNOW OVR W COUNTIES                
DURG THE AFTN...AND OVR THE IL COUNTIES ON SAT EVE. ALL MODELS                  
KEEP SYSTEM OPEN...WITH NO WELL-DEFINED SFC OR 850 MB LOW TRACK ON              
WHICH TO BASE SNOW POTENTIAL. USING CONSENSUS QPF AND MODEL SNDGS               
TO TIME CHGOVER TO SNOW SUGGESTS BEST CHC FOR ACCUM SNOW WILL BE                
OVR N/W COUNTIES...RUFLY FROM N OF COU TO NR UIN. SINCE SYSTEM IS               
MOVING SO FAST DON`T THINK SNOWFALL ACCUMULATIONS WILL BE                       
EXTREMELY HIGH...BUT AM WORRIED ABT THE EFFECT OF VRY STG WNDS IN               
WAKE OF SYSTEM COMBINING WITH ANY SNOW THAT DOES ACCUMULATE. TO                 
HIGHLIGHT THE THREAT HV CONTD MENTION OF BLOWING AND DRIFTING SNOW              
IN AREAS THAT APPEAR TO HV A CHC OF OVER AN INCH OF                             
ACCUMULATION...AND WL ALSO EMPHASIZE THIS CONCERN IN HWO.                       
ALL PCPN WITH SYSTEM SHUD END BY 12Z SUN...ALTHO GUSTY WINDS SHUD               
CONT THRUOUT THE DAY...SPCLY IN N SECTIONS OF THE FA.                           
TRUETT                                                                          
&&                                                                              
.AVIATION...                                                                    
FOR THE 12Z TAFS...SHOULD ONLY SEE A SLOW IMPROVEMENT IN VSBYS AND              
A SLOW RISE IN CEILING HGTS BGNG AT 15Z TO 16Z WITH SLOWLY INCRSG               
SELY SFC WNDS. WITH FCTS SOUNDINGS SHOWING BNDRY LYR MOISTURE                   
TRAPPED BLW AN INVERSION THRU THE DAY THE STRATUS CEILING SHOULD                
CONT. THE LATEST RUC FCST DOES SHOW LWRG RH IN THE 925 MB LYR BY                
21Z FRI OVR COU. WILL FCST BKN020 IN COU AT 21Z...BUT WILL KEEP AN              
OVERCAST CEILING AT 700 FT IN UIN...STL AND SUS THRU THE AFTN HRS.              
WILL IMPROVE THE VSBYS TO 2SM BR BY 16Z...AND THEN TO 4SM BR AT                 
18Z FRI AT THE TAF SITES. VSBYS SHOULD CONT TO IMPROVE THIS EVNG WITH           
THE STRATUS LYR CONTG TO SLOWLY RISE WITH MDLS DEPICTING INCRSG                 
LOW LVL S-SELY WNDS...ALTHOUGH THE BNDRY LYR REMAINS VERY MOIST.                
GKS                                                                             
&&                                                                              
.LSX WATCHES/WARNINGS/ADVISORIES...                                             
MO...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR AUDRAIN-               
     BOONE-CALLAWAY-COLE-CRAWFORD-FRANKLIN-GASCONADE-IRON-                      
     JEFFERSON-KNOX-LEWIS-LINCOLN-MADISON-MARION-MONITEAU-MONROE-               
     MONTGOMERY-OSAGE-PIKE-RALLS-REYNOLDS-SHELBY-ST. CHARLES-ST.                
     FRANCOIS-ST. LOUIS-ST. LOUIS CITY-STE. GENEVIEVE-WARREN-                   
     WASHINGTON.                                                                
IL...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR ADAMS IL-              
     BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-               
     JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-                      
     MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON                  
     IL.                                                                        
&&                                                                              
$$                                                                              
WFO LSX                                                                         
</pre> mo                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE BINGHAMTON NY                                          
1121 AM EST FRI DEC 21 2007                                                     
.SYNOPSIS...                                                                    
MARINE MOISTURE WILL RIDE UP THE MOUNTAINS OF NORTHEASTERN                      
PENNSYLVANIA, AND BRING CLOUDS AND PATCHY FREEZING DRIZZLE TO THE               
REGION TONIGHT. LOW PRESSURE WILL SPREAD STRONG WINDS AND RAIN                  
INTO NY AND PA FOR SUNDAY. BEHIND THE STORM WILL BE COLDER AIR AND              
LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT INTO MONDAY.                              
&&                                                                              
.NEAR TERM /THROUGH TONIGHT/...                                                 
LOW LEVEL SOUTHEAST FLOW OFF OF ATLANITC KEEPING CLOUDS OVER MOST               
OF THE CWA TODAY INTO SATURDAY. WITH THE THICK LOW CLOUDS DROPPED               
THE HIGH TEMPERATURES BY A FEW DEGREES. FEW OTHER CHANGES TO THE                
NEAR TERM.                                                                      
&&                                                                              
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...                                  
MAIN CONCERN IN THE NEAR TERM IS FOR PATCHY FREEZING DRIZZLE                    
OVERNIGHT, AND EARLY SATURDAY. MARINE LAYER MOISTURE WILL FLOW                  
NORTHWEST THROUGH PA TONIGHT. THE BEST CHANCE FOR FREEZING DRIZZLE              
WILL BE JUST NORTH OF THE HIGH TERRAIN IN NORTHEASTERN PA, AND ALSO             
INTO DELAWARE AND OTSEGO COUNTIES, WHERE THE ADDED LIFT SHOULD                  
ALLOW FOR SOME LIGHT DRIZZLE.                                                   
WE BRING CHC POPS INTO NY/PA SATURDAY AFTERNOON WITH WARM FRONTAL               
PUSH, THEN QUICKLY RAMP POPS SATURDAY NIGHT INTO SUNDAY. MODELS                 
ARE IN GOOD AGREEMENT REGARDING MOISTURE FLOW AND LIFT. THERE ARE               
SOME QPF DISCREPANCIES, WHICH COULD COME INTO PLAY ON SUNDAY. WITH              
1.50-2.00 INCHES OF LIQUID IN THE SNOW PACK MAINLY EAST OF I-81,                
AND AN ADDITIONAL 0.75-1.50 INCHES OF PRECIPITATION EXPECTED,                   
THERE IS A POSSIBILITY FOR HYDRO CONCERNS. GIVEN THE STRENGTH OF                
THE WINDS, THE HIGH DEW POINTS, AND THE MILD TEMPERATURES OVER AN               
EXTENDED PERIOD OF TIME, A LOT OF SNOW PACK COULD BE MELTED TO                  
RELEASE ITS WATER CONTENT.                                                      
&&                                                                              
.LONG TERM /MONDAY THROUGH THURSDAY/...                                         
MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT WITH FEATURES BEHIND THE                
STRONG LOW PRESSURE AND COLD FROPA SUNDAY NIGHT. CYCLONIC FLOW                  
ALOFT AND CAA ACROSS LAKE ONTARIO WILL MAINTAIN PLENTY OF CLOUDS                
AND LAKE EFFECT SNOW STREAMERS. MODELS DIVERGE TUES AND WEDNESDAY.              
ALL MODELS AGREE ON HIGH AMPLITUDE TROF DEVELOPING OVER INTERMOUNTAIN           
WEST...BUT THE LAST FEW RUNS OF GFS SEEM TO BE OUT ON THEIR OWN WITH            
MAINTAINING A STRONG RIDGE OVER THE SW ATLANTIC AND SE CONUS.THE                
GEFS/EC/GGEM/UKMET CAMP...AND EVEN NOGAPS SHOW SOME NRN/SRN STREAM              
PHASING OF UL LOW PRESSURE OVER THE SOUTHEASTERN STATES ON TUESDAY              
AND WEDNESDAY. THIS LEADS TO SIGNIFICANT CYCLOGENESIS OFFSHORE.                 
THAT SAID...THIS DOES NOT SEEM TO HAVE MUCH BEARING ON CNY/NEPA                 
WEATHER FOR THE MIDDLE OF NEXT WEEK...BARRING A SIGNIFICANT WWD                 
SHIFT IN MODEL TRACKS OF THE LOW FEATURE. BOTH MODEL CAMPS OFFER                
UP AT LEAST SOME DERIVATION OF HIGH PRESSURE FORMING OVER THE                   
NORTHEAST WITH FAIR WX BOTH CHRISTMAS DAY...AND WEDNESDAY AND WILL              
GO WITH THAT FOR NOW. THURSDAY ALSO BECOMES ANOTHER PROBLEM WITH                
MORE MODEL SPREAD. GFS AND IT/S GEFS ENSEMBLES LIFTS OUT THE                    
INTERMOUNTAIN WEST LOW BY THURSDAY...WHILE EC SEEMS TO HOLD BACK A              
COUPLE DAYS. CAN GGEM WOULD SUGGEST SOME PRECIP AS EARLY AS THURS.              
PREV FCST INDICATES CHC...AND WILL STICK WITH THAT CONSIDERING                  
OVERALL LOW PRESSURE INDICATED OVER UPR MIDWEST/GTLKS BY DAY 7 HPC              
PROG.                                                                           
PRETTY MUCH WENT WITH WHAT 00Z GMOS HAS OFFERED FOR TEMPS.                      
&&                                                                              
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...                                       
ANOTHER DAY...MORE CRAZY FLIGHT CONDITIONS IN CNY/NEPA. LATEST FOG              
PRODUCT SHOWS PLENTY OF HOLES HAD DEVELOPED IN THE STRATUS LAYER                
BETWEEN 08Z-11Z...WITH CIGS SCATTERING OUT TO VFR AT BGM-ELM-ITH-               
RME. ON THE FLIP SIDE...THIS CLEARING HAS ALLOWED MVFR AND BRIEF                
IFR VSBYS TO DEVELOP. MEANWHILE...MARINE LAYER STRATUS WAS NOT                  
THAT FAR AWAY...AND HAS INVADED AVP WITH MVFR CIGS. NOT EXACTLY                 
SURE WHY ALL THIS HAS TRANSPIRED...BUT COULD BE THAT SELY BLYR                  
FLOW HAS INCREASED WITH A LITTLE DOWNSLOPING WAS OCCURRING FROM THE             
CATSKILLS AND POCONOS WAS AFFECTING BGM-ELM-ITH...WHILE MOISTURE                
WAS INCRG ON THE LEE SIDE AT AVP. RUC AND NAM MODELS DO SEEM TO BE              
CAPTURING THIS IN THE 925 MB RH FIELDS...AND BOTH SUGGEST THAT BKN-OVC          
MVFR CIGS FROM THE MARINE LAYER WILL RETURN TO THE CLEARED OUT AREAS            
BY 15Z. SYR REMAINS SOCKED IN LIFR CIG. THINKING IS THAT THEY TOO               
WILL LIFT THE LOW LAYER TO MVFR BY 13Z OR 14Z. ONCE THE MARINE                  
STRATUS LAYER IS IN...IT IS PROGGED TO STAY THROUGH THIS PERIOD                 
WITH MINOR FLUCTUATIONS. ALSO EXPECT AS LAYER COOLS TONIGHT SOME                
WEAK UPSLOPE LIFT MAY CAUSE IFR CIGS AGAIN WITH FREEZING DRIZZLE                
AT AVP AND BGM...WITH LESS OF A CHC AT ELM-ITH AND VRY LITTLE CHC               
AT RME-SYR. CONFIDENCE IN THE DETAILS OF THIS FCST AT ANY STATION               
IS VERY LOW...NOT A GOOD DAY FOR VFR ONLY RATED AVIATORS.                       
HIGH PRESSURE STRENGTHENS A LITTLE ON SATURDAY WITH MODELS                      
SHOWING DRYING OF THE LOW LVLS IN THE AFTERNOON. THIS SHOULD AT                 
LEAST ALLOW CIGS TO REACH VFR. THEN...THE NEXT STORM SYSTEM APPCHS              
LATE SATURDAY NIGHT WITH PCPN DEVELOPING AFTER 06Z SUNDAY. RAIN                 
EXPECTED ON SUNDAY BEFORE STRONG COLD FRONTAL PASSAGE TOWARD                    
EVENING...WITH PRECIPITATION CHANGING OVER TO ALL SNOW. EXPECT                  
VARIABLE MVFR-IFR CIG RESTRICTIONS ON SUNDAY AND SUNDAY NIGHT.                  
WINDS INCREASE OUT OF THE SOUTHEAST SUNDAY MORNING WITH LOW-LEVEL               
WINDS OF 50+ KTS DURING THE DAY ON SUNDAY WITH LLWS POSSIBLE...FOLLOWED         
BY BLUSTERY WEST-NW WINDS POST FROPA ON SUNDAY NIGHT. COLD                      
ADVECTIVE NORTHWEST FLOW WILL CAUSE LAKE EFFECT ON MONDAY AND                   
MONDAY NIGHT WITH STRATOCUMULUS MVFR/IFR CIGS...AND ALSO POOR VSBY              
IN SHSN. HIGH PRESSURE BEGINNING TO BUILD IN ON TUESDAY WILL SHUT               
LAKE EFFECT OFF BY MID-WEEK.                                                    
&&                                                                              
.BGM WATCHES/WARNINGS/ADVISORIES...                                             
PA...NONE.                                                                      
NY...NONE.                                                                      
&&                                                                              
$$                                                                              
SYNOPSIS...TAC                                                                  
NEAR TERM...TAC                                                                 
SHORT TERM...DJP                                                                
LONG TERM...JAB                                                                 
AVIATION...JAB                                                                  
</pre> ny                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE NORTHERN INDIANA                                       
357 PM EST FRI DEC 21 2007                                                      
.SHORT TERM (TONIGHT AND SATURDAY)...                                           
FOCUS TONIGHT WILL BE ON ADVANCING AREA OF INCREASED DEWPOINTS AND              
ANTICIPATED LOWER VISIBILITIES IN FOG. LOCATIONS SEEING DEWPTS IN               
THE 34 DEGREE OR HIGHER RANGE TO THE SOUTH AND WEST ARE SEEING THE              
DENSER FOG HOLDING ON. RUC40/NAM12 ALL SHOWING SLOWER ARRIVAL OF                
HIGHER DEWPOINTS...WITH BEST ADVECTION NOT OCCURRING TILL CLOSER                
TO 6Z IN THE SW AND SPREADING NORTH OVERNIGHT. AS A RESULT WILL                 
MAKE FURTHER ADJUSTMENTS AND SLOW DOWN ONSET OF FOG AND DRIZZLE.                
KIWX 88D SHOWS SOME LIGHT RETURNS THAT MAY REACH THE GROUND IN THE              
FORM OF A BIT OF DRIZZLE OR FLURRIES. SOME CONCERNS AS STUBBORN AS              
THE DRIER FLOW IS INTO THE AREA THAT FOG MAY STRUGGLE TO GET TOO                
FAR NORTH. WILL REMAIN OPTIMISTIC AS 925/850 MB WINDS RAMP UP                   
LATER TONIGHT AND SHOULD ALLOW THE MSTR TO GET ON THE MOVE.                     
ON SATURDAY...CONTINUATION OF SNOWMELT AND HIGHER DEWPTS WILL                   
CONTINUE IN INCREASING S TO SW FLOW. NAM/GFS/SREF HAVE ALL TRENDED              
SLOWER WITH ARRIVAL OF PRECIP NOT BRINGING IN TILL LIKELY OUTSIDE               
THIS PERIOD. DID NOT WANT TO DROP ALL POPS AT THIS POINT SO WENT                
DRASTIC DOWNWARD TREND AND REPOSITION OF BEST CHC FOR ANY PRECIP                
BY LATE AFTERNOON. WITH SLOWER ARRIVAL OF PRECIP...WARMER TEMPS                 
MAY BE POSSIBLE ESPECIALLY IF FOG CAN LIFT OUT SOONER OR DOESN`T                
MATERIALIZE AS MUCH. FOR NOW HAVE LEFT THINGS ALONE TEMP WISE.                  
&&                                                                              
.LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...                                   
SATURDAY NIGHT THROUGH SUNDAY                                                   
AMPLIFIED PATTERN ACROSS THE CENTRAL AND EASTERN CONUS WITH DEEP                
TROUGH OVER THE CENTRAL CONUS AND RIDGING ACROSS THE EAST. SFC                  
WAVE MOVING UP FROM MID MS VALLEY TOWARDS LAKE MICHIGAN BY LATE                 
SATURDAY NIGHT INTO EARLY SUNDAY. SFC LOW MOVES THRU THE LP OF                  
MICHIGAN AN NORTH INTO CENTRAL ONTARIO BY SUNDAY AFTERNOON...BEFORE             
PULLING NORTHEAST INTO NORTHERN QUEBEC BY EARLY MONDAY. THERMAL                 
PROFILE ACROSS THE REGION SUGGESTS ALL RAIN THRU THE OVERNIGHT                  
BEFORE STARTING THE TRANSITION PERIOD AROUND DAYBREAK SUNDAY.                   
MODELS HAVING BEEN SLOWING THE SYSTEM DOWN AND HAVE THEREFORE                   
SLOWED THE PRECIP CHANGEOVER DOWN SOME AS WELL...AS THE H850 TEMPS              
DROP FROM +5 C TO BELOW 0C ACROSS THE ENTIRE REGION BETWEEN                     
12-15Z. ANY WRAP AROUND OR LAKE ENHANCED PRECIP WILL BE SNOW THEN               
THROUGH THE LATE MORNING INTO THE AFTERNOON WITH VERY STRONG CAA                
INTO THE REGION. TEMPS WILL CONTINUE TO DROP FROM LATE SATURDAY                 
NIGHT THRU SUNDAY NIGHT...FROM 40S LATE SATURDAY NIGHT INTO THE                 
20S BY SUNDAY AFTERNOON...AND TEENS FOR LOWS OVERNIGHT INTO EARLY               
MONDAY.                                                                         
SIGNIFICANT AMOUNTS OF MOISTURE FOR THE SYSTEM TO WORK WITH WITH                
PWATS ABOVE 1 INCH EARLY SUNDAY...LIQUID QPF AMOUNTS WILL PUSH .5               
INCHES FOR MOST OF THE AREA...BUT VERY LITTLE SNOW ACCUMS EXPECTED              
THRU THE PERIOD. MAINLY WITH LAKE ENHANCED OR LAKE EFFECT ACROSS                
THE FAR NW PORTIONS OF THE AREA AND ACROSS THE FAR NORTHERN TIER                
OF COUNTIES AS THE FLOW ACROSS THE LAKE BECOME MORE WESTERLY WITH               
TIME...MAYBE AN INCH OR TWO. UPPER LEVEL LOW STARTS TO PUSH INTO                
THE GREAT LAKES EARLY SUNDAY AND THRU THE DAY...VERY TIGHT                      
PRESSURE GRADIENT ACROSS THE REGION WITH NORTHWEST/WEST FLOW                    
THROUGH THE DAY. GUSTY WINDS WILL INCREASE FROM EARLY SUNDAY                    
THROUGH SUNDAY AFTERNOON. LAKE EFFECT SNOW ACROSS THE NORTHERN                  
TIER OF THE CWA WILL CONTINUE TO BE A POSSIBILITY WITH DELTA T/S                
REACHING LEVELS OF -15 OR MORE BY SUNDAY EVENING.                               
MONDAY THROUGH FRIDAY                                                           
SPLIT FLOW ACROSS THE WEST BECOMES MORE CONFLUENT ACROSS THE                    
EASTERN CONUS...UPPER LEVEL LOW PUSHING EAST THRU THE ST LAW RVR                
VALLEY WITH ANOTHER SW CONUS SHRTWV PULLING OUT AND WEAKENING AS                
IT MOVES TO THE NORTHEAST. LARGE SFC HIGH ENTRENCHED ACROSS THE                 
GREAT LAKES/OH AND MS VALLEYS INTO TUESDAY...WITH SOME UPPER LEVEL              
RIDGING BUILDING ACROSS THE REGION TUESDAY INTO WEDNESDAY WITH                  
ANOTHER UPPER LEVEL LOW OVER THE SW CONUS. BELOW NORMAL TEMPS                   
EXPECTED MONDAY...SLIGHTLY WARMER AND NEAR SEASONAL VALUES OF                   
LOWER TO MID 30S FOR HIGHS. DRY THRU THE PERIOD...A SMALL CHANCE                
OF LAKE EFFECT ACROSS THE FAR NORTH EARLY MONDAY.                               
MID RANGE MODELS HAVING SOME ISSUES THRU THE END OF THE                         
PERIOD...SIGNIFICANT DISAGREEMENTS WITH RESPECT TO THE STRENGTH AND             
TIMING BUT THE LATEST GFS AND THE ENSEMBLE MEANS HAVE BEEN                      
SHOWING SOME SIGNIFICANT WINTRY POTENTIAL TOWARDS THE END OF THE                
MONTH. FIRST POTENTIAL SIGNIFICANT SYSTEM WILL BE WEDNESDAY NIGHT               
INTO THURSDAY TIMEFRAME. CUT-OFF LOW PUSHES EAST INTO THE                       
RIDGE...POSSIBLE NEG TILT WITH SFC LOW MOVING FROM THE LOWER MS                 
VALLEY INTO THE REGION. MOISTURE SHOULD NOT BE A CONCERN WITH THE               
GULF APPEARING TO BE OPEN...PWATS AT OR MORE THAN DOUBLE NORMAL                 
FOR THE TIME OF YEAR. THE TRACK STILL UNCERTAIN...WILL LIMIT THE                
DETAILS...BUT CURRENT BUFKIT AND MODEL THERMAL PROFILES WOULD                   
SUGGEST ALL SNOW. HAVE UPPED POPS TO 50 THRU THE PERIOD WITH                    
HIGHER CONFIDENCE THAT A SYSTEM WILL BE THERE...BUT LOWER                       
CONFIDENCE ON TRACK AND P-TYPE AS THE MODELS THIS SEASON HAVE HAD               
SOME SIGNIFICANT SHIFTS OVER TIME OF UP TO 300-500 MILES.                       
ANOTHER DIGGING UPPER LEVEL LOW INTO THE SOUTHWEST LATE IN THE                  
WEEK...THURSDAY INTO FRIDAY...WILL START KICK OUT AND WILL ALLOW                
FOR THE SECOND POTENTIAL WINTER SYSTEM BY THE WEEKEND. PRECIP                   
COULD START AS SOON AS FRI NIGHT/SATURDAY...WITH TRACK AND P-TYPE               
HIGHLY UNCERTAIN...STILL 6-7 DAYS OR MORE OUT MUCH TO CHANGE MOST               
LIKELY. STRONG MODEL SUPPORT FROM THE GFS ENSEMBLES.                            
&&                                                                              
.IWX WATCHES/WARNINGS/ADVISORIES...                                             
IN...NONE.                                                                      
MI...NONE.                                                                      
OH...NONE.                                                                      
LM...NONE.                                                                      
&&                                                                              
$$                                                                              
SHORT TERM...FISHER                                                             
LONG TERM...SCHOTT                                                              
</pre> in                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE NORTHERN INDIANA                                       
1214 PM EST FRI DEC 21 2007                                                     
.UPDATE...                                                                      
UPDATED GRIDS/ZONES EARLIER TO SLOW DOWN ARRIVAL OF FOG BASED ON                
TRENDS AND RUC40 DATA. HIGHER DEWPTS SLOWLY COMING IN BUT LOOK TO               
BE DELAYED UNTIL LATER TODAY INTO TONIGHT. HAVE PUSHED BACK                     
MENTION OF DENSE FOG TO TONIGHT WHEN MOISTURE WILL INCREASE                     
DRAMATICALLY AS LOW LEVEL FLOW BEGINS TO INCREASE. HAVE JUST WENT               
PATCHY DENSE AT THIS POINT. TEMPS STILL LOOK OK FOR NOW SO HAVE                 
LEFT THEM AND THE REMAINDER OF THE GRIDS ALONE.                                 
&&                                                                              
.AVIATION...                                                                    
AS MENTIONED IN UPDATE...HAD PREVIOUSLY SLOWED DOWN ARRIVAL OF                  
MAINLY LOWER VSBYS. WILL NEED TO CONTINUE THIS TREND WITH GENERAL               
MVFR VSBY/IFR CIGS STARTING THE PERIOD THEN DROPPING TO LIFR                    
CONDITIONS BY EARLY EVENING AT KSBN. MAY BE A BIT SLOWER ARRIVAL                
AT KFWA. ONCE THESE ARRIVE...LITTLE OVERALL CHANGE EXPECTED UNTIL               
SATURDAY AS WINDS BEGIN TO INCREASE AND ALLOW FOR BETTER MIXING                 
AND INCREASE IN HGTS/VSBYS.                                                     
&&                                                                              
.PREV DISCUSSION... /ISSUED 640 AM EST FRI DEC 21 2007/                         
SHORT TERM...                                                                   
TODAY AND TONIGHT LOTS OF LOW LEVEL MOISTURE...DRIZZLE AND FOG IS               
THE STORY FOR TODAY AND TONIGHT. WARM AIR ADVECTION WILL CONTINUE               
TODAY. THE SNOW COVER ACROSS THE AREA WILL KEEP TEMPERATURES NEAR               
THE SURFACE COOLER THAN UP ABOVE...SETTING UP A DECENT INVERSION                
TODAY. THIS WILL HELP TO KEEP THE MOISTURE FROM THE MELTING SNOW                
TODAY TRAPPED NEAR THE SURFACE...RESULTING IN FOG ACROSS THE AREA.              
WITH DECENT MOISTURE UP TO ABOUT 5KFT TO 7KFT...DRIZZLE IS ALSO                 
POSSIBLE. THE LARGE DEWPOINT DEPRESSIONS IN THE CWA THIS NIGHT                  
HAVE KEPT THE LIGHT RAIN/DRIZZLE OFF TO THE WEST...BUT THE                      
ATMOSPHERE IS EXPECTED TO BECOME MORE AND MORE SATURATED AS THE                 
HOURS PASS BY...AND EVENTUALLY THE LOWER CEILINGS AND VISIBILITIES              
WILL MOVE INTO THE CWA. JUST WHEN THESE LOWER CONDITIONS WILL MOVE              
IN AND WHERE THEY WILL DROP THE MOST HAS BEEN THE TRICKIEST PART                
OF THE FORECAST FOR TODAY. VISIBILITIES ARE STILL UP ACROSS THE                 
CWA SO HAVE SLOWED DOWN THE FOG MOVING INTO/FORMING IN THE AREA.                
ALSO TO NOTE WHERE TEMPERATURES ARE AT FREEZING AND BELOW...MAINLY              
IN THE NORTHEASTERN TO EASTERN PARTS OF THE CWA...EARLY THIS                    
MORNING ANY DRIZZLE WILL BE FREEZING DRIZZLE. BUT TEMPERATURES ARE              
EXPECTED TO WARM UP ABOVE THE FREEZING MARK ACROSS THE ENTIRE CWA               
BY MID MORNING. TRICKY YET AS TO HOW FAR EASTWARD AREAS OF DENSE                
FOG COULD MAKE IT...BUT FOR RIGHT NOW JUST HAVE THE WESTERN PART                
OF THE CWA SEEING AREAS OF DENSE FOG FORM THIS MORNING.                         
THE WARM AIR ADVECTION WILL CONTINUE THROUGH THIS EVENING AND                   
TONIGHT...RESULTING IN NON DIURNAL TEMPERATURES FOR TONIGHT.                    
TEMPERATURES WILL EITHER REMAIN FAIRLY STEADY OR SLOWLY INCREASE A              
FEW DEGREES THROUGHOUT THE NIGHT. THEREFORE THIS DAY/S LOW                      
TEMPERATURES ARE EXPECTED TO OCCUR EARLY THIS MORNING. THE                      
ATMOSPHERE IS GOING TO REMAIN FAIRLY WELL SATURATED IN THE LOWER                
LEVELS THROUGH TONIGHT WITH THE LOW LEVEL INVERSION CONTINUING                  
THROUGH TONIGHT. THEREFORE AREAS OF FOG AND DRIZZLE ARE CONTINUED               
FOR TONIGHT.                                                                    
LONG TERM...                                                                    
SATURDAY THROUGH THURSDAY                                                       
MAIN EMPHASIS ON WEST COAST SYSTEM TO ARRIVE SAT NIGHT. NAM                     
FAVORED SOLN WITH INITIALIZATION OF COMPLEX WESTERN TROF WITH                   
ALBERTA ENERGY AND STRATOSPHERIC INTRUSION ACRS WCENTL NV/SOCAL AT              
00 UTC. RATHER BROAD TONGUE OF 40F PLUS DEWPOINTS ALREADY POISED                
NORTH OF OHIO RIVER AND WITH SEVERAL HOURS OF ADDITIONAL SNOWMELT               
AND ADVECTIVE COMPONENT WILL AID IN TOTAL MOISTURE INCREASE                     
AHEAD OF STRONG FULL LATITUDINAL SYSTEM THAT WILL UNDERGO RAPID                 
INTENSIFICATION.                                                                
FROM F36-60 RAPID ML HEIGHT FALLS ON ORDER OF 160-190/12 HRS                    
REFLECTS NEAR BOMBO SURFACE CYCLOGENESIS AS RED RIVER VLY SFC LOW               
AT F36/12 UTC SAT NEAR RED RIVER VLY TX SURGES NE TO 1001 MB CNTL               
IL THEN TO 987MB OVER CNTL UP. PWAT APPROACH 1 INCH WITH 7.5-7.8                
G/KG IN 1000-850MB LAYER WITH TREMENDOUS LOW LEVEL KINEMATICS                   
UPPED POPS TO 90 PERCENT WITH STRONG SIGNALS/MOISTURE...CONSIDERED              
ISOLD TSRA THOUGH OVERALL CHANCES SLIGHT. DRY SLOT BEHIND FRONT                 
QUICKLY BRING POPS DOWN TO CHC CATEGORY...AND PTYPE QUICKLY TO                  
SNOW LATE SATURDAY NIGHT WEST IN STRONG/DEEP CAA WITH ABRUPT                    
CHANGEOVER THOUGH LITTLE IF ANY ACCUM EXPECTED. RAMPED WINDS SAT                
THRU SUN NIGHT...ESP SUN GIVEN INTENSITY OF SFC LOW. BEYOND LITTLE              
CHANGE MADE.                                                                    
&&                                                                              
.IWX WATCHES/WARNINGS/ADVISORIES...                                             
IN...NONE.                                                                      
MI...NONE.                                                                      
OH...NONE.                                                                      
LM...SMALL CRAFT ADVISORY FROM 1 AM SUNDAY TO 7 AM EST MONDAY FOR               
     LMZ043-046.                                                                
&&                                                                              
$$                                                                              
SHORT TERM...LOTHAMER                                                           
LONG TERM...MURPHY                                                              
AVIATION/UPDATE...FISHER                                                        
</pre> in                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GOODLAND KS                                            
200 PM MST FRI DEC 21 2007                                                      
.DISCUSSION...FORECAST CONCERNS ARE ON WINDS AND SNOW TONIGHT                   
THROUGH EARLY IN THE DAY SATURDAY. MORE SNOW EXPECTED AGAIN                     
CHRISTMAS DAY INTO WEDNESDAY WITH ANOTHER THURSDAY INTO FRIDAY.                 
.SHORT TERM (TONIGHT-MONDAY NIGHT)...                                           
TONIGHT-SATURDAY...UPPER TROUGH AXIS CURRENTLY EXTENDING ALONG THE              
CONTINENTAL DIVIDE WILL MOVE ACROSS THE AREA OVERNIGHT AND BY 18Z               
BE EAST OF THE AREA. THE COMBINATION OF 850-500MB MOISTURE/MID                  
LEVEL FRONTOGENESIS AND 250 JET DIVERGENCE WILL FAVOR HIGHEST POPS              
ACROSS SOUTHERN 2/3 OF THE AREA...HIGHEST ACROSS THE FAR SOUTH. TOTAL           
ACCUMULATIONS IN THIS AREA WILL RANGE FROM 1 TO 3 INCHES...HIGHEST              
SOUTH. LATEST NAM/RUC SHOWING SOME ORGANIZATION TO THE SNOW ACROSS              
INTERSTATE 70 WITH A LULL IN SNOW IN THE DOWNSLOPE AREAS OF                     
CHEYENNE COUNTY COLORADO AND WALLACE KS. WILL ISSUE A SNOW AND                  
BLOWING SNOW ADVISORY AS A RESULT FROM 03Z TONIGHT THROUGH 18Z                  
SATURDAY. ELSEWHERE...WILL UPDATE THE HWO TO TALK ABOUT THE SNOW                
AND POTENTIAL FOR BLOWING SNOW OUTSIDE THE ADVISORY AREA. WILL                  
KEEP SOME POPS MENTIONED ACROSS THE FAR EAST/SOUTHEAST THROUGH 18Z              
SATURDAY GIVEN TIMING DIFFERENCES AMONGST THE MODELS WITH REGARD                
TO HOW FAST THE SYSTEM LEAVES THE AREA. GFS/09Z SREF THE SLOWER OF              
THE MODELS WITH THE NAM/NGM A BIT QUICKER. AFTER 18Z IT SHOULD BE               
PRETTY MUCH OVER WITH...EXCEPT THE WIND.                                        
ONCE THE SNOW ENDS WE STILL HAVE TO DEAL WITH STRONG WINDS JUST                 
OFF THE SURFACE AND INCREASING SUNSHINE AS THE SYSTEM MOVES EAST.               
QUESTION BECOMES WHETHER THE WIND WILL FULLY MIX TO THE SURFACE                 
GIVEN EXISTING SNOW COVER AND EXPECTED LIGHT ACCUMULATIONS. FOR                 
NOW WILL NOT ISSUE A WIND ADVISORY FOR THE 18Z- 22Z TIME FRAME                  
GIVEN THE CONCERN LISTED ABOVE.                                                 
SATURDAY NIGHT-SUNDAY...WILL HAVE A BRIEF PERIOD OF CLEAR SKIES                 
BEFORE MID AND UPPER LEVEL MOISTURE SPREADS ACROSS THE AREA FROM                
THE NORTHWEST AFTER MIDNIGHT AS ANOTHER QUICK MOVING SYSTEM MAKES               
ITS WAY TOWARD THE AREA. COLUMN STARTS TO SATURATE IN THE 850-500               
LAYER DURING THE DAY SUNDAY FROM NORTHWEST TO SOUTHEAST. DESPITE                
THE INCREASE IN MOISTURE DYNAMICS AND LIFT ARE LACKING...THUS WILL              
MAINTAIN A NO POP FORECAST.                                                     
SUNDAY NIGHT-MONDAY NIGHT...WELL ORGANIZED UPPER DISTURBANCE                    
EMBEDDED IN A DEEP AND COMPACT TROUGH WILL MOVE SOUTH THROUGH THE               
FRONT RANGE AND EASTERN PLAINS OF COLORADO INTO SOUTHWEST/SOUTH                 
CENTRAL KANSAS BY THE END OF THE PERIOD. LOOKS LIKE THIS SYSTEM                 
WILL SLIDE JUST FAR ENOUGH WEST AND SOUTH OF THE AREA TO KEEP                   
SILENT POPS IN THE FORECAST...GENERALLY ACROSS THE SOUTHWEST PART               
OF THE AREA. WILL NEED TO KEEP AN EYE ON IT FOR POSSIBLE INCREASE               
IN POPS FOR SOME LIGHT SNOW...AGAIN GENERALLY ACROSS THE SOUTHWEST              
1/3 OF THE AREA SUNDAY NIGHT. LITTLE TO TALK ABOUT MONDAY BUT                   
MONDAY NIGHT FEATURES ANOTHER TROUGH AND INCREASING                             
MOISTURE/CLOUDINESS MOVING TOWARD THE AREA FROM THE NORTHWEST.                  
.LONG TERM (TUESDAY-FRIDAY)...                                                  
GENERALLY FOLLOWED ECMWF GUIDANCE FOR THE EXTENDED AS IT HAS                    
SHOWN THE BEST RUN TO RUN CONTINUITY AND ALSO RECEIVES SUPPORT                  
FROM THE CANADIAN ENSEMBLE MEAN. APPEARS THE ACTIVE SYNOPTIC SCALE              
FLOW PATTERN WILL CONTINUE WITH A SERIES OF SHORTWAVE TROUGHS                   
TRAVERSING THE CWA DURING THIS TIME FRAME.                                      
THE FIRST SYSTEM LOOKS TO ARRIVE ON CHRISTMAS DAY AS THE H5 RIDGE               
SLIDES OFF TO THE EAST. WHILE IT APPEARS MAIN AREA OF H85-H7                    
FRONTOGENESIS WILL STAY SOUTH OF OUR CWA...IT WILL BE CLOSE ENOUGH              
TO ALLOW AT LEAST SOME LIGHT SNOW TO FALL. WITH H85 WINDS AOB                   
20KTS...TRAVEL ISSUES DO NOT APPEAR TO BE A CONCERN AT THIS TIME. EC            
IS SLOWER IN MOVING THE SYSTEM OUT OF THE AREA SO HAVE SLIGHT CHC TO            
CHC POPS CONTINUING INTO WEDNESDAY.                                             
APPEARS WE WILL HAVE A VERY SHORT BREAK BEFORE THE NEXT SHORTWAVE               
TROUGH MOVES IN AROUND MIDDAY ON THURSDAY. DYNAMICS APPEAR A LITTLE             
BETTER FOR US WITH THIS STORM AS THE EC TRACKS THE H5 OPEN WAVE                 
TROUGH OVER SOUTHWEST KANSAS. WENT WITH SLIGHT CHC POPS FOR NOW BUT             
WILL NEED TO MONITOR FUTURE RUNS FOR ANY NECESSARY ADJUSTMENTS. WILL            
SEE WEAK RIDGING START TO SET BY LATE FRIDAY AS THE SHORTWAVE TROUGH            
SHIFTS OFF TO THE NORTHEAST AND INTO THE WESTERN GREAT LAKES REGION.            
&&                                                                              
.AVIATION...                                                                    
FOR THE 00Z TAF...NORTHWEST WINDS OF 25 TO 30 KTS WITH HIGHER                   
GUSTS WILL BLOW THROUGH THE TAF PERIOD. SNOWFALL WILL BEGIN IN THE              
KGLD AREA SHORTLY BEFORE 06Z WHILE KMCK WILL NOT START TIL THE                  
06-09Z TIME FRAME. THE COMBINATION OF THE WIND AND SNOW WILL                    
PRODUCE REDUCED VISIBILITIES IN SNOW AND BLOWING SNOW THROUGH                   
ROUGHLY 12-15Z SATURDAY MORNING. FROM 15Z-22Z WINDS WILL REMAIN                 
IN THE 20 TO 30 KT RANGE THEN QUICKLY FALL OFF WITH A GRADUAL                   
CLEARING FROM WEST TO EAST. CIGS WILL BE IN THE MVFR/IFR RANGE                  
THROUGH THE PRECIPITATION DURATION.                                             
&&                                                                              
.GLD WATCHES/WARNINGS/ADVISORIES...                                             
KS...SNOW AND BLOWING SNOW ADVISORY FROM 8 PM MST /9 PM CST/ THIS               
     EVENING TO 11 AM MST /12 PM CST/ SATURDAY FOR KSZ013>016-                  
     028-029-041-042.                                                           
NE...NONE.                                                                      
CO...SNOW AND BLOWING SNOW ADVISORY FROM 8 PM THIS EVENING TO 11 AM             
     MST SATURDAY FOR COZ091.                                                   
&&                                                                              
$$                                                                              
DDT/FOLTZ/BURTIS                                                                
</pre> ks                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE DODGE CITY KS                                          
254 PM CST FRI DEC 21 2007                                                      
.DISCUSSION...                                                                  
DAYS 1-2...                                                                     
CONCERNS HAVE INCREASED THIS FORECAST PACKAGE REGARDING DANGEROUS               
SNOW AND BLOWING/DRIFTING SNOW THREAT...TO THE POINT THAT BLIZZARD              
WARNING IS NECESSARY ACROSS PORTIONS OF SOUTHWEST KANSAS.                       
EARLY AFTERNOON WATER VAPOR LOOP WITH RUC ANALYSIS OVERLAY SHOWS                
CLUSTER OF MID LEVEL PV MAXIMA ACROSS FOUR CORNERS REGION. PRIMARY              
VORT MAX WAS JUST ENTERING WESTERN NEW MEXICO WITH PERSISTENT                   
LIGHTNING STRIKES NOTED AS WELL. THE PRIMARY MID LEVEL VORT WILL                
CONTINUE TO ROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD                
DURING THE EVENING HOURS...SPAWNING SUBSTANTIAL LOWER TROPOSPHERIC              
DEVELOPMENT TO THE SOUTH OF DDC CWA ACROSS THE PANHANDLES. LATEST               
12HR FORECAST OF RUC AND NAM SHOW FAIRLY STRONG CYCLOGENESIS IN                 
THE H85-7 LAYER ALONG THE "GOLDEN PATH" FOR SOUTHWEST KANSAS HEAVY              
PRECIPITATION EVENT. AS A MATTER OF FACT...THE LATEST RUC AND NAM               
18Z RUNS SUGGEST MORE LOWER TROPOSPHERIC DEVELOPMENT AND                        
SUBSEQUENTLY STRONGER LIFT FOR HEAVIER PRECIPITATION. THE 18Z NAM               
SHOWS MORE QPF AS WELL AS A RESULT (ON THE ORDER OF 5 TO 8                      
INCHES OVER THE SOUTHWESTERN COUNTIES). THE GREATEST H7                         
FRONTOGENESIS ASSOCIATED WITH THE CYCLONE WILL BE FOCUSED MAINLY                
ALONG AND SOUTH OF THE ARKANSAS RIVER. IT STILL APPEARS THAT THE                
DURATION OF SNOWFALL AT ANY ONE LOCATION WILL BE AROUND 6 TO 8                  
HOURS ON AVERAGE. DURING THIS TIME FRAME...SUBSTANTIAL SURFACE                  
WINDS WILL PREVAIL WITH SUSTAINED NORTH WINDS ON THE ORDER OF 25                
TO 35 MPH. GUSTS ARE EXPECTED TO BE FREQUENTLY IN THE 35 TO 45 MPH              
RANGE...AND GIVEN THIS...HAVE DECIDED TO UPGRADE THE WINTER STORM               
WATCH TO A BLIZZARD WARNING FOR ROUGHLY SYRACUSE TO JETMORE TO                  
KINSLEY...SOUTH TO THE OKLAHOMA BORDER. NORTH AND EAST OF THIS                  
BLIZZARD WARNING WILL GO WITH A SNOW AND BLOWING SNOW ADVISORY.                 
IN THE BLIZZARD WARNING AREA...AM EXPECTING WIDESPREAD 3 TO 5                   
INCHES WITH SOME LOCAL 6 OR 7 INCH AMOUNTS POSSIBLE...ALTHOUGH                  
MEASURING THE SNOW WILL BE A DIFFICULT ENDEAVOR TO SAY THE LEAST.               
IN THE SNOW/BLOWING SNOW ADVISORY AREA...WILL GO WITH MAINLY 1 TO               
3 INCHES WITH THE 3-HR WINDOW OF BELOW 1/4 MILE VISIBILITY                      
LESS CERTAIN TO MEET BLIZZARD CRITERIA.                                         
TRAVEL IS EXPECTED TO BE NEARLY IMPOSSIBLE DURING THE OVERNIGHT                 
HOURS AND EARLY SATURDAY MORNING ACROSS MUCH OF SOUTHWEST                       
KANSAS...AND WILL EMPHASIZE THIS IN THE UPDATED WSW PRODUCT. IF                 
THERE IS A SILVER LINING TO THIS STORM IT IS THE FACT THAT IT WILL              
BE AT ITS HEIGHT DURING THE OVERNIGHT AND EARLY MORNING HOURS SUCH              
THAT TRAVEL WILL LIKELY BE LIMITED AS IT IS -- THAT SAID...IF THE               
SYSTEM EVOLVES AND EJECTS JUST A FEW HOURS SLOWER...THIS WILL PUT               
THE BULK OF SATURDAY MORNING/THROUGH MIDDAY IN EXTREMELY HAZARDOUS              
CONDITIONS ACROSS MUCH OF THE AREA. THE WINDS WILL NOT DECREASE                 
MUCH AT ALL THROUGH THE AFTERNOON...SO EVEN ONCE THE SNOW                       
ENDS...LINGERING BLOWING AND DRIFTING WILL REMAIN A PROBLEM.                    
THE LOW SHIFTS RAPIDLY EAST BY SAT AFTERNOON AND EVENING...WITH                 
MUCH LIGHTER WESTERLY WINDS TAKING OVER. DOWNSLOPE FLOW SHOULD                  
HELP ERODE COLD AIR FROM THE LOWER TROPOSPHERE...HOWEVER IF THERE               
IS SUBSTANTIAL NEW SNOW COVER...TEMPERATURES WILL BE DIFFICULT TO               
RECOVER SUNDAY (ABOVE THE LOWER 30S).  -UMSCHEID                                
DAYS 3-7...                                                                     
MAIN FORECAST CHALLENGES IN THIS EXTENDED PERIOD CONTINUE TO BE                 
CHANCES OF SNOW WITH SEVERAL PROGRESSIVE SHORTWAVES INTO FRIDAY.                
AN UPPER SHORTWAVE TROUGH WILL BRING A CHANCE FOR SNOW ON MONDAY                
FOLLOWED BY A STRONGER WAVE ON TUESDAY NIGHT INTO WEDNESDAY, THEN               
ANOTHER ON THURSDAY INTO FRIDAY MORNING. IT IS MUCH TOO EARLY TO                
TELL HOW MUCH SNOW WITH ANY OF THESE SYSTEMS HOWEVER THE ONE ON                 
MONDAY DOES NOT LOOK LIKE TOO MUCH ACCUMULATION. MODELS HAVE COME TO            
A GENERAL AGREEMENT ON THE POSITION OF THESE SHORTWAVES BUT THE                 
EXACT STORM TRACK AND UPPER LIFT WITH EACH ARE STILL NOT IN THE                 
REALM OF PREDICTION THEREFORE SNOW AMOUNTS WILL BE HARD TO GUESS.               
STILL SOME ACCUMULATIONS ARE PROBABLE WITH EACH SYSTEM ESPECIALLY               
THE LATTER ONES. AS FOR TEMPERATURES HIGHS SHOULD ONLY BE IN THE 30S            
WITH LOWS FROM THE UPPER TEENS TO LOW 20S. LOOKS LIKE A POSSIBLE                
WARMING TREND BY AROUND NEW YEARS.                                              
.AVIATION...                                                                    
VFR CONDITIONS WILL RAPIDLY DETERIORATE TO IFR BY AROUND 06Z TONIGHT            
AS SNOW AND BLOWING SNOW BEGINS WITH WINDS PICKING UP TO 25 TO                  
35KTS. THE SNOW COULD BECOME HEAVY ENOUGH BY 8Z TO 14Z WITH STRONG              
WIND GUSTS TO 45KTS WITH LIFR CONDITIONS. LOOK FOR RAPID IMPROVEMENT            
AROUND 18Z SATURDAY WITH WINDS GRADUALLY DECREASING WITH SNOW MOVING            
OFF TO THE EAST. VFR CONDITIONS SHOULD RETURN AFTER 20Z SATURDAY.               
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
DDC  23  28  15  37 /  90  90   0   0                                           
GCK  21  28  12  37 /  80  80   0   0                                           
EHA  22  28  13  37 /  90  80   0   0                                           
LBL  23  28  14  38 /  90  90   0   0                                           
HYS  22  26  14  34 /  80  90   0   0                                           
P28  27  30  16  36 /  80  90   0   0                                           
&&                                                                              
.DDC WATCHES/WARNINGS/ADVISORIES...                                             
SNOW AND BLOWING SNOW ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM                   
CST SATURDAY FOR KSZ030-031-043>046-065-066-081-090.                            
BLIZZARD WARNING FROM MIDNIGHT CST /11 PM MST/ TONIGHT TO 12 PM                 
CST /11 AM MST/ SATURDAY FOR KSZ061>064-074>080-084>089.                        
&&                                                                              
$$                                                                              
FN25/06/06                                                                      
</pre> ks                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE GAYLORD MI                                             
145 PM EST FRI DEC 21 2007                                                      
.AVIATION...A LARGE AREA OF HIGH PRESSURE CURRENTLY LOCATED OVER                
QUEBEC...WILL KEEP SOUTHEAST FLOW OVR THE GREAT LAKES REGION THIS               
AFTERNOON INTO SATURDAY. THE SOUTHEAST FLOW OVR LAKE HURON WILL KEEP            
AT LEAST A BKN LAKE INDUCED LOW CLOUD DECK...OVER THE APN TAF SITE              
INTO TONIGHT. THE REST OF NRN LWR WILL SEE MVFR/VFR CONDS                       
INTO THIS EVENING. LATER TONIGHT WARMER AIR WILL BEGIN TO MOVE INTO             
THE GREAT LAKES REGION...FROM A STORM SYSTEM MOVING INTO THE                    
WRN LAKES. THE WARMER AIR MOVING OVER THE SNOW PACK ACROSS NRN                  
MICHIGAN...WILL GENERATE LOW CLOUDS/FOG AND DRIZZLE. THIS WILL                  
GENERATE IFR CIG AND VSBY CONDS OVERNIGHT ACROSS THE NRN MI TAF                 
SITES. LIFR CIGS AND VSBYS ARE EXPECTED OVER NRN MICHIGAN SATURDAY              
BTW 12Z AND 18Z...AS WARM AIR CONTS TO PUSH NORTH INTO THE REGION...            
GENERATING LOW CLOUDS/DRIZZLE/RAIN AND FOG.                                     
SWR                                                                             
&&                                                                              
.UPDATE...ISSUED 1117 AM FRI DEC 21                                             
LITTLE TO NONE OF THE RETURNS ON THE RADAR ARE MAKING IT TO THE                 
GROUND. SO HAVE SLASHED THE POPS FOR THE REST OF THE DAYTIME AS MID             
LEVEL DRY AIR CONTINUES OVER THE REGION. SO FAR, THE NAM AND RUC                
HAVE THE BETTER HANDLE ON THE 850 MB MOISTURE MOVING IN WHICH LOOKS             
THE BEST. SO HAVE SCT SPRINKLES IN THE FORECAST FOR THE AFTERNOON.              
BASED ON THE LOWER CLOUDS (AROUND 1500 FEET) AT ANJ, AS WELL AS                 
BELOW FREEZING TEMPERATURES, PUT PATCHY ZL- IN FOR E UPPER WITH IT              
CHANGING TO SCT SPRINKLES FOR THE AFTERNOON AS THE TEMEPERATURES                
WARM AND THE DRY AIR PUSHES THE LOWER CLOUDS OUT. OTHERWISE,                    
TEMPERATURES AND WINDS LOOK GOOD.                                               
LUTZ                                                                            
&&                                                                              
.PREV DISCUSSION... /ISSUED 738 AM EST FRI DEC 21 2007/                         
AVIATION...BKN MVFR CIGS ANTICIPATED ACROSS PORTIONS OF NRN LOWER               
MICHIGAN THIS MORNING...PARTICULARLY AT PLN/APN WITH SE FLOW OFF                
LAKE HURON PUSHING LOW CLOUD COVER INTO THOSE AREAS. OTHERWISE...               
SPOTTY ELEVATED SHOWER ACTIVITY WILL BE FOUND ACROSS THE REGION                 
TODAY ALONG ADVANCING NOSE OF WARM AIR AND MOISTURE ALOFT. LOWERING             
CIGS/VSBYS ALONG WITH AREAS OF DRIZZLE ANTICIPATED TONIGHT LEADING              
TO MVFR AND EVENTUALLY IFV CONDITIONS AT ALL THREE TAF LOCATIONS.               
ADAM                                                                            
&&                                                                              
DISCUSSION...ISSUED AT 509 AM.                                                  
LONGWAVE TROUGH PATTERN PREVALENT ACROSS NORTH AMERICA WITH A MYRIAD            
OF AMPLIFYING SHORTWAVES MOVING THROUGH THE FLOW. MOST SIGNIFICANT              
OF THESE WAVES...AND WHAT WILL BE THE MAIN FOCUS IN THE FORECAST FOR            
THE WEEKEND...BEGINNING TO TRAVERSE THE EXPANSE OF THE ROCKIES. ONE             
PIECE OF ENERGY NOW DIGGING INTO THE SW STATES WHILE ANOTHER WAVE IN            
WESTERN CANADA. OPERATIONAL NAM/GFS SOLUTIONS AS WELL AS THE GFS                
ENSEMBLES AND ECMWF SOLUTION ALL STILL DEPICTING A TROUGH MERGER                
BETWEEN THESE TWO SYSTEMS OVER THE UPPER MIDWEST... LATE SATURDAY               
THROUGH SUNDAY...AND ASSOCIATED RAPID SPIN-UP OF A DEEP SFC LOW OVER            
NRN MICHIGAN. IN THE MEANTIME...STILL PLENTY TO THINK ABOUT IN THE              
SHORT TERM. BUILDING MID LEVEL RIDGING DOWNSTREAM OF THIS SYSTEM AND            
INCREASING LOW LEVEL WARM/MOISTURE ADVECTION INTO THE WESTERN GREAT             
LAKES EXPECTED TO DOMINATE TODAY THROUGH MUCH OF SATURDAY...WITH                
CHANCES FOR LIGHT SHOWER AND DRIZZLE/FREEZING DRIZZLE ACTIVITY THE              
MAIN FORECAST ISSUES.                                                           
TODAY AND TONIGHT...MID CLOUD COVER AND ELEVATED RADAR RETURNS ALONG            
ADVANCING MID LEVEL MOISTURE GRADIENT CONTINUE TO PRESS INTO THE                
REGION FROM THE WEST-SOUTHWEST. HOWEVER...MORE WIDESPREAD LOW CLOUD             
COVER AND DRIZZLE ACTIVITY STILL WAY BACK ACROSS CENTRAL WISCONSIN              
INTO WESTERN UPPER MICHIGAN...ALTHOUGH SOME STRATUS HAS DEVELOPED/              
EXPANDED ACROSS THE HIGHER TERRAIN OF NE LOWER MICHIGAN OVERNIGHT.              
THUS FAR...RADAR RETURNS LOOK CONVECTIVE IN NATURE AS AXIS OF                   
STEEPER MID LEVEL LAPSE RATES PRESSES OUT OF WISCONSIN. BUT OUTSIDE             
OF A COUPLE OBS IN SW LOWER MICHIGAN SHOWING PRECIP OVERNIGHT...                
NOTHING REALLY GETTING TO THE GROUND THUS FAR. HOWEVER...RADAR                  
RETURNS HAVE INCREASED IN COVERAGE OVER THE LAST HOUR OR SO AND                 
PROBABLY NEED TO CARRY SOME SORT OF PRECIP THIS MORNING AS THE                  
MOISTURE AXIS AND STEEPER LAPSE RATES LIFT UP THROUGH THE REGION.               
QUESTION IS...WHAT WILL IT BE? FORECAST NAM SOUNDINGS FOR THIS                  
MORNING DEPICT ABOVE FREEZING LAYER ALOFT NOSING INTO THE REGION.               
BUT GIVEN THE DRY LOW LEVEL AIR STILL IN PLACE AND CONVECTIVE NATURE            
TO THE PRECIP...THINK ANYTHING THAT DOES REACH THE GROUND WILL BE OF            
THE FROZEN VARIETY. TIME WILL TELL OF COURSE BUT FOR NOW WILL CARRY             
CHANCY SNOW SHOWER WORDING THROUGH MIDDAY.                                      
THEN BY LATER THIS AFTERNOON THROUGH SATURDAY...LOW LEVEL                       
MOISTURE FINALLY GETS SHOVED INTO THE REGION LATER THIS AFTERNOON               
AND ESPECIALLY THIS EVENING...SETTING THE STAGE FOR AREAS OF FOG AND            
DRIZZLE TO DEVELOP. HAVE NOT CHANGED MUCH TO THE GOING FORECAST IN              
THIS REGARD OTHER THAN SLOWING DOWN THE DEVELOPMENT OF WIDESPREAD               
FOG AND DRIZZLE UNTIL LATER IN THE EVENING...AND ADDING FREEZING                
DRIZZLE TO SOME OF THE HIGHER TERRAIN AREAS WHERE TEMPS WILL LIKELY             
HOVER AROUND FREEZING. SOUPY CONDITIONS THEN EXPECTED TO PERSIST                
THROUGH SATURDAY ALTHOUGH CONTINUING WARM ADVECTION/MOISTENING ALOFT            
MAY BRING BETTER CHANCES FOR MEASURABLE PRECIP INTO THE REGION. IN              
ANY EVENT...A DREARY...DAMP COOL DAY LOOKS ON TAP FOR NRN MICHIGAN              
WITH TEMPS SLOWLY REACHING THE 35 TO 40 DEGREE MARK.                            
SATURDAY NIGHT THROUGH SUNDAY...TROUGH MERGER SLATED TO TAKE SHAPE              
OVER THE UPPER MIDWEST BRINGING ABOUT A RAPID SPIN UP OF A DEEP SFC             
LOW NEARLY OVER THE STATE...TRACKING UP ACROSS EASTERN LAKE SUPERIOR            
ON SUNDAY. VERY STRONG DYNAMICS COME INTO PLAY IN THIS SCENARIO AND             
AT THIS POINT CATEGORICAL POPS ARE JUSTIFIED SATURDAY NIGHT INTO                
SUNDAY WITH A GOOD SWATH OF PRECIP RUNNING UP THROUGH THE REGION.               
ALSO AT THIS POINT...MAINLY RAIN ANTICIPATED SATURDAY NIGHT WITH THE            
LOW DEEPENING JUST WEST OF THE REGION AND +4C OR BETTER H8 AIR                  
GETTING SHOVED UP THROUGH EASTERN UPPER MICHIGAN. A RAPID CHANGEOVER            
TO SNOW AS WELL AS SOUTHWEST-WEST LAKE EFFECT/ENHANCED SNOW SHOWERS             
EXPECTED TO FOLLOW SUNDAY AS CORE OF -14C OR COLDER H8 AIR ROTATES              
AROUND INTO LOWER MICHIGAN. A LOT OF WIND AND THE POTENTIAL FOR                 
HEAVY SNOW/NEAR BLIZZARD CONDITIONS WITH THIS SYSTEM SUNDAY AND                 
SUNDAY NIGHT WILL LIKELY WARRANT HEADLINES IN THE NEXT 1 TO 2                   
FORECAST CYCLES.                                                                
TBA                                                                             
CHRISTMAS EVE AND CHRISTMAS...LAKE AGGREGATE TROUGHING WILL CONTINUE            
ACROSS THE GREAT LAKES THROUGH THE DAY ON MONDAY...BEFORE 850MB                 
TEMPERATURES WARM TO AROUND -5C BY 00Z MONDAY. WITH SURFACE TROUGH              
ROTATING ACROSS NORTHERN MICHIGAN EARLY MONDAY MORNING...EXPECT TO              
SEE FAIRLY WIDESPREAD SNOW SHOWERS AND BLOWING SNOW. DURING THE DAY             
ON MONDAY...DEEPER MOISTURE STARTS TO PULL OUT AND PRECIPITATION                
SLOWLY BECOMES PURELY LAKE EFFECT. FINALLY...AS THE BOUNDARY LAYER              
WARMS...LAKE EFFECT WILL END MONDAY EVENING. HIGH PRESSURE WILL                 
BECOME ESTABLISHED OVER THE GREAT LAKES BY CHRISTMAS DAY...PROVIDING            
A FAIRLY PLEASANT DAY WITH HIGHS WARMING INTO THE LOWER 30S UNDER               
PARTLY SUNNY SKIES AFTER STARTING THE DAY IN THE TEENS.                         
KAS                                                                             
&&                                                                              
.APX WATCHES/WARNINGS/ADVISORIES...                                             
MI...NONE.                                                                      
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LMZ341.             
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LHZ346.             
LS...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR LSZ321.             
&&                                                                              
$$                                                                              
</pre> mi                                                                       

AREA FORECAST DISCUSSION                                                        
NATIONAL WEATHER SERVICE BISMARCK ND                                            
337 PM CST FRI DEC 21 2007                                                      
.SHORT TERM...                                                                  
THE FCST IS CERTAINLY COMPLICATED TODAY...BUT ONCE AGAIN SPLIT FLOW             
ALOFT HAS SHOWN ITSELF NOT TO BE A MAJOR SNOW PRODUCER IN THIS AREA.            
THE 12Z GFS GETS OUR NOD PER ITS INITIALIZATION OF THE UPPER LOW IN             
ALBERTA AT 12Z AND ITS HANDLING OF THE PRECIP BAND WORKING INTO                 
CENTRAL ND AS OF 21Z. HOWEVER...ITS QPF AMOUNTS ARE MUCH TOO HIGH               
WITH LACK OF MORE FOCUSED DEEP LAYERED ASCENT...AND HENCE WE HAVE               
CUT THIS BACK. WINTER WEATHER HEADLINES REMAIN THE CONCERN INTO                 
THE EVE WITH TRAVEL IMPACTS...BUT TEMPS BECOME THE MAIN ISSUE OVER              
THE WEEKEND.                                                                    
LOOKING THROUGH MODEL DIAGNOSTICS TELLS US WHY SNOW HAS NOT BEEN                
AS INTENSE AS QPF WOULD SHOW...WITH THE PRIMARY QG FORCING ACROSS               
THE FA RATHER DISJOINTED...AND FOCUSED IN WSTRN SD WHERE CLOUD                  
TOPS HAVE COOLED MOST TODAY. WE ALSO LACKED JET DYNAMICS WITH A                 
DOMINANT SRN STREAM...AND ISENTROPIC LIFT WAS ALSO MINIMIZED. MOST              
UPWARD VERTICAL MOTION HAS COME VIA DIFFERENTIAL PVA ALOFT                      
COURTESY THE SE-MOVING UPPER LOW NOW IN CENTRAL SASKATCHEWAN.                   
THERMAL FORCING IS NOT FAVORABLE...HENCE THE POOR DEEP LAYER                    
Q-VECTOR RESPONSE. THE 12Z GFS AND MORE RECENT RUC RUNS HAVE                    
HOWEVER CAUGHT THE BAND OF SNOW SPREADING JUST AHEAD OF THE                     
PRIMARY CAA INTO CENTRAL ND. WE GOT 1-3 INCHES OF SNOW IN THIS                  
BAND AND SINCE IT IS PROGRESSIVE DO NOT EXPECT MUCH MORE THAN                   
THAT. SNOW RATIOS WILL WILL DROP AS STRONG 925-850MB CAA CONTINUES              
INTO THE EVE...BUT PWATS ALSO DROP TO 0.25 INCHES IN THE 50-75NM                
ZONE BEHIND THE PRIMARY LOW LEVEL BAROCLINIC ZONE. THE MAIN ISSUE               
IS GOING TO BE BLSN...WITH 30KT GUSTS COMMON ACROSS SW ND ALREADY.              
GFS BUFR SOUNDINGS SHOW 30-35KTS AT THE TOP OF THE MIXED LAYER                  
INTO THIS EVE SO WE WILL CONTINUE TO GET THESE GUSTS AT THE                     
SFC...BUT THE PRIMARY ISALLOBARIC COMPONENT /3-HOUR PRESSURE RISE               
CENTER OF ONLY 3MB AS OF 21Z/ HAS WEAKENED THE PAST 6 HOURS. WITH               
FALLING SFC TEMPS AND BLOWING/DRIFTING...ROADS WILL BE SLICK AND                
HENCE WE WILL CONTINUE WITH THE SN/BS ADVZY. WE DID HOWEVER                     
UTILIZE THE 12Z GFS TIMING OF THE SNOW BAND TO DROP THE ADVZY IN                
THE WEST AT 02Z...THE CENTRAL AT 06Z...AND HUNG ON TO THE HEADLINE              
IN THE JMS AREA UNTIL 12Z. KDIK HAS OCCASIONALLY BEEN DOWN 1SM THE              
PAST FEW HOURS SO EVEN BEHIND THE PRIMARY SN BAND SOME TRAVEL                   
PROBLEMS WILL CONTINUE. DRY AIR AHEAD OF THE SFC HIGH HAS WORKED                
INTO NW ND THOUGH SO WE WILL DROP THE ADVZY FROM NW ND.                         
THE UPPER VORT DROPS INTO CENTRAL ND SAT AND THE COLUMN COOLS                   
DRASTICALLY WITH 850MB TEMPS DOWN TO -20 C. THERE WILL STILL BE                 
SOME MIXING WITH PROG SOUNDINGS SHOWING 25KTS TO BRING TO THE                   
SFC...BUT THIS WILL DO NOTHING FOR THE TEMP RISE. WE UNDERCUT                   
GUIDANCE CONSIDERABLY GIVEN THE STRENGTH OF COOLING AND APPROACH                
OF THE SFC HIGH...AND ADDITION OF SOME SNOW PACK...ALBEIT MINOR IN              
MOST SPOTS. THE SAME GOES FOR SUNDAY...WHEN MIXING WILL BE EVEN                 
MORE LIMITED WITH THE SFC RIDGE AXIS SITTING ON TOP OF US. WIND                 
CHILLS WILL BE A PROBLEM...PERHAPS AS EARLY AS LATE TONIGHT...AND               
MORE LIKELY LATER ON SATURDAY. HOWEVER...WE WILL STOP SHORT OF                  
ISSUING THOSE HEADLINES FOR NOW IN ORDER TO AVOID CONFUSION WITH                
THE PRESENT EVENT.                                                              
S/W RIDGING PROGRESSES ACROSS THE NRN PLAINS ON MON AHEAD OF THE                
NEXT TROUGH STILL SET TO APPROACH BY 12Z TUE. THE 12Z GFS IS A BIT              
MORE AGGRESSIVE WITH HEIGHT FALLS WITH THIS NEXT SYSTEM...SO A                  
CHANCE OF SNOW IS IN THE CARDS IN WSTRN ND. AGAIN THOUGH THE                    
ENERGY WILL BE SPLIT AND HENCE CONFIDENCE IN GETTING MUCH OUT OF                
THE SYSTEM IS LOW.                                                              
.LONG TERM...                                                                   
FEW CHANGES IN THE LONG TERM PERIOD TODAY. THE ECMWF AND GFS ARE IN             
FAIR AGREEMENT AND HPC WENT MAINLY WITH THE ECMWF FOR DETAILS. KEPT             
MENTION OF LIGHT SNOW TUESDAY WITH LONGWAVE TROUGH EXTENDING FROM               
THE MAIN LOW IN NORTH CENTRAL CANADA AND ANOTHER LOW IN THE SOUTHERN            
PLAINS. THE ECMWF CUTS OFF THE SOUTHERN LOW FROM THE                            
WESTERLIES...WHILE THE GFS KEEPS THE LONGWAVE TROUGH MAINTAINED AS              
THE SYSTEMS MOVE EAST ACROSS CENTRAL NORTH AMERICA. AFTER THIS...THE            
STATE REMAINS BETWEEN LOWS THAT TRACK ACROSS CANADA AND LOWS                    
TRACKING ACROSS THE SOUTHERN PART OF THE CONUS. THIS WILL KEEP THE              
FORECAST DRY WITH NO BIG ARCTIC OUTBREAKS BUT ALSO NO WARM-UPS FROM             
THE SOUTHWEST. EXPECTING HIGHS IN THE TEENS AND 20S WITH LOWS 5 TO              
15 ABOVE - CLOSE TO AVERAGE FOR THIS TIME OF YEAR.                              
&&                                                                              
.AVIATION...                                                                    
SURFACE LOW PRESSURE OVER EASTERN NEBRASKA WITH AN INVERTED TROUGH              
EXTENDING FROM THE LOW INTO THE RED RIVER VALLEY OF NORTH DAKOTA.               
GUSTY NORTHWEST WINDS OVER WESTERN AND CENTRAL NORTH DAKOTA WITH                
AREAS OF SNOW AND BLOWING SNOW CENTRAL. THIS SNOW EXPECTED TO                   
PERSIST THROUGH 02Z TO 05Z. THE BACK EDGE OF THE CLOUDS WITH DRY AIR            
IS MOVING INTO NORTHWESTERN NORTH DAKOTA AT THIS TIME. EXPECT                   
FALLING SNOW TO END OVER CENTRAL NORTH DAKOTA BY AROUND 03Z. MVFR               
AND IFR CEILINGS AND VSBYS TO IMPROVE TO VFR OVER WESTERN ROUTES BY             
02Z AND OVER CENTRAL NORTH DAKOTA BY 06Z...BUT PERSIST UNTIL 12Z IN             
THE RED RIVER VALLEY. ANOTHER MVFR/IFR CLOUD SHIELD EXPECTED TO MOVE            
INTO NORTHWESTERN NORTH DAKOTA AFTER 06Z AND SPREAD TO CENTRAL NORTH            
DAKOTA BY 12Z.                                                                  
&&                                                                              
.BIS WATCHES/WARNINGS/ADVISORIES...                                             
SNOW AND BLOWING SNOW ADVISORY UNTIL MIDNIGHT CST /11 PM MST/                   
TONIGHT FOR NDZ003>005-011>013-019>022-034-035-042-045-046.                     
SNOW AND BLOWING SNOW ADVISORY UNTIL 8 PM CST /7 PM MST/ THIS                   
EVENING FOR NDZ018-031>033-040-041-043-044.                                     
SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM CST SATURDAY FOR                      
NDZ023-025-036-037-047-048-050-051.                                             
&&                                                                              
$$                                                                              
CJS/HW/JV                                                                       
</pre> nd                                                                       

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA             
NATIONAL WEATHER SERVICE SIOUX FALLS SD   ..UPDATED AVN DISCUSSION              
1157 AM CDT FRI DEC 21 2007                                                     
.DISCUSSION...                                                                  
UPDATED THE GRIDS AND ZFP. MAIN CONCERN WAS OVR THE ERN AND WRN                 
SECTIONS OF THE FSD FA FOR THIS AFTERNOON. FIRST FOR OUR WEST...12Z             
RAOBS CAME IN AND SHOW A HUGE WARM LYR ABOVE THE SFC AT KABR AND                
KLBF. THIS WAS PICKED UP BY THE NAM/RUC MODEL SNDGS SO DECIDED TO               
CHANGE THE PCPN TYPE TO PURE RAIN GIVEN CURRENT SFC TEMP READINGS.              
EXCEPT FOR A POSSIBILITY MIX OF -RA/-FZRA IN KINGSBURY AND BROOKINGS            
COUNTIES FOR LATER THIS AFTERNOON WHERE SFC TEMPS ARE A BIT COOLER.             
ALSO BROUGHT IN A MIX OF -RA/-FZRA IN THE LATE AFTERNOON HRS TOWARD             
EVENING IN THE HURON AND CHAMBERLAIN VICINITIES AS SFC TEMPS COOL               
JUST BEHIND THE FROPA. HOWEVER FOR THE BULK OF THE AFTERNOON...WITH             
THEIR RISING DEWPT TEMPS...THEY SHOULD JUST GO OVER TO PURE RAIN IN             
OUR FAR WEST. IN OUR FAR EAST...DECIDED TO JUST GO AREAS OF FOG ALL             
AFTERNOON. THE WALL OF STRATUS CONTINUES TO HUG RIGHT ALONG THE CWA             
BORDER BETWEEN US AND DMX. BUT THERE ARE INDICATIONS ON SATELLITE               
THAT THIS SHOULD BEGIN TO BACK INTO OUR FA AS THE AFTERNOON                     
PROGRESSES...AND ALSO THE H925 WINDS SHIFT FM THE S TO THE SE. AM               
HOPEFUL THOUGH...THAT THERE WILL BE ENUF THICKER HIGH CLOUDS OVR THE            
STRATUS TO KEEP DENSE FOG FM FORMING FM THE WINDOM MN TO STORM LAKE             
IA STRETCH. TONIGHT MAY BE A DIFFERENT STORY THOUGH...RIGHT AHEAD OF            
THE FROPA WHEN THE SFC WINDS GO DEAD. WL RE EVALUATE THAT A BIT                 
LATER.                                                                          
&&                                                                              
.AVIATION...                                                                    
LOW CIGS AND VIS ABOUND FOR THE TAF SITES THRU THE NEXT 24 HRS.                 
FIRST FOR KSUX...THE LOW LEVEL WINDS WILL BACK TO AN ESE DIRECTION              
AS THE AFTERNOON PROGRESSES...LASTING INTO THIS EVENING. THEREFORE              
AM CONCERNED THAT THE LOW STRATUS AND FOG CURRENTLY TO THE E OF THIS            
AREA WILL BACK IN TOWARD EVENING...INTO THE IFR AND LIFR RANGE. WL              
HAVE TO MONITOR TO SEE IF THE FOG GOES 1/4SM DURING THE EVENING HRS             
BEFORE THE FROPA. AFTER THE FROPA...VIS WL GO UP...BUT WL STILL BE              
REDUCED IN ANY AREAS OF SN/BLSN WITH LOW CIGS STAYING PUT THRU SAT              
MORNING. SAME PROBLEM AT KFSD...WITH SOME POSSIBLE IFR CIGS BACKING             
IN FM THE EAST THIS EVENING. SNOW SHOWERS AFT MIDNIGHT WITH TEMPO               
IFR CIGS/VIS WARRANTED. AT KHON...NOT EXPECTING THE LOW VIS/CIGS TO             
THE EAST TO BACK INTO THIS AREA. BUT KHON WL LIKELY SEE MVFR/IFR                
CIGS/VIS AFTER THE FROPA IN SNOW/BLSN.                                          
&&                                                                              
.PREV DISCUSSION...                                                             
NEXT PBLM IS TIMIMG OF FNT. MODELS NOW SLOWER AND REALLY DO NOT PUSH            
FNT INTO WRN CWA UNTIL AFTN. S/W WAVE IN NRN FLOW WL SKIM BY THE NRN            
CWA THIS AFTN AND WL KEEP CHC OF S THERE WITH REST OF CWA DRY TODAY.            
FOCUS SHIFTS TO THE S WITH SRN STREAM WAVE FOR TONIGHT. BULK OF                 
PRECIP TONIGHT WL OCCUR BEHIND FNT AND CLOSER TO SRN STREAM WAVE. AM            
CONCERNED THAT BULK OF PRECIP WL REMAIN. HAVE TRIMMED BACK POPS TO              
LIKELY OVR NW IA LATER TONIGHT AS FEEL PRECIP WL LIKELY HOLD OFF                
THERE UNTIL AAFTER 06Z WHEN SRN STREAM WAVE PUSHES ENE. AHEAD OF FNT            
TONIGHT...WL LIKELY SEE AREAS OF OFG ALONG WITH PATCHY DRIZZLE OR               
FREEZING DRIZZLE IN THE EVE SO PUT THAT IN FCST ACRS NW IA.                     
ACRS REST OF CWA TONIGHT...WL SEE A CHC OF LIGHT SNOW WITH NRN TROF             
AND WNDS SHUD PICK UP BEHIND FNT AS CAA KICKS IN. WL BE CLOSE TO WND            
ADVY WRN CWA BUT FOR NOW WL NOT ISSUE HEADLINE.                                 
SAT LOOKS WINDY AND COLD WITH TEMPS NOT CLIMBING MUCH AT ALL. WUD               
EXPECT PLENTY OF STRATUS ERN CWA DURING THE DAY WITH CHC OF S- ACRS             
ERN CWA IN THE MORN.                                                            
SUN LOOKS WINDS OND COLD AS UPPER LOW SITS OVR MN. EXPECT PLENTY OF             
SC OVR ERN CWA WITH A PSBLTY OF FLURRIES OVR SW MN. MOST PLACES WILL            
NOT GET OUT OF TEENS FOR HIGHS.                                                 
HOLIDAY LOOKS DRY WITH NO MAJOR STORMS THRU NEXT WEEK.                          
&&                                                                              
.FSD WATCHES/WARNINGS/ADVISORIES...                                             
SD...NONE.                                                                      
MN...NONE.                                                                      
IA...NONE.                                                                      
NE...NONE.                                                                      
&&                                                                              
$$                                                                              
 MJF                                                                            
</pre> sd                                                                       

AREA FORECAST DISCUSSION...AMENDED FOR WIND ADVISORY                            
NATIONAL WEATHER SERVICE EL PASO TX/SANTA TERESA NM                             
213 PM MST FRI DEC 21 2007                                                      
.SYNOPSIS...                                                                    
A STRONG UPPER LEVEL TROUGH WILL CONTINUE TO SUPPLY THE BORDERLAND              
WITH BREEZY TO WINDY WESTERLY WINDS INTO THE OVERNIGHT HOURS                    
TONIGHT...ESPECIALLY ALONG EAST-FACING SLOPES. IN ADDITION...THIS               
SYSTEM BRINGS WITH IT A GOOD SHOT FOR SIGNIFICANT SNOWFALL ACROSS               
THE MOUNTAINS OF SOUTHERN NEW MEXICO...BUT ONLY A SLIGHT CHANCE                 
FOR PRECIPITATION NEARER THE INTERNATIONAL BORDER. MUCH COOLER                  
TEMPERATURES CAN BE EXPECTED TOMORROW...AND OUR READINGS WILL HAVE              
A TOUGH TIME RECOVERING TO NORMAL LEVELS THROUGH THE REMAINDER OF               
THE WEEK.                                                                       
&&                                                                              
.DISCUSSION...                                                                  
AS A STRONG BERING STRAIGHTS 500MB CYCLONE CONTINUES TO EJECT                   
ENERGY INTO THE JET...EACH BURST STRENGTHENS AND PULLS SOUTH-                   
SOUTHEAST AS THEY ENTER THE PACIFIC NW. MORE SPECIFICALLY...4 SUCH              
SYSTEMS WILL SKIRT THE CWA THROUGH THE 7-DAY PERIOD.                            
THE FIRST TROUGH...ALREADY STRETCHING THROUGH UTAH AND ARIZONA AS               
OF 18Z TODAY...LOOKS TO BE OUR BEST SHOT FOR PRECIPITATION OF ANY               
OF THESE SYSTEMS. RUC-ANALYZED NEGATIVE LI`S JUST AHEAD OF THE                  
500 MB TROUGH AXIS HAVE BEEN HOST TO AN AREA OF CONVECTION ALL                  
MORNING...AND HAVE PUSHED INTO WESTERN NEW MEXICO AS OF 20Z THIS                
AFTERNOON. THIS ACTIVITY WILL BE MAINLY RAIN EXCEPT ABOVE AROUND                
7500 FEET AS IT MOVES INTO THE GILA ZONE THIS AFTERNOON. SNOW                   
LEVELS WILL DROP QUICKLY TO BELOW 5000 FEET NORTH OF LAS CRUCES BY              
MIDNIGHT TONIGHT AS COLD AIR FILTERS IN FROM THE NORTH AT THE                   
SURFACE BEHIND A SIDE-DOOR FRONT. BY THIS TIME OUR MAIN TROUGH                  
AXIS WILL HAVE PUSHED FAR ENOUGH EAST TO LIMIT THE RISK FOR                     
SIGNIFICANT SNOWS IN THE LOWLANDS. WITH THE MAIN BAND OF ENERGY                 
HOLDING OFF UNTIL LATER TO EFFECT THE SACRAMENTO MOUNTAIN                       
AREA...MORE SIGNIFICANT SNOWS LOOK TO BE MORE LIKELY THERE.                     
AMOUNTS APPEAR TO BE WELL-HANDLED WITH THE CURRENT ADVISORIES.                  
A STRONG SURFACE PRESSURE GRADIENT WILL REMAIN ESTABLISHED                      
OVERNIGHT TONIGHT AS A STRENGTHENING LEE-SIDE LOW SLIDES ACROSS                 
NORTHERN TX. THIS WILL SUPPORT BREEZY TO WINDY CONDITIONS -                     
ESPECIALLY ACROSS THE EAST-SLOPES OF AREA MOUNTAINS - THROUGH THE               
NIGHT.                                                                          
MUCH COOLER TEMPERATURES FOR TOMORROW WILL BE HARD TO BRING UP AS               
DISTURBANCE AFTER DISTURBANCE CROSSES THE AREA BRINGING WITH THEM               
REINFORCING SHOTS OR COOL AIR. OUR SECOND DISTURBANCE...SLATED FOR              
SUNDAY NIGHT/MONDAY CONTINUES TO LOOK DRIER. AS SUCH...HAVE                     
REMOVED MENTIONABLE POPS FOR THE SYSTEM.                                        
THE THIRD DISTURBANCE IS SLATED FOR CHRISTMAS DAY. AS READINGS                  
FINALLY RETURN TO LATE-DECEMBER NORMS...A STRONG UPPER LEVEL                    
TROUGH IS PROGGED TO DIG INTO THE SOUTHWEST. CURRENT MODEL                      
SOLUTIONS INDICATE WINDY CONDITIONS WITH THE POTENTIAL FOR MAINLY               
THE NORTHERN PORTIONS OF THE CWA TO SEE AND PRECIPITATION. THIS                 
WOULD BE FOLLOWED AGAIN BY A COLD AIR INTRUSION FROM THE NORTH FOR              
THE 26TH.                                                                       
OUR FOURTH AND FINAL DISTURBANCE OF THE PERIOD LOOKS MUCH LIKE THE              
3RD...AND WOULD MAKE FOR BREEZY TO WINDY CONDITIONS AND A SLIGHT                
CHANCE OF PRECIPITATION MAINLY NORTH OF LAS CRUSES THURSDAY                     
AFTERNOON/EVENING.                                                              
&&                                                                              
.AVIATION...VALID 22/00Z-23/00Z                                                 
MOSTLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. HOWEVER...THERE              
WILL BE AREAS OF MVFR AND IFR TONIGHT INTO SATURDAY MORNING FOR CIGS            
AND VSBY IN RAIN/SNOW SHOWERS THAT WILL OBSCURE MTN TOPS. WINDS                 
OF 20 TO 25 KTS GUSTING TO 35 KTS THIS EVENING INTO TONIGHT WILL                
LIKELY CAUSE MODERATE MECHANICAL TURBULENCE...ESPECIALLY ACROSS                 
EASTERN SLOPES OF AREA MOUNTAINS. WINDS DIMINISHING DURING THE NIGHT            
AND VFR CONDITIONS RETURNING FROM WEST TO EAST SATURDAY MORNING.                
&&                                                                              
.PRELIMINARY POINT TEMPS/POPS...                                                
EL PASO                 36  50  25  53  30 /  10   0   0   0   0                
SIERRA BLANCA TX        35  48  23  53  26 /  10   0   0   0   0                
LAS CRUCES              33  50  24  52  29 /  10   0   0   0   0                
ALAMOGORDO              32  50  21  50  25 /  20  10   0   0   0                
CLOUDCROFT              25  33  10  37  16 /  60  20   0   0   0                
TRUTH OR CONSEQUENCES   31  47  21  50  26 /  20   0   0   0   0                
SILVER CITY             28  43  19  45  22 /  30   0   0   0   0                
DEMING                  32  49  22  51  28 /  10   0   0   0   0                
LORDSBURG               31  49  21  51  27 /  20   0   0   0   0                
&&                                                                              
.EPZ WATCHES/WARNINGS/ADVISORIES...                                             
NM...WIND ADVISORY UNTIL 6 PM MST THIS AFTERNOON FOR NMZ022>025-                
     030>032.                                                                   
     SNOW ADVISORY UNTIL 6 AM MST SATURDAY FOR NMZ022.                          
     SNOW ADVISORY FROM 6 PM THIS EVENING TO 12 PM MST SATURDAY FOR             
     NMZ025.                                                                    
TX...WIND ADVISORY UNTIL 6 PM MST THIS AFTERNOON FOR TXZ055-056.                
&&                                                                              
$$                                                                              
PIEPER                                                                          
</pre> tx