AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
244 PM MDT FRI SEP 22 2006
.SHORT TERM...
(TONIGHT AND SATURDAY)
CURRENTLY...FIRST SHORTWAVE MOVED THROUGH THE REGION DURING THE
MORNING AND EARLY AFTERNOON.  SOME BANDING IN THE SHORTWAVE PRODUCE
SOME LOCALLY HEAVY SNOW IN THE SOUTHWEST MOUNTAINS.  THE SHORTWAVE
AND ACCOMPANYING WEAK SURGE WAS ALSO ABLE TO TURN THE FLOW UPSLOPE
FOR SOME PRECIPITATION ON THE INTERSTATE 25 CORRIDOR AND EASTERN
MOUNTAINS.  SOME SPOTTERS REPORTED SEVERAL TENTHS OF LIQUID AND SOME
SPOTTERS IN THE EASTERN MOUNTAINS HAD A COUPLE INCHES OF SNOW.
.TONIGHT...SECOND SHORTWAVE/PV LOBE OVER SOUTHWEST COLORADO WILL
SWING THROUGH TONIGHT.  CLOUD TOPS AHEAD OF THIS SECOND SHORTWAVE
ARE WARMER THAN AHEAD OF THE FIRST SHORTWAVE...SUPPORTING THE IDEA
OF DRIER AIR ALOFT. THIS SHORTWAVE WILL CONTINUE THE CHANCES FOR
SNOW THIS EVENING...BUT WITH THE DRIER AIR AND NOT VERY FAVORABLE
OROGRAPHICS...I WILL NOT EXTEND THE ADVISORY BEYOND 00Z.  LAKE
COUNTY WILL BE CLOSEST TO THE DEEPER MOISTURE...AND NORTHERLY FLOW
AT 700MB IS NOT CONDUCIVE TO HEAVY SNOW.  IF EVOLUTION CHANGES IN
THE NEXT THREE HOURS...THAN EVENING SHIFT CAN EXTEND THE ADVISORY.
I EXPECT MODEST ACCUMULATIONS OVERNIGHT...BUT NOT ENOUGH TO WARRANT
EXTENDING THE ADVISORY.
OTHER CONCERN IS THE EASTERN MOUNTAINS.  ANOTHER WEAK SURGE WILL
ACCOMPANY THE SHORTWAVE THIS EVENING.  12Z AND 18Z WRF HINT AT THE
700MB FLOW GOING NORTHEAST ALONG PORTIONS OF THE INTERSTATE 25
CORRIDOR.  RUC ALSO HAS A SIMILAR IDEA.  I INCREASED POPS TONIGHT TO
LIKELY FOR THE EASTERN MOUNTAINS.  I WOULD NOT BE SURPRISED TO GET
ANOTHER ROUND WITH A FEW TENTHS OF LIQUID.  GIVEN IT IS EARLY IN THE
SEASON AND TEMPERATURES WILL NOT BE VERY COLD...SNOW ACCUMULATIONS
SHOULD MOSTLY BE ON THE GRASS EXCEPT AT THE HIGHER ELEVATIONS.  ON
THE PLAINS...THE WRF...RUC AND GFS SUGGEST THE POTENTIAL FOR AN AREA
OF PRECIPITATION ALONG THE FRONT...BUT IN DIFFERENT LOCATIONS.  THIS
SUGGESTS THE POSSIBILITY FOR A PERIOD OF RAIN ON THE PLAINS THIS
EVENING...AND I INCREASED THE POPS TO SCATTERED DURING TH EVENING.
.SATURDAY...ANOTHER TROUGH WILL MOVE IN FROM THE NORTH.  OUR
CWA WILL BE ON THE SOUTHERN FRINGES OF THE TROUGH...WITH BEST POPS
TO THE NORTH.  THERE WILL BE ENOUGH MOISTURE AND INSTABILITY FOR
MOUNTAINS SHOWERS.  ON THE PLAINS...LOWER LEVELS WILL BE DRY WITH
THE NORTHWEST FLOW...BUT THERE WILL STILL BE THE CHANCE FOR A FEW
SHOWERS.  TEMPERATURES WILL REMAIN BELOW AVERAGE.  --PGW--
.LONG TERM...
(SATURDAY NIGHT THROUGH THURSDAY)
SATURDAY NIGHT...NAM/WRF FORECASTS TROUGH AXIS TO BE OVER EXTREME
SOUTHEAST COLORADO WITH CYCLONIC FLOW ESPECIALLY ACROSS THE
SOUTHEAST PLAINS. FAIRLY TIGHT PRESSURE GRADIENT SHOULD MAKE FOR A
BREEZY EVENING ACROSS THE PLAINS...WITH SOME GUSTS ABOVE 30 MPH...
BEFORE WINDS TAPER OFF IN THE LATE EVENING. SLIGHT CHANCE POPS
EARLY...THEN JUST OVER THE HIGHER TERRAIN LATER ON SEEMS REASONABLE.
SUNDAY DEPICTED TO BE A RATHER COOL DAY...WITH 700MB TEMPERATURES
ONLY NEAR 0C IN THE EAST TO AROUND 4C OUT WEST. ALSO...THE LAPSE
RATES IN THE AFTERNOON GET A BIT STEEP IN THE HIGH TERRAIN WITH
SOME VERY LIMITED MOISTURE...SO THERE COULD BE A FEW LIGHT SHOWERS
ABOVE 9K FEET. ANY VIRGA OR LIGHT SHOWERS SHOULD END QUICKLY IN
THE EVENING...PAVING THE WAY FOR A COOL MONDAY MORNING.
TEMPERATURES SHOULD DROP INTO THE TEENS AND 20S ACROSS THE
MOUNTAINS AND HIGH VALLEYS...BUT STAY ABOVE FREEZING IN THE EAST.
MONDAY AND TUESDAY...RIDGING FORECAST BY GFS AND NAM/WRF WITH MID
LEVEL TEMPERATURES RISING SOME 4 TO 6 DEGREES CELSIUS OVER THE
AREA. THAT SHOULD TRANSLATE INTO 70S TO LOWER 80S ACROSS THE
PLAINS AND 40S WAY UP HIGH IN THE MOUNTAINS TO AROUND 70 IN THE HIGH
VALLEYS.
TUESDAY NIGHT AND WEDNESDAY THE GFS...WHICH HAS HAD FAIRLY GOOD
RUN TO RUN CONTINUITY...SHOWS A VIGOROUS SHORTWAVE ROTATING
AROUND THE UPPER LOW OVER EASTERN CANADA. IF THIS PANS OUT...A
QUICK SHOT OF COOL AIR WILL INVADE SOUTHEAST SECTIONS OF OUR AREA
WEDNESDAY. HAVE KEPT POPS ON WEDNESDAY IN THE SLIGHT CHANCE
CATEGORY...ALONG WITH LOWER TEMPERATURES IN THE PLAINS. WOULD BE
COOL ENOUGH IN THE HIGHER ELEVATIONS OF THE EASTERN MOUNTAINS FOR
SOME LIGHT SNOW ACCUMULATIONS...IF PRECIPITATION BECOMES MORE
PROBABLE.
ON THURSDAY...THE SHORTWAVE PASSES ON TO THE SOUTHEAST...AND BY
AFTERNOON MID LEVELS TEMPERATURES REBOUND NICELY WITH DRIER
CONDITIONS...SO GOING FORECAST OF DRY AND MILDER LOOKS GOOD.
-TLM-
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
SNOW AND BLOWING SNOW ADVISORY UNTIL 6 PM MDT THIS AFTERNOON FOR
COZ058-COZ059-COZ060-COZ061-COZ064-COZ065-COZ066-COZ067-COZ068.
&&
$$
06/13
</PRE></TT></td>   co
WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
942 AM EDT FRI SEP 22 2006
.UPDATE...12Z RAOB AND SURFACE OBSERVATIONAL DATA INDICATES THAT THE
AIR MASS ACROSS THE FORECAST AREA HAS MOISTENED UP SOME FROM YESTERDAY
WITH DEW POINTS NOW RUNNING IN THE UPPER 60S TO LOWER 70S WITH PW'S
~1.4" WHICH IS UP ABOUT HALF INCH FROM YESTERDAY. THIS SUBTLE INCREASE
IN MOISTURE ALONG WITH DAYTIME HEATING SHOULD RESULT IN SOME ISOLATED
SHOWER AND THUNDERSTORM ACTIVITY ALONG THE SEA BREEZE CIRCULATIONS LATER
THIS AFTERNOON. CURRENTLY HAVE 20% POPS IN THE FORECAST FROM MANATEE
TO HIGHLANDS COUNTY SOUTH FOR THE LATE AFTERNOON HOURS...BUT WILL EXPAND
THIS LOW POP MENTION NORTHWARD INTO HILLSBOROUGH AND POLK COUNTIES AS
WELL GIVEN THE LATEST RAOB...GFS/NAM AND RUC OUTPUT. ACROSS THE NORTHERN
FORECAST AREA LINGERING MORE PRONOUNCED DRY SUBSIDENT AIR MASS PER KJAX
SOUNDING DATA WILL SUPPORT DRY AND WARM CONDITIONS. WILL ADD THE LOW
RAIN CHANCE (20%) POSSIBILITY TO THE COUNTIES MENTION ABOVE IN A LATE
MORNING ZONE UPDATE...OTHERWISE NO OTHER CHANGES EXPECTED.
&&
.MARINE...A LIGHT EAST TO SOUTHEAST WIND FLOW AND SLIGHT SEAS WITH AN
ONSHORE SEA BREEZE COMPONENT DEVELOPING NEAR SHORE IS EXPECTED OVER
THE ADJACENT GULF COASTAL WATERS THIS AFTERNOON. ONGOING FORECAST IN
GOOD SHAPE WITH NO CHANGES EXPECTED IN THE NEXT FORECAST ISSUANCE
LATER THIS MORNING.
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES TODAY AND
TONIGHT AS HIGH PRESSURE REMAINS OVER THE AREA...HOWEVER BRIEF MVFR
CONDITIONS WILL BE POSSIBLE LATE THIS AFTERNOON OVER THE CENTRAL AND
SOUTHERN TAF SITES AS A FEW SHOWERS OR THUNDERSTORMS DEVELOP ALONG
THE SEA BREEZE.
&&
.FIRE WEATHER...MAY SEE A FEW POCKETS OF MARGINALLY LOW HUMIDITY VALUES
OVER INTERIOR LOCATIONS THIS AFTERNOON...BUT OVERALL INCREASING
LOW LEVEL MOISTURE (DEW POINTS UPPER 60S TO LOWER 70S) SHOULD PRECLUDE
ANY RED FLAG CONDITIONS.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE/FIRE WEATHER...JCM
AVIATION...AR
</PRE></TT></td>   fl
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
745 PM EDT FRI SEP 22 2006
.UPDATE...
AM LOWERING POPS FOR THE OVERNIGHT HOURS ONE OR MORE CATEGORIES IN
MOST CASES. WILL COMPROMISE BETWEEN RUC WHICH SAYS POPS SHOULD GO TO
ZERO BY MIDNIGHT WITH GFS WHICH HOLDS ONTO 40 AND 50 PERCENT POPS
OVERNIGHT. ALSO...REDUCED MENTION OF TSRA WORDING. A LITTLE BIT
WORRIED ABOUT POSSIBLE REDEVELOPMENT LATER TONIGHT ACROSS THE NW/W
CENTRAL AREAS...BUT ISOLD TSRA SHOULD SUFFICE FOR NOW. ALSO LOWERED
POPS ONE CATEGORY FOR SAT AS WELL AS STRONG UPPER RIDGE INTRUDES
FROM THE SE AND PUSHES BEST CHANCE OF SHRA/TSRA BACK TO THE NW INTO
MIDDLE TN. SHOULD TURN OUT TO BE A FAIRLY NICE SATURDAY FOR MUCH OF
THE CWA AFTERALL...AND QUITE WARM AS WELL. DID NOT MAKE ANY
SIGNIFICANT CHANGES TO TEMPERATURES AT THIS TIME.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
STRONG STORMS IN ALABAMA DISSIPATED ALMOST COMPLETELY AS THEY MOVED
TOWARD THE GA BORDER. NOT EVEN ANY SWAS REQUIRED IN OUR CWA AS
BASICALLY ONLY LIGHT SHRA OR EVEN VIRGA MADE IT ACROSS THE FFC CWA.
SLIGHTLY DRIER AIR MASS WITH DEWPOINTS MOSTLY IN THE 65 TO 68 RANGE
AS COMPARED TO THE 70-72 DEWPOINTS IN AL MADE ALL THE DIFFERENCE.
AXIS OF BETTER INSTABILITY REMAINED ALONG AND WEST OF THE GA/AL
BORDER THROUGHOUT. THIS DOES NOT CHANGE IN THE SHORT TERM. RUC MODEL
SHOWS LITTLE OR NO PRECIP ACROSS THE FFC CWA OVERNIGHT...ALTHOUGH
THE GFS DOES KEEP AN AREA OF MOISTURE AND INSTABILITY CONCENTRATED
ACROSS N GA OVERNIGHT. HOWEVER...THE GFS SHOWED THE BEST AREA OF
PRECIP FOR THE AFTERNOON HOURS ACROSS NE GA...AND THIS DID NOT
VERIFY WELL AT ALL. NAM AGREES WITH RUC IN HOLDING OFF PRECIP UNTIL
AFTER 12Z. OVERALL...NOT EXPECTING MUCH OVERNIGHT ACROSS THE
CWA...BUT CANNOT RULE OUT SOME SHRA LATER TONIGHT AS WARM FRONT
STARTS TO LIFT NE. KEY TO HOLDING OFF SHRA/TSRA ACROSS THE CWA WILL
BE AMPLIFYING UPPER RIDGE OFF THE SE U.S. COAST. THIS WILL TEND TO
PUSH THE DYNAMICS AND INSTABILITY BACK TO THE NW ACROSS TN/KY AND
FURTHER AWAY FROM GA THROUGH SAT. THE RIDGE WILL THEN FLATTEN AND
MOVE BACK TO THE SE SUN AND ALLOW THE ENTIRE UPPER SYSTEM TO SWEEP
THROUGH THE AREA AT THAT TIME. THIS IS NOT AN IMPRESSIVE SYSTEM FOR
OUR CWA AND THE THREAT OF SEVERE APPEARS MINIMAL TO ME. UPPER TROUGH
IS POSITIVELY TILTED AND SHEARS OUT WITH TIME. THE BEST INSTABILITY
ACTUALLY EXISTS SAT NIGHT/EARLY SUN. I COULD WELL SEE A SITUATION
WHERE THE BULK OF THE SHRA/TSRA COMES THROUGH EARLY SUN...LEAVING
THE AREA WITH EXTENSIVE CLOUD COVER AND RAIN COOLED AIR IN
PLACE...THUS SIGNIFICANTLY LIMITING THE THREAT OF SEVERE. IN
ADDITION...HEAVY RAIN SHOULD NOT BE A THREAT EITHER AS THE SYSTEM
MOVES THROUGH FAIRLY QUICKLY.
.LONG TERM...(MONDAY THROUGH FRIDAY)
A VERY DRY AIR MASS WILL SPREAD ACROSS THE AREA EARLY MON AND
PREVAIL THROUGH MIDWEEK. VERY DRY WNW DOWNSLOPE FLOW WILL PREVAIL
ALOFT. TEMPERATURES WILL REMAIN NEAR SEASONAL AS THERE IS REALLY
LITTLE COOLING BEHIND THIS CURRENT SYSTEM. ANOTHER BROAD UPPER
TROUGH WILL DEVELOP TOWARD THE END OF THE WEEK BRINGING THE NEXT
WEATHER SYSTEM TO THE AREA. THIS APPEARS TO BE A FAIRLY SHARP
TROUGH...AND APPEARS MORE SIGNIFICANT ON THE 18Z RUN THAN IT DID ON
THE 12Z RUN. INSTABILITY PARAMETERS NOT IMPRESSIVE BUT DYNAMICS
FAIRLY INTERESTING. THIS SYSTEM WILL NEED TO BE WATCHED AS THE WEEK
PROGRESSES. IN ADDITION...MUCH COLDER AIR FOLLOWS THIS SYSTEM WITH
THE FIRST SIGN OF 0C AT 850MB INTO N GA BY NEXT WEEKEND. WILL
SEE...AS GFS OFTEN OVERDOES COOLING IN THE EXTENDED...AS WELL AS THE
STRENGTH OF SUCH SYSTEMS.
&&
.AVIATION...SHOWERS AND STRONG THUNDERSTORMS DEVELOPING IN VICINITY
OF WARM FRONT STRETCHING FROM SOUTHWEST GA INTO NORTHERN AL.
THUNDERSTORMS SHOULD DIMINISH AFTER SUNSET...BUT ISOLATED CONVECTION
POSSIBLE ANYWHERE ACROSS NORTHWEST GA THIS EVENING. SCT TO BKN
STRATOCU BETWEEN 3 AND 4THSD FT THIS EVENING SHOULD LOWER AFTER
MIDNIGHT TO AROUND 15 HND TO 2THSD FT BY SUNRISE. WINDS SHOULD
REMAIN LIGHT SOUTHEAST AS HIGH PRESSURE REMAINS CENTERED OFF MID
ATLANTIC COAST. VISIBILITY GENERALLY UNRESTRICTED EXCEPT IN SHOWERS
AND LOCALLY 3 TO 5SM IN FOG AFTER MIDNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS          66  86  67  85 /  20  30  30  60
ATLANTA         68  84  69  81 /  20  40  30  60
BLAIRSVILLE     65  80  66  78 /  30  30  40  60
CARTERSVILLE    66  85  66  79 /  30  40  40  60
COLUMBUS        70  91  71  86 /  30  30  20  60
GAINESVILLE     66  83  67  80 /  30  30  40  60
MACON           67  90  69  89 /  20  20  20  30
ROME            69  87  68  81 /  30  40  50  60
PEACHTREE CITY  65  86  66  83 /  20  30  30  60
VIDALIA         68  91  69  89 /   5   5  10  30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19/41
</PRE></TT></td>   ga
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
645 PM CDT FRI SEP 22 2006
.DISCUSSION FOR AFTERNOON GRIDS/ZFP...
335 PM CDT
MAIN FOCUS HAS BEEN PLACED ON NR TERM OF FCST DUE TO ANTICIPATED
CONVECTIVE DVLPMT.  LASTEST VIS SATLT LOOPS SHOW DEEP MOISTURE CONTG
TO ADVECT RPDLY NWD AHD OF SHRT WAVE TROF AND ASSD JET MAX NOW
RUNNING FROM ERN IA-NERN MO AND ON INTO XTRM NWRN AR.  THIS FEATURE
IS EXPECTED TO ACT ON INCRSGLY UNSTABLE AIR E OF MS RVR AND TRIGGER
ADDITIONAL STG TO SVR TSTM DVLPMT RMNDR OF THIS AFTN.  THESE STORMS
WILL ALSO BE MOVG INTO STGLY SHEARED ENVIRONMENT ALG/JUST AHD OF
WARM FRONT RUNNING ACRS NRN IL/NWRN IND...ALG/S OF I-80.  THIS IS
EXPECTED TO CAUSE STMS THAT DO DVLP TO QUICKLY DVLP ROTATION AND
THIS ASPECT OF DVLPMT HAS ALREADY BEEN NOTED WITH A FEW UPDRAFTS
THAT HAVE ALREADY BEGUN TO POP UP OVR NRN LASALLE CO.
LTL CHG TO RMNDR FCST.
MERZLOCK
&&
.AVIATION DISCUSSION REGARDING 00Z TAFS...
645 PM CDT
THUNDERSTORMS RADIDLY MOVING OUT OVER LAKE MI AND DISIPATING OVER
NRN IL. WILL KEEP TEMPO OR VCNTY GROUP FOR THUNDERSTORMS IN TAFS
EXCEPT RFD FOR NEXT COUPLE HOURS. BELIEVE SEVERE THREAT IS GREATLY
DIMINISHING WITH SUNSET. THEN WILL KEEP FORECAST DRY FOR THE
OVERNIGHT. SATELLITE AND SURFACE OBS SHOWING NICE DRYING ACROSS
WRN IL AND ERN IA. WINDS ALL OVER THE PLACE IN THE WAKE OF THE
STORMS BUT SSWLY GARDIENT AROUND 10 KNOTS SHOULD RE-ESTABLISH ITSELF
IN NEXT HOUR OR TWO. WILL FOLLOW RUC WITH WINDS BECOMING LIGHT SW
LATE TONIGHT THEN BACKING SE SATURDAY. ANOTHER ROUND OF
THUNDERSTORMS EXPECTED SATURDAY AFTERNOON AND WILL COVER THIS WITH A
PROB GROUP FOR NOW.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
.IL...NONE.
.IN...NONE.
.LM...SMALL CRAFT ADVISORY FROM 1 AM TONIGHT THROUGH LATE
      FRIDAY NIGHT FOR THE ILLINOIS NEAR SHORE.
&&
$$
</PRE></TT></td>   il
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
948 PM CDT FRI SEP 22 2006
.DISCUSSION...
QUESTIONS THIS EVENING ARE WHETHER PRECIP WILL DEVELOP OVERNIGHT.
00Z GUIDANCE IS COMING IN AND CONTINUES TO SHOW ISENTROPIC LIFT
DEVELOPING ACROSS SOUTHERN AND EAST KANSAS. THIS IS SEEN IN THE
MODELS AS THE 850 WINDS BACK ACROSS NORTHEASTERN OK AND SOUTHWESTERN
MO. WHILE MID LEVEL MOISTURE LOOKS TO BE PLENTIFUL...LOW LEVELS
REMAIN RELATIVELY DRY IN THE FORECAST SOUNDINGS FROM THE RUC AND
NAM. THERE IS ALSO CONCERN WHETHER DEEP CONVECTION ACROSS EASTERN OK
WILL LIMIT THE AMOUNT OF MOISTURE RETURNING WITH THE ISENTROPIC
LIFT. HAVE ADJUSTED POPS DOWN SLIGHTLY BUT WILL CONTINUE THE CHANCE
FOR LIGHT SHOWERS DEVELOPING OVERNIGHT AND CONTINUING INTO THE
MORNING SATURDAY. TOOK OUT THE MENTION OF THUNDERSTORMS SINCE MID
LEVEL LAPSE RATES SHALLOW UP TO AROUND 5 C/KM.
THERE REALLY ARE NOT MANY AVIATION CONCERNS THIS EVENING. EXPECT
CEILINGS AND VSBY TO REMAIN VFR. WILL KEEP ANY MENTION OF SHOWERS AS
VCNTY...AND MONITOR TRENDS TO SEE WHERE SHOWERS WILL DEVELOP. LOW
MVFR OR IFR CEILINGS LOOK TO HOLD OFF UNTIL SATURDAY NIGHT AS WRAP
AROUND JUNK MOVES IN ON THE BACK SIDE OF THE UPPER LEVEL SYSTEM.
&&
WOLTERS
.PREV DISCUSSION /310 PM FRI/...
LATEST SATELLITE LOOP SHOWS UPPER LOW SPINNING OVER EASTERN SOUTH
DAKOTA WITH A SHORTWAVE TROUGH MOVING INTO WESTERN COLORADO AT 19Z.
SURFACE LOW WAS OVER SOUTHEASTERN SOUTH DAKOTA.
FOR TONIGHT THE SHORTWAVE TROUGH WILL EJECT OUT OF THE ROCKIES INTO
THE CENTRAL PLAINS. LAYER MOISTURES WILL INCREASE ACROSS CENTRAL AND
EASTERN KANSAS AS 850 MB WINDS BACK AHEAD OF THE UPPER TROUGH. THIS
ALONG WITH WARM ADVECTION AND INCREASING DYNAMICS WILL INCREASE POPS
AFTER MIDNIGHT TO NEAR 50 PERCENT ACROSS THE AREA. MODELS SUGGEST
THAT BEST CHANCE FOR PRECIPITATION WILL BE AFTER 06Z INTO MID
MORNING SATURDAY. MODEL TIMING WITH THE ENDING OF THE PRECIPITATION
DIFFERS BETWEEN THE GFS...SREF AND THE NAM. THE NAM IS SLOWER WHILE
THE GFS IS FASTER AND PROGRESSIVE WITH THE TROUGH. HAVE GONE WITH A
GFS SOLUTION FOR SATURDAY BUT HAVE ADJUSTED THE TIMING OF THE ENDING
OF THE PRECIPITATION SOME BY INCREASING POPS EARLY THEN GOING DRY BY
MID DAY. LOWS TONIGHT LITTLE CHANCE WITH LOW TO MID 50S...COOLER ON
SATURDAY WITH CLOUDS PRECIPITATION AND COOL ADVECTION.
SATURDAY NIGHT AND SUNDAY...AGAIN...GENERALLY WENT ALONG WITH GFS
SOLUTION IN PULLING SURFACE LOW INTO THE GREAT LAKES REGION FASTER
WITH BETTER SUPPORT FROM OTHER FORECAST MODELS. NAM APPEARS TO BE A
SLOW OUTLIER. ABUNDANT LOW LEVEL MOISTURE ON BACK SIDE OF THE
SURFACE LOW WILL KEEP CLOUDS AROUND FOR MUCH OF THE DAY
SUNDAY...ESPECIALLY ACROSS THE EASTERN CWA. GIVEN THE EXPECTANT
CLOUDY SKIES...HELD HIGHS IN THE MID TO UPPER 60S.
MONDAY AND TUESDAY...SURFACE LOW AND H5 TROUGH WILL CONTINUE TO MOVE
NORTHEAST...WITH RIDGING MOVING BACK IN ALOFT. SURFACE HIGH WILL
MOVE ACROSS THE SOUTHERN PLAINS...BRINGING A QUICK WARM UP FOR THE
AREA WITH A WEST TO SOUTHWEST WIND TAKING HOLD. H85 TEMPS QUICKLY
SHOOT BACK INTO THE MID TEENS BY TUESDAY AFTN. SUNNY SKIES ON MONDAY
AND TUESDAY WILL ALLOW HIGHS TO REBOUND TO THE MID 70S MONDAY...AND
UPPER 70S/LOW 80S TUESDAY.
WEDNESDAY...POTENT H5 WAVE WILL WORK SOUTH ACROSS THE UPPER
PLAINS...WHICH WILL SUPPORT COLD FRONTAL PASSAGE THROUGH THE TOP CWA
EARLY WEDS. FRONT WILL COME THROUGH DRY...BUT AS UPPER WAVE
CONTINUES SOUTH...PRECIPITATION CHANCES WILL INCREASE. FRONT LOOKS
TO BE PRETTY POTENT WITH A TIGHT BAROCLINIC ZONE. H85 TEMPS ARE
FORECAST TO START OFF THE DAY AROUND 15C...WHILE ENDING THE DAY
AROUND 2C. HIGH TEMPS WILL COME IN THE MORNING OR EARLY AFTN AT THE
LATEST.
THURSDAY AND FRIDAY...ANY LINGERING SHOWER ACTIVITY WILL COME TO AN
END ACROSS THE SE CWA EARLY THU. EC AND GFS SIMILAR IN SHIFTING H5
TROUGH EAST WHILE BUILDING RIDGING OVER THE WESTERN TWO THIRDS OF
THE COUNTRY. AT THE SURFACE...HIGH PRESSURE WILL PUSH ACROSS THE
CENTRAL PLAINS. PERIOD LOOKS COOL AND TRANQUIL WITH A SLIGHT WARM UP
ON FRIDAY AS WINDS SWITCH TO THE SOUTH.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
</PRE></TT></td>   ks
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
230 PM MDT FRI SEP 22 2006
.DISCUSSION...FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION
THROUGH SATURDAY...WINDS SATURDAY...AND TEMPERATURE RECOVERY AT THE
BEGINNING OF THE WEEK BEFORE THE NEXT COOL DOWN. SATELLITE SHOWING
AN AMPLIFIED BUT SOMEWHAT PROGRESSIVE FLOW FROM THE PACIFIC INTO
NORTH AMERICA. BROAD AND COMPLICATED UPPER TROUGH OVER THE CENTRAL
PORTION OF THE COUNTRY. SYSTEM THAT BROUGHT WIDESPREAD RAIN TO THE
AREA YESTERDAY IS SPINNING OVER THE NORTH CENTRAL PORTION OF THE
COUNTRY.
SECOND...RATHER STRONG LOOKING SYSTEM...ROTATING AROUND THIS TROUGH
IS MOVING THROUGH COLORADO. ALSO VERY STRONG JET IS MOVING IN FROM
THE SOUTH AND WEST WITH THIS SYSTEM. AT JET LEVEL...JET SEGMENT OVER
THE WESTERN PORTION OF THE COUNTRY WAS NOT SAMPLED WELL. IF
SATELLITE/AIRCRAFT SPEEDS ARE CORRECT...MODELS INITIALIZED ABOUT 25
KNOTS TOO LOW. AT 18Z...THEY WERE DOING BETTER AND CLOSER WITH THE
GFS DOING THE BEST ON THE 140 KNOT JET COMING IN FROM NORTHERN NEW
MEXICO.
AT MID LEVELS...OVERALL THROUGH 18Z...THE GFS/UKMET/RUC DID THE BEST
ON THE TWO SYSTEMS OF INTEREST. THE NAM/WRF WAS NOT TOO FAR BEHIND.
BASED ON PERFORMANCE THROUGH 18Z...AND JET STRUCTURE...WILL GO WITH
A BLEND OF THE GFS AND UKMET.
TONIGHT/SATURDAY...HIGHEST JET WINDS ROAR UP THE EAST SIDE OF THE
UPPER TROUGH DURING THE NIGHT WHICH SYSTEM SHOULD KICK OUT FAIRLY
FAST. LEFT FRONT QUADRANT OF JET TO OUR SOUTHWEST WILL MOVE ACROSS
THE AREA DURING THE EVENING AS INCOMING SYSTEM ALSO MOVES THROUGH.
SOUNDINGS AND OBSERVATIONS SHOW DRY LOW LEVELS...AND LIFT WILL HAVE
TO OCCUR FOR A WHILE BEFORE PRECIPITATION BEGINS...AND BELIEVE IT
WILL. HARD TO SAY WHERE ANY ONE SPOT WILL GET PRECIPITATION WITH
MOISTURE AND LIFT NOT COINCIDING VERY WELL. BEST CHANCE ACCORDING TO
THE SOUNDINGS WILL BE IN THE NORTHWEST PORTION OF THE AREA. WILL
HAVE SCATTERED RAIN SHOWERS THROUGH THE NIGHT.
MOST OF THE LIFT EXITS THE AREA SHORTLY AFTER 12Z. HOWEVER...COLD
POOL ALOFT MOVES OVER THE AREA...AND SOUNDINGS BECOME MORE
SATURATED. TQ INDEX VALUES SUPPORT INSTABILITY SHOWERS. WILL HAVE
SLIGHT CHANCE TO CHANCE THROUGH THE DAY. ALSO WITH LITTLE DOWNWARD
MOTION...MIXING/ENOUGH SUNSHINE...DO NOT BELIEVE THE WINDS WILL
REACH WIND ADVISORY CRITERIA. WILL HAVE WINDY IN THE FORECAST. ALSO
WITH CLOUDS AND COLD ADVECTION...WILL GO UNDERNEATH GUIDANCE.
SATURDAY NIGHT/SUNDAY...SOME INSTABILITY SHOWERS WILL CONTINUE EARLY
INTO THE EVENING THEN DRY. TEMPERATURES WILL RECOVER SOME BUT
BELIEVE THE COOLER GUIDANCE WILL BE THE MOST REASONABLE.
SUNDAY NIGHT/MONDAY...WARMUP WILL CONTINUE. BUT BELIEVE WITH A
SHARPER UPPER RIDGE...MODELS MAY BE A LITTLE FAST IN WARMING THINGS
UP. WILL GO NEAR TO SLIGHTLY BELOW GUIDANCE.
FOR TUESDAY THROUGH FRIDAY...ONE PROBLEM AS OF THIS MORNING WITH THE
MODELS IS THEY DO NOT LOOK SHARP ENOUGH WITH RIDGE AND TROUGH OVER
THE CENTRAL PACIFIC. BASED ON WHAT SATELLITE IS SHOWING ME...RECENT
PATTERN/BIASES...AND JET STRUCTURE...BELIEVE WILL HAVE A SHARPER
AND FURTHER WEST UPPER RIDGE. BELIEVE THE LATEST GFS CAPTURES THIS
THE BEST...AND WILL FOLLOW/BASE THE FORECAST OFF OF IT.
NEW MODEL RUN CAME IN COOLER FOR WEDNESDAY AND THURSDAY. ALSO POPS
HAVE RISEN INTO THE SLIGHT CHANCE TO LOW CHANCE CATEGORY FOR TUESDAY
NIGHT AND WEDNESDAY NIGHT INTO THURSDAY. THINK THE GFS IS PRODUCING
TOO HIGH OF POPS AND HOLDING ONTO THEM TOO LONG DESPITE ITS DOING
BETTER WITH THE PATTERN. MAIN JET DYNAMICS LOOK TO STAY NORTH AND
SOUTH OF THE AREA. ALSO AREA LOOKS TO BE IN CONFLUENCE ALOFT AS WELL.
MOISTURE IS LACKING THROUGH MID LEVELS AND UPSLOPE IS NOT THAT
STRONG. SO WILL BE KEEPING THIS PERIOD DRY...ALTHOUGH WOULD NOT BE
SUPRISED TO SEE A FEW SPRINKLES/SHOWERS TUESDAY NIGHT AND WEDNESDAY
MORNING AS STRONG FRONT PUSHES THROUGH.
RAISED MAXES ON TUESDAY IN ADVANCE OF THE FRONT. BEHIND FRONT...MEX
LOOKS TOO WARM BASED ON THE 850 MB TEMPERATURES. SO LOWERED MAXES ON
WED AND THU. ALSO TWEEKED MINS DOWN A LITTLE AS WELL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
BULLER
</PRE></TT></td>   ks
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
934 PM EDT FRI SEP 22 2006
.UPDATE...ADIABATIC OMEGA ON THE 305K SURFACE DIMINISHING FROM
WEST-EAST AS WEAK MID LEVEL VORT CENTER PUSHES EAST OF THE AREA.
LOW CLOUD SATELLITE IMAGERY SHOWS DRIER AIR MOVING ACROSS LAKE
MICHIGAN...WITH PARTIAL CLEARING NOW ENTERING MANISTEE COUNTY.  BIG
QUESTION OF THE NIGHT IS HOW TO HANDLE CLOUD TRENDS AND ISSUES OF
STRATUS/FOG.  TIME/HEIGHT CROSS SECTIONS AND RUC FORECAST SOUNDINGS
SHOW SHALLOW MOISTURE /1000-950MB/ TRAPPED BENEATH A DEVELOPING
INVERSION AFTER MIDNIGHT.  LOOKING AT 950MB RH PROGS FROM THE ETA12
AND RUC...90%+ RH FIELDS STAY FROM I-75 EASTWARD OVERNIGHT...WITH AT
LEAST SOME CLEARING FURTHER WEST.  STRATUS DEVELOPMENT FURTHER
DISRUPTED IN THE WEST BY VEERING 950MB FLOW AND 10-15KTS OF WIND
NEAR THE LAKE SHORE.  I WILL GO PARTLY CLOUDY WEST OF I-75 OVERNIGHT
WITH CLOUDY EAST.  I WILL MENTIONS AREAS OF FOG ALL AREAS.
I WILL KEEP SCA/S UP FOR LAKE MICHIGAN NEARSHORE...AS VEERING LOW
LEVEL FLOW TO SOUTHWEST WILL RESULT IN CONVERGENCE ALONG THE LAKE
MICHIGAN SHORELINE AND LIKELY KEEP AT LEAST MARGINAL SCA CONDITIONS
GOING.
JK
&&
.PREV DISCUSSION...ISSUED 318 PM FRI SEP 22
1ST BAND OF SHOWERS HAS LIFTED OUT OF EASTERN UPPER MI. 2ND BAND IS
WORKING ACROSS NORTHERN LOWER MI FROM SW TO NE. BOTH BANDS SUFFERED
FROM STILL DRY AIR BELOW 800MB...RESULTING IN ONLY SPOTTY AND LIGHT
RAIN TO THIS POINT. SE LOW LEVEL WINDS ARE ACTING TO REINFORCE THE
DRY LOW LEVELS. MORE SUBSTANTIAL PRECIP IS FALLING IN THE OHIO
VALLEY. THIS IS ALL OCCURRING AHEAD OF A WELL-DEFINED AND NEARLY
STACKED LOW NEAR SD/MN BORDER. PRECIP TRENDS ARE THE OBVIOUS MAIN
CONCERN FOR TONIGHT.
TONIGHT...RAIN BAND OVERHEAD APPEARS TO REPRESENT AN 850MB WARM
FRONT (SURFACE WARM FRONT STILL WELL DOWNSTATE). 850MB FRONT WILL
MOVE STEADILY NORTHWARD...CLEARING EASTERN UPPER MI THIS EVENING...
WITH THE SURFACE BOUNDARY TRAILING SEVERAL FEW HOURS BEHIND. MAIN
SYNOPTIC FOCUS FOR PRECIP WILL BE NORTH OF THIS BOUNDARY...AND AGAIN
THE MAIN INHIBITING FACTOR THERE IS LOW LEVEL DRY AIR. WILL CARRY
LIGHT SHOWERS LIKELY IN THE NE ZONES VERY EARLY ON TO ACCOUNT FOR
THIS.
IN THE WARM SECTOR...VERY LITTLE IS GOING ON AT THE MOMENT IN THE
SOUTHERN LAKES. AS MENTIONED EARLIER...FOCUS OF THE LOW LEVEL JET
WILL REMAIN WELL TO THE SOUTH...FROM THE LOW/MID OHIO VALLEY TOWARD
LAKE ERIE...WITH ANOTHER SURGE POINTING TOWARD CENTRAL IL LATE.
THERE IS SOME 300MB DIVERGENCE IN LEFT EXIT REGION OF 120KT JET
EJECTING INTO THE SOUTHERN LAKES...BUT IN GENERAL IT LOOKS RATHER
UNFOCUSED...AND WILL DIMINISH LATE AS JET CORE HEAD EAST. 700-500MB
LAPSE RATES NEAR 6.5C/KM...KINDA STEEPISH BUT AGAIN NOT REALLY
IMPRESSIVE.
SO NOT A LOT OF FORCING TO GENERATE PRECIP. BUT AS CONVECTIVE
ELEMENTS LIFT NE FROM THE MID MS VALLEY...THERE IS ENOUGH SUPPORT TO
ALLOW THEM TO HOLD TOGETHER TO SOME DEGREE. SO UNTIL CONVECTIVE
EVOLUTION UPSTREAM REVEALS ITSELF MORE FULLY...HARD TO IDENTIFY WHO
WILL GET WET AND WHO WON/T. PLACES NEAR SAGINAW BAY SHOULD HAVE A
BETTER CHANCE OF SEEING SHOWERS LIFT NORTH...WITH THE DYNAMIC FOCUS
OFF TO THE SE...AND WITH THE EXPECTED ENE/NE PROPAGATION OF STORMS
IN MO. THIS SHOULD ALSO BE THE AREA WITH THE BEST CHANCE OF THUNDER.
MARINE...STILL BREEZY OUR THERE...AND SMALL CRAFTS WILL CONTINUE
THRU THE EVENING. PRESSURE GRADIENT RELAXES AS SURFACE LOW IN MN
FILLS DURING THE NIGHT. HOWEVER...AS LOW LEVEL WINDS VEER SSW
COASTAL CONVERGENCE AND THE LONG FETCH WILL COME INTO PLAY ON LAKE
MI. WILL EXTEND SCA THRU THE NIGHT ON LAKE MI WATERS.
ZOLTOWSKI
REMAINDER OF THE FORECAST (SATURDAY THROUGH NEXT FRIDAY)...LOTS OF
QUESTIONS OVER THE NEXT 48 HOURS ABOUT THE EVOLUTION OF THE STORM
SYSTEM CURRENTLY CENTERED ACROSS THE NORTH CENTRAL PLAINS. BEHIND
THAT A BREAK IN THE ACTION IS EXPECTED EARLY NEXT WEEK BEFORE
ANOTHER TROUGH AFFECTS THE REGION DURING THE MIDDLE AND END OF NEXT
WEEK. THE MAIN FORECAST CONCERNS WILL REVOLVE AROUND THE DETAILS OF
THE SYSTEM THIS WEEKEND WITH AMOUNT OF CONVECTION ON SATURDAY THE
MOST PRESSING ISSUE.
SATURDAY...MODEL SOLUTIONS DIFFER ON THE EVOLUTION OF UPPER AND
LOWER LEVEL SYSTEMS. AT THIS POINT WILL TAKE A COMPROMISE SOLUTION
WITH THE NAM TO START AS THE GFS SEEMS TO BE SUFFERING FROM SOME
CONVECTIVE FEEDBACK ISSUES BUT LEAN TOWARD THE FASTER TIMING OF THE
GFS/ECMWF SATURDAY NIGHT INTO SUNDAY. IN A NUTSHELL...UPPER LEVEL
SYSTEM CONTINUES TO MEANDER NORTH NORTHWEST THROUGH SATURDAY EVENING
WHILE DRAGGING A COLD FRONT ACROSS THE REGION LATE SATURDAY OR
SATURDAY EVENING. MID LEVEL DRY SLOT IS EXPECTED TO BE ACROSS THE
REGION IN THE MORNING SO ITS HARD TO SAY JUST HOW MUCH SUNSHINE
THERE WILL BE. THIS WILL OBVIOUSLY IMPACT POTENTIAL INSTABILITY AS
TEMPERATURES RISE TO NEAR 70 OR SO. AT THIS POINT EXPECT A CHANCE OF
SHOWERS IN THE MORNING BEFORE DEEPER MOISTURE (MEAN 1000-500 MB RH
INCREASES FROM 60 TO 70 PERCENT TO 80 TO 90 PERCENT) AND BETTER
DYNAMICS ENCROACH THE REGION FROM THE SOUTH IN THE AFTERNOON. AS FAR
AS SEVERE POTENTIAL GOES...WIND FIELDS ARE FAIRLY STRONG WITH 130
KNOT JET NEARLY OVERHEAD BUT OTHERWISE...THETA-E RIDGE AND HIGHER
SURFACE DEWPOINTS REMAIN TO OUR SOUTH. WILL BRING IN LIKELY POPS AND
A CHANCE OF TSTORMS ACROSS SOUTHERN COUNTIES IN THE AFTERNOON AND A
CHANCE OF SHOWERS AND SLIGHT CHANCE OF STORMS NORTH.
SATURDAY NIGHT AND SUNDAY...AS STATED ABOVE WILL FOLLOW THE NAM BUT
SPEED UP THE TIMING SO EXPECT SURFACE COLD FRONT TO MOVE THROUGH IN
THE EVENING WITH ABUNDANT WRAP AROUND MOISTURE TO FOLLOW AS SURFACE
AND UPPER LEVEL WAVES TAKE THEIR TIME MOVING ACROSS THE REGION.
HAVE INCREASED QPF WITH UPWARDS OF A HALF INCH PLUS EXPECTED
(SHOWERS) AND UPPED POPS TO LIKELY SATURDAY NIGHT INTO SUNDAY
MORNING THEN BACK THEM DOWN TO CHANCE SUNDAY AFTERNOON DUE TO TIMING
UNCERTAINTY (GFS WOULD END ACTIVITY MUCH FASTER WHILE THE NAM WOULD
LINGER SHOWERS INTO SUNDAY AFTERNOON). IT WILL TURN BRISK AND COOLER
DURING THE DAY ON SUNDAY AS WELL WITH TEMPERATURES GENERALLY HOLDING
IN THE 50S.
MONDAY AND TUESDAY...A NICE BREAK IN THE ACTION COURTESY OF
INCREASING SHORT WAVE RIDGING AT THE SURFACE AND ALOFT OUT AHEAD OF
ANOTHER SYSTEM DUE IN FOR MIDWEEK. PARTLY CLOUDY CONDITIONS EXPECTED
WITH HIGHS GENERALLY IN THE 60S WITH LOWS IN THE UPPER 30S AND 40S.
WEDNESDAY...A FAIRLY POTENT UPPER TROUGH AND ASSOCIATED SURFACE COLD
FRONT WILL APPROACH THE REGION BRINGING MORE CHANCES FOR SHOWERS AND
EVEN THUNDERSTORMS. HAVE INCREASED POPS INTO THE HIGH CHANCE
CATEGORY. THE EXACT TIMING OF THE FRONT WILL DETERMINE HOW WARM IT
WILL GET BUT WILL STICK WITH HIGHS RANGING FROM AROUND 60 NORTHWEST
TO NEAR 70 SOUTHEAST (COULD EVEN END UP SEEING FALLING TEMPERATURES
IN THE AFTERNOON).
THURSDAY AND FRIDAY...COLD UPPER TROUGH RESIDES OVER THE REGION
LEADING TO POSSIBLE LAKE EFFECT RAIN SHOWERS FOR AT LEAST THURSDAY
INTO EARLY THURSDAY NIGHT. DRIER AIR IS THEN SHOWN TO ADVECT INTO
THE REGION WHICH MAY SPELL A FROST OR FREEZE FOR FRIDAY MORNING.
HIGHS ARE ONLY EXPECTED TO BE IN THE 50S WITH A CHILLY NORTHWEST
WIND BOTH DAYS.
SULLIVAN
&&
.APX...WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
419 PM EDT FRI SEP 22 2006
.DISCUSSION...
MAIN FCST CONCERNS ARE PCPN TRENDS THRU SUN.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A BROAD TROF DOMINATING
THE W HALF OF THE CONUS. A CLOSED MIDLEVEL LOW WAS LOCATED ALONG THE
SD/MN BORDER WHILE A WELL-DEFINED SHORTWAVE WAS OVER UT/CO.
SHRA HAVE BEEN LIFTING N INTO THE UPPER GREAT LAKES TODAY WITH BULK
OF PCPN OCCURRING ALONG AND AHEAD OF NORTHWARD MOVING 850MB WARM
FRONT ANALYZED FROM SRN MN THRU E CNTRL WI AT 12Z. CURRENTLY RUC
ANALYSIS SHOWS MDT/STRONG MOIST ISENTROPIC ASCENT ON THE 300K SFC
SPREADING ACROSS UPPER MI. AT THE SFC...OCCLUDED SFC LOW WAS LOCATED
ALONG SD/MN BORDER.
MODEL DISAGREEMENT CONTINUES (NAM VS THE REST OF THE MODELS) WITH
REGARD TO FUTURE SFC RESPONSE AS SHORTWAVE CURRENTLY OVER CO/UT
MOVES ACROSS THE PLAINS TOWARD THE GREAT LAKES. NAM HAS BEEN AND
CONTINUES TO BE MUCH STRONGER AND FARTHER NW WITH THE NEW SFC LOW
PRES DEVELOPING IN RESPONSE TO SHORTWAVE. HOWEVER...IT IS TRENDING A
LITTLE WEAKER AND FARTHER S AND E WITH LOW AS IT MOVES INTO THE
GREAT LAKES. THUS...IT IS AT LEAST TRENDING TOWARD THE CONSENSUS
SOLUTION OF OTHER MODELS (SFC LOW TRACKING THRU SRN LWR MI SAT
EVENING). COMBINATION OF NAM/GFS WILL BE UTILIZED THRU 12Z SAT...
THEN GFS/CANADIAN/UKMET THEREAFTER AS THOSE MODELS HAVE BEEN
RELATIVELY CONSISTENT ON EVOLUTION OF SHORTWAVE AND SFC FEATURES.
850MB WARM FRONT WILL LIFT N ACROSS UPPER MI THIS EVENING AND STALL
OUT ACROSS NRN/WRN LAKE SUPERIOR. AS IT DOES SO...ISENTROPIC ASCENT
(300K SFC) DIMINISHES TO ALMOST NOTHING. THUS...BAND OF SHRA
CURRENTLY LIFTING THRU NRN WI/UPPER MI SHOULD LIFT MOSTLY N OF UPPER
MI BY MIDNIGHT. KEWEENAW/FAR W WILL HAVE A BETTER CHC OF SEEING SHRA
THRU THE NIGHT WITH CLOSE PROXIMITY OF 850MB FRONT. MEANWHILE...LEFT
EXIT OF UPPER JET MOVING THRU LWR MI MAY ALSO SPARK A FEW ADDITIONAL
SHRA AND MAYBE A TSRA OR TWO ACROSS SE UPPER MI...BUT EVEN THAT
FORCING SHIFTS TO THE NE OVERNIGHT. OTHERWISE...FCST WILL SHOW
DIMINISHING POPS THRU THE NIGHT. GFS FCST SOUNDINGS HINT AT ENOUGH
MIDLEVEL DRYING FOR POSSIBLE -DZ. LOW LEVEL MOISTURE ADVECTION AND
MOISTENING FROM EARLIER RAINFALL WILL ALSO AID FOG FORMATION.
PCPN DURING THE FIRST HALF OF SAT SHOULD BE CONFINED TO MAINLY THE
NW PART OF UPPER MI IN THE VCNTY OF 850MB FRONT. THEN...AS
SHORTWAVE CURRENTLY OVER CO/UT MOVES INTO THE MIDWEST SAT AFTN...
FAIRLY STRONG MID/UPPER LEVEL QVECTOR CONVERGENCE DEVELOPS. THIS
OVERLAYS STRENGTHENING LOW-LEVEL FRONTOGENESIS. END RESULT OF THIS
COUPLED LOW AND UPPER FORCING SHOULD BE A RAPIDLY
DEVELOPING/EXPANDING AREA OF RAIN INTO UPPER MI DURING THE
AFTN/EVENING. PREVIOUS FCST REFLECTED THIS SCENARIO WELL...SO FEW
CHANGES WERE NEEDED OTHER THAN BUMPING UP POPS SLIGHTLY AS THERE IS
INCREASED CONFIDENCE OF RAIN DEVELOPING. ONLY EXCEPTION IS THE
KEWEENAW WHERE CHC POPS WERE KEPT AS MAIN FORCING SHOULD PASS SE OF
THAT AREA.
RAIN WILL DIMINISH AND THEN END FROM NW TO SE LATER SAT NIGHT/SUN
MORNING AS SYSTEM PULLS AWAY. ANOTHER SHORTWAVE IS STILL PROGGED TO
SWIPE THE UPPER LAKES REGION SUN NIGHT/MON MORNING...POTENTIALLY
BRINGING A FEW SHRA TO ERN LAKE SUPERIOR AND ERN UPPER MI.
TUE THRU FRI...THIS PORTION OF THE FCST IS FAIRLY STRAIGHT FORWARD
TODAY AS THE ECMWF/CANADIAN/UKMET/GFS ARE IN GOOD AGREEMENT.
THE ONLY FEATURE OF SIGNIFICANT INTEREST IS A STRONG SHORTWAVE
PASSING THRU THE UPPER LAKES EARLY IN THE PERIOD WITH SUBSEQUENT
PROGRESSIVE TROF AMPLIFICATION FROM THE GREAT LAKES TO THE E COAST.
SURPRISINGLY...FOR HOW FAR OUT IN THE MODEL RUNS THIS SYSTEM IS...
THE MODELS SHOW ONLY MINOR TIMING ISSUES (ALL SHOW FROPA OCCURRING
ROUGHLY TUE NIGHT). DEPENDING ON EXACT TIMING OF FRONT...TUE SHOULD
BE A WARM DAY WITH 850MB THERMAL RIDGE OF 10C OR POSSIBLY HIGHER
SHIFTING NE ACROSS UPPER MI. FOR NOW...WILL ASSUME FRONT WILL BE
SLOW ENOUGH TO MAXIMIZE WARMTH. PREVIOUS FCST HIGHS IN THE UPPER
60S/AROUND 70 LOOK ON TRACK. WILL CARRY CHC -SHRA ALONG/JUST AHEAD
OF FRONT TUE NIGHT. IT WILL TURN MUCH COOLER WED/THU WITH 850MB
TEMPS DROPPING TOWARD -2C...SUFFICIENT FOR SCT LAKE EFFECT RAIN
SHOWERS. COVERAGE WILL DEPEND ON SYNOPTIC SUPPORT...EITHER THRU
PASSAGE OF ANY WEAK SHORTWAVES OR DEEPER MOISTURE (BOTH OF WHICH ARE
UNCERTAIN). SO LOW END CHC POPS WILL BE UTILIZED FOR NOW. ANY
LINGERING LAKE EFFECT -SHRA SHOULD END EARLY FRI WITH HIGH PRES
BUILDING INTO THE WRN LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
ROLFSON
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1040 AM EDT FRI SEP 22 2006
.UPDATE...MOISTENING PROCESS CONTINUES OVER THE FORECAST AREA THIS
MORNING...AS INITIAL BAND OF LIGHT PRECIP (MAINLY SPRINKLES) LIFTS
NWD INTO ERN UPPER. 1200 UTC APX/GRB/DTX SOUNDINGS REVEAL
CONSIDERABLE DRY AIR BELOW ABOUT 10 KFT...PER EARLIER DISCUSSION.
THIS DRY AIR WILL HAVE TO BE OVERCOME BEFORE MORE WIDESPREAD RAIN
CAN OCCUR (FOR SOME AREAS...THIS MAY BE DELAYED INTO THIS EVENING).
TIMING OF MORE SUBSTANTIAL RAIN CONTINUES TO BE MAIN CONCERN FOR THE
AFTERNOON.
NEXT BATCH OF RAIN WITH EMBEDDED THUNDER WAS LIFTING NE THROUGH
CENTRAL/SOUTHERN LAKE MICHIGAN. 850 MB ANALYSIS SHOWED 50 KT LLJ WITH
NARROW RIBBON OF +11C DEW POINTS OVER ILLINOIS...WHICH WAS FUELING
THE SHOWERS. ADDITIONAL SUPPORT WAS BEING PROVIDED BY LEFT EXIT
FORCING (DIVERGENCE ALOFT) FROM 500-300 MB JETS PUNCHING ENE ACROSS
MO AND NRN IL. THIS AFTERNOON...NAM/RUC SUGGEST THAT LLJ OVER IL
WILL WEAKEN -- AS WEAKER 850 MB JET ENERGY SHIFTS TO WI WITH ANOTHER
BRANCH OVER OH VALLEY. SIMILARLY...LATEST 1200 UTC SHORT RANGE MODEL
OUTPUT SUPPORTS BEST LARGE-SCALE ASCENT OVER WI THIS AFTERNOON --
AND THIS IS WHERE MOST WIDESPREAD RAIN SHOULD OCCUR.
OVERALL CHANGES FROM GOING FORECAST MINOR. HOWEVER...HAVE TRIMMED
RAIN CHANCES SLIGHTLY OVER ERN AREAS. BASED ON EXTRAPOLATION...WILL
KEEP RAIN LIKELY OVER AREAS W OF I-75 THIS AFTERNOON. WITH
DECREASING JET SUPPORT...WILL NOT INCLUDE THUNDER. WITH BEST LIFT
FOCUSED TO OUR WEST...AND AFOREMENTIONED DRY AIR...WILL OPT FOR ONLY
SCATTERED SPRINKLES THIS AFTERNOON FOR FAR ERN AREAS...INCLUDING APN
AND VICINITY. APPEARS THAT STEADIER RAIN WILL LIKELY HOLD OFF FOR
AREAS ALONG AND E OF I-75 UNTIL (POSSIBLY WELL INTO) THIS EVENING.
AFTERNOON HIGHS WILL RANGE FROM AROUND 60 TO THE MID 60S...PER GOING
FORECAST.
SMITH
&&
.PREV DISCUSSION...ISSUED 500 AM FRI SEP 22
SFC/RUC/SATELLITE/RADAR AND UPPER AIR ANALYSIS SHOWING WELL DEFINED
UPPER/SFC LOWS SPINNING OVER THE NEBRASKA/IOWA BORDER AND HEADING
NORTH. INITIAL VORTICITY LOBE AND BAND OF DEEPER MOISTURE TRAPPED
MORE SO IN THE MID LEVELS IS WORKING NORTHWARD AND SCRAPING THE SRN
AND WESTERN PORTIONS OF THE CWA. RADAR SUGGESTING THAT SPRINKLES OR
LIGHT RAIN IS ALL THAT CAN OCCUR AS AIR MASS WAS RATHER DRY
INITIALLY PER 00Z APX SOUNDING (0.42"). WINDS WERE BELOW 10KT FROM
THE SE AND TEMPERATURES RANGED FROM THE UPPER 30S TO MIDDLE 50S.
FORECAST CONCERNS...MANY. MARINE ISSUES TODAY AND THIS EVENING WITH
WINDS/WAVES UNDER STRENGTHENING SE FLOW. TOUGHEST ISSUE TO TACKLE IS
THE CHANCE FOR PRECIPITATION THROUGH THE WEEKEND...ALONG WITH THE
CHANCE FOR THUNDER.
SFC LOW WILL FILL/WEAKEN TODAY...THEN A NEW SFC LOW DEVELOPS AS
UPPER TROUGH LIFTS OUT OF THE MISSISSIPPI VALLEY AND INDUCES
CYCLOGENESIS IN ILLINOIS SATURDAY. THIS NEW LOW WILL RIDE UP THROUGH
CENTRAL LOWER MICHIGAN. EXACT TRACK/STRENGTH OF THIS LOW REMAINS
SOMEWHAT IN QUESTION AND MODELS CONTINUE TO HAVE A DIFFICULT TIME IN
DEALING WITH SOME OF THE FINER DETAILS.
TODAY...DEEP/FILLING SFC LOW WILL TRACK NORTHWARD TODAY AND THE
PRESSURE GRADIENT ACROSS NRN MICHIGAN WILL TIGHTEN INTO THIS
EVENING...MAINLY FOR THE WESTERN PORTIONS OF THE CWA. 950-850MB
WINDS INCREASE TO 25-30KTS WITH MIXING OVER LAND EXPECTED TO TAP
INTO RIGHT AROUND 25 KNOTS RESULTING IN OFF SHORE GUSTS AT SMALL
CRAFT ADVISORY LEVELS. LOCAL EFFECTS AND LONGER FETCHES ACROSS THE
LAKE HURON SHORELINE WILL LEAD TO SOME GUSTS TO 25 KNOTS AND WAVES
NEARING 3 TO 5 FEET BY LATER THIS AFTERNOON. THEREFORE...HAVE
HOISTED SMALL CRAFT ADVISORIES FOR ALL AREAS EXCEPT ST. MARY'S RIVER
(WHERE WEAKEST OF WINDS SHOULD RESIDE).
OBSERVATIONS SHOWING THAT RAIN IN A VERY LIGHT FORM HAS MADE IT DOWN
TO THE SFC FOR THE SW CWA ASSOCIATED WITH VORT LOBE/305-315K
ISENTROPIC ASCENT AND NICE H4-H2 LAYER DIVERGENCE...SO WILL GO WITH
LIKELY LIGHT RAIN THIS MORNING FOR THE GTV BAY REGION...AS FAR EAST
AS HOUGHTON LAKE. THIS VORT LOBE SWINGS THROUGH THE NORTHERN CWA
EARLY THIS MORNING...BUT AIR MASS IS LIKELY TOO DRY FURTHER NE FOR
MUCH OF NE LOWER TO SEE ANY OF THIS LIGHT RAIN AT THE SFC...SO WILL
KEEP THINGS DRY THERE FOR THE MORNING HOURS. HOWEVER...ADDITIONAL
SHORTWAVE ENERGY/LAYER ISENTROPIC ASCENT (305-315K)/INCREASED
850-700MB FRONTOGENESIS SWINGS INTO THE CWA THIS AFTERNOON...AND
WITH INITIAL WAVE MOISTENING THE ATMOSPHERE UP...THIS ROUND OF
PRECIP SHOULD MORE EFFICIENTLY REACH THE SFC. HAVE GONE WITH LIKELY
CHANCES FOR LIGHT RAIN FOR ALL BUT NE LOWER WHERE THE DRIEST OF AIR
WILL RESIDE. CHANCES ARE CERTAINLY THERE THOUGH. RAINFALL AMOUNTS
SHOULD BE RATHER SMALL/LIGHT WITH MOST AREAS SEEING ONLY A FEW
HUNDREDTHS.
TONIGHT...SFC LOW CONTINUES TO FILL AND THE PRESSURE GRADIENT
RELAXES IN THE EVENING...BUT NOT AFTER A FEW 25 KNOT GUSTS HOLD ON
INTO THE EARLY EVENING. THE FRONTOGENESIS/DEEPER H8-H5 LAYER -DIVQ
EXITS NORTH OF EASTERN UPPER BY MID EVENING...ONLY TO BE REPLACED BY
LEFT EXIT REGION OF 130KT JET/ANOTHER ROUND OF H4-H2 LAYER
DIVERGENCE AND MID LEVEL LAPSE RATES TO 6.5C/KM. STRONGEST DYNAMICS
LOOKS TO BE ACROSS NRN LOWER AND HAVE BUMPED CHANCES FOR
PRECIPITATION TO LIKELY...AND ADDED CHANCES FOR THUNDER DUE TO THE
STEEPER LAPSE RATES. LLJ LOOKS TO BE PRETTY FAR TO THE SE OF THE
AREA BUT EXACT EVOLUTION OF THIS SYSTEM REMAINS UNCLEAR TO SOME
DEGREE. TEMPERATURES ARE LIKELY TO NOT FALL OUT OF THE 50S
ANYWHERE.
SATURDAY AND SATURDAY NIGHT...LOW LEVEL JET AND UPPER AIR DYNAMICS
WORK WELL EAST OF US SATURDAY MORNING...AND MID LEVEL DRYING SEEMS
TO WANT TO MOVE IN. JUST WENT WITH CHANCES FOR SHOWERS...AND WOULD
HAVE THOUGHT ABOUT GOING DRY FOR THIS TIME PERIOD IF IT WASN'T FOR
THE UNCERTAINTY IN THE MODELS. SATURDAY AFTERNOON...UPPER TROUGH
LIFTS NE AND NEXT SFC LOW DEVELOPS IN THE ILLINOIS VICINITY...WHICH
IS FORECAST TO RIDE UP THROUGH CENTRAL LOWER SATURDAY NIGHT. NEXT
UPPER LEVEL JETLET AND LLJ JET MOVE IN/DEVELOP MAINLY AROUND 06Z IN
THE SAGINAW BAY AREA. STRONG H8-H5 -DIVQ FINDS ITS WAY INTO THE SRN
STRETCHES OF NRN MICHIGAN LATE IN THE AFTERNOON...BUT REALLY HOLD
OFF UNTIL MAINLY SATURDAY NIGHT. WILL KEEP THINGS ON THE CHANCE SIDE
FOR NOW...AND BRING IN THE LIKELY CHANCES FOR PRECIPITATION SATURDAY
NIGHT. SFC LOW TRACK WILL BE KEY...CURRENT IDEA IS FOR A FAR ENOUGH
SOUTH TRACK FOR THUNDERSTORMS...FIRED OFF ALONG LEADING EDGE OF DRY
SLOT...TO BE JUST TO OUR SE MORE IN SRN LOWER. HOWEVER...DID NOT
VEER FROM ONGOING FORECAST OF THUNDER CHANCES ACROSS NRN LOWER AS
DYNAMICS ALONE WILL BE RATHER STRONG. DO NOT EVEN THINK I COULD RULE
OUT THUNDER FOR EASTERN UPPER TOO...BUT WILL WAIT FOR SOME OF THE
DETAILS TO COME MORE INTO FOCUS. ALSO HAVE TO WATCH FOR DEEPER
MOISTURE WRAPPED ON NW FLANK OF UPPER TROUGH...WHICH COULD PROVIDE
SOME DECENT RAINFALL AMOUNTS SATURDAY NIGHT. AGAIN...UNCERTAINTIES
IN EVOLUTION OF THIS SYSTEM PREVENT FROM GETTING TOO SPECIFIC WITH
THE FORECAST ATTM.
SUNDAY...NO REAL CHANGES...BUT WILL KEEP CHANCES FOR SHOWERS AS
WRAP-AROUND MOISTURE WILL SWING IN ACROSS THE CWA...WITH BRISK NW
WINDS DEVELOPING WITH THE PASSAGE OF THE COLD FRONT. SMALL CRAFT
ADVISORIES LOOK LIKE A GOOD BET BY SUNDAY AFTERNOON.    SMD
&&
.APX...WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
310 PM CDT FRI SEP 22 2006
.DISCUSSION...
CONCERN IN THE VERY SHORT TERM IS POTENTIAL THUNDERSTORM
DEVELOPMENT OVER THE NEXT FEW HOURS JUST SE OF OUR CWA. RUC
CONVECTIVE PARAMETERS SHOW THAT IF THUNDERSTORMS DO DEVELOP THEY
WOULD BE TO THE SOUTHEAST OF KEAU BETWEEN 21Z AND 00Z. WHAT MAKES
THIS AREA EXPLOSIVE IS THE LEFT EXIT REGION OF A 120 KNOT JET
POKING INTO THE AREA. DRY SLOT AND SUNSHINE/WARMER AIR IS MAKING
SLOW PROGRESSION INTO SW WISCONSIN ATTM. PLAN IS TO LEAVE
CONVECTION OUT OF THE WI CWA. EVENING CREW WILL NEED TO MONITOR.
OVERNIGHT AND SATURDAY STILL ON TRACK FOR RAIN. AGREEMENT IN THE
GFS/NAM-WRF HOLDS INTO MIDDAY SATURDAY AND THEN THE GFS BEGINS TO
ACCELERATE THE UPPER AIR SYSTEM TO THE EAST QUICKER THAN THE NAM-
WRF. 250MB JET PROGS FROM THE TWO SOLUTIONS ARE SIMILAR SATURDAY
AND SATURDAY NIGHT AND THE DPROG/DT ON THE GFS HAD BETTER RUN TO
RUN CONSISTENCY. THEREFORE...FOLLOWED THE GFS SATURDAY NIGHT AND
SUNDAY WHICH ENDS THE PRECIPITATION OVER THE WESTERN CWA DURING THE
FIRST HALF OF THE NIGHT AND OVER THE FAR EASTERN CWA BY SUNDAY
MORNING. GOOD FORCING SEEN OVER MUCH OF THE CWA TONIGHT AND
SATURDAY. 600-700MB FWF STRENGTHENS OVER EASTERN MN AND WEST WI
TONIGHT AND PERSISTS INTO SATURDAY AFTERNOON. A GOOD RESPONSE
SEEN IN THE -FN VECTOR DIVERGENCE. A COUPLED JET ALSO COMES INTO
THE PICTURE DURING THE DAY TOMORROW OVER THE EASTERN CWA WITH
SUBSTANTIAL LAYER DIVERGENCE PROGGED. THROUGHOUT TONIGHT AND MUCH
OF SATURDAY THERE IS UPGLIDE AND ISENTROPIC OMEGA SEEN ON THE 300K
THETA SURFACE. SO LIKELY TO CATEGORICAL POPS USED FOR MUCH OF THE
AREA TONIGHT AND SATURDAY. BETTER CONDITIONS FOR SUNDAY WITH A
BREEZY AFTERNOON IN STORE AS HIGH PRESSURE BUILDS IN FROM THE
WEST. LOW LEVEL WAA BEGINS SUNDAY NIGHT. THIS IS A LITTLE
TROUBLESOME AS SOME HINTS IN LOW/MID LEVEL CLOUDINESS MAY BE ON
THE INCREASE...ESPECIALLY ON MONDAY. THEREFORE...KEPT HIGHS ON
MONDAY IN THE 65 TO 70 DEGREE RANGE.
LONGER TERM...MONDAY NIGHT THROUGH FRIDAY
MILD TEMPERATURES START THE PERIOD WITH H5 TROF DIVING DOWN ACROSS
SRN CANADA WITH ASSOCIATED COLD FRONT ACROSS THE ERN DAKOTAS BY
TUESDAY AFTERNOON.  MOISTURE LOOKS TO BE ON THE LOW END OF THE
SPECTRUM FOR THIS SYSTEM BUT STILL EXPECT AT LEAST SOME SHOWER AND
THUNDERSTORM ACTIVITY TUESDAY EVENING INTO WEDNESDAY MORNING. UPPER
TROF LAGS THE FRONT AND CROSSES THE AREA EARLY THURSDAY.
TEMPERATURES EXPECTED TO BE IN THE LOW 70S TUESDAY WITH +10 TO +14
CELSIUS H85 TEMPS THEN FALLING TO AROUND 0 C FOR WEDNESDAY. WITH
CENTER OF UPPER LOW TRACKING WELL TO THE NORTHEAST OF THE LOCAL
AREA...WRAP AROUND MOISTURE WILL BE LIMITED THUS EXPECT SOME
SUNSHINE AND TEMPS THAT MAY MODERATE MORE THAN WE HAVE SEEN WITH
RECENT SYSTEMS AS A RESULT...WITH HIGHS IN THE UPPER 50S TO AROUND
60 WEDNESDAY THROUGH FRIDAY. WAA RETURNS FROM WEST TO EAST FRIDAY
BUT LOOKS TO BE BRIEF AS GFS AND ECMWF BRING ANOTHER TROF ACROSS SRN
CANADA AS STRONG UPPER JET DIGS INTO THE NORTHERN PLAINS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/MDB
</PRE></TT></td>   mn
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
329 PM CDT FRI SEP 22 2006
.DISCUSSION...
FOCUS TURNS FROM CONCERNS OF AFTERNOON SEVERE WEATHER TO WHETHER
THERE WILL BE ANY WEATHER OVERNIGHT. A WELL STACKED UPPER LEVEL LOW
IS STILL LOCATED OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A
SHORTWAVE DIVING UNDER ITS SOUTHWEST SIDE THROUGH WESTERN COLORADO.
THE SURFACE FRONT EXTENDING FROM THE LOW SNAKES DOWN THROUGH THE
IOWA/ILLINOIS/MISSOURI TRIPLE POINT...TO COLUMBIA...AND INTO THE
VICINITY OF JOPLIN BEFORE HEADING WEST TO A SECONDARY SURFACE LOW IN
THE PANHANDLE OF TEXAS.
FOR THE REST OF THE AFTERNOON AND INTO THE FIRST HALF OF THE
OVERNIGHT HOURS...THE STRONGEST H8 WINDS AND BEST 0-3KM SHEAR WILL
REMAIN FOCUSED SOUTH OF THE FRONT ACROSS THE SOUTHERN HALF OF
MISSOURI. THIS ALSO APPLIES TO THE MOISTURE FIELDS. THE UPSHOT FOR
OUR FORECAST AREA IS THAT THUNDERSTORM CHANCES ARE ALMOST
NONEXISTENT FOR THE REST OF THE AFTERNOON AND EVENING HOURS. HAVE
TRIMMED POPS TO SLIGHT CHANCES THROUGH MIDNIGHT AS A RESULT.
BEFORE MIDNIGHT THE 12Z MODELS ARE IN FAIRLY GOOD AGREEMENT ON
KEEPING MUCH...IF NOT ALL...OF THE FORECAST AREA DRY. DIFFERENCES
START TO POP UP AFTER MIDNIGHT AS THE GFS AND WRF BEGIN TO DIVERGE
ON HOW TO HANDLE THE FRONT. THE WRF BRINGS THE FRONT NORTH SOME 60
TO 80 MILES EARLY SATURDAY MORNING AS THE SURFACE WAVE MOVES ALONG
THE FRONT. IN CONTRAST THE GFS HOLDS THE FRONT ALONG OUR SOUTHEAST
EDGE...EFFECTIVELY ONLY MOVING IT NORTH SOME 30 MILES. WRF APPEARS
TO BE EMPHASIZING THE SECONDARY SHORTWAVE DIVING THROUGH COLORADO A
BIT TOO MUCH. THIS HAS THE EFFECT OF PULLING THE CENTER OF THE MAIN
LOW BACK TO THE SOUTHWEST INTO EASTERN NEBRASKA...WHICH THEN LIFTS
THE FRONT NORTH IN MISSOURI. PREFERENCE IS FOR THE GFS WHICH KEEPS
THE CENTER OF THE WELL STACKED LOW IN SOUTHEASTERN SOUTH DAKOTA.
UKMET/ECMWF/UKMET AND THE 18Z WRF BACK THIS IDEA UP.
WITH EXPECTATIONS THAT THE FRONT WILL STAY CONFINED TO OUR SOUTHEAST
EDGE I HAVE KEPT THE FOCUS FOR THUNDERSTORM ACTIVITY CONFINED TO
AREAS FROM CLINTON MISSOURI NORTHEAST THROUGH SEDALIA AND MOBERLY
FOR TOMORROW MORNING. FARTHER NORTHWEST...FOR THE HOURS BEFORE AND
AFTER SUNRISE...SOME SHOWERS AND ISOLATED THUNDER LOOK POSSIBLE.
BY TOMORROW AFTERNOON ENOUGH COOL DRY AIR WILL HAVE MOVED INTO THE
AREA TO FORCE ALL OF THE CONVECTIVE ACTIVITY TO OUR EAST. HAVE KEPT
SOME TOKEN CHANCE SHOWERS IN NORTHEAST MISSOURI FOR WRAP AROUND
SHOWER ACTIVITY UNDER THE LOW.
CUTTER
GFS AND ECMWF ARE NOW REMARKABLY SIMILAR WITH THE MID WEEK ARRIVAL
OF A STRONG COLD FRONT. BOTH MODELS ADVERTISE A PATTERN CHANGE AS A
STRONG MID/UPPER LEVEL TROUGH DEEPENS AS IT DROPS SOUTHEAST FROM
CENTRAL CANADA. TIMING IS ALSO VERY SIMILAR WITH THE COLD FRONT
MOVING INTO NORTHERN MO BY 12Z WEDNESDAY WITH STRONG COLD AIR
ADVECTION LAGGING BEHIND...ARRIVING WEDNESDAY NIGHT. EARLIER ECMWF
DID NOT HAVE AS MUCH COLD AIR COMING DOWN BUT NOW IS ON THE SAME
PAGE AS THE GFS AS BOTH MODELS FORECAST THE 0C LINE AT 850MB
REACHING THE MO/IA STATE LINE BY 12Z THURSDAY. CURRENT FORECAST WENT
A TAD COOLER THAN PREVIOUS FORECASTS BUT MAY NOT BE COLD ENOUGH
GIVEN EXPECTED 850MB TEMPERATURES BUT FORECAST TRIED TO BLEND IN
WITH SURROUNDING OFFICES. POST FRONTAL PRECIPITATION POSSIBLE WITH
THE CONVERGENCE MORE TIED TO THE 850MB FRONT AS THE GULF LOOKS LIKE
IT WILL BE CLOSED OFF DUE TO THE PREVIOUS FRONT CLEANING OUT THE
DEEPER LOW LEVEL MOISTURE.
PRIOR TO THE ARRIVAL OF THE MID WEEK COOL DOWN THERE SHOULD BE A TWO
DAY WINDOW OF INCREASING WARM AIR ADVECTION WITH TUESDAY HIGH
TEMPERATURES GOING ABOVE SEASONAL VALUES BY 1 TO 2 CATEGORIES.
MJ
&&
.PREVIOUS DISCUSSION...
1222 PM...
FOCUS IS ON THE POTENTIAL FOR SEVERE WEATHER LATER THIS AFTERNOON.
THE UPPER LEVEL LOW IS IN EASTERN SOUTH DAKOTA AT THIS HOUR WITH A
SHORTWAVE WAVE DIVING DOWN ITS SOUTHWEST SIDE ACROSS WESTERN
COLORADO. CLOSER TO HOME A FRONT EXTENDS FROM NORTHEAST MISSOURI TO
JUST NORTH OF JOPLIN...SKATING THE SOUTHEAST EDGE OF THE CWA. SHEAR
ACROSS THE FRONT IS QUIT HIGH WITH THE LATEST RUC ANALYSIS SHOWING
0-3KM SHEAR AROUND 45-50 KTS. HOWEVER...SATELLITE IMAGERY AND
SURFACE DEW POINTS SHOW THE BETTER SURFACE AND ELEVATED MOISTURE
LOCATED SOUTH OF THE FRONT. CLOUDS ACROSS SOUTHERN MISSOURI ON
VISIBLE SATELLITE IMAGERY LOOK TO SHOW THE EXPECTED LOCATION OF THIS
AFTERNOONS EXPECTED ACTIVITY...BASICALLY ALONG AND SOUTH OF A LINE
FROM PITTSBURG KANSAS NORTHEAST THROUGH COLUMBIA MISSOURI. STILL...
THERE IS THE POTENTIAL FOR SOME SCATTERED THUNDERSTORM ACTIVITY TO
GRAZE THE SOUTHEAST EDGE OF THE FORECAST AREA...BUT THAT POTENTIAL
IS LOOKING INCREASINGLY SMALL FOR THE AFTERNOON HOURS AS THE WIND AT
SEDALIA REMAINS VEERED AND DEW POINTS ARE BEGINNING TO MIX OUT.
CUTTER
300 AM....
STILL SOME QUESTIONS CONCERNING THE EVOLUTION OF THE NEXT CONVECTIVE
THREAT FOR THE CWA.
CURRENTLY...THE UPPER LEVEL LOW WAS LIFTING NNE ACROSS WRN IA WITH A
DRY LINE/WK COLD FRONT MOVING EAST INTO THE XTRM WRN CWA. PROFILERS
IN KANSAS AND OKLAHOMA DEPICT STG WESTERLIES AT H8 WITH THE DEEP
MOIST AXIS NOW SHIFTING EAST TO AN ERN OKLAHOMA TO CENTRAL MO.
MAIN CONCERN IS EXACTLY WHERE THE SURFACE BOUNDARIES AND H8 MOIST
AXIS WILL BE LOCATED LATE THIS AFTERNOON AND TONIGHT WITH THE NEXT
IN THE SERIES OF SHORTWAVE TROUGHS PIVOTS EAST INTO THE CENTRAL
PLAINS TONIGHT.
GFS/WRF SIMILAR IN DEVELOPING A WEAK SFC LOW IN WRN OKLAHOMA BY LATE
THIS EVENING WITH THE WK BOUNDARY STRETCHING ACROSS CENTRAL AND
SOUTHWESTERN MO. THE GFS IS A LITTLE FURTHER SOUTH THAN THE WRF WITH
THE BOUNDARY POSITION TNGT AS THE SFC LOW RIDES NORTHEAST. THE GFS
SUGGESTS THAT THE BOUNDARY WILL BE JUST SE OF OUR CWA WITH THE WRF
ABOUT 50 NM FURTHER NORTH. THE BIGGEST DISCREPANCIES IN THE MODELS
IS THE LOCATION OF THE H8 MOIST AXIS. THE GFS HOLDS THE MOIST AXIS
ALONG THE I-44 CORRIDOR WITH THE WRF SUGGESTING THE MOIST AXIS WILL
SURGE NORTH TO A MCI TO IRK LINE. THE FURTHER NORTH POSITION OF THE
WRF DOES NOT APPEAR REASONABLE AT THIS TIME GIVEN SUCH STG DRYING AT
H8 OCCURRING IN WRN MO. IN ADDITION...THE STG H3 JET FM THE 4
CORNERS TO IA SHOWS LITTLE LONG STREAM SPEED VARIATION WITH THE
BOUNDARY TONIGHT ACTUALLY ON THE ANTICYCLONIC SIDE OF THE JET. THE
SHORTWAVE TNGT ALSO BECOMES RATHER CHANNELED AS THE UPPER TROUGH
BECOMES POSITIVELY TILTED. THE RIGHT ENTRANCE REGION OF THE JET WILL
ALSO NOT COME INTO PLAY TNGT. THE ABOVE REASONING SUGGEST THAT ONLY
WEAK PRESSURE FALLS ARE LIKELY NORTH AND WEST OF THE BOUNDARY LATE
THIS AFTERNOON WHICH WILL MAKE SIGNIFICANT NWD TRANSPORT OF DEEP
MOISTURE TNGT DIFFICULT.
PREFER THE SCENARIO DISCUSSED BY SPC WHICH KEEPS THE GREATEST THREAT
OF SEVERE FOR AREAS JUST SOUTH AND EAST OF OUR CWA. THIS SCENARIO
FITS A COMPROMISE BETWEEN THE GFS AND WRF. THE GFS DOES HAVE SOME
SUPPORT FROM THE CANADIAN AND UKMET.
ALTHOUGH THE GREATEST THREAT WILL BE TO OUR SOUTH AND EAST TONIGHT.
THE PROXIMITY OF THE MOIST AXIS TO OUR EXTREME SERN COUNTIES
WARRANTS THE MENTION OF SEVERE GIVEN THE POTENTIAL FOR SFC-1KM
HELICITIES OF 100-200M2/S2...SFC BASED CAPES FROM 1000-1500 J/KG AND
AND STG SFC-6KM OF 60-70 KNOTS. ISOLATED TORNADOES WILL BE POSSIBLE
WITHIN THIS AREA TONIGHT WITH THE THREAT OF MORE ELEVATED
CONVECTION...DAMAGING WINDS AND LARGE HAIL...FURTHER NORTH...FROM A
BUTLER TO MARSHALL TO MACON LINE.
IF THE GFS IS MORE CORRECT...THE AXIS OF SEVERE WEATHER WILL BE
LOCATED JUST OUTSIDE OF THE CWA. ON THE FLIP SIDE...IF THE WRF IS
MORE CORRECT...MORE WIDESPREAD SEVERE WEATHER WILL BE POSSIBLE FOR
THE SERN HALF OF THE CWA. DAY SHIFT WILL NEED TO MONITOR CLOSELY
DEVELOPMENTS THROUGHOUT THE DAY.
OTHERWISE...THE SHORTWAVE PIVOTING EAST ACROSS MISSOURI TNGT WILL
PROVIDE FOR A THREAT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS THE
NORTHWESTERN HALF OF THE CWA TONIGHT. THE THUNDERSTORMS ARE EXPECTED
TO END DURING THE MORNING ON SATURDAY WITH ONLY A FEW SHOWERS
POSSIBLE ALONG THE NRN AND ERN BORDERS DURING THE AFTN.
COOLER AND DRIER AIR WILL FILTER INTO THE CWA SATURDAY NIGHT AND
SUNDAY. CAA SC TO SURGE SE LATE SATURDAY NIGHT AND EARLY SUNDAY
BEFORE ERODING SUNDAY AFTN.
DB
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
$$
WFO EAX
</PRE></TT></td>   mo
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1222 PM CDT FRI SEP 22 2006
.DISCUSSION...
FOCUS IS ON THE POTENTIAL FOR SEVERE WEATHER LATER THIS AFTERNOON.
THE UPPER LEVEL LOW IS IN EASTERN SOUTH DAKOTA AT THIS HOUR WITH A
SHORTWAVE WAVE DIVING DOWN ITS SOUTHWEST SIDE ACROSS WESTERN
COLORADO. CLOSER TO HOME A FRONT EXTENDS FROM NORTHEAST MISSOURI TO
JUST NORTH OF JOPLIN...SKATING THE SOUTHEAST EDGE OF THE CWA. SHEAR
ACROSS THE FRONT IS QUIT HIGH WITH THE LATEST RUC ANALYSIS SHOWING
0-3KM SHEAR AROUND 45-50 KTS. HOWEVER...SATELLITE IMAGERY AND
SURFACE DEW POINTS SHOW THE BETTER SURFACE AND ELEVATED MOISTURE
LOCATED SOUTH OF THE FRONT. CLOUDS ACROSS SOUTHERN MISSOURI ON
VISIBLE SATELLITE IMAGERY LOOK TO SHOW THE EXPECTED LOCATION OF THIS
AFTERNOONS EXPECTED ACTIVITY...BASICALLY ALONG AND SOUTH OF A LINE
FROM PITTSBURG KANSAS NORTHEAST THROUGH COLUMBIA MISSOURI. STILL...
THERE IS THE POTENTIAL FOR SOME SCATTERED THUNDERSTORM ACTIVITY TO
GRAZE THE SOUTHEAST EDGE OF THE FORECAST AREA...BUT THAT POTENTIAL
IS LOOKING INCREASINGLY SMALL FOR THE AFTERNOON HOURS AS THE WIND AT
SEDALIA REMAINS VEERED AND DEW POINTS ARE BEGINNING TO MIX OUT.
CUTTER
&&
.PREVIOUS DISCUSSION...
STILL SOME QUESTIONS CONCERNING THE EVOLUTION OF THE NEXT CONVECTIVE
THREAT FOR THE CWA.
CURRENTLY...THE UPPER LEVEL LOW WAS LIFTING NNE ACROSS WRN IA WITH A
DRY LINE/WK COLD FRONT MOVING EAST INTO THE XTRM WRN CWA. PROFILERS
IN KANSAS AND OKLAHOMA DEPICT STG WESTERLIES AT H8 WITH THE DEEP
MOIST AXIS NOW SHIFTING EAST TO AN ERN OKLAHOMA TO CENTRAL MO.
MAIN CONCERN IS EXACTLY WHERE THE SURFACE BOUNDARIES AND H8 MOIST
AXIS WILL BE LOCATED LATE THIS AFTERNOON AND TONIGHT WITH THE NEXT
IN THE SERIES OF SHORTWAVE TROUGHS PIVOTS EAST INTO THE CENTRAL
PLAINS TONIGHT.
GFS/WRF SIMILAR IN DEVELOPING A WEAK SFC LOW IN WRN OKLAHOMA BY LATE
THIS EVENING WITH THE WK BOUNDARY STRETCHING ACROSS CENTRAL AND
SOUTHWESTERN MO. THE GFS IS A LITTLE FURTHER SOUTH THAN THE WRF WITH
THE BOUNDARY POSITION TNGT AS THE SFC LOW RIDES NORTHEAST. THE GFS
SUGGESTS THAT THE BOUNDARY WILL BE JUST SE OF OUR CWA WITH THE WRF
ABOUT 50 NM FURTHER NORTH. THE BIGGEST DISCREPANCIES IN THE MODELS
IS THE LOCATION OF THE H8 MOIST AXIS. THE GFS HOLDS THE MOIST AXIS
ALONG THE I-44 CORRIDOR WITH THE WRF SUGGESTING THE MOIST AXIS WILL
SURGE NORTH TO A MCI TO IRK LINE. THE FURTHER NORTH POSITION OF THE
WRF DOES NOT APPEAR REASONABLE AT THIS TIME GIVEN SUCH STG DRYING AT
H8 OCCURRING IN WRN MO. IN ADDITION...THE STG H3 JET FM THE 4
CORNERS TO IA SHOWS LITTLE LONG STREAM SPEED VARIATION WITH THE
BOUNDARY TONIGHT ACTUALLY ON THE ANTICYCLONIC SIDE OF THE JET. THE
SHORTWAVE TNGT ALSO BECOMES RATHER CHANNELED AS THE UPPER TROUGH
BECOMES POSITIVELY TILTED. THE RIGHT ENTRANCE REGION OF THE JET WILL
ALSO NOT COME INTO PLAY TNGT. THE ABOVE REASONING SUGGEST THAT ONLY
WEAK PRESSURE FALLS ARE LIKELY NORTH AND WEST OF THE BOUNDARY LATE
THIS AFTERNOON WHICH WILL MAKE SIGNIFICANT NWD TRANSPORT OF DEEP
MOISTURE TNGT DIFFICULT.
PREFER THE SCENARIO DISCUSSED BY SPC WHICH KEEPS THE GREATEST THREAT
OF SEVERE FOR AREAS JUST SOUTH AND EAST OF OUR CWA. THIS SCENARIO
FITS A COMPROMISE BETWEEN THE GFS AND WRF. THE GFS DOES HAVE SOME
SUPPORT FROM THE CANADIAN AND UKMET.
ALTHOUGH THE GREATEST THREAT WILL BE TO OUR SOUTH AND EAST TONIGHT.
THE PROXIMITY OF THE MOIST AXIS TO OUR EXTREME SERN COUNTIES
WARRANTS THE MENTION OF SEVERE GIVEN THE POTENTIAL FOR SFC-1KM
HELICITIES OF 100-200M2/S2...SFC BASED CAPES FROM 1000-1500 J/KG AND
AND STG SFC-6KM OF 60-70 KNOTS. ISOLATED TORNADOES WILL BE POSSIBLE
WITHIN THIS AREA TONIGHT WITH THE THREAT OF MORE ELEVATED
CONVECTION...DAMAGING WINDS AND LARGE HAIL...FURTHER NORTH...FROM A
BUTLER TO MARSHALL TO MACON LINE.
IF THE GFS IS MORE CORRECT...THE AXIS OF SEVERE WEATHER WILL BE
LOCATED JUST OUTSIDE OF THE CWA. ON THE FLIP SIDE...IF THE WRF IS
MORE CORRECT...MORE WIDESPREAD SEVERE WEATHER WILL BE POSSIBLE FOR
THE SERN HALF OF THE CWA. DAY SHIFT WILL NEED TO MONITOR CLOSELY
DEVELOPMENTS THROUGHOUT THE DAY.
OTHERWISE...THE SHORTWAVE PIVOTING EAST ACROSS MISSOURI TNGT WILL
PROVIDE FOR A THREAT OF SHOWERS AND A FEW THUNDERSTORMS ACROSS THE
NORTHWESTERN HALF OF THE CWA TONIGHT. THE THUNDERSTORMS ARE EXPECTED
TO END DURING THE MORNING ON SATURDAY WITH ONLY A FEW SHOWERS
POSSIBLE ALONG THE NRN AND ERN BORDERS DURING THE AFTN.
COOLER AND DRIER AIR WILL FILTER INTO THE CWA SATURDAY NIGHT AND
SUNDAY. CAA SC TO SURGE SE LATE SATURDAY NIGHT AND EARLY SUNDAY
BEFORE ERODING SUNDAY AFTN.
DB
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
$$
WFO EAX
</PRE></TT></td>   mo
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1010 PM EDT FRI SEP 22 2006
.UPDATE /OVERIGHT/...
NO ZONE UPDATE ANTICIPATED. LOWS TONIGHT PRETTY MUCH GOING TO BE
DEWPOINTS...WEAK HYDROLAPSE RATES WILL PREVENT CRASHING THROUGH
THEM. DO EXPECT POCKETS OF LOW CLOUDS TO DEVELOP AND SKY GRIDS MAY
NEED TO BE TRENDED UPWARDS. IF THIS ENDS UP NECESSITATING A ZFP
UPDATE TO MOCLDY THEN THAT ADJUSTMENT MAY BE NEEDED LATER ON. ALSO
OF INTEREST IS THE POSSIBILITY OF A FEW SPRINKLES ALONG THE COAST
ESP FROM CAROLINA BEACH SWWD ACRS ALL OF SC. RUC IS MOST BULLISH ON
THIS IDEA BUT IS ALSO OVERDONE FOR THE CURRENT HOUR. FOR NOW FEEL
THAT ANY ACTIVITY...IF ANY AT ALL...WILL BE ISOLATED TO THE DEGREE
THAT IT WILL ONLY BE NOWCAST-WORTHY AND NOT ZFP-UPDATE-WORTHY.
&&
.AVIATION...
TERMINALS CURRENTLY VFR. COASTAL TERMINALS ARE REPORTING VFR...BUT
WITH A SCATTERED TO BROKEN CLOUD DECK AT 2000-2500 FEET. SOME
ISOLATED SHOWERS OFFSHORE TRYING TO MOVE NORTHWEST BUT CURRENTLY
DISSIPATING. LOW LEVEL MOISTURE WILL CONTINUE TO INCREASE ON
SOUTHEAST WINDS OVERNIGHT. TEMPO MVFR CEILINGS WILL REMAIN POSSIBLE
THROUGHOUT THE NIGHT AT THE COASTAL TERMINALS WITH NO REDUCTIONS IN
VISIBILITIES EXPECTED. LOW LEVEL MOISTURE EVENTUALLY ADVECTS TOWARDS
FLO/LBT BY 03Z GIVING THOSE TERMINALS A CHANCE OF TEMPO MVFR
CEILINGS AFTER 03Z. TEMPO IFR CEILINGS ARE POSSIBLE AT FLO/LBT AFTER
08Z BUT VISIBILITIES SHOULD REMAIN VFR DUE TO CLOUD COVER AND GOOD
MIXING. ISOLATED SHOWERS POSSIBLE AT THE COASTAL TERMINALS FROM
AFTER 09Z UNTIL 18Z BUT FEEL ACTIVITY IS TOO ISOLATED TO INCLUDE IN
TAFS. ALL TERMINALS BECOME VFR BY 13-15Z SATURDAY WITH WORSE CASE
MID LEVEL CEILINGS AND SOUTH TO SOUTHWEST WINDS 10-15 KNOTS.
&&
.MARINE...
EASTERLY LONG PERIOD SWELL (CURRENTLY 15-16 SECOND PERIOD AS
MEASURED BY BUOY 41013) CONTINUES MOVING INTO THE COASTAL WATERS
THIS EVENING...AND SHOULD CONTINUE THROUGH THE NEXT COUPLE DAYS.
AMPLITUDE IS CURRENTLY 4 FT BUT SHOULD BUILD TOWARD 5 FT OVERNIGHT
IN OPEN WATERS PER LATEST WAVEWATCH GUIDANCE. DIRECTLY WEST OF THE
SHALLOW WATER ON FRYING PAN SHOALS SEAS ARE SIGNIFICANTLY LESS AS
MEASURED AT THE OCEAN CREST PIER WAVE GAUGE...ONLY 2 FT. THIS EFFECT
IS DUE TO THE LONG PERIOD SWELLS FEELING BOTTOM AND BREAKING ON THE
SHOALS LEAVING LESS WAVE ENERGY TO MOVE ON INTO LONG BAY.
IN ADDITION TO THE CHANGES MADE TO SEAS...HAVE ADJUSTED WINDS
CLOCKWISE AND INCREASED SPEEDS SLIGHTLY AS SUGGESTED BY LATEST LOCAL
WRF MODEL. KLTX VWP SUGGESTS A SE LOW LEVEL JET IS ALREADY
ORGANIZING IN GOOD AGREEMENT WITH THE MODEL. THANKS FOR
COLLABORATION WFO CHS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
UPDATE...MBB
AVIATION...MRR
MARINE...TRA
</PRE></TT></td>   nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1107 AM EDT FRI SEP 22 2006
.SHORT TERM /REST OF TODAY THROUGH TONIGHT/...
MID-LEVEL DRY PUNCH MOVING INTO WESTERN NORTH CAROLINA ON WATER
VAPOR IMAGERY. HOWEVER...AMPLE MOISTURE AS OBSERVED ON THE KFFC
AND KOKX 12Z SOUNDINGS BETWEEN 850MB AND 600MB...WITH A MODERATE
MID-LEVEL SHORTWAVE AS ANALYZED BY THE RUC AND NAM...ENOUGH TO
PROVIDE FOR ISOLATED SHOWERS OR SPRINKLES IN THE WESTERN THIRD OF
THE STATE. RUC AND NAM FORECAST GOOD LIFT OVER THE WESTERN
PIEDMONT THROUGH 18Z...WITH INCREASING SUBSIDENCE FOR THE
AFTERNOON. ALTHOUGH 850MB DIVERGENCE IS STRONG AND THE KGSO
SOUNDING WAS DRY AND STABLE...ANTICIPATE ENOUGH MOISTURE AND MID-
LEVEL LIFT TO SUPPORT A FEW SPRINKLES IN THE TRIAD AND TOWARD
ROXBORO AS WAS FORECAST EARLY THIS MORNING. TREND SHOULD BE FOR
GRADUALLY REDUCED COVERAGE IN SPRINKLES/ISOLATED SHOWERS AS 850MB
THETA-E VALUES DECREASE THIS AFTERNOON. OVERALL DRIER AIR EAST
TOWARD THE TRIANGLE WHICH IS FORECAST TO REMAIN THROUGHOUT THE DAY
SHOULD LIMIT POTENTIAL FOR SPRINKLES OR AN ISOLATED SHOWER THAT
FAR EAST AND HAVE KEPT THE MENTION OF ANY VERY LIGHT PRECIPITATION
MAINLY OVER THE NORTHWEST PIEDMONT INTO THIS EVENING.
UPDATED GRIDDED AND WORDED FORECASTS ALREADY ISSUED. IN THE UPDATE
LEFT TEMPERATURES ABOUT AS PREVIOUSLY FORECAST. LOCAL THICKNESS
SCHEME FOR TEMPERATURE WOULD SUGGEST HIGHS IN THE UPPER 70S UNDER
FULL SUN. SOME BREAKS IN THE VISIBLE IMAGES EVEN OVER THE TRIAD
AND NUDGED TEMPERATURES UP A DEGREE OR TWO...MOST APPARENT ON THE
GRIDDED FORECASTS.
&&
.PREV DISCUSSION...
 (ISSUED 250 AM EDT FRI SEP 22 2006)
SHORT TERM /TODAY THROUGH MONDAY/...
TODAY THROUGH TONIGHT: A SOLID DECK OF CONVECTIVE DEBRIS CIRRUS
PASSING OVER NC SHOULD CONTINUE MOVING ENE AND EXIT THE REGION...
HOWEVER WEAK ISENTROPIC UPGLIDE AT 295-300K OVERNIGHT HAS GENERATED
A BROKEN TO OVERCAST STRATOCUMULUS DECK OVER THE NORTHWEST PIEDMONT.
DEWPOINTS ACROSS CENTRAL NC ARE RUNNING ROUGHLY 4-8 DEGREES HIGHER
THAN 24H AGO. AS THE SURFACE HIGH SHIFTS OFFSHORE TODAY AND THE
LIGHT EASTERLY BOUNDARY LAYER FLOW INCREASES FROM THE SOUTHEAST...
DEWPOINTS WILL CONTINUE TO CLIMB THROUGH THE 50S AND LOWER 60S.
LIGHT PRECIP INDUCED BY ISENTROPIC UPGLIDE IN THE 300-305K LAYER HAS
FALLEN TO OUR SOUTHWEST OVER MS/AL... AND THIS FORCING IS
MODEL-PROJECTED TO SHIFT OVER NORTHWEST NC WITH 850 MB WINDS PICKING
UP FROM THE SOUTHWEST... AND THIS COULD SQUEEZE OUT A SPRINKLE OVER
THE WESTERN PIEDMONT. BUT IT SHOULD TAKE SOME TIME TO MOISTEN THE
MID LEVELS TODAY... PARTICULARLY OVER THE EASTERN CWA WITH 700 MB
WINDS GOING WESTERLY AND WITH DIFFLUENT 850 MB WINDS... AND PRECIP
SHOULDN'T BE WIDESPREAD OR MEASURABLE. THE GENERAL BROKEN-OVERCAST
CEILING WILL NECESSITATE A LOWERING OF MAX TEMPS TODAY IN THE
WESTERN PIEDMONT... AND WILL HAVE 71-80 ACROSS THE CWA. THE 850 MB
WARM FRONT CONTINUES TO PUSH TO OUR NORTHEAST TONIGHT WITH A
SOUTH-SOUTHEAST SURFACE FLOW AND RISING MID LEVEL HEIGHTS OVER THE
SOUTHEAST COAST. WITH THIS PATTERN EXPECT LITTLE IN THE WAY OF
MID-HIGH CLOUDS TONIGHT... AND AS SUCH THE OVERALL DRIER NAM-WRF'S
MOISTURE PROFILE IS PREFERRED HERE. THIS DOES HOWEVER INCREASE THE
CHANCES FOR LOW STRATUS TONIGHT AND SKIES SHOULD BECOME OVERCAST
MOST PLACES. PREFER THE NAM-WRF'S LOWS IN THE LOWER-MID 60S. APART
FROM WEAK LOW LEVEL ISENTROPIC LIFT SPREADING OVER THE STATE...
DON'T SEE ANY MECHANISM TO INDUCE MEASURABLE RAIN AND WILL CUT BACK
ON POPS OVERNIGHT... ISOLATED SPRINKLES OR DRIZZLE AT WORST.
SATURDAY THROUGH MONDAY: THE STRONG UPPER VORTEX EXPECTED TO PRODUCE
PROBLEMS FOR THE MID MISSISSIPPI VALLEY TODAY OPENS UP AS IT TRACKS
NORTHEAST THROUGH THE GREAT LAKES REGION OVER THE WEEKEND. THE MID
LEVEL ANTICYCLONIC FLOW OVER NC GRADUALLY FLATTENS AS THE SURFACE
ANAFRONT SLOWLY APPROACHES FROM THE WEST... HOWEVER WITH LIMITED
INSTABILITY AND A LACK OF DEEP MOISTURE... EXPECT ONLY ISOLATED
SHOWERS AND A POSSIBLE STORM NEAR THE TIME OF MAX HEATING ON
SATURDAY. MUCH BETTER RAIN CHANCES WILL ARRIVE WITH AND JUST BEHIND
THE FRONT LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT... THE TIMING
OF WHICH ON THE LATEST MODEL RUNS AGREES WELL WITH THE CURRENT
FORECAST. WILL RETAIN CHANCE POPS FOR THIS PERIOD. WITH THE MID
LEVEL FLOW ROUGHLY PARALLEL TO THE SURFACE FRONT... PREFER THE
SLIGHTLY SLOWER NAM-WRF FRONTAL PASSAGE. HIGH TEMPS IN THE MID-UPPER
80S SATURDAY AND SUNDAY SHOULD FALL BACK TO THE LOWER-MID 70S FOR
MONDAY AS THE POSITIVELY TILTED TROUGH DROPS INTO THE REGION. -GIH
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AN ELONGATED SURFACE HIGH WILL STRETCH FROM TX NORTHEASTWARD THROUGH
THE MIDATLANTIC REGION MONDAY NIGHT INTO TUESDAY WITH BROAD MID
LEVEL TROUGHING OVER EASTERN NORTH AMERICA. BOTH THE ECMWF AND GFS
DO INDICATE A PERTURBATION PUSHING THROUGH EASTERN NC... INDUCING
SOME DEGREE OF SURFACE CYCLOGENESIS OFF THE NC COAST ALONG THE OLD
FRONT IN THE DEPARTING UPPER JET'S ENTRANCE REGION. EVEN IF IT DOES
OCCUR THOUGH... IT SHOULD HAVE FEW IMPLICATIONS FOR CENTRAL NC
CONSIDERING THE SCANT MOISTURE AVAILABLE. WITH LOW LEVEL THICKNESSES
PROJECTED TO BE 20-25M BELOW NORMAL... WILL HAVE HIGHS TUESDAY OF
72-78. LITTLE CHANGE NEEDED TO THE REST OF THE WEEK'S FORECAST AS
THE SURFACE HIGH CONTINUES TO BUILD OVERHEAD. LIGHT NORTHERLY 850 MB
WINDS BECOME WESTERLY AND DIFFLUENT AHEAD OF THE NEXT VORTICITY MAX
THAT DROPS INTO THE GREAT LAKES REGION WEDNESDAY INTO THURSDAY AND
ATTEMPTS TO REAMPLIFY THE TROUGH OVER THE NORTHEASTERN STATES. ANY
FRONT THAT DROPS TO OUR LATITUDE IN THIS REGIME WOULD HAVE MINIMAL
MOISTURE TO WORK WITH AND A CONTINUED DRY FORECAST BUT WITH AN
INCREASE IN CLOUDS FOR THURSDAY STILL LOOKS REASONABLE IN LIGHT OF
THESE LATEST MODEL TRENDS. STILL EXPECT TEMPERATURES TO BE NEAR TO A
COUPLE DEGREES BELOW SEASONAL NORMALS. -GIH
AVIATION...
HIGH PRESSURE OVER THE AREA WILL MOVE EAST AS A COLD FRONT THROUGH
THE CENTRAL U.S. WORKS ITS WAY EAST. SOUTHERLY FLOW AHEAD OF THE
FRONT HAS INCREASED MOISTURE OVER THE REGION. THEREFORE WE CAN
EXPECT CLOUD BASES 4 TO 5 THOUSAND FEET WITH CIRRUS DECK ABOVE.
VISIBILITY UNRESTRICTED EXCEPT IFR IN FOG RWI 09Z-13Z. WIND FROM THE
SOUTH AT 5 TO 10 MPH. -RHJ
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJF
</PRE></TT></td>   nc
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CLEVELAND OHIO
1027 PM EDT FRI SEP 22 2006
.AVIATION(02Z-00Z)...
WARM FRONT HEADING NORTH AND WILL MOVE NORTH OF THE FORECAST AREA
SATAURDAY MORNING. IN THE MEANTIME MVFR AND LOWER CONDITIONS WILL
OCCUR. AIRMASS IS STABLE IN NORTHERN OHIO THUS THUNDERSTORMS SEEM TO
BE DECREASING AS THEY MOVE NORTHEAST. HOWEVER...LOW LEVEL JET IS
FORECAST TO DEVELOP BY 06Z AND THAT MAY HELP AID THUNDERSTORM
DEVELOPMENT. ADDED THUNDER TO MOST TAF SITES FOR THE OVERNIGHT. THE
SLUG OF SHOWERS CONTINUES TO SPREAD TO THE NORTHEAST WITH IFR AND
LOWER CONDITIIONS. AS THE WARM FRONT MOVES NORTH SATURDAY MORNING
CONDITIONS WILL DRY OUT SOME WITH VFR OR HIGH MVFR CONDITIONS UNTIL
MORE MOISTURE AND THE COLD FRONT GET CLOSER LATER SATURDAY
AFTERNOON. THE THREAT FOR SEVERE THUNDERSTORMS SATURDAY AFTERNOON
AND EVENING WILL HAVE TO BE MONITORED. SOUTHWEST WINDS WILL INCREASE
SATURDAY AHEAD OF THE APPROACHING COLD FRONT.
&&
.SHORT TERM UPDATE (TONIGHT)...
RAIN BEGINNING TO REACH INTO THE WRN COUNTIES THIS EVG AND SHWRS AND
TSTMS ARE TO OUR WEST.   CONSERNED ABOUT TSTMS INTO THE AREA
OVERNIGHT ALTHOUGH SPC FCST TOOLS SUGGEST LIMITED IF ANY CAPE ACRS
CWA AT THIS TIME AND WHILE THE NAM12 DOES BRING IN 500 OR SO J/KG
OVERNIGHT TO THE WEST THE RUC20 DOES NOT.  STILL BLV WE COULD GET A
FEW TSTMS INTO THE AREA AND THUS WILL LV THE MENTION OF THUNDER IN
THE FCST.  OTRW TIMING OF PCPN IN PRVS FCST WAS GOOD BUT GVN THE
HOUR WL REMOVE TIMING FROM THE WORDING.  ALSO WITH WARM ADVN ACRS
THE AREA BLV TEMPS HAVE STEADIED OR BOTTOMED ACRS THE CWA.  EARLIER
HAVE SEEN A FEW UPPER 50S BUT READINGS NOW ARE ALL IN THE LOW/MID
60S.  WL REMOVE LOW TEMP WORDING TO REFLECT STEADY OR RISING TEMPS
OVERNIGHT.  MADE ON TEMP CHG FOR SAT TO THE CLE GROUP AND RAISED
HIGHS TO THE MID 70S FROM LOWER 70S.
&&
.SHORT TERM(TNT-MON)...
TEMPERATURES NEVER REALLY GOT AS HIGH AS PREDICTED TODAY. EXPECTING
EARLY LOWS TONIGHT AROUND 60...WITH TEMPS RISING A FEW DEGREES
TOWARD MORNING WITH THE APPROACH/PASSAGE OF A WARM FRONT.  RIGHT NOW
WRAPPED UP SYSTEM ACROSS THE CENTRAL PLAINS WITH LOW CENTER ACROSS
SOUTHERN MN AND OCCLUDED/COLD FRONT INTO EASTERN IOWA AND MISSOURI.
THE WARM FRONT IS LOCATED ACROSS MISSOURI.  RAIN WITH A CHC OF TS
SHOULD DEVELOP AND EXPAND NORTHWARD AROUND AND AFTER MIDNIGHT.
EXPECTING A LULL IN PRECIP FOR THE FIRST HAVE OF SAT UNTIL DYNAMICS
KICK IN.  AREA IN A SLT RISK OF SEVERE THUNDERSTORMS.  AMPLE SHEAR
WILL BE PRESENT ALONG WITH MOISTURE...WILL JUST HAVE TO GET ENOUGH
INSTABILITY TOGETHER.  MAV TEMPS WERE IN THE UPPER 70S...HAVE
UNDERCUT AND GONE WITH LOWER/MID 70S SAT IN THE WARM SECTOR.  FRONT
SAT NIGHT/SUN MORNING.  THIS IS WHERE MODELS SPREAD SOME WITH GFS
FASTER AND MORE SOUTHERN WITH THE LOW TRACK...AND THE NAM SLOWER AND
FURTHER NORTH.
SHOWERS ON THE BACKSIDE WITH UPPER TROUGH AXIS STILL TO COME
THROUGH.  H8 TEMPS GET INTO THE SINGLE DIGITS.  SFC TEMPS COOL IN
THE 60S.  MONDAY SHRA WILL WANE...BUT WILL STILL BE FAIRLY CLOUDY.
HIGH PRESSURE WORKS IN TO OUR SOUTH.
&&
.EXTENDED (TUE-FRI)...
NORTHWEST FLOW DEVELOPS INTO ANOTHER DEEP EASTERN TROUGH WITH AN
ASSOCIATED COLD FRONTAL PASSAGE AROUND WED EVE.  WE WILL BE STUCK IN
THE UPPER TROUGH THROUGH THE END OF THE FORECAST WITH LARGE WESTERN
RIDGE BUILDING INTO CANADA.  HAVE PRECIP CHCS IN ASSOCIATION WITH
THE FRONT AND THEN IN THE DAYS FOLLOWING WITH THE UPPER TROUGH. SKY
COVER AND TEMPS COINCIDE.  GFS AND ITS ENSEMBLE MEMBERS RUNNING
FAIRLY CONSISTENTLY THROUGH THE EXTD...WHICH IS GOOD NEWS FOR
CONFIDENCE LEVELS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
.OH...NONE.
.PA...NONE.
&&
$$
SHORT TERM UPDATE...TK
SHORT TERM...OUDEMAN
LONG TERM...OUDEMAN
AVIATION...KIELTYKA
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OHIO
940 PM EDT FRI SEP 22 2006
.SHORT TERM UPDATE (TONIGHT)...
RAIN BEGINNING TO REACH INTO THE WRN COUNTIES THIS EVG AND SHWRS AND
TSTMS ARE TO OUR WEST.   CONSERNED ABOUT TSTMS INTO THE AREA
OVERNIGHT ALTHOUGH SPC FCST TOOLS SUGGEST LIMITED IF ANY CAPE ACRS
CWA AT THIS TIME AND WHILE THE NAM12 DOES BRING IN 500 OR SO J/KG
OVERNIGHT TO THE WEST THE RUC20 DOES NOT.  STILL BLV WE COULD GET A
FEW TSTMS INTO THE AREA AND THUS WILL LV THE MENTION OF THUNDER IN
THE FCST.  OTRW TIMING OF PCPN IN PRVS FCST WAS GOOD BUT GVN THE
HOUR WL REMOVE TIMING FROM THE WORDING.  ALSO WITH WARM ADVN ACRS
THE AREA BLV TEMPS HAVE STEADIED OR BOTTOMED ACRS THE CWA.  EARLIER
HAVE SEEN A FEW UPPER 50S BUT READINGS NOW ARE ALL IN THE LOW/MID
60S.  WL REMOVE LOW TEMP WORDING TO REFLECT STEADY OR RISING TEMPS
OVERNIGHT.  MADE ON TEMP CHG FOR SAT TO THE CLE GROUP AND RAISED
HIGHS TO THE MID 70S FROM LOWER 70S.
&&
.AVIATION(00Z-00Z)...
WARM FRONT HEADING NORTH AND WILL MOVE NORTH OF THE FORECAST AREA
SATAURDAY MORNING. IN THE MEANTIME MVFR AND LOWER CONDITIONS WILL
OCCUR. AIRMASS IS STABLE IN NORTHERN OHIO THUS THUNDERSTORMS SEEM TO
BE DECREASING AS THEY MOVE NORTHEAST...NO THUNDER MENTIONED IN THE
TAFS FOR THE OVERNIGHT...CANNOT RULE OUT AN ISOLATED
THUNDERSTORM...THIS WILL CONTINUED TO BE MONITORED. A SLUG OF
SHOWERS WILL BE SPREADING FROM WEST TO EAST STARTING AT 03Z WITH IFR
AND LOWER CONDITIIONS. AS THE WARM FRONT MOVES NORTH SATURDAY
MORNING CONDITIONS WILL DRY OUT SOME WITH VFR OR HIGH MVFR
CONDITIONS UNTIL MORE MOISTURE AND THE COLD FRONT GET CLOSER LATER
SATURDAY AFTERNOON. THE THREAT FOR SEVERE THUNDERSTORMS SATURDAY
AFTERNOON AND EVENING WILL HAVE TO BE MONITORED. SOUTHWEST WINDS
WILL INCREASE SATURDAY AHEAD OF THE APPROACHING COLD FRONT.
&&
.SHORT TERM(TNT-MON)...
TEMPERATURES NEVER REALLY GOT AS HIGH AS PREDICTED TODAY. EXPECTING
EARLY LOWS TONIGHT AROUND 60...WITH TEMPS RISING A FEW DEGREES
TOWARD MORNING WITH THE APPROACH/PASSAGE OF A WARM FRONT.  RIGHT NOW
WRAPPED UP SYSTEM ACROSS THE CENTRAL PLAINS WITH LOW CENTER ACROSS
SOUTHERN MN AND OCCLUDED/COLD FRONT INTO EASTERN IOWA AND MISSOURI.
THE WARM FRONT IS LOCATED ACROSS MISSOURI.  RAIN WITH A CHC OF TS
SHOULD DEVELOP AND EXPAND NORTHWARD AROUND AND AFTER MIDNIGHT.
EXPECTING A LULL IN PRECIP FOR THE FIRST HAVE OF SAT UNTIL DYNAMICS
KICK IN.  AREA IN A SLT RISK OF SEVERE THUNDERSTORMS.  AMPLE SHEAR
WILL BE PRESENT ALONG WITH MOISTURE...WILL JUST HAVE TO GET ENOUGH
INSTABILITY TOGETHER.  MAV TEMPS WERE IN THE UPPER 70S...HAVE
UNDERCUT AND GONE WITH LOWER/MID 70S SAT IN THE WARM SECTOR.  FRONT
SAT NIGHT/SUN MORNING.  THIS IS WHERE MODELS SPREAD SOME WITH GFS
FASTER AND MORE SOUTHERN WITH THE LOW TRACK...AND THE NAM SLOWER AND
FURTHER NORTH.
SHOWERS ON THE BACKSIDE WITH UPPER TROUGH AXIS STILL TO COME
THROUGH.  H8 TEMPS GET INTO THE SINGLE DIGITS.  SFC TEMPS COOL IN
THE 60S.  MONDAY SHRA WILL WANE...BUT WILL STILL BE FAIRLY CLOUDY.
HIGH PRESSURE WORKS IN TO OUR SOUTH.
&&
.EXTENDED (TUE-FRI)...
NORTHWEST FLOW DEVELOPS INTO ANOTHER DEEP EASTERN TROUGH WITH AN
ASSOCIATED COLD FRONTAL PASSAGE AROUND WED EVE.  WE WILL BE STUCK IN
THE UPPER TROUGH THROUGH THE END OF THE FORECAST WITH LARGE WESTERN
RIDGE BUILDING INTO CANADA.  HAVE PRECIP CHCS IN ASSOCIATION WITH
THE FRONT AND THEN IN THE DAYS FOLLOWING WITH THE UPPER TROUGH. SKY
COVER AND TEMPS COINCIDE.  GFS AND ITS ENSEMBLE MEMBERS RUNNING
FAIRLY CONSISTENTLY THROUGH THE EXTD...WHICH IS GOOD NEWS FOR
CONFIDENCE LEVELS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
.OH...NONE.
.PA...NONE.
&&
$$
SHORT TERM UPDATE...TK
SHORT TERM...OUDEMAN
LONG TERM...OUDEMAN
AVIATION...KIELTYKA
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
931 PM EDT FRI SEP 22 2006
.SHORT TERM /REST OF TONIGHT/...
WIDESPREAD AREA OF -SHRA WITH EMBEDDED TSTMS NOW ACRS WESTERN 1/2 FCST
AREA THIS EVNG AS WARM FRONT CONTINUES TO SLOWLY LIFT NORTH ACRS
WESTERN/CNTRL KY. RUC INDCG ELEVATED INSTABILITY WILL CONTINUE TO
OVERSPREAD FCST AREA THRU OVERNIGHT HOURS ON NOSE OF 40-50KT 850
LLJ. LO LVL CONV AXIS WILL SET UP ACRS SRN 1/2 FCST AREA OVERNIGHT
AND THIS SHOULD PROMOTE CONTINUED PCPN THRU THE NIGHT. RADAR AND
SAT IMAGES CONFIRM THIS THINKING WITH CLUSTERS OF TSTMS EXTNDG ALL
THE WAY BACK INTO SRN MISSOURI. MAY SEE STRONG TSTMS...BUT SEVERE
THREAT SHOULD REMAIN SW OF FCST AREA. HAVE INCREASED TO CAT POPS
ACRS ALL BUT SE FCST AREA FOR OVERNIGHT AS WARM FRONT LIFTS NORTH
INTO REGION.
UPDATE OUT...PREV DISCUSSION FOLLOWS.
RYAN
&&
.PREV DISCUSSION...
 /ISSUED 738 PM EDT FRI SEP 22 2006/
AVIATION /00Z-24Z/...
COMPLICATED FCST THIS EVNG. DEEP SFC LO ACRS NRN PLAINS WITH AN
OCCLUDED FRONT EXTENDING THRU MID MISSISSIPPI VLY BACK SW INTO SRN
PLAINS. WARM FRONT EXTNDG SE ACRS WESTERN AND SOUTHERN ILLINOIS
INTO WESTERN KY. MARGINAL LLWS ALONG WARM FRONT LATE TONIGHT...AND
HAVE LEFT OUT OF TAFS ATTM. LARGE CLUSTER OF TSRA HAS DVLPD OVER
LAST SVRL HOURS IN ALONG WARM FRNTL BNDRY AND IS MOVING NORTHEAST
TOWARDS FCST AREA THIS EVNG. SHOULD SEE THIS MCS MOVE INTO REGION
THIS EVNG AS WARM FRONT CONTINUES TO PROGRESS NORTHEAST. BROAD LO
LVL WAA PATTERN AND A STRENGTHENING 40-50 KT 850 LLJ TONIGHT WILL
ALSO CONTRIBUTE TO NMRS -SHRA AFFECTING ALL TAF SITES OVERNIGHT.
HAVE INDICATED PREVAILING -SHRA AT ALL TAF SITES BTWN 03-06Z WITH
A CB MENTION FOR THUNDER. RUC INDCG SOME WEAK ELEVATED INSTABILITY
OVERNIGHT ACRS WESTERN FCST AREA WHICH SHOULD SUPPORT A FEW -TSRA.
EXPECTING A BREAK IN TERMS OF PCPN COVERAGE AS WARM FRONT LIFTS
THRU REGION AFTER DAYBREAK SAT MRNG BEFORE INCREASE IN CONVECTION
FOR AFTN HOURS. 12Z GFS INDCG DVLPG AND DEEPENING SFC LO ALONG
FRNTL BNDRY MOVING FROM THE MID MISSISSIPPI VLY ON SAT MRNG INTO
NRN INDIANA BY 00Z SUN. IN WARM SECTOR SAT AFTN...MODERATE
INSTABILITY COMBINED WITH HIGH AMOUNTS OF BL SHEAR SHOULD SUPPORT
SCT SVR -TSRA AFT 18Z. HAVE BROUGHT VCTS INTO ALL TAF SITES FOR
AFTN HOURS WITH FOUR HOUR TEMPO GROUPS AFT 18Z. ADDL TSRA ARE
LIKELY IN FORM OF A SQUALL LINE AFT 00Z SUN AHEAD OF COLD FRONT.
THIS WILL BE ADDRESSED IN 06Z TAF FCST. SE WINDS TONIGHT WILL VEER
TO SSW ON SAT IN WARM SECTOR AND BECOME GUSTY DURING AFTN HOURS.
RYAN
PREV DISCUSSION...
 /ISSUED 348 PM EDT FRI SEP 22 2006/
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
BIG DIFFERENCES BETWEEN NAM AND GFS...BUT IN COMPARING WITH ECMWF
AND UKMET...GFS SEEMS TO BE MORE REASONABLE DESPITE STILL HAVING
SOME CONVECTIVE FEEDBACK.
GFS PRETTY PROGRESSIVE WITH CLOSED LOW JUST TO NORTH OF FA THROUGH
EARLY SUNDAY MORNING. MOST PROMISING DYNAMICS AND PLENTY OF LOW
LEVEL SHEAR AND INSTABILITY AHEAD OF MAIN SQALL LINE TO PRODUCE
POTENTIAL SUPERCELL ACTIVITY LATE AFTERNOON SAT...WITH MORE OF A
POSSIBLE SQUALL LINE EVENT IN THE MID AND LATE EVENING. HAVE GONE
CATEGORICAL CHANCES FOR SATURDAY...WITH MORNING THUNDERSTORMS NOT
AS LIKELY SEVERE...BUT SOME THREAT OF ISOLATED HEAVY RAIN IN THE
SOUTHWEST. SFC WARM FNT APPROACHING FROM CENTRAL PLAINS BRINGING GOOD
SHOT OF 70 TO LOW 70 DEWPOINTS ESPECIALLY IN THE WEST FOR
SATURDAY. HAVE MENTION OF SEVERE IN GRIDS WITH DAMAGING WINDS
GREATEST THREAT FROM ESPECIALLY 18-02Z.
LINGERING CHANCE OF SHOWERS WITH A MENTION OF EARLY MORNING
THUNDERSTORMS IN THE FAR EAST FOR SUNDAY...THEN CHANCE FOR SHRA IN
THE NORTH IN WRAP AROUND THROUGH EARLY SUNDAY AFTERNOON.
LONG TERM /MONDAY THROUGH FRIDAY/...
EXTENDED FCST STARTING MON HAS HIGH PRESSURE BUILDING OVER OHVLY
FROM THE MIDWEST AS LOW PRESSURE RETREATS FROM GTLKS REGION. EXPECT
A GRADUAL WARMING OF THE AIRMASS THROUGH MIDWEEK AS A SFC LOW TRACKS
INTO THE GTLKS WED. THIS WILL SEE A TRAILING COLD FRONT MOVE THROUGH
OHVLY ON WED NITE AND THURS IN RESPONSE TO A STRONG AND PERSISTENTLY
DEEPENING H5 TROF OVER THE ERN 1/2 OF CONUS. MILD AIR WILL SURGE
AHEAD OF THE CDFNT...AND THE STRENGTHENING H5 L/W TROF WILL ALLOW
FOR A STRONG PUSH OF COOL CONTINENTAL AIR INTO THE OHVLY ON NRLY
FLOW AS STRONG SFC HIGH IN THE MIDWEST SETS UP.
STRENGTH OF SYSTEM WED NITE AND THURS HAS ME INCREASE POPS AS THE
FLOW AHEAD OF IT AND SIGNIFICANT HEIGHT FALLS BEHIND IT WOULD LIKELY
SEE A LINE OF CONVECTION MOVE THROUGH THE REGION. COLD POOL SHOWERS
POSSIBLE FOR REMAINDER OF THURS AND INTO FRI...BUT ONLY HAVE 20%
POSSIBILITY HERE BEING THE LAST DAY OF FCST.
TEMPS WERE GENERALLY BUMPED UP AHEAD OF WED NITE FRONT AND DROPPED
BEHIND IT...NOT TOO FAR FROM MEX GUID.
FRANKS
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
738 PM EDT FRI SEP 22 2006
.AVIATION /00Z-24Z/...
COMPLICATED FCST THIS EVNG. DEEP SFC LO ACRS NRN PLAINS WITH AN
OCCLUDED FRONT EXTENDING THRU MID MISSISSIPPI VLY BACK SW INTO SRN
PLAINS. WARM FRONT EXTNDG SE ACRS WESTERN AND SOUTHERN ILLINOIS
INTO WESTERN KY. MARGINAL LLWS ALONG WARM FRONT LATE TONIGHT...AND
HAVE LEFT OUT OF TAFS ATTM. LARGE CLUSTER OF TSRA HAS DVLPD OVER
LAST SVRL HOURS IN ALONG WARM FRNTL BNDRY AND IS MOVING NORTHEAST
TOWARDS FCST AREA THIS EVNG. SHOULD SEE THIS MCS MOVE INTO REGION
THIS EVNG AS WARM FRONT CONTINUES TO PROGRESS NORTHEAST. BROAD LO
LVL WAA PATTERN AND A STRENGTHENING 40-50 KT 850 LLJ TONIGHT WILL
ALSO CONTRIBUTE TO NMRS -SHRA AFFECTING ALL TAF SITES OVERNIGHT.
HAVE INDICATED PREVAILING -SHRA AT ALL TAF SITES BTWN 03-06Z WITH
A CB MENTION FOR THUNDER. RUC INDCG SOME WEAK ELEVATED INSTABILITY
OVERNIGHT ACRS WESTERN FCST AREA WHICH SHOULD SUPPORT A FEW -TSRA.
EXPECTING A BREAK IN TERMS OF PCPN COVERAGE AS WARM FRONT LIFTS
THRU REGION AFTER DAYBREAK SAT MRNG BEFORE INCREASE IN CONVECTION
FOR AFTN HOURS. 12Z GFS INDCG DVLPG AND DEEPENING SFC LO ALONG
FRNTL BNDRY MOVING FROM THE MID MISSISSIPPI VLY ON SAT MRNG INTO
NRN INDIANA BY 00Z SUN. IN WARM SECTOR SAT AFTN...MODERATE
INSTABILITY COMBINED WITH HIGH AMOUNTS OF BL SHEAR SHOULD SUPPORT
SCT SVR -TSRA AFT 18Z. HAVE BROUGHT VCTS INTO ALL TAF SITES FOR
AFTN HOURS WITH FOUR HOUR TEMPO GROUPS AFT 18Z. ADDL TSRA ARE
LIKELY IN FORM OF A SQUALL LINE AFT 00Z SUN AHEAD OF COLD FRONT.
THIS WILL BE ADDRESSED IN 06Z TAF FCST. SE WINDS TONIGHT WILL VEER
TO SSW ON SAT IN WARM SECTOR AND BECOME GUSTY DURING AFTN HOURS.
RYAN
&&
.PREV DISCUSSION...
 /ISSUED 348 PM EDT FRI SEP 22 2006/
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
BIG DIFFERENCES BETWEEN NAM AND GFS...BUT IN COMPARING WITH ECMWF
AND UKMET...GFS SEEMS TO BE MORE REASONABLE DESPITE STILL HAVING
SOME CONVECTIVE FEEDBACK.
GFS PRETTY PROGRESSIVE WITH CLOSED LOW JUST TO NORTH OF FA THROUGH
EARLY SUNDAY MORNING. MOST PROMISING DYNAMICS AND PLENTY OF LOW
LEVEL SHEAR AND INSTABILITY AHEAD OF MAIN SQALL LINE TO PRODUCE
POTENTIAL SUPERCELL ACTIVITY LATE AFTERNOON SAT...WITH MORE OF A
POSSIBLE SQUALL LINE EVENT IN THE MID AND LATE EVENING. HAVE GONE
CATEGORICAL CHANCES FOR SATURDAY...WITH MORNING THUNDERSTORMS NOT
AS LIKELY SEVERE...BUT SOME THREAT OF ISOLATED HEAVY RAIN IN THE
SOUTHWEST. SFC WARM FNT APPROACHING FROM CENTRAL PLAINS BRINGING GOOD
SHOT OF 70 TO LOW 70 DEWPOINTS ESPECIALLY IN THE WEST FOR
SATURDAY. HAVE MENTION OF SEVERE IN GRIDS WITH DAMAGING WINDS
GREATEST THREAT FROM ESPECIALLY 18-02Z.
LINGERING CHANCE OF SHOWERS WITH A MENTION OF EARLY MORNING
THUNDERSTORMS IN THE FAR EAST FOR SUNDAY...THEN CHANCE FOR SHRA IN
THE NORTH IN WRAP AROUND THROUGH EARLY SUNDAY AFTERNOON.
LONG TERM /MONDAY THROUGH FRIDAY/...
EXTENDED FCST STARTING MON HAS HIGH PRESSURE BUILDING OVER OHVLY
FROM THE MIDWEST AS LOW PRESSURE RETREATS FROM GTLKS REGION. EXPECT
A GRADUAL WARMING OF THE AIRMASS THROUGH MIDWEEK AS A SFC LOW TRACKS
INTO THE GTLKS WED. THIS WILL SEE A TRAILING COLD FRONT MOVE THROUGH
OHVLY ON WED NITE AND THURS IN RESPONSE TO A STRONG AND PERSISTENTLY
DEEPENING H5 TROF OVER THE ERN 1/2 OF CONUS. MILD AIR WILL SURGE
AHEAD OF THE CDFNT...AND THE STRENGTHENING H5 L/W TROF WILL ALLOW
FOR A STRONG PUSH OF COOL CONTINENTAL AIR INTO THE OHVLY ON NRLY
FLOW AS STRONG SFC HIGH IN THE MIDWEST SETS UP.
STRENGTH OF SYSTEM WED NITE AND THURS HAS ME INCREASE POPS AS THE
FLOW AHEAD OF IT AND SIGNIFICANT HEIGHT FALLS BEHIND IT WOULD LIKELY
SEE A LINE OF CONVECTION MOVE THROUGH THE REGION. COLD POOL SHOWERS
POSSIBLE FOR REMAINDER OF THURS AND INTO FRI...BUT ONLY HAVE 20%
POSSIBILITY HERE BEING THE LAST DAY OF FCST.
TEMPS WERE GENERALLY BUMPED UP AHEAD OF WED NITE FRONT AND DROPPED
BEHIND IT...NOT TOO FAR FROM MEX GUID.
FRANKS
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
133 PM CDT FRI SEP 22 2006
.MESOSCALE UPDATE...
AT 1 PM...DRYLINE HAD PUSHED TO NEAR A NOWATA...TO EUFAULA...TO
MCALESTER LINE WITH THE AXIS OF DEEPER MOISTURE FURTHER EASTWARD
MARKED BY EXTENSIVE CUMULUS FIELD. PROFILER DATA AND RUC ANALYSIS
SHOW WIND FIELDS OVER THE AREA REMAINED VEERED WITH LITTLE
DIRECTIONAL SHEAR NOTED. SPEEDS REMAIN STRONG ENOUGH TO PRODUCE
AMPLE DEEP LAYER SHEAR...AND AS SUCH...STORMS WHICH INITIATED OVER
NORTHWEST ARKANSAS QUICKLY DEVELOPED ROTATION. THE LACK OF
DIRECTION SHEAR HOWEVER HAS RESULTED IN NEAR STRAIGHT LIGHT
HODOGRAPHS...MAKING DEVIANT STORM MOTIONS NECESSARY TO REALIZE
SIGNIFICANTLY HIGHER HELICITIES. INSTABILITY AXIS REMAINS IN PLACE
OVER EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...WITH CAP STRENGTH
CONTINUING TO WEAKEN EAST OF THE DRYLINE. ADDITIONAL STORM ARE
LIKELY TO DEVELOP BY BY 4 PM...AND ONCE UPDRAFTS BECOME
ESTABLISHED AND ANY EASTWARD MOTION CAN BE REALIZED...THE RISK OF
SIGNIFICANT SEVERE WEATHER WILL INCREASE.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
</PRE></TT></td>   ok
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
948 PM EDT FRI SEP 22 2006
...HIGH RISK FOR RIP CURRENTS SATURDAY...
.SHORT TERM /TONIGHT/...A FULL ONSHORE FLOW HAS FINALLY BEEN
ESTABLISHED ACROSS THE RGN AS HIGH PRES CNTRD OFF THE MID ATLC COAST
CONTINUES TO PROPAGATE E AND A STRONG VERTICALLY STACKED MID-
LATITUDE CYCLONE CHURNS ACROSS THE CNTRL/NRN PLAINS. KCLX VWP IS
ALREADY SHOWING A RATHER POTENT NOCTURNAL JET SETTING UP WITH 1000
FT AS HIGH AS 25 KT. UNLIKE THE PAST FEW NGTS...THE 23/00Z OBSERVED
CHS RAOB AND RUC FCST SOUNDINGS SUGGEST THE BNDRY LYR WL REMAIN
FAIRLY WELL MIXED THROUGH THE NGT WHICH RESULT IN A SLGTLY WARMER
TEMPS COMPARED TO THIS MRNG ESP AT THE COAST. XPCT LOWS TO RANGE
FROM THE UPR 60S INLAND TO THE MID 70S ALONG THE IMMEDIATE COAST.
COULD SEE AN ISOLD SHOWER OR TWO MOVE TOWARD THE CHARLESTON COUNTY
COAST LATE TNGT AS THE SLY FLOW INCRS BUT WE BELIEVE THE CHANCES FOR
MEASURABLE PCPN ARE LIKELY TOO LOW TO INCLUDE A MENTION ATTM. WL
MAKE A FEW TWEAKS TO THE GRIDDED FCSTS MAINLY TO ACCOUNT FOR NEAR
TERM TRENDS BUT THE FCST PKG AS A WHOLE IS IN EXCELLENT SHAPE. AN
UPDATE TO THE ZONE FCSTS WL THEREFORE NOT BE ISSUED.
&&
.MARINE...SEAS CONTINUE TO BE DOMINATED BY ELY SWELLS OF 14-15
SECONDS WITH OCNL SWELL SETS OF 16-17 SECONDS. BUOY...PILOT BOAT AND
TOWER OBSERVATIONS SUGGEST SEAS ARE GENERALLY 3-5 FT WITHIN 20 NM
AND 4-6 FT PSBLY AS HIGH AS 7 FT ACROSS THE GA OFFSHORE WTRS. THE
SCA FOR HAZARDOUS SEAS WL OBVIOUSLY CONTINUE FOR THE GA OFFSHORE
WTRS. BUOY 41004 IS CURRENTLY REPORTING COMBINED SEAS OF 6 FT AND
THE 18Z HURCN WW3 GUIDANCE SUGGESTS 6 FT SEAS COULD GET INTO THE
WTRS N OF EDISTO BEACH AFT MIDNGT. THE OVERALL CONFIDENCE OF THIS
OCCURRING REMAINS QUIET LOW SO AFT COORD WITH THE GREAT FOLKS UP AT
WFO ILM... WE WL KEEP CONDITIONS JUST BELOW SCA CRITERIA AND CARRY A
HEADLINE THAT SMALL CRAFT SHOULD EXERCISE CAUTION. THE MAIN HAZARD
HERE WL BE FOR DANGEROUS WAVE ACTION NEAR THE CHARLESTON HARBOR
ENTRANCE AS WELL AS OTHER INLET/BAY/SOUND AND RIVER ENTRANCES. THE
CHARLESTON HARBOR PILOT BOAT REPORTED RATHER HAZARDOUS WAVE ACTION
IN THE HARBOR ENTRANCE EARLIER THIS EVNG.
&&
.AVIATION...XPCT VFR CONDITIONS TO PREVAIL FOR THE NXT 24 HRS.
PATCHES OF STRATOCU WL CROSS THE TERMINALS FOR MUCH OF THE NGT. A
BRIEF PERIOD OF MVFR CIGS COULD OCCUR AFT MIDNGT AS LARGER OR
THICKER PATCHES MOVE INLAND FROM THE ATLC BUT THE XPCTD TIME
DURATION WL LIKELY REMAIN LESS THAN 15-30 MIN AT ANY ONE TIME. THUS
A TEMPO GROUP WAS NOT ADDED TO EITHER TAF /KCHS OR KSAV/. THIS WL
NEED TO BE REEVALUATED FOR THE 06Z TAF CYCLE ONCE THE 00Z MODEL
GUIDANCE IS RCVD.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS AMZ374.
&&
$$
ST
</PRE></TT></td>   sc
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
830 PM MDT FRI SEP 22 2006
.DISCUSSION...AS CONFIRMED BY THE 00Z KUNR SOUNDING...WINDS OFF THE
SFC HAVE VEERED TO THE NORTH WHICH HAS ALLOWED THE DOWNSLOPE AREA
AROUND THE BLKHLS TO SHIFT A BIT TO THE S/W. THIS HAS ALLOWED THE
PCPN TO MOVE BACK INTO THE RAPID CITY TO HERMOSA AREA. FCST
SOUNDINGS SHOW WINDS OFF THE SFC FROM A N TO NNE DIRECTION INTO SAT
MRNG WHICH SHOULD KEEP THE PCPN IN THE RAPID CITY TO HERMOSA.
FREEZING LEVELS HAVE CHANGED VERY LITTLE FROM THE 12Z TO 00Z
SOUNDING (7300-7500 FT). HOWEVER...TEMPS ABOVE 700MB HAVE COOLED A
COUPLE DEGREES CENTIGRADE...AND BOTH THE NAM/RUC AT 00Z SUGGEST THIS
COOLING WILL DESCEND WITH FREEZING LEVELS DROPPING TO ABOUT 6000 FT
OVERNIGHT. HEAVIER PCPN IN THE NRN BLKHLS WILL LIKELY DROP THIS LVL
EVEN FURTHER. THEREFORE...EVEN THOUGH RECENT CALLS TO SPOTTERS IN
THE 6000 TO 6500 RANGE REVEAL MOSTLY RAIN...THIS WILL CHANGE
OVERNIGHT. SNOW LEVELS WILL DROP TO AROUND 5500 FT...AND POSSIBLY AS
LOW AS 5000 FT. THIS WOULD LIKELY KEEP DEADWOOD ALL RAIN WITH A
CHANGEOVER TO SNOW NEAR LEAD. WITH BOTH NAM/RUC PAINTING A QPF
BULLSEYE OF ANOTHER 1.75 INCHES OVERNIGHT OVR THE NRN
BLKHLS...SIGNIFICANT ACCUMULATIONS ARE LIKELY ABOVE 5500 FT AS
INDICATED IN CURRENT FCST SO WILL NOT BE CHANGING MUCH IN THE WINTER
WEATHER HIGHLIGHTS.
MOISTURE WRAPPING AROUND THE UPR LOW OVR ERN SD WILL CONTINUE TO
BRING WDSPRD RAIN TO THE REST OF THE AREA THRU SAT MRNG...WITH A
GRADUAL END FROM NORTH TO SOUTH DURING THE AFTN...WITH THE VAST
MAJORITY OF PCPN OVER BY SAT EVE. WILL UP POPS ACCORDINGLY THRU SAT
MRNG.
WINDS SHOULD REMAIN JUST BELOW ADVISORY CRITERIA OVERNIGHT...BUT
LIKELY PICK BACK UP ON SAT. THUS...WILL KEEP WIND ADVISORY GOING.
&&
.AVIATION...WDSPRD MVFR/IFR CONDS ACRS ALL RTES THROUGH SAT MRNG
WITH RAIN AND HIGHER ELEVATION SNOWS CONTINUING. PCPN WILL GRADUALLY
END FROM NORTH TO SOUTH BY SAT AFTN ACRS THE RTES. NW WIND GUSTS OF
35 TO 40KTS REMAIN POSSIBLE THRU SAT.
&&
UNR...WATCHES/WARNINGS/ADVISORIES...
SD...HEAVY SNOW WARNING NORTHERN BLACK HILLS THROUGH SATURDAY
     MORNING.
  ...WIND ADVISORY THROUGH SATURDAY FOR NORTHWESTERN SD.
WY...NONE.
&&
$$
JOHNSON
</PRE></TT></td>   sd
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
220 PM MDT FRI SEP 22 2006
.DISCUSSION...CURRENT SURFACE MAP SHOW DEEP LOW PRESSURE ALONG THE
SOUTH DAKOTA/MINNESOTA BORDER WITH INVERTED TROF EXTENDING INTO
NORTHWEST SOUTH DAKOTA. WIDESPREAD RAIN FALLING ACROSS THE NORTHERN
PLAINS. SNOW LEVEL IN THE NORTHERN BLACK HILLS IS 5800-6000 FEET.
SNOW ACCUMULATIONS OF 3-4 INCHES SO FAR ABOVE 6000 FEET...POSSIBLY
MORE ON SOME OF THE HIGHER PEAKS. PORTION OF CENTRAL/SOUTHERN BLACK
HILLS HAVE HAD VERY LITTLE PRECIPITATION DUE TO DOWNSLOPE FLOW.
WIDESPREAD PRECIPITATION WILL CONTINUE THROUGH THE NIGHT...WITH
HEAVIEST AMOUNTS ACROSS THE PLAINS OF NORTHWEST SOUTH DAKOTA AND
NORTHERN BLACK HILLS. HEAVY SNOW WILL CONTINUE ACROSS THE NORTHERN
BLACK HILLS...AND SHOULD START TO ACCUMULATE AT A FASTER RATE ONCE
THE SUN SETS. NAM/RUC INDICATE ANOTHER 1-2 INCHES OF LIQUID FOR THE
NORTHERN BLACK HILLS ON TOP OF WHAT HAS ALREADY FALLEN. SNOW LEVELS
WILL DROP OVER NIGHT...DOWN TO AROUND 5000 FEET. THE HEAVIEST
ACCUMULATIONS WILL BE ABOVE 5500 FEET...WHERE ANOTHER 4 TO 6 INCHES
IS LIKELY. AGAIN...IF TEMPERATURES COOL JUST A FEW DEGREES MORE
OVERNIGHT...LEAD/DEADWOOD WOULD HAVE A BETTER CHANCE OF HEAVY SNOW.
WILL KEEP HEAVY SNOW WARNING IN PLACE FOR THE NORTHERN BLACK HILLS.
FOR THE CENTRAL BLACK HILLS...LITTLE IF ANY SNOW HAS ACCUMULATED SO
FAR. THE THREAT OF HEAVY SNOW IS IN THE MORE REMOTE AREAS OF
NORTHWEST PENNINGTON COUNTY ZONE...NORTHWEST OF DEERFIELD AND
ROCHFORD. ONLY MINOR SNOW ACCUMULATIONS EXPECTED FURTHER SOUTH
AROUND HILL CITY/MT. RUSHMORE. WILL DROP THE WINTER STORM WATCH FOR
THE CENTRAL BLACK HILLS...AND MENTION LOCALLY HIGHER AMOUNTS IN THE
HIGHER ELEVATIONS OF FAR WESTERN PART OF THE CENTRAL BLACK HILLS.
FORECAST SOUNDING SUPPORT A MIX OR RAIN/SNOW ACROSS PORTIONS OF
NORTHEAST WYOMING TONIGHT...WITH LITTLE IN THE WAY OF ACCUMULATIONS.
GUSTY WINDS WILL CONTINUE ON THE PLAINS OF NORTHWESTERN SOUTH
DAKOTA...WILL LEAVE WIND ADVISORY IN PLACE THROUGH SATURDAY
AFTERNOON.
UPPER LEVEL LOW BEGINS TO PULL OUT OF EASTERN SOUTH DAKOTA
SATURDAY...WITH DRIER AIR WORKING IN FROM THE NORTH. SHOULD BE
WIDESPREAD PRECIPITATION ACROSS THE AREA IN THE MORNING...WITH BEST
FOCUS SHIFTING INTO SOUTH CENTRAL SOUTH DAKOTA DURING THE DAY.
PRECIPITATION WILL QUICKLY END ACROSS THE FORECAST AREA LATE
SATURDAY. DRY WEATHER EXPECTED SUNDAY/MONDAY...WITH TEMPERATURES
WARMING BACK INTO THE 70S BY MONDAY.
EXTENDED...WEAK HIGH PRESSURE WILL BRING DRY AND WARM CONDITIONS
TO THE AREA FOR THE BEGINNING OF THE WORK WEEK. THE GFS CONTINUES
TO SHOW A MID WEEK SYSTEM AND AFFILIATED COLD FRONT MOVING THROUGH
THE NORTHERN PLAINS...SO HAVE CONTINUED TO GO WITH A SLIGHT CHANCE
OF RAIN SHOWERS TUES NIGHT INTO WEDNESDAY...ALONG WITH COOLING HIGH
TEMPS DOWN ON WEDNESDAY. DRY WEATHER IS EXPECTED FOR THE REMAINDER
OF THE WEEK.
&&
.AVIATION...RAIN WILL CONTINUE ACROSS THE AREA TODAY...WITH SOME
SNOW OVER THE BLACK HILLS INTO PARTS OF NORTHEAST WYOMING...BRINGING
MVFR AND IFR CEILINGS AND VISIBILITIES WHICH WILL LAST THROUGH
SATURDAY MORNING BEFORE SLOWLY IMPROVING. NORTHWEST WINDS OF 25 TO
35KTS WITH SOME GUSTS UP TO 40 KTS WILL ALSO LAST THROUGH THIS
EVENING.
&&
UNR...WATCHES/WARNINGS/ADVISORIES...
SD...HEAVY SNOW WARNING NORTHERN BLACK HILLS THROUGH SATURDAY
     MORNING.
  ...WIND ADVISORY TODAY THROUGH SATURDAY FOR NORTHWESTERN SD.
WY...NONE.
&&
$$
</PRE></TT></td>   sd
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
940 AM MDT FRI SEP 22 2006
.DISCUSSION...CURRENT SURFACE MAP SHOW DEEP LOW PRESSURE NEAR SIOUX
FALLS...WITH INVERTED TROF EXTENDING INTO NORTHWEST SOUTH DAKOTA.
LARGE AREA OF RAIN FALLING ACROSS THE NORTHERN PLAINS. NUMEROUS
REPORTS OF RAINFALL OVER AN INCH ACROSS THE SOUTH DAKOTA PLAINS
OVERNIGHT...WITH MORE TO FALL TODAY/TONIGHT. SOME SNOWFALL ABOVE
6000 FEET THIS MORNING. SNOTEL SITES IN NORTHERN BLACK HILLS ABOVE
6100 FEET INDICATE THAT AN INCH OR TWO OF SNOW MAY HAVE ACCUMULATED.
ALSO HAVE A REPORT OF 4 INCHES NEAR O'NEIL PASS.
12Z KUNR SOUNDING SHOWS WINDS FROM 330-360 DEGREES BELOW 600MB.
DOWNSLOPE PRECIPITATION VOID IS ACROSS SOUTHERN BLACK HILLS TO JUST
SOUTH OF RAPID CITY. 12Z NAM/RUC SIMILAR THROUGH TODAY...WITH
WIDESPREAD PRECIPITATION FALLING ACROSS THE CWA. QPF AMOUNTS
TODAY/TONIGHT RANGE FROM 1.00-1.50 INCHES ON THE PLAINS...TO 2.00+
INCHES IN THE NORTHERN BLACK HILLS. EXCEPTION WILL BE SOUTHERN BLACK
HILLS WHICH WILL REMAIN IN THE DOWNSLOPE HOLE THROUGH TONIGHT.
NAM/RUC HAVE WINDS FROM 850-600MB VEERING TO THE NORTHEAST THIS
AFTERNOON...WITH UPSLOPE ENHANCEMENT ACROSS NORTHERN BLACK HILLS TO
RAPID CITY. TEMPERATURES REMAIN COLD ENOUGH FOR SNOW ABOVE 6000 FEET
TODAY...WITH NAM/RUC SHOWING 700MB TEMPERATURES COOLING ANOTHER
DEGREE OR TWO DURING THE DAY. THIS WOULD ALLOW SNOW LEVELS WILL DROP
A LITTLE DURING THE DAY. WITH CURRENT REPORTS AND EXPECTED
SNOWFALL...WILL UPGRAGE NORTHERN BLACK HILLS TO HEAVY SNOW WARNING
WITH UPDATE. WILL LEAVE CENTRAL HILLS IN A WATCH...AS ONLY A SMALL
PART OF THAT ZONE IS GETTING HEAVY PRECIPITATION. SNOW ACCUMULATIONS
TODAY WILL BE CONFINED TO 6000 FEET AND ABOVE...WITH SNOW LEVELS
DROPPING TO AROUND 5300-5500 FEET TONIGHT. IF TEMPERATURES WERE TO
DROP JUST A FEW DEGREES MORE...HEAVY SNOW COULD FALL IN THE
LEAD/DEADWOOD AREA TONIGHT.
&&
UNR...WATCHES/WARNINGS/ADVISORIES...
SD...HEAVY SNOW WARNING NORTHERN BLACK HILLS THROUGH SATURDAY
     MORNING.
     WINTER STORM WATCH TONIGHT THROUGH SATURDAY MORNING FOR
     THE CENTRAL BLACK HILLS.
  ...WIND ADVISORY TODAY THROUGH SATURDAY FOR NORTHWESTERN SD.
WY...NONE.
&&
$$
</PRE></TT></td>   sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1232 PM CDT FRI SEP 22 2006
.DISCUSSION...
THE MID STATE IS NEARLY CLEAR OF PRECIPITATION AT THIS TIME. ONLY A
FEW LIGHT SHOWERS ARE OCCURRING ACROSS FAR NORTHWESTERN COUNTIES.
A WARM FRONT WILL CONTINUE TO MOVE SLOWLY NORTHWARD THROUGH THE MID
STATE TODAY. HOWEVER...LITTLE IN THE WAY OF CONVERGENCE IS INDICATED
ALONG THE BOUNDARY.
LATEST RUC MODEL SHOWING LITTLE IN THE WAY OF DYNAMICS WORKING UNTIL
LATE THIS AFTERNOON WHEN SOME PVA MOVES INTO WESTERN TN. A FEW
BREAKS IN THE CLOUD COVER MAY OCCUR...PARTICULARLY ACROSS SOUTHERN
ZONES. ANY ADDITIONAL HEATING WILL ACT TO FURTHER DESTABILIZE THE
ATMOSPHERE AND THUS...SCATTERED CONVECTION WILL BE POSSIBLE.
FOR THE FCST...WILL UPDATE AND LOWER POPS DOWN TO AROUND 50% FOR
MOST AREAS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
21
</PRE></TT></td>   tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
1123 PM CDT FRI SEP 22 2006
.UPDATE...RUC IS ANALYZING A WEAK S/WV ACROSS THE TEXAS COAST
W/ THE COASTAL BEND ON BACKSIDE OF THE FEATURE. THINK THIS FEATURE
MAY HAVE CAUSED SLT BUCKLING IN THE PGRAD AND CONTRIBUTED TO
UNEXPECTED DROP OFF IN WINDS ACROSS THE NEARSHORE WATERS THIS
EVENING. AS THE S/WV MOVES FURTHER AWAY FROM THE REGION ITS
INFLUENCE ON THE PGRAD WILL DECREASE AND THE WINDS SHOULD INCREASE
ONCE AGAIN OVERNIGHT (IN FACT PTAT2 ALREADY SHOWING SIGNS OF
INCREASING AGAIN MOST RECENT OB). THEREFORE...KEPT THE SCA GOING ALL
MARINE ZONES INCLUDING THE BAYS DESPITE SOME OF THE RECENT LOWER
WIND SPEEDS IN A FEW OF THE TCOON AND NDBC SITES. ALSO UPDATED ZONES
TO SHOW MORE CLOUD COVER AS WE ARE SEEING MUCH MORE STRATUS
FORMING TONIGHT AS COMPARED TO LAST NIGHT AND CLEANED UP SOME WIND
WORDING THERE AS WELL.
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM SATURDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20
     NM...COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL
     OUT 20 NM...WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM...
     AND WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60
     NM.
     SMALL CRAFT ADVISORY UNTIL 7 AM SATURDAY FOR THE FOLLOWING
     ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
     AND BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR.
&&
$$
MJG
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
906 PM CDT FRI SEP 22 2006
.UPDATE...
SEVERE CONVECTION CONTINUES TO DEVELOP IN MOIST/UNSTABLE AND
STRONGLY SHEARED AIRMASS NORTH OF THE RED RIVER THIS EVENING...
LIKELY IN RESPONSE TO INTENSIFYING LOW-LEVEL JET INCREASING MASS
CONVERGENCE ALONG RETREATING DRYLINE.  MODELS HAVE BEEN CONSISTENT
ON BACKBUILDING THE AXIS OF SCATTERED THUNDERSTORMS ACROSS THE NORTH
CENTRAL AND NORTHWEST PORTIONS OF THE FORECAST AREA THROUGH THE
NIGHT...BUT VERY LITTLE CONVECTION HAS DEVELOPED THUS FAR SOUTH OF
THE RED RIVER.  WILL MAINTAIN STATUS QUO WITH THE CURRENT FIRST
PERIOD POPS...AS DRYLINE AND ZONE OF STRONGEST CONVERGENCE WILL
CONTINUE TO RETREAT NORTHWESTWARD IN RESPONSE TO MID-LEVEL SHORTWAVE
TROUGH CURRENTLY APPROACHING SOUTHEAST COLORADO.
OTHER ELEMENTS OF THE FORECAST APPEAR TO BE ON TRACK AS WELL THIS
EVENING...AND ONLY MINOR ADJUSTMENTS WILL BE MADE TO DEWPOINT...
WIND...AND CLOUD COVER GRIDS TO ACCOUNT FOR CURRENT TRENDS.  UPDATED
PRODUCTS WILL BE ISSUED SHORTLY.
65/DD
&&
.AVIATION...
AGREE WITH CWSU THAT CONVERGENCE HAS BEEN MINIMIZED ALONG DRYLINE
THIS AFTN...BUT SHOULD INCREASE AS LOW LVL FLOW BECOMES MORE
SSE/SELY THROUGH 04-05Z. HOWEVER...ELEVATED MIXED LAYER (CAP)
SEEMS MORE STOUT S OF 580DM LINE WHICH PER RUC...XTNDS FROM
KGYI...TO KDTO/KLUD...TO NEAR KRPH. THUS ONLY ISOLD SHRA/TSRA
MNLY NW-NE OF D/FW TAF SITES THROUGH 08-10Z...WHEN COLD FRONT
SHOULD START TO OVERTAKE DRYLINE TO THE NW AND INITIATE ELEVATED
STORMS AS S/W OVER TX/OK PANHANDLES APPROACHES AND HEIGHTS FALL.
WILL KEEP TIMING OF MVFR CIGS ARND SAME TIMES 06-07Z AT KACT...TO
09-10Z AT D/FW SITES...WITH VFR CONDS TIL THEN.
LOOK FOR BEST PROBS TO OCCUR D/FW AREA 10Z-17Z TIME FRAME AS CD
FNT APPROACHES AND FORCING GETS BETTER WITH LINEAR...ELEVATED
ACTIVITY EARLY...BECMG MORE SFC-BASED BY 18Z/AFTR NEAR D/FW...THEN
ARRIVING INTO KACT VCNTY BY 21Z/AFTR. CD FRONT ARRIVES ACRS D/FW
FROM 19-21Z WITH WND SHIFT TO WNW/NW...THEN INTO KACT LIKELY AFTR 00Z
SUN.
&&
.PREV DISCUSSION... /ISSUED 305 PM CDT FRI SEP 22 2006/
DISCUSSION...
NEXT LOBE OF ENERGY SWINGING AROUND UPPER LOW IN THE CENTRAL
PLAINS WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO NORTHERN
PORTIONS OF THE CWA TONIGHT...AND SPREAD SOUTHEAST ACROSS THE
REGION EARLY SATURDAY. MODELS HAVE BEEN CONSISTENT AND IN GENERAL
AGREEMENT IN DEVELOPING PRECIP OVER NORTHERN PORTIONS TONIGHT...WITH
A COLD FRONT MOVING THROUGH THE AREA LATE SATURDAY. RAINS WILL END
IN SOUTHERN PORTIONS BY EARLY SUNDAY WITH TEMPERATURES BECOMING
MORE MODERATE AS WE HEAD INTO THE FIRST FULL WEEK OF FALL.
WEAK RIDGING TO BEGIN SUNDAY BUT THE PERSISTENT BROAD TROUGH OVER
THE EASTERN HALF OF THE U.S. WILL SEND ANOTHER SHOT OF COLD AIR
AND ENERGY SOUTHWARD MIDWEEK...WITH A FRONT AND RAIN MOVING
THROUGH LATE WEDNESDAY AND THURSDAY. DESPITE THESE RAIN
CHANCES...IT SHOULD BE A PLEASANT WEEK AS TEMPERATURES REMAIN
MILD...QUITE A CHANGE FROM RECENT WEEKS.
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/42/05
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
644 PM CDT FRI SEP 22 2006
.AVIATION...
AGREE WITH CWSU THAT CONVERGENCE HAS BEEN MINIMIZED ALONG DRYLINE
THIS AFTN...BUT SHOULD INCREASE AS LOW LVL FLOW BECOMES MORE
SSE/SELY THROUGH 04-05Z. HOWEVER...ELEVATED MIXED LAYER (CAP)
SEEMS MORE STOUT S OF 580DM LINE WHICH PER RUC...XTNDS FROM
KGYI...TO KDTO/KLUD...TO NEAR KRPH. THUS ONLY ISOLD SHRA/TSRA
MNLY NW-NE OF D/FW TAF SITES THROUGH 08-10Z...WHEN COLD FRONT
SHOULD START TO OVERTAKE DRYLINE TO THE NW AND INITIATE ELEVATED
STORMS AS S/W OVER TX/OK PANHANDLES APPROACHES AND HEIGHTS FALL.
WILL KEEP TIMING OF MVFR CIGS ARND SAME TIMES 06-07Z AT KACT...TO
09-10Z AT D/FW SITES...WITH VFR CONDS TIL THEN.
LOOK FOR BEST PROBS TO OCCUR D/FW AREA 10Z-17Z TIME FRAME AS CD
FNT APPROACHES AND FORCING GETS BETTER WITH LINEAR...ELEVATED
ACTIVITY EARLY...BECMG MORE SFC-BASED BY 18Z/AFTR NEAR D/FW...THEN
ARRIVING INTO KACT VCNTY BY 21Z/AFTR. CD FRONT ARRIVES ACRS D/FW
FROM 19-21Z WITH WND SHIFT TO WNW/NW...THEN INTO KACT LIKELY AFTR 00Z
SUN.
&&
.PREV DISCUSSION... /ISSUED 305 PM CDT FRI SEP 22 2006/
DISCUSSION...
NEXT LOBE OF ENERGY SWINGING AROUND UPPER LOW IN THE CENTRAL
PLAINS WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO NORTHERN
PORTIONS OF THE CWA TONIGHT...AND SPREAD SOUTHEAST ACROSS THE
REGION EARLY SATURDAY. MODELS HAVE BEEN CONSISTENT AND IN GENERAL
AGREEMENT IN DEVELOPING PRECIP OVER NORTHERN PORTIONS TONIGHT...WITH
A COLD FRONT MOVING THROUGH THE AREA LATE SATURDAY. RAINS WILL END
IN SOUTHERN PORTIONS BY EARLY SUNDAY WITH TEMPERATURES BECOMING
MORE MODERATE AS WE HEAD INTO THE FIRST FULL WEEK OF FALL.
WEAK RIDGING TO BEGIN SUNDAY BUT THE PERSISTENT BROAD TROUGH OVER
THE EASTERN HALF OF THE U.S. WILL SEND ANOTHER SHOT OF COLD AIR
AND ENERGY SOUTHWARD MIDWEEK...WITH A FRONT AND RAIN MOVING
THROUGH LATE WEDNESDAY AND THURSDAY. DESPITE THESE RAIN
CHANCES...IT SHOULD BE A PLEASANT WEEK AS TEMPERATURES REMAIN
MILD...QUITE A CHANGE FROM RECENT WEEKS.
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/42/05
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
907 AM CDT FRI SEP 22 2006
.UPDATE...
THE PROBLEM OF THE DAY WILL BE WINDS ACROSS SE TX. THE WIND SPEEDS
WERE ALREADY IN THE 15 TO 20 MPH RANGE AT 14Z OVER THE INLAND
AREAS AND 20 TO 25 MPH RANGE AT THE COAST. THE VAD WIND PROFILE
COUPLED WITH THE ADJACENT PROFILERS AND THE NAM AND RUC ALL
INDICATE 35 TO 40 KNOT WINDS AT EITHER 2000 FEET OR THE 925 MB
SURFACE. FIGURED THAT WITH HEATING THE WINDS WILL PICK UP OVER
WIND ADVISORY CRITERIA OVER ALL OF SE TX...AND ISSUED THE
ADVISORY THROUGH 6 PM.
THE OTHER ISSUE FOR THE DAY WILL BE RAIN CHANCES. THE MSAS DATA
SHOWED THE SURFACE THETA-E RIDGE JUST OFF THE COAST AND OVER THE
BPT AREA. WILL KEEP THE 20 PERCENT CHANCE IN FOR TODAY.
40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...SMALL CRAFT ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES:
     AND GALVESTON.
     WIND ADVISORY UNTIL 6 PM FRIDAY FOR THE FOLLOWING ZONES:
     AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
     COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
     HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
     MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
     WALLER...WASHINGTON...AND WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES:
     GALVESTON BAY...AND MATAGORDA BAY.
     SMALL CRAFT ADVISORY UNTIL 7 AM SATURDAY FOR THE FOLLOWING
     ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
     20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
     CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
     TO 60 NM...AND WATERS FROM HIGH ISLAND TO FREEPORT OUT 20
     NM.
&&
$$
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1005 AM CDT FRI SEP 22 2006
.UPDATE...DATA ANALYSIS CONTINUES TO SHOW NEARLY VERTICALLY
STACKED LOW PRESSURE NEAR THE KFSD AREA. DRY SLOT EVIDENT ON
VISIBLE SATELLITE AND WATER VAPOR IMAGERY WORKING AROUND SOUTH
SIDE OF THE SYSTEM. IN ADDITION...MAIN BAND OF RAIN HAD LIFTED
INTO NORTH CENTRAL WI...AS Q-G CONVERGENCE LIFTING NORTHWARD TOWARD
LAKE SUPERIOR.
LATEST RUC SUPPORTS DRY SLOT TO CONTINUE PUSHING INTO PORTIONS OF
THE FORECAST AREA...ESPECIALLY NORTHEAST IOWA AND SOUTHWEST WI.
RUC ALSO INDICATED MAIN FORCING MANIFESTED BY UPPER LEVEL
DIVERGENCE AND DEEP Q-G CONVERGENCE SHOULD CONTINUE LIFTING
NORTHWARD THIS AFTERNOON.
AS MIDNIGHT SHIFT ARX FORECASTER NOTED...BEST INSTABILITY APPEARS
TO RESIDE SOUTH OF OUR FORECAST AREA. MUCAPE VALUES BUILD TO NEAR
1000J/KG IN FAR SOUTHWEST CORNER OF WI...GENERALLY ALONG AND EAST
OF LINE FROM KDLL TO KDBQ BETWEEN 20Z-02Z. THUS...SEVERE WEATHER
THREAT STILL LOOKS TO RESIDE SOUTH OF THE FORECAST AREA THIS
AFTERNOON AND EVENING.
CURRENT DATA BASE APPEARS ON TRACK...TAKING INTO ACCOUNT EFFECTS OF
DRY SLOT. THEREFORE...BEST RAIN PROBABILITIES WILL BE ACROSS EAST
AND NORTH SECTIONS OF THE FORECAST AREA THIS AFTERNOON. UPDATED
ZONES SHOULD BE ISSUED BY ABOUT 1530Z THIS MORNING...WITH ONLY
MINOR TWEAKS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
THOMPSON
</PRE></TT></td>   wi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
446 AM CDT SAT SEP 23 2006
.DISCUSSION...
MAIN DILEMMA FOR TDAS FCST IS TRYING TO FIGURE OUT WHAT THE WALL
OF WATER FROM NE OK TO W KY IS GOING TO DO TO THE PCPN CHCS AND
SVR WX THRT OVR THE SE HLF OF FA. WV ALG CDFNT NOW MOVING INTO NE OK
HAS BGN TO GENERATE THE NXT ROUND OF CNVTN...AND XTRAP OF N EDGE
OF THIS PCPN TAKES IT TO NR A KVIH...KSPI LN DURG THE MRNG. WITH
OUTFLO BNDRY RMNG SO ACTIVE OVR N AR AM SMWHAT SKEPTICAL THAT HVY
RAIN WL GET THAT FAR N...BUT SINCE MDLS HV PEGGED THIS REDVLPMT HV
MENTIONED HVY RAINS ALG AND S OF ABV MENTIONED LINE FOR THIS MRNG.
SM AREAS OF E OZARKS CULD GET OVR AN INCH OF RAIN THIS MRNG...BUT
SINCE YSTDAS HVY RAIN IN OUR FA WAS VRY SPOTTY THINK THAT MOST
AREAS SHUD BE ABLE TO HOLD THIS RAINFALL. AS FAR AS SVR WX THRT
WITH THIS FIRST ROUND OF CNVTN...BLV THAT IT WL PRIMARILY STAY S
OF OUR AREA...IN VCNTY OF OUTFLO BNDRY NR AR/MO BDR.
AFT THIS MRNGS FIRST WV OF CNVTN PASSES THRU THE SE HLF OF
FA...QUESTION BCMS HOW MUCH AND HOW INTS REDVLPMT WL OCR AHD OF
CDFNT DURG THE AFTN. BLV THAT MRNG CNVTN/RAIN COOLED AMS/CLD CVR IS
REALLY GOING TO INHIBIT DESTABLIZATION DURG THE ERY AND MID AFTN
HRS...SO WHILE CAN'T TOTALLY RULE OUT REDVLPMNT BGNG TO THINK
THAT INTENSITY MAY BE LIMITED. NAM FCSTS MLCAPES TO REBOUND TO
ARND 400 J/KG BY LT AFTN...WHILE BOTH THE GFS AND LATEST RUC INCR
CAPES INTO THE 1500-2000 J/KG RANGE. OTHER QUESTION IS WHERE THE
CDFNT WL BE DURG AFTN. IF GFS IS CORRECT FNT WL BE EXITING OUR FA
IN THE 18- 20Z TIME FRAME...PLACING MAIN THRT OF AFTN DVLPMT E OF
OUR AREA. FOR THE TIME BEING HV GONE WITH A BLEND OF THE GFS/NAM
FOR THIS AFTN PARAMETERS...AND KEPT POPS HI.
MEANWHILE...SHWRS ASSOC WITH MAIN TROF IN COOLER AIR OVR E KS/NW
MO SHUD MV ACR NW SECTIONS OF THE FA DURG THE MRNG. KEPT A LO POP
GOING IN THESE AREAS DURG AFTN...BUT EVEN THESE LO POPS MAY BE A
BIT TOO HI IF MID LVL DRY SLOT EVOLVES AS DEPICTED BY GFS AND NAM.
WITH THE UPR LO AND TROF FINALLY BGNG TO MOVE COOLER AND MORE
STBL AMS SHUD BE ADV INTO THE MID MSVLY THIS AFTN AND TNGT. THIS
MEANS THAT ANY CNVTN THAT DOES REFORM OVR SE MO/S IL THIS AFTN
SHUD BE EXITING OUR FA BY ERY THIS EVE...AND ANY LINGERING SHWRS
IN THE COOLER AIR SHUD DSPT AS WELL. CERTAINLY...COOLER AND MORE
TRANQUIL CONDITIONS ARE IN THE OFFING FOR MOST OF TNGT AND
SUN...ALTHO MDL RH PROGS SUGGEST A GD DEAL OF LO LVL CLDNS
SPREADING ACR AREA LT TNGT AND SUN...AND CULD SEE A FEW SPRINKLES
AS WELL.
TRUETT
&&
.AVIATION...
FOR THE 06Z TAFS...MOST OF THE SHRA AND TSRA SHOULD REMAIN S OF
THE TAF SITES DURING THE LT NGT HRS. TSRA WILL LIKELY RETURN TO
COU AND STL AREA SAT MRNG AS THE FNT LFTS SLIGHTLY NWD WITH
APPROACH OF SFC WV MOVG NEWD THRU ERN OK AND INTO SWRN MO.
SHRA/TSRA WILL LIKELY ALSO OCCUR FURTHER N IN UIN AS THE MID-
UPR LVL TROF APPROACHES FM THE WEST. MOST OF THE SHRA AND TSRA
ACTIVITY SHOULD EVENTUALLY PUSH S AND E OF THE TAF SITES BY SAT
EVNG WITH THE PASSAGE OF THE CDFNT. VFR CEILINGS AND VSBYS SHOULD
CONT THRU AT LEAST 12Z SAT TIL THE SHRA/TSRA PUSH BACK INTO THE
CWA.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
</PRE></TT></td>   mo
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
339 AM EDT SAT SEP 23 2006
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
SFC HIGH PRESSURE OVER NORTHEAST/MIDATL STATES WILL SINK SSE
TODAY. REMAINDER OF THE BL WILL FOLLOW SUIT LEADING TO A DEEP
LAYER OF WARM AND MOIST S TO SWRLY FLOW. AS SUCH A WARM AND MUGGY
AFTERNOON IS EXPECTED THIS FIRST DAY OF FALL AND CU DEVEL SHOULD
BE FARILY ROBUST. WEAK SHOWER ACTIVITY JUST OFFSHORE FROM WRN
BRUNSWICK AND OFF OF SC....A COMBO OF WEAK LLJ AND CONV
AXIS...WILL PROBABLY DIMINISH WITHIN A FEW HRS OF SUNRISE. THIS
IDEA IS SUPPORTED BY THE RUC, WHICH HAS RECENTLY INITIALIZED WITH
THE ACTIVITY PRETTY WELL. AND ALTHOUGH A LAST MINUTE DECISION TO
INCLUDE THEM MAY BE MADE FOR NOW THEY WILL LIKELY ONLY MERIT A
NOWCAST OR TWO...IF EVER MAKING IT ONSHORE THAT IS.
WITH CONTINUED WARM AND MOIST ADVECTION OVERNIGHT EXPECT GRADUAL INC
IN MIDLVL CLOUDS AND A MUGGY NIGHT. FLOW SHOULD BE PARELLEL
ENOUGH TO THE COAST THAT IF OFFSHORE SHOWERS REDEVEL THEY SHOULD
REMAIN OVER WATER. BL APPEARS TO STAY MIXED ENOUGH TO PRECLUDE
MUCH FOG DEVEL EVEN IF THE MID CLOUDS STAY JUST TO OUR NW, WHICH
IS A POSSIBILITY SINCE THE OVERALL EVOLUTION OF THE SUNDAY/MONDAY
PATTERN APPEARS SLOWER THAN PREV THOUGHT.
ACCORDINGLY...POPS HAVE BEEN TRIMMED SUNDAY TO SHOW SLOWER TIMING.
MOST OF THE DAY SHOULD BE MUGGY WITH MORE ROBUSTLY INCREASING MID
LVL CLOUDS. LATER IN THE AFTERNOON POPS WILL STILL BE RISING AS
THE COLD FRONT NEARS...AND THE SEA BREEZE MAY EVEN MAKE A
CONTRIBUTION ALTHOUGH THE SYNOPTIC FLOW WILL KEEP IT FROM MOVING
INLAND VERY FAR OR VERY QUICKLY.
IF THE GFS TIMING IS CORRECT THEN POPS SHOULD START RAMPING UP
QUICKLY AOA 03Z MONDAY (MAYBE A BIT SOONER W) AS DEEP ASCENT
OVERSPREADS THE AREA. THE ASCENT IS DEEP BUT NOT TERRIBLY STRONG
SO MODERATE RAIN WILL BE POSSIBLE DUE TO A DEEP NEARLY SATURATED
LAYER BUT ANY HEAVY RAIN SHOULD BE CONFINED TO LOCALIZED POCKETS OF
CONVECTION. THE FRONT WILL PROGRESSING ACRS THE AREA AT THIS TIME
AND SHOULD ROUGHLY PARELLEL THE COAST AND BE JUST OFFSHORE AOA 12Z
MON.
THE EASTERMOST COUNTIES WILL HAVE A TOUGH TIME SHAKING RAIN
CHANCES THROUGH MOST OF MONDAY. AS THE TROUGH THAT DROVE THE FRONT
INTO THE AREA ALREADY BEGINS LIFTING OUT A POTENT SHORTWAVE
LAGGING BEHIND WILL BEING TO MOVE IN FROM THE WEST. ACCORDING TO
THE GFS THE TROP WILL BE FOLDING DOWN TO ABOUT 500MB OVER ATL BY
MONDAY AFTERNOON WITH THIS FEATURE. THIS WILL RESULT IN FAIRLY STRONG
VERTICAL MOTION OVER THE ERN CAROLINAS. MOST OF THIS STRONG ASCENT
WILL BE OCCURRING OVER THE DEEP STABLE BL OVER WRN ZONES BUT
COASTAL COUNTIES MAY STILL HAVE A SHALLOW ENOUGH STABLE LAYER FOR
SOME ELEVATED MOISTURE AND INSTABILITY AND COULD SEE ANOTHER ROUND
OF APPREACIABLE RAINFALL. SHOULD THE BOUNDARY BE JUST A BIT
FARTHER TO THE EAST MOST OF THE RAIN WILL REMAIN OFFSHORE. TOO
EARLY TO IRON OUT THE DETAILS.
&&
.AVIATION...
PROBLEMATICAL FORECAST THIS MORNING...ESPECIALLY AT FLO
WHICH IS NOW EXPERIENCING VLIFR CONDITIONS FOR VSBY AND CIG. HAVE NO
GOOD EXPLANATION WHY IT HAS GONE SO LOW HERE...NEITHER GUIDANCE NOR
CLIMO NOR THE SYNOPTIC SITUATION WOULD SUGGEST THIS SCENARIO. REST
OF THE TAFS ARE BEHAVING. RADAR HAS PATCHES OF LIGHT SHOWER ACTIVITY
MOVING ASHORE BEFORE DISSIPATING SOUTH OF CAPE FEAR WHICH IS LEADING
TO TEMPO MVFR FOR CIGS AT CRE AND MYR. PATCHY MVFR FOG ELSEWHERE
THIS MORNING EXCEPT FOR ILM WHICH SEEMS TO LIE JUST OUTSIDE OF THE
BEST MOISTURE TAP.
&&
.MARINE...
LONG PERIOD SWELL FROM DISTANT TROPICAL CYCLONE HELENE
CONTINUES TO IMPACT THE COASTAL WATERS. SWELLS ABOUT 4 FT WITH A
PERIOD OF 15 SECONDS OUT AT 41013 ACCORDING TO SPECTRAL PLOTS. WITH
TIGHTENING SOUTHERLY GRADIENT OVER THE COASTAL WATERS WIND DRIVEN
WAVES HAVE ALSO INCREASED...LEADING TO COMBINED SEAS OF 5 FT AT
41013 AND AROUND 4 FT CLOSER TO SHORE. BASED ON LATEST FROM TPC ON
HELENE...EXPECT SIGNIFICANT CONTRIBUTION TO COMBINED SEAS FROM THE
SWELL COMPONENT TO CONTINUE INTO THE WEEKEND...ALTHOUGH IT LOOKS
LIKE WE HAVE ALREADY SEEN ITS PEAK. PRESENT SHADOWING EFFECT OF
SWELL ENERGY FOR WATERS WEST OF CAPE FEAR DUE TO FRYING PAN SHOALS
WILL BECOME LESS OF A FACTOR DURING THE DAY TODAY AS SWELL ENERGY
DECREASES. WINDS AND SEAS WILL PICK UP AGAIN SUNDAY IN ADVANCE OF
COLD FROPA SET FOR EARLY MONDAY. MAY SEE SCA CRITERIA MET FOR SEAS
SUNDAY NIGHT IN THE OUTER REACHES OF OUR NC WATERS. STUCK WITH THE
GFS FOR MOST OF THE FORECAST EXCEPT FOR THE FIRST COUPLE OF PERIOD.
AS NOTED BY OPC...THE GFS IS SUPPORTED BY THE ECMWF AND BY THE
LATEST HPC MEDIUM RANGE FORECASTER GUIDANCE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SHORT TERM...MBB
AVIATION...REK
MARINE...REK
</PRE></TT></td>   nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OHIO
145 AM EDT SAT SEP 23 2006
.AVIATION(06Z-06Z)...
WARM FRONT ACROSS SE LOWER MI THRU NE OH WILL LIFT NORTH FORECAST
AREA EARLY THIS MORNING. ONE LARGE AREA OF SHOWERS ACRSS SE OH AND
KY SHOULD SLIDE OFF TO THE EAST. COUPLE OTHER AREA SHOWERS AND TSTMS
NW OH AND EXTRM NERN PTN FORECAST AREA. SHOULD SEE SHOWERS EXPAND
FOR AWHILE EARLY THIS MORNING WITH WARM FRONT VCNTY AND 8H JET
NOSING INTO AREA BUT THEN SHOULD SEE SHOWERS DCRS IN COVERAGE LATER
THIS MORNING AND PERHAPS INTO EARLY AFTERNOON...BEFORE BECOMING MORE
WIDESPREAD LATE THIS AFTERNOON AND EARLY TONIGHT WITH APPROACH OF
FRONT. MIXSED CIGS AND VSBYS ACROSS THE AREA ATTM MOST MVFR. EXPECT
THIS HOLD THIS MORNING THOUGH MFD THRU YNG EXPECTING IFR CIGS. CIGS
AND VSBY SHOULD LIFT TO VFR LATE MORNING EARLY AFTERNOON BEFORE
LOWERING AGAIN TO WIDESPREAD MVFR CIGS AND VSBYS AS SHOWERS EXPAND
LATE AFTERNOON AND TONIGHT. THE THREAT FOR SEVERE THUNDERSTORMS
SATURDAY AFTERNOON AND EVENING WILL HAVE TO BE MONITORED. HIGH SHEAR
FOR THREAT OF SEVERE WEATHER BUT STABILITY MAY BE LIMITED BECAUSE OF
CLOUDS THOUGH SHEAR WOULD MAINTAIN ANY STRONG STORMS THAT INITIATE.
&&
.SHORT TERM UPDATE (TONIGHT)...
RAIN BEGINNING TO REACH INTO THE WRN COUNTIES THIS EVG AND SHWRS AND
TSTMS ARE TO OUR WEST.   CONSERNED ABOUT TSTMS INTO THE AREA
OVERNIGHT ALTHOUGH SPC FCST TOOLS SUGGEST LIMITED IF ANY CAPE ACRS
CWA AT THIS TIME AND WHILE THE NAM12 DOES BRING IN 500 OR SO J/KG
OVERNIGHT TO THE WEST THE RUC20 DOES NOT.  STILL BLV WE COULD GET A
FEW TSTMS INTO THE AREA AND THUS WILL LV THE MENTION OF THUNDER IN
THE FCST.  OTRW TIMING OF PCPN IN PRVS FCST WAS GOOD BUT GVN THE
HOUR WL REMOVE TIMING FROM THE WORDING.  ALSO WITH WARM ADVN ACRS
THE AREA BLV TEMPS HAVE STEADIED OR BOTTOMED ACRS THE CWA.  EARLIER
HAVE SEEN A FEW UPPER 50S BUT READINGS NOW ARE ALL IN THE LOW/MID
60S.  WL REMOVE LOW TEMP WORDING TO REFLECT STEADY OR RISING TEMPS
OVERNIGHT.  MADE ON TEMP CHG FOR SAT TO THE CLE GROUP AND RAISED
HIGHS TO THE MID 70S FROM LOWER 70S.
&&
.SHORT TERM(TNT-MON)...
TEMPERATURES NEVER REALLY GOT AS HIGH AS PREDICTED TODAY. EXPECTING
EARLY LOWS TONIGHT AROUND 60...WITH TEMPS RISING A FEW DEGREES
TOWARD MORNING WITH THE APPROACH/PASSAGE OF A WARM FRONT.  RIGHT NOW
WRAPPED UP SYSTEM ACROSS THE CENTRAL PLAINS WITH LOW CENTER ACROSS
SOUTHERN MN AND OCCLUDED/COLD FRONT INTO EASTERN IOWA AND MISSOURI.
THE WARM FRONT IS LOCATED ACROSS MISSOURI.  RAIN WITH A CHC OF TS
SHOULD DEVELOP AND EXPAND NORTHWARD AROUND AND AFTER MIDNIGHT.
EXPECTING A LULL IN PRECIP FOR THE FIRST HAVE OF SAT UNTIL DYNAMICS
KICK IN.  AREA IN A SLT RISK OF SEVERE THUNDERSTORMS.  AMPLE SHEAR
WILL BE PRESENT ALONG WITH MOISTURE...WILL JUST HAVE TO GET ENOUGH
INSTABILITY TOGETHER.  MAV TEMPS WERE IN THE UPPER 70S...HAVE
UNDERCUT AND GONE WITH LOWER/MID 70S SAT IN THE WARM SECTOR.  FRONT
SAT NIGHT/SUN MORNING.  THIS IS WHERE MODELS SPREAD SOME WITH GFS
FASTER AND MORE SOUTHERN WITH THE LOW TRACK...AND THE NAM SLOWER AND
FURTHER NORTH.
SHOWERS ON THE BACKSIDE WITH UPPER TROUGH AXIS STILL TO COME
THROUGH.  H8 TEMPS GET INTO THE SINGLE DIGITS.  SFC TEMPS COOL IN
THE 60S.  MONDAY SHRA WILL WANE...BUT WILL STILL BE FAIRLY CLOUDY.
HIGH PRESSURE WORKS IN TO OUR SOUTH.
&&
.EXTENDED (TUE-FRI)...
NORTHWEST FLOW DEVELOPS INTO ANOTHER DEEP EASTERN TROUGH WITH AN
ASSOCIATED COLD FRONTAL PASSAGE AROUND WED EVE.  WE WILL BE STUCK IN
THE UPPER TROUGH THROUGH THE END OF THE FORECAST WITH LARGE WESTERN
RIDGE BUILDING INTO CANADA.  HAVE PRECIP CHCS IN ASSOCIATION WITH
THE FRONT AND THEN IN THE DAYS FOLLOWING WITH THE UPPER TROUGH. SKY
COVER AND TEMPS COINCIDE.  GFS AND ITS ENSEMBLE MEMBERS RUNNING
FAIRLY CONSISTENTLY THROUGH THE EXTD...WHICH IS GOOD NEWS FOR
CONFIDENCE LEVELS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
.OH...NONE.
.PA...NONE.
&&
$$
SHORT TERM UPDATE...TK
SHORT TERM...OUDEMAN
LONG TERM...OUDEMAN
AVIATION...WCR
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
137 AM EDT SAT SEP 23 2006
.AVIATION /06Z-06Z/...
THE MORE CONTIGUOUS THUNDERSTORM ACTIVITY WILL CONTINUE TO MOVE
SOUTH AND EAST OF THE TERMINALS THIS EVENING. SOME ISOLATED STORMS
WILL AFFECT KCVG AND KLUK OVER THE NEXT FEW HOURS...AND PERHAPS
DAYTON. CIGS WILL BE MVFR AT TIMES THROUGH 12Z WITH SW WINDS
AROUND 12 KTS AND GUSTS NEAR 20 KTS.
THERE WILL BE LESS COVERAGE THROUGH 16Z-18Z BEFORE INSTABILITY
BUILDS IN ADVANCE OF AN APPROACHING COLD FRONT. SW WINDS WILL GUST
OVER 20 KTS AT TIMES WITH MVFR CIGS AND VISIBILITIES LIKELY AGAIN AFTER
23Z AS THE FRONT BEGINS TO PASS ACROSS THE AREA.
&&
.PREV DISCUSSION...
 /ISSUED 931 PM EDT FRI SEP 22 2006/
SHORT TERM /REST OF TONIGHT/...
WIDESPREAD AREA OF -SHRA WITH EMBEDDED TSTMS NOW ACRS WESTERN 1/2 FCST
AREA THIS EVNG AS WARM FRONT CONTINUES TO SLOWLY LIFT NORTH ACRS
WESTERN/CNTRL KY. RUC INDCG ELEVATED INSTABILITY WILL CONTINUE TO
OVERSPREAD FCST AREA THRU OVERNIGHT HOURS ON NOSE OF 40-50KT 850
LLJ. LO LVL CONV AXIS WILL SET UP ACRS SRN 1/2 FCST AREA OVERNIGHT
AND THIS SHOULD PROMOTE CONTINUED PCPN THRU THE NIGHT. RADAR AND
SAT IMAGES CONFIRM THIS THINKING WITH CLUSTERS OF TSTMS EXTNDG ALL
THE WAY BACK INTO SRN MISSOURI. MAY SEE STRONG TSTMS...BUT SEVERE
THREAT SHOULD REMAIN SW OF FCST AREA. HAVE INCREASED TO CAT POPS
ACRS ALL BUT SE FCST AREA FOR OVERNIGHT AS WARM FRONT LIFTS NORTH
INTO REGION.
UPDATE OUT...PREV DISCUSSION FOLLOWS.
RYAN
PREV DISCUSSION...
 /ISSUED 348 PM EDT FRI SEP 22 2006/
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
BIG DIFFERENCES BETWEEN NAM AND GFS...BUT IN COMPARING WITH ECMWF
AND UKMET...GFS SEEMS TO BE MORE REASONABLE DESPITE STILL HAVING
SOME CONVECTIVE FEEDBACK.
GFS PRETTY PROGRESSIVE WITH CLOSED LOW JUST TO NORTH OF FA THROUGH
EARLY SUNDAY MORNING. MOST PROMISING DYNAMICS AND PLENTY OF LOW
LEVEL SHEAR AND INSTABILITY AHEAD OF MAIN SQALL LINE TO PRODUCE
POTENTIAL SUPERCELL ACTIVITY LATE AFTERNOON SAT...WITH MORE OF A
POSSIBLE SQUALL LINE EVENT IN THE MID AND LATE EVENING. HAVE GONE
CATEGORICAL CHANCES FOR SATURDAY...WITH MORNING THUNDERSTORMS NOT
AS LIKELY SEVERE...BUT SOME THREAT OF ISOLATED HEAVY RAIN IN THE
SOUTHWEST. SFC WARM FNT APPROACHING FROM CENTRAL PLAINS BRINGING GOOD
SHOT OF 70 TO LOW 70 DEWPOINTS ESPECIALLY IN THE WEST FOR
SATURDAY. HAVE MENTION OF SEVERE IN GRIDS WITH DAMAGING WINDS
GREATEST THREAT FROM ESPECIALLY 18-02Z.
LINGERING CHANCE OF SHOWERS WITH A MENTION OF EARLY MORNING
THUNDERSTORMS IN THE FAR EAST FOR SUNDAY...THEN CHANCE FOR SHRA IN
THE NORTH IN WRAP AROUND THROUGH EARLY SUNDAY AFTERNOON.
LONG TERM /MONDAY THROUGH FRIDAY/...
EXTENDED FCST STARTING MON HAS HIGH PRESSURE BUILDING OVER OHVLY
FROM THE MIDWEST AS LOW PRESSURE RETREATS FROM GTLKS REGION. EXPECT
A GRADUAL WARMING OF THE AIRMASS THROUGH MIDWEEK AS A SFC LOW TRACKS
INTO THE GTLKS WED. THIS WILL SEE A TRAILING COLD FRONT MOVE THROUGH
OHVLY ON WED NITE AND THURS IN RESPONSE TO A STRONG AND PERSISTENTLY
DEEPENING H5 TROF OVER THE ERN 1/2 OF CONUS. MILD AIR WILL SURGE
AHEAD OF THE CDFNT...AND THE STRENGTHENING H5 L/W TROF WILL ALLOW
FOR A STRONG PUSH OF COOL CONTINENTAL AIR INTO THE OHVLY ON NRLY
FLOW AS STRONG SFC HIGH IN THE MIDWEST SETS UP.
STRENGTH OF SYSTEM WED NITE AND THURS HAS ME INCREASE POPS AS THE
FLOW AHEAD OF IT AND SIGNIFICANT HEIGHT FALLS BEHIND IT WOULD LIKELY
SEE A LINE OF CONVECTION MOVE THROUGH THE REGION. COLD POOL SHOWERS
POSSIBLE FOR REMAINDER OF THURS AND INTO FRI...BUT ONLY HAVE 20%
POSSIBILITY HERE BEING THE LAST DAY OF FCST.
TEMPS WERE GENERALLY BUMPED UP AHEAD OF WED NITE FRONT AND DROPPED
BEHIND IT...NOT TOO FAR FROM MEX GUID.
FRANKS
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
</PRE></TT></td>   oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
315 AM CDT SAT SEP 23 2006
.DISCUSSION...
SURFACE COLD FRONT HAS ESSENTIALLY CAUGHT UP WITH THE DRYLINE...AND
CURRENTLY EXTENDS FROM SW MO TO TULSA AND SW INTO SCNTRL OK.
STRONG/SEVERE STORMS CONTINUE IN THE HIGHER CAPE AIR ACROSS FAR ERN
OK AND NW AR...WITH ADDITIONAL CONVECTIVE DEVELOPMENT NOW OCCURRING
ALONG THE FRONTAL BOUNDARY FROM CNTRL INTO NE OK. STRONG FORCING AND
MOISTURE CONVERGENCE WILL ALLOW FOR CONTINUED DEVELOPMENT ALONG THE
COLD FRONT OVER THE NEXT SEVERAL HOURS. GIVEN THE VERY STRONG SHEAR
(0-6KM BULK SHEAR OVER 60 KTS) AND IMPRESSIVE MUCAPES (2000 J/KG)
SEVERE WEATHER WILL BE POSSIBLE INTO THE EARLY MORNING HOURS. WILL
ALSO NEED TO KEEP A CLOSE EYE ON SE OK...WHERE SURFACE WINDS ARE
LOCALLY BACKED IN THE VICINITY OF AN OUTFLOW BOUNDARY.
WILL FOLLOW THE SLIGHTLY FASTER RUC/GFS IN THE NEAR TERM CONCERNING
THE COLD FRONT TIMING. EXPECT SURFACE FRONT TO BE PUSHING INTO FAR
NW AR AROUND 14-15Z...AND SHOULD BE CLOSE TO EXITING THE FORECAST
AREA BY 18Z. HIGHEST POPS OBVIOUSLY NEEDED IN THE FIRST HALF OF THE
PERIOD...BUT WILL TAKE A LAST LOOK AT RADAR BEFORE DECIDING ON FINAL
NUMBERS.
POSITIVE TILT UPPER TROF WILL BE SLOW TO MOVE THROUGH THE REGION.
DEVELOPING LOW-LEVEL CAA AND DEEP CYCLONIC FLOW SHOULD ALLOW FOR LOW
CLOUDS TO PUSH S INTO NE OK/NW AR LATE SATURDAY NIGHT OR EARLY
SUNDAY MORNING. SHORT RANGE MODELS HAVE A DECENT HANDLE ON THIS
SCENARIO...BUT GENERALLY FAVORED THE SLIGHTLY COOLER MET FOR HIGHS.
COOL NIGHT FOR SUNDAY NIGHT...WITH GRADUALLY CLEARING SKIES AND DRY
LOW-LEVEL AIR IN PLACE.
GRADUAL WARMUP TO ENSUE EARLY NEXT WEEK IN THE DRIER NWLY FLOW
ALOFT. 00Z GFS CONTINUES SLOWER TREND WITH NEXT FRONT...WHICH IS
POISED TO MOVE THROUGH THE AREA WEDNESDAY NIGHT INTO THURSDAY.
TWEAKED TEMPERATURES A BIT IN THE EXTENDED...OTHERWISE NO CHANGES
WHERE MADE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL   78  52  73  49 /  40  10  10  10
FSM   81  55  72  50 /  70  30  10  10
MLC   81  52  74  48 /  60  20  10  10
BVO   77  49  72  43 /  30  10  10  10
FYV   76  50  67  42 /  80  20  10  10
BYV   75  48  66  46 /  80  20  10  10
MKO   78  50  71  48 /  60  10  10  10
MIO   75  52  71  46 /  50  10  10  10
F10   77  50  72  48 /  50  10  10  10
HHW   85  59  76  53 /  60  30  10  10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM FORECASTER ID= 17
LONG TERM FORECASTER ID= 18
</PRE></TT></td>   ok
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
428 AM CDT SAT SEP 23 2006
.SHORT TERM (TODAY THROUGH SUNDAY)...MODELS CONTINUE TO SHOW A WEAK
SHORT WAVE TROUGH MOVING OUT OF NORTHERN MEXICO INTO SOUTH TEXAS BY
THIS AFTERNOON. WATER VAPOR IMAGERY/LATEST RUC MODEL ALSO INDICATES
THIS ALONG WITH A WEAK UPPER LEVEL JET STREAK. WILL CONTINUE WITH
LOW END CHANCE POPS FOR CONVECTIVE INITIATION ALONG THE SEABREEZE
THIS AFTERNOON FOR THE NORTHERN INLAND COASTAL PLAINS AND SLIGHT
CHANCE FOR SOUTHERN COASTAL PLAINS. WINDS WILL NOT BE QUITE AS
STRONG AS YESTERDAY WITH BREEZY CONDITIONS EXPECTED FOR THE
COASTAL PLAINS.
MAIN EMPHASIS ON FORECAST WILL BE TONIGHT INTO FIRST HALF OF
SUNDAY. GFS AND NAM INDICATED VERY STRONG LOW LEVEL CONVERGENCE
AND MOISTURE POOLING IN ADVANCE OF THE COLD FRONT THAT WILL BE
ENTERING THE NORTHERN COUNTIES AFTER MIDNIGHT. STRONG UPPER
LEVEL DIVERGENCE IS ALSO INDICATED ACROSS THE NORTHERN COUNTIES
TONIGHT INTO EARLY SUNDAY. THIS IS A REGION WHERE SATURATED
SOILS EXIST FROM HEAVY RAIN THIS PAST SUNDAY. ONLY NEGATIVE
FACTOR IS QUALITY OF MOISTURE DEPTH OVER THE REGION COMPARED
TO THE LAST EVENT. WILL WORD LOCALLY HEAVY RAINFALL POSSIBLE
LATE TONIGHT/EARLY SUNDAY AND ISSUE A SPECIAL WEATHER STATEMENT
TO COVER INCREASED FLASH FLOOD THREAT. MODELS INDICATED STRONG
INSTABILITY OVER THE REGION BUT THE MID LEVEL SHEAR IS ALMOST
NON-EXISTENT. WITH WARM MID LEVEL TEMPERATURES...HAIL THREAT
IS ALSO SLIM. COULD SEE ISOLATED PULSE SEVERE LATER TONIGHT
BUT MAIN FOCUS WILL BE HEAVY RAIN THREAT. FRONT WILL ADVANCE
THROUGH THE COASTAL BEND SUNDAY WITH RAIN CHANCES DIMINISHING
IN THE AFTERNOON. WITH NORTH WINDS AND TEMPS IN THE LOWER TO
MID 80S...WILL FEEL LIKE AUTUMN HAS ARRIVED IN SOUTH TEXAS.
&&
.MARINE...THE STRONG LOW LEVEL JET IN PLACE OVER THE COASTAL
BEND WILL SHIFT EAST BY THIS AFTERNOON. CONTINUED SCA FOR THE
BAYS FOR TODAY...THE WINDS WILL BE STRONG THIS MORNING. THE
PRESSURE GRADIENT WILL RELAX SOME BY THIS AFTERNOON BUT THE
THERMAL GRADIENT SHOULD MAINTAIN SCA THROUGH THE AFTERNOON.
SEAS WILL BE SLOW TO DIMINISH WHILE WINDS GO BELOW SCA DURING
THE EVENING. EXTENDED THE SCA FOR THE GULF WATERS UNTIL 06Z
SUNDAY. NUMEROUS SHOWERS/T-STORMS WILL MOVE INTO THE GULF
WATERS IN ADVANCE OF THE COLD FRONT MOVING INTO SOUTH TEXAS
EARLY SUNDAY MORNING. WINDS WILL SHIFT TO THE NORTHEAST AND
INCREASE DURING THE AFTERNOON.
&&
.AVIATION...STRATUS A BIT MORE WIDESPREAD ACROSS SOUTH TEXAS
THIS MORNING. MVFR CONDS WILL EXIST THRU ABOUT 15Z ACROSS
THE AREA. VFR CONDS ARE EXPECTED THRU THE AFTERNOON INTO THE
EARLY EVENING HOURS. SCATTERED TO NUMEROUS THUNDERSTORMS ARE
EXPECTED TO DEVELOP IN ADVANCE OF A COLD FRONT MOVING SOUTH
THRU CENTRAL TEXAS THIS EVENING. STORMS PRODUCING VERY HEAVY
RAIN WILL LEAD TO IFR/LIFR CEILINGS/VSBYS FROM BEEVILLE TO
COTULLA BETWEEN 03Z-06Z SUNDAY AND SPREAD SLOWLY SOUTH INTO
THE SOUTHERN COASTAL BEND BY 12Z-15Z SUNDAY. STORMS WILL BE
SLOW TO MOVE OUT BUT CONDS SHOULD IMPROVE BY LATE AFTERNOON
TO VFR.
&&
.LONG-TERM (SUNDAY NIGHT THROUGH FRIDAY)...RESIDUAL RAIN IS EXPECTED
BEHIND THE COLD FRONT SUNDAY NIGHT THROUGH MON MORNING WITH POPS AND
CLOUDS DECREASING FROM N TO S.  DRIER AIRMASS/COLD AIR ADVECTION
WILL FILTER ACROSS THE REGION THROUGH MONDAY. A STRONG OFFSHORE FLOW
WILL CONTINUE INTO MONDAY BEFORE RELAXING AS HIGH PRESSURE SETTLES
ACROSS THE REGION. BY MONDAY NIGHT/TUESDAY MORNING MIN TEMPS ARE
EXPECTED TO BE IN THE UPPER 50S ACROSS THE NRN CWA TO 60S SRN CWA
DUE TO LOWER DEWPOINTS...LIGHT WINDS AND GOOD RADIATIONAL COOLING
UNDER CLR SKIES. SFC HIGH THEN SHIFTS E THROUGH TUE WITH AN ONSHORE
FLOW RESUMING AND USHERING IN HIGHER DEWPOINTS AND WARMER TEMPS. MID
AND UPPER LEVELS ARE PROGD TO REMAIN DRY THROUGH THE REMAINDER OF
THE WEEK. THE GFS HAS BACKED OFF ON BRINGING A COLD FRONT THROUGH S
TX ON THU WITH MORE OF A BACKDOOR FRONT BRIEFLY BACKING WINDS TO THE
ENE. HOWEVER THE UPPER LEVEL PATTERN STILL LOOKS CONDUCIVE FOR
BRINGING A COLD FRONT THRU THE AREA. THE GFS LATEST SOLN ALSO PROGS
A MUCH DRIER AIRMASS WITH THIS SYSTEM. DUE TO UNCERTAINTY THIS FAR
OUT...HAVE COMPROMISED WITH THE WIND DIRECTION AND AM INDICATING A
WEAKER NE FLOW VS THE STRONG N FLOW IN PREVIOUS FCST. ALSO WILL
CONTINUE WITH A SLIGHT CHC FOR NOW UNTIL CONFIDENCE INCREASES WITH
LATER RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    94  78  82  66  86  /  10  50  70  20  20
VICTORIA          93  74  81  61  85  /  30  60  70  10  10
LAREDO           100  78  85  66  89  /  10  60  60  20  20
ALICE             97  76  84  64  87  /  20  50  70  20  20
ROCKPORT          92  80  83  69  86  /  20  40  70  20  20
COTULLA           98  73  84  63  88  /  10  80  60  10  10
KINGSVILLE        96  77  85  67  87  /  20  50  70  20  20
NAVY CORPUS       91  80  84  72  85  /  10  40  70  20  20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM SUNDAY FOR THE FOLLOWING ZONES:
     COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM...
     COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT
     20 NM...WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM...AND
     WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM.
     SMALL CRAFT ADVISORY UNTIL 5 PM SATURDAY FOR THE FOLLOWING
     ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
     AND BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR.
&&
$$
TT/89...SHORT-TERM
TE/81...LONG-TERM
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1216 AM CDT SAT SEP 23 2006
.OVERNIGHT AVIATION...
ONLY CHANGES TO PREV 00Z TAF FCST WILL BE TO SLOW DOWN THE FRONT
AND THUNDERSTORM CHANCES TO AFTER 12Z AT D/FW SITES...THEN BTWN 20-
01Z SAT AT KACT...AS CD FNT RMNS WELL UP INTO TX/OK PANHANDLES.
THE CD FNT WON'T CATCH UP TO DRYLINE OVER NW SECTIONS UNTIL BTWM
09Z-12Z SAT...ABOUT THE TIME BETTER LIFT FROM HEIGHT FALLS ARRIVES.
CD FNT MAY NOT MAKE IT THROUGH KACT UNTIL AFTER 00Z SUN.
OTRW...WILL BRING IN VFR CIGS INTO KACT AS OF THIS ISSUANCE...WITH
FOG SATL IR IMAGERY/OBS SHOWING FAST DEVELOPMENT ON 35-45KT LLJ.
I'LL MAINTAIN AN ARRIVAL AT D/FW SITES BY 09Z.
CIGS SHOULD RISE TO VFR LVLS OR SCT OUT OVR ALL TAF SITES BY 03Z
SUNDAY...AS SFC HI BUILDS INTO ERN NM/W TX AND UPPER FLOW BECOMES
MORE WLY ORIENTED.
&&
.PREV DISCUSSION... /ISSUED 906 PM CDT FRI SEP 22 2006/
UPDATE...
SEVERE CONVECTION CONTINUES TO DEVELOP IN MOIST/UNSTABLE AND
STRONGLY SHEARED AIRMASS NORTH OF THE RED RIVER THIS EVENING...
LIKELY IN RESPONSE TO INTENSIFYING LOW-LEVEL JET INCREASING MASS
CONVERGENCE ALONG RETREATING DRYLINE.  MODELS HAVE BEEN CONSISTENT
ON BACKBUILDING THE AXIS OF SCATTERED THUNDERSTORMS ACROSS THE NORTH
CENTRAL AND NORTHWEST PORTIONS OF THE FORECAST AREA THROUGH THE
NIGHT...BUT VERY LITTLE CONVECTION HAS DEVELOPED THUS FAR SOUTH OF
THE RED RIVER.  WILL MAINTAIN STATUS QUO WITH THE CURRENT FIRST
PERIOD POPS...AS DRYLINE AND ZONE OF STRONGEST CONVERGENCE WILL
CONTINUE TO RETREAT NORTHWESTWARD IN RESPONSE TO MID-LEVEL SHORTWAVE
TROUGH CURRENTLY APPROACHING SOUTHEAST COLORADO.
OTHER ELEMENTS OF THE FORECAST APPEAR TO BE ON TRACK AS WELL THIS
EVENING...AND ONLY MINOR ADJUSTMENTS WILL BE MADE TO DEWPOINT...
WIND...AND CLOUD COVER GRIDS TO ACCOUNT FOR CURRENT TRENDS.  UPDATED
PRODUCTS WILL BE ISSUED SHORTLY.
65/DD
AVIATION...
AGREE WITH CWSU THAT CONVERGENCE HAS BEEN MINIMIZED ALONG DRYLINE
THIS AFTN...BUT SHOULD INCREASE AS LOW LVL FLOW BECOMES MORE
SSE/SELY THROUGH 04-05Z. HOWEVER...ELEVATED MIXED LAYER (CAP)
SEEMS MORE STOUT S OF 580DM LINE WHICH PER RUC...XTNDS FROM
KGYI...TO KDTO/KLUD...TO NEAR KRPH. THUS ONLY ISOLD SHRA/TSRA
MNLY NW-NE OF D/FW TAF SITES THROUGH 08-10Z...WHEN COLD FRONT
SHOULD START TO OVERTAKE DRYLINE TO THE NW AND INITIATE ELEVATED
STORMS AS S/W OVER TX/OK PANHANDLES APPROACHES AND HEIGHTS FALL.
WILL KEEP TIMING OF MVFR CIGS ARND SAME TIMES 06-07Z AT KACT...TO
09-10Z AT D/FW SITES...WITH VFR CONDS TIL THEN.
LOOK FOR BEST PROBS TO OCCUR D/FW AREA 10Z-17Z TIME FRAME AS CD
FNT APPROACHES AND FORCING GETS BETTER WITH LINEAR...ELEVATED
ACTIVITY EARLY...BECMG MORE SFC-BASED BY 18Z/AFTR NEAR D/FW...THEN
ARRIVING INTO KACT VCNTY BY 21Z/AFTR. CD FRONT ARRIVES ACRS D/FW
FROM 19-21Z WITH WND SHIFT TO WNW/NW...THEN INTO KACT LIKELY AFTR 00Z
SUN.
PREV DISCUSSION... /ISSUED 305 PM CDT FRI SEP 22 2006/
DISCUSSION...
NEXT LOBE OF ENERGY SWINGING AROUND UPPER LOW IN THE CENTRAL
PLAINS WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO NORTHERN
PORTIONS OF THE CWA TONIGHT...AND SPREAD SOUTHEAST ACROSS THE
REGION EARLY SATURDAY. MODELS HAVE BEEN CONSISTENT AND IN GENERAL
AGREEMENT IN DEVELOPING PRECIP OVER NORTHERN PORTIONS TONIGHT...WITH
A COLD FRONT MOVING THROUGH THE AREA LATE SATURDAY. RAINS WILL END
IN SOUTHERN PORTIONS BY EARLY SUNDAY WITH TEMPERATURES BECOMING
MORE MODERATE AS WE HEAD INTO THE FIRST FULL WEEK OF FALL.
WEAK RIDGING TO BEGIN SUNDAY BUT THE PERSISTENT BROAD TROUGH OVER
THE EASTERN HALF OF THE U.S. WILL SEND ANOTHER SHOT OF COLD AIR
AND ENERGY SOUTHWARD MIDWEEK...WITH A FRONT AND RAIN MOVING
THROUGH LATE WEDNESDAY AND THURSDAY. DESPITE THESE RAIN
CHANCES...IT SHOULD BE A PLEASANT WEEK AS TEMPERATURES REMAIN
MILD...QUITE A CHANGE FROM RECENT WEEKS.
FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
$$
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/42/05
</PRE></TT></td>   tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1215 PM EDT SAT SEP 23 2006
.UPDATE...
THE THREAT OF SEVERE WEATHER CONTINUES FOR LATE THIS AFTERNOON INTO
THIS EVENING. 15Z SURFACE ANALYSIS SHOWS THE STRONGEST SURFACE
PRESSURE FALLS EXTENDING FROM WESTERN TENNESSEE TO SOUTHWEST
ILLINOIS ALONG THE WARM FRONT. THE TEMPERATURE AT PADUCAH KENTUCKY
CLIMBED FROM 68 TO 75 IN TWO HOURS AS THE FRONT STARTED TO COME
THROUGH. THE TREND OVER THE NEXT SEVERAL HOURS SHOULD BE FOR
PRESSURE TO CONTINUE FALLING OVER SOUTHWEST ILLINOIS AND AHEAD OF
THIS WARM FRONTAL BOUNDARY AS THIS FEATURE LIFTS NORTH. PRESSURE
FALLS AT THE SURFACE WILL BE IN RESPONSE TO A STRONG SHORTWAVE
MOVING THROUGH THE UPPER LEVEL TROUGH CURRENTLY SEEN ON WATER VAPOR
OVER NEBRASKA AND KANSAS. THE UPPER LEVEL CLOSED CIRCULATION OVER
EASTERN SOUTH DAKOTA IS STARTING TO OPEN AND THE WHOLE UPPER LEVEL
TROUGH AXIS IS EXPECTED TO PIVOT AND MOVE EASTWARD. AT THE
SURFACE...THE LOW OVER SOUTHERN ILLINOIS WILL TRACK NORTHEAST AHEAD
OF THE SHORTWAVE WITH BOTH THE 12Z NAM AND RUC INDICATING A PATH
FROM SOUTH BEND TO SOUTHERN LAKE HURON EARLY THIS EVENING. THIS
TRACK WILL LIKELY BRING THE SURFACE WARM FRONT INTO EXTREME
SOUTHEAST MICHIGAN WITH THUNDERSTORMS ACTIVITY ALSO POSSIBLE ALONG
THE COLD FRONT WITH STRONG DYNAMICAL FORCING. A MODIFIED NAM
SOUNDING AT DETROIT DURING THIS TIME WITH A SURFACE PARCEL OF 75/67
YIELDS 1200 J/KG OF CAPE WITH LITTLE IF ANY CONVECTIVE INHIBITION.
TEMPERATURES NEAR THE OHIO BORDER ARE ALREADY IN THE LOW 70S WITH
DEWPOINTS IN THE MID 60S. STRATUS HAS STARTED TO THIN BUT WILL
EXPECT CLOUDS TO THICKEN AGAIN AS LOW LEVEL THETA-E ADVECTION
INCREASES ACROSS SOUTHEAST MICHIGAN THIS AFTERNOON. ANY SHOWERS OR
THUNDERSTORMS THAT DEVELOP ALONG THIS ADVECTION WILL LIKELY REMAIN
ELEVATED WITH THE MOST FAVORABLE TIME FOR SEVERE STORMS STILL LATE
THIS AFTERNOON INTO THIS EVENING. MODELS STILL GENERALLY IN
AGREEMENT SHOWING STRONG OMEGA BETWEEN 21-00Z AS WELL AS A COUPLED
UPPER LEVEL JET. IF STORMS ARE ABLE TO BECOME SURFACE BASED BY EARLY
EVENING...SEVERE THREAT WILL BE FOCUSED SOUTH OF I-69 WITH STRONG
WIND GUSTS AND TORNADOS CONTINUING TO BE THE MAIN THREAT. FORECAST
GENERALLY ON TRACK AND HAVE RAISED POPS FOR EARLY AFTERNOON ACROSS
OUR SOUTHERN COUNTIES.
.PREV DISCUSSION...ISSUED 706 AM EDT SAT SEP 23 2006
AVIATION...
LOW LEVEL MOISTURE ADVECTION OVERNIGHT HAS RESULTED IN WIDESPREAD
IFR CEILINGS AND MVFR VISIBILITY ACROSS SOUTHERN MICHIGAN THIS
MORNING. WITH THE ONSET OF DAYTIME HEATING...CONDITIONS WILL
GRADUALLY IMPROVE TO VFR BY 18Z. A STRONG STORM SYSTEM OVER THE
PLAINS AND MISSISSIPPI VALLEY REGION WILL MOVE EAST INTO THE GREAT
LAKES TONIGHT. AN ASSOCIATED AREA OF LOW PRESSURE WILL MOVE FROM THE
MISSISSIPPI VALLEY INTO SOUTHERN MICHIGAN THIS EVENING. THIS ALONG
WITH THE APPROACH OF THE UPPER LEVEL LOW WILL TRIGGER WIDESPREAD
SHOWERS AND THUNDERSTORMS AFTER 21Z. CONVECTION WILL SLOWLY LIFT
NORTH ACROSS SOUTHEAST MICHIGAN BETWEEN 21Z AND 05Z. THE SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO LOWER CEILINGS BACK TO MVFR DURING THE
EVENING.
&&
SHORT TERM...TODAY AND TONIGHT ISSUED 352 AM EDT SAT SEP 23 2006
THE CURRENT WATER VAPOR IMAGE SHOWS A POSITIVELY TILTED LONG WAVE
TROUGH EXTENDING FROM THE UPPER GREAT LAKES TO THE SOUTHERN ROCKIES.
THE 07Z SURFACE ANALYSIS SHOWS A LOW OVER MINNESOTA WITH AN OCCLUDED
FRONT EXTENDING INTO THE SOUTHERN PLAINS. A WARM FRONT IS ALSO
LOCATED ACROSS CENTRAL ILLINOIS AND INDIANA AND A SECONDARY SURFACE
LOW IS LOCATED NEAR THE TEXAS/OKLAHOMA BORDER. SHORT WAVE ENERGY
NEAR THE BASE OF THE LONG WAVE TROUGH OVER THE SOUTHERN ROCKIES IS
FORECAST TO LIFT INTO THE MIDWEST TODAY AND PHASE WITH THE CLOSED
LOW CURRENTLY OVER THE NORTHERN PLAINS. THE UPPER TROUGH AXIS IS
THEN FORECAST TO SWING THROUGH THE GREAT LAKES REGION LATE TONIGHT.
THE 00Z MODEL SUITE FORECAST STRONG UPPER LEVEL JET COUPLING
DEVELOPING ACROSS THE SOUTHERN GREAT LAKES REGION LATE IN THE
AFTERNOON AND PERSISTING THROUGH THE EVENING. THIS ALONG WITH THE
MID LEVEL HEIGHT FALLS WILL LEAD TO WIDESPREAD SHOWERS AND
THUNDERSTORMS THIS EVENING.
THE 00Z MODEL SUITE STILL HAVE SOME DIFFERENCES IN TIMING AND TRACK
OF THE ASSOCIATED SURFACE LOW NOW OVER TEXAS INTO THE SOUTHERN GREAT
LAKES REGION TONIGHT. THE UKMET...WRFHEMI AND GLOBAL TAKE THE LOW
JUST SOUTHEAST OF DETROIT OVERNIGHT AND FOCUS THE HIGHER INSTABILITY
SOUTH OF THE STATE. THE NAM...AND TO SOME EXTEND THE GFS...TAKES THE
LOW ACROSS SOUTHERN LOWER MI THIS EVENING. ALL OF THE 00Z MODEL
SUITE HAD SOME INITIALIZATION PROBLEMS WITH THE HEIGHT FIELDS
UPSTREAM. GIVEN THE STRONG UPPER JET COUPLING OVER THE SOUTHERN
LAKES THIS EVENING...PREFER THE NAM SURFACE LOW TRACK. THE NAM ALSO
HAD A GOOD HANDLE ON THE STRENGTH AND POSITION OF THE LOW AS OF 06Z.
THE FORECAST AREA IS IN A SLIGHT RISK FOR SEVERE WEATHER
TODAY...WHICH WILL BE MORE LIKELY THIS EVENING AS STRONGER MID LEVEL
FORCING MOVES INTO THE REGION. GIVEN THE STRONGLY SHEARED
ENVIRONMENT...0-6KM SHEAR OF 40-50 KNOTS...THE SEVERE POTENTIAL
WILL RELY ON HOW MUCH INSTABILITY CAN BE REALIZED. THE EXTENSIVE
STRATUS DECK ACROSS THE AREA THIS MORNING WILL LIFT INTO A BROKEN
STRATO CU FIELD BY AFTERNOON. SO SUNSHINE WILL BE VERY LIMITED
TODAY. IF AFTERNOON TEMPS REACH THE MID 70S...MODIFIED NAM
SOUNDINGS WITH LOWER 60 DEWPOINTS SHOW 0-1KM MIXED LAYER CAPE
APPROACHING 1000 J/KG. GIVEN THE 50-60KT MID LEVEL WINDS AND
EXPECTED BACKED SURFACE FLOW AHEAD OF THE APPROACHING LOW...STORM
TYPE IS EXPECTED TO BE SUPERCELLULAR WITH DAMAGING WINDS AND
TORNADOES THE PRIMARY SEVERE WEATHER HAZARDS.
SOME DRYER MID LEVEL AIR HAS MOVED ACROSS THE FORECAST AREA THIS
MORNING IN THE WAKE OF LAST EVENINGS CONVECTION. THUS UNTIL THE
STRONGER MID LEVEL FORCING ARRIVES AFTER 21Z...POPS WILL BE FAIRLY
LOW THIS MORNING AND AFTERNOON. WEAK SHORT WAVES EMBEDDED WITHIN THE
SOUTHWEST FLOW ALOFT AND INCREASING UPPER JET FORCING WILL SUPPORT
ISOLATED TO SCATTERED POPS THROUGH 21Z. AN INCREASE IN 850MB THETA E
LATE THIS MORNING AND AFTERNOON SHOULD ALSO SUPPORT SCATTERED
CONVECTION ALONG AND SOUTH OF I-94 THROUGH THE AFTERNOON.
LONG TERM...SUNDAY THROUGH FRIDAY
SURFACE LOW WILL LIFT THROUGH THE LOWER GREAT LAKES AND UP THE ST
LAWRENCE VALLEY ON SUNDAY...LEAVING SOME DEGREE OF TROUGHING BACK
ACROSS THE CENTRAL GREAT LAKES. 00Z NAM REVERSED ITS EARLIER TREND
AND IS NOT A BIT FASTER TAKING THE LOW OUT OF THE REGION...WITH THE
GFS ALREADY FASTER AND CONTINUING TO ACCELERATE. WITH THE FASTER
CONSENSUS AND OVERALL TREND...DO NOT NECESSARILY BUY THE SHARP
SURFACE TROUGH THE NAM LINGERS ACROSS SOUTHEAST MICHIGAN. HOWEVER
SOME DEGREE OF LOW-LEVEL CYCLONIC FLOW AND CONVERGENCE CAN BE
EXPECTED WITH THE COLD ADVECTION BEHIND THE SYSTEM. WILL CARRY
LIKELY POPS ACROSS LAKE HURON DURING THE MORNING...OTHERWISE
SCATTERED SHRA DURING THE AFTERNOON WITH SOME DIURNAL ENHANCEMENT TO
LAPSE RATES/INSTABILITY.
NAM ALSO CONTINUES TO TREND TOWARD THE GFS SOLUTION WITH THE NEXT
SHORTWAVE DIGGING OUT OF NORTHERN CANADA MONDAY/MONDAY NIGHT. WITH
THE FASTER APPROACH AND STRONGER/MORE DEFINED SHORTWAVE...WE WILL
NOT SEE AS MUCH OF A PROLONGED PERIOD OF COLD NORTHERLY FLOW. MIXED
LAYER FLOW BACKS AROUND TO THE WEST/SOUTHWEST ON MONDAY...WITH THE
LOW-LEVEL THERMAL TROUGH WEAKENING/SHIFTING DOWNSTREAM...LIMITING
LAKE EFFECT POTENTIAL. HOWEVER THIS WILL BE OFFSET BY INCREASING
SYNOPTIC LIFT AHEAD OF THE SHORTWAVE...WITH ENHANCED LOW-LEVEL
CONVERGENCE ALONG THE SURFACE TROUGH. AM CONCERNED THAT THE GFS IS
TOO STRONG WITH THE SHORTWAVE...AND CONSEQUENTLY DIVES IT TOO FAR
SOUTHWEST ACROSS THE CENTRAL GREAT LAKES. CONSENSUS WOULD OTHERWISE
SUPPORT PRECIP TO THE EAST ACROSS LAKE HURON/ONTARIO. IF THE
STRONGER GFS SOLUTION PANS OUT...WOULD NEED TO CARRY A CHANCE SHRA
LATE MONDAY/MONDAY NIGHT ACROSS SOUTHEAST MICHIGAN. AS IT STANDS
MOISTURE MAY BE RATHER LIMITED...BUT WILL INCREASE SKY COVER MONDAY
NIGHT. THEREFORE WILL ALSO RAISE MINS A COUPLE DEGREES WITH
ADDITIONAL CLOUDS/WEAK WARM ADVECTION.
ADDITIONAL DIFFERENCES DEVELOP WITH THE NEXT LONGWAVE SYSTEM THAT
DIGS ACROSS THE PLAINS TUESDAY/WEDNESDAY AND AMPLIFIES ACROSS THE
GREAT LAKES BY THURSDAY. 00Z GFS HAS TRENDED SLOWER WITH THIS SYSTEM
CRESTING THE WESTERN RIDGE...AND AMPLIFIES IT FARTHER WEST...LEADING
TO A MUCH SLOWER TIMING INTO THE GREAT LAKES. OTHER 12Z MODELS WERE
PRETTY SIMILAR AND CONSISTENT WITH THE EVOLUTION OF THE SYSTEM.
TEMPTED TO LEAVE THE FORECAST AS IS FOR NOW GIVEN THIS BREAK FROM
CONTINUITY...TO SEE WHETHER THE NEXT RUN SETTLES DOWN ON A SIMILAR
SOLUTION. A QUICK LOOK AT THE 00Z ECMWF SHOWS A SIMILAR TREND...MORE
AMPLIFIED AND ABOUT 12 HOURS SLOWER THAN THE 12Z RUN. IT LOOKS LIKE
THERE IS SOMETHING IN THE 00Z INITIALIZATION THAT BOTH THE GFS/ECMWF
LATCHED ONTO TO AFFECT THEIR SOLUTIONS. WE WILL SEE IF THIS FEATURE
HOLDS INTO THE 12Z RUNS...WHICH WOULD LEAD TO A SLOWER ONSET BUT
MORE PROLONGED PERIOD OF POPS THROUGH THE END OF THE WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CONSIDINE
LONG TERM....BRAVENDER
AVIATION...CONSIDINE
UPDATE...KEK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1143 AM EDT SAT SEP 23 2006
.UPDATE...
THE MAIN CONCERN DEALS WITH THE POTENTIAL FOR SEVERE WEATHER
THIS AFTERNOON AND EVENING.  THE CONVECTION ALONG THE OHIO VALLEY
AND MIDDLE MISSISSIPPI VALLEY HAS LIMITED THE MOISTURE TRANSPORT
INTO NORTHERN IN AND INTO SRN LOWER MI.  12Z RAOB FROM ILX SHOWS
THIS WITH LIMITED MOISTURE IN THE 925MB TO 850 MB LAYER.  CLOUDS
COVERED MUCH OF THE AREA...LIMITING THE RATE OF DESTABILIZATION. AT
THIS TIME...MSAS WAS SHOWING LIFTED INDEX VALUES DOWN TO -3 DEG C
INTO SOUTHERN LOWER MI...THE RUC SOUNDING NEAR AZO HAS AROUND 100
J/KG CIN SO ANY CONVECTION FOR A FEW HOURS SHOULD REMAIN ELEVATED.
THE PROFILER IN NORTHERN INDIANA SHOWS BACKING FLOW BELOW 2KM
SUGGESTING THE NEXT WAS WAVE APPROACHES.  PLENTY OF SHEAR EXISTS IN
THE 0 TO 6 KM LAYER FROM THIS PROFILER WITH VALUES UP AROUND 60 KTS
FOR ORGANIZED CONVECTION.  THE WAVE OF LOW PRESSURE WAS DEVELOPING
DOWN NEAR STL.  THE LATEST DATA SUGGESTS THIS FEATURE WILL TRACK
NORTHEAST THIS AFTERNOON AND THROUGH SOUTHERN LOWER MI THIS
EVENING.  THE LOW LEVEL JET IS SHOWN TO BE FOCUSED FURTHER
SOUTH...GENERALLY SOUTH OF INTERSTATE 94 THIS AFTERNOON AND
EVENING.  THIS WOULD IMPLY A HIGH SEVERE WEATHER THREAT SOUTH OF
AZO.  HOWEVER...THE SURFACE BOUNDARY WILL BE LOCATED FROM NEAR AZO
TO MOP LATER THIS AFTERNOON.  SUFFICIENT INSTABILITY WILL BE PRESENT
FOR CONVECTION...PERHAPS SURFACE BASED...FAVORABLE 0 TO 6 KM SHEAR
IS PRESENT FOR ORGANIZED STORMS.  THUS THE SEVERE WEATHER THREAT
CONTINUES...AND APPEARS TO BE MAXIMIZED LATER THIS AFTERNOON WHEN
THE SURFACE WAVE ARRIVES.  HEAVY RAIN COULD BE AN ISSUE WITH THE
SURFACE BOUNDARY AROUND FOR 3 TO 6 HRS THIS AFTERNOON AND EVENING
COUPLED WITH A VERY MOIST AIRMASS IN PLACE AS THE WAVE ARRIVES.
WILL UPDATE THE HAZARDOUS WEATHER OUTLOOK AND INCREASE THE HEAVY
RAIN THREAT..
&&
.GRR WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
MJS
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1140 AM EDT SAT SEP 23 2006
.UPDATE...
MAIN FCST ISSUE IS REDEVELOPMENT OF MORE WIDESPREAD RAIN THIS AFTN
AND EVENING.
WATER VAPOR IMAGERY/RUC ANALYSIS AND 12Z RAOBS SHOW THAT THE
MIDLEVEL LOW OVER THE NRN PLAINS HAS WEAKENED OVER THE LAST 12-24HRS
AND HAS OPENED UP. OVERALL TROF ORIENTATION IS ALSO MORE POSITIVELY
TILTED. SHORTWAVE THAT WAS OVER CO/UT YESTERDAY IS NOW RACING NE
THRU THE CNTRL PLAINS. AT THE SFC...LOW PRES CENTER OVER SRN MN
CONTINUES TO FILL...LEAVING A BROAD LOW PRES TROF FROM SRN MN TO
UPPER MI AND SE LAKE SUPERIOR. STIFF NE WINDS DOMINATE LAKE SUPERIOR
JUST N OF SFC TROF (WINDS HAVE BEEN GUSTING TO GALE FORCE TOWARD THE
APOSTLES AND DULUTH). FARTHER S...THERE IS BEGINNING TO BE SOME SFC
RESPONSE DUE TO SHORTWAVE HEADING ACROSS CNTRL PLAINS WITH HINTS OF
NEW LOW PRES DEVELOPING IN MO/WRN IL. DEVELOPING WEAK 3HR PRES FALLS
IN THAT AREA ARE MORE TELLING. PCPN CONTINUES TO BE CONFINED MOSTLY
ALONG THE 850MB TROF WHICH IS ESSENTIALLY COINCIDENT WITH SFC TROF.
FOG WHICH BRIEFLY BECAME DENSE ACROSS THE S EARLIER THIS MORNING HAS
THINNED.
AS SHORTWAVE ENERGY CONTINUES TO RACE NE...STRENGTHENING MID/UPPER
LEVEL QVECTOR CONVERGENCE WILL OVERSPREAD LOW-LEVEL FRONTOGENESIS.
THIS IS DEPICTED BY 06Z GFS AND 12Z RUC/NAM. COUPLED FORCING SHOULD
LEAD TO AN EXPANSION OF PCPN IN THE AFTN THRU THIS EVENING...
FOCUSED ALONG 850MB TROF THAT WILL CONTINUE TO MOVE S. SOME MINOR
TIMING ADJUSTMENTS WILL BE MADE TO GOING FCST...BUT IN GENERAL...
GOING FCST HAS SITUATION COVERED QUITE WELL. WILL ADD A MENTION OF A
SLIGHT CHC OF THUNDER ACROSS MUCH OF THE CNTRL/E THIS AFTN/EARLY
EVENING AS RUC MLCAPE IS A FEW HUNDRED J/KG. MODIFIED FCST SOUNDINGS
FOR SFC T/TD OF MID TO UPPER 60S/UPPER 50S YIELD SIMILAR SBCAPE
NUMBERS.
&&
.PREV DISCUSSION... ISSUED AT 255 AM EDT
MAIN FORECAST CONCERNS ARE PRECIP TRENDS TODAY/TONIGHT AND THEN
AGAIN SUN NIGHT/EARLY MONDAY.
CURRENT WV IMAGERY SHOWING CLOSED LOW SPINNING OVER EASTERN SD. A
WELL DEFINED S/WV ROTATING AROUND THE EASTERN PERIPHERY OF THE UPPER
LOW IS CURRENTLY LIFTING NORTHEAST ACROSS NRN WI INTO UPPER MI.
FORCING ALONG THE LEADING EDGE OF THE S/WV HAS BEEN ENOUGH TO TOUCH
OFF A FEW BANDS OF SHRAS AND EVEN A FEW TSRAS WITH ONE CURRENTLY
PASSING OVER THE OFFICE. EXPECT THE S/WV AND SHRAS TO LIFT
NORTHEASTWARD THROUGH THE REMAINDER OF THE OVERNIGHT HOURS.
AFTER S/WV PASSES AREA WILL BE LEFT IN A MOIST LOW LEVEL ENVIRONMENT
WITH LITTLE IN THE WAY OF UPPER FORCING THROUGH MIDDAY.  THE
EXCEPTION WILL BE ACROSS LAKE SUPERIOR WHERE 85H FRONT SHOULD HELP
FOCUS BETTER CHANCES OF RAIN DURING THE MORNING IN THAT AREA.
ELSEWHERE...EXPECT AREAS OF DRIZZLE AND LOCALLY DENSE FOG THROUGH
THE MORNING HOURS.
BY THIS AFTERNOON...S/WV DROPPING SEWD OUT OF CENTRAL CANADA WILL
KICK UPPER LOW OUT TO THE NORTHEAST.  AS THIS OCCURS...SFC LOW
WILL REDEVELOP OVER SOUTHERN LAKE MICHIGAN/LOWER MICHIGAN. FAIRLY
STRONG MID/UPPER LEVEL QVECTOR CONVERGENCE WILL DEVELOP ACROSS MUCH
OF UPPER MI DURING THE LATE AFTERNOON/EARLY EVENING AND WILL
COINCIDE WITH STRONGEST LOW LEVEL FRONTOGENESIS IN NW QUADRANT OF
SFC LOW. THUS...EXPECT AN EXPANDING SHIELD OF RAIN TO OVERSPREAD
MUCH OF THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS. ONLY
EXCEPTION WILL BE UP IN THE KEWEENAW AND OVER PARTS OF LAKE SUPERIOR
WHERE MAIN FORCING WILL REMAIN OFF TO THE SOUTH.
EXPECT RAIN TO TAPER OFF FROM WEST TO EAST OVERNIGHT AS SFC LOW
MOVES OFF TO THE EAST. GFS IS THE QUICKEST OF ALL THE MODELS WITH
THE TIMING OF THE SFC LOW AND IS THE PREFERRED MODEL AS IT HAS BEEN
THE MOST CONSISTENT. ALTHOUGH...OTHER MODELS ARE NOT SHOWING
SIGNIFICANT DISAGREEMENTS.
SOME SUN SHOULD RETURN ON SUNDAY WITH NEAR SEASONAL TEMPS AS SYSTEM
CONTINUES TO DEPART TO THE EAST.  NEXT QUICK MOVING S/WV WILL DROP
SOUTHEASTWARD OUT OF CANADA SUN NIGHT/EARLY MONDAY.  TREND IN BOTH
GFS AND NAM IS TOWARDS A MORE AMPLIFIED TROF. WHILE MOISTURE WILL BE
QUITE LIMITED...BASED ON CURRENT TRENDS WILL ADD A SLIGHT CHC POP
FOR MUCH OF THE AREA FOR LATE SUN NIGHT/MONDAY AM AS THE S/WV AND
SFC TROF SWING THROUGH THE AREA.
WILL NOT MAKE ANY SIGNIFICANT CHANGES TO THE TUE THROUGH END OF THE
WEEK FCST AT THIS TIME.  HOWEVER...GFS IS NOW ALMOST 24 HOURS SLOWER
WITH MIDWEEK UPPER TROF AND SFC FRONT MOVING THROUGH THE AREA
SHOWING THE FEATURE MOVING THROUGH WED EVENING VS. TUE NIGHT. AS
THIS IS THE FIRST RUN SHOWING THE TREND WILL AWAIT ONE MORE MODEL
CYCLE BEFORE MAKING ADJUSTMENTS. OBVIOUSLY IF SLOWER SOLN PANS OUT
TEMPS ON WED WILL NEED TO BE RAISED.
BEHIND THE FRONT EXPECT A PRETTY DECENT COOL SHOT WITH 85H TEMPS
FALLING INTO THE 0 TO -4 RANGE FOR THU/FRI. GFS MAY BE SHOWING A BIT
OF ITS COOL BIAS BUT LAKE WEEK TEMPS MAY NEED TO BE TRENDED DOWN A
FEW DEGREES FROM CURRENT FCST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
ROLFSON (UPDATE)
MZ (PREV DISCUSSION)
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GAYLORD MI
1030 AM EDT SAT SEP 23 2006
.UPDATE...LATEST SATELLITE/RUC ANALYSIS SHOWING STACKED NORTHERN
PLAINS STORM SYSTEM BEGIN TO SHOW SIGNS OF OPENING UP AS SHORTWAVE
ENERGY ROUNDS BASE OF TROUGH OVER THE SOUTHERN PLAINS. AT THE
SURFACE...WEAK LOW PRESSURE BEGINNING TO DEVELOP ACROSS CENTRAL
MISSOURI IN RESPONSE TO APPROACHING SHORTWAVE. LARGE AREA OF SHOWERS
AND THUNDERSTORMS REMAINS ANCHORED ACROSS THE LOWER OHIO RIVER
VALLEY WHERE REMNANT OUTFLOWS FROM OVERNIGHT CONVECTION HAS FOCUSED
BEST MASS CONVERGENCE. ADDITIONAL LIGHTER SHOWERS DEVELOPING OVER
NORTHERN ILLINOIS IN DEVELOPING DEFORMATION AXIS NORTH OF MISSOURI
LOW. CLOSER TO HOME...LOW STRATUS DECK HAVING A HARD TIME MIXING OUT
THIS MORNING BENEATH REMAINING NOCTURNAL INVERSION AND LATE
SEPTEMBER SUN. FORECAST CONCERNS FOR THE REMAINDER OF THE DAY CENTER
ON CLOUD COVERAGE AND PRECIPITATION CHANCES.
EXPECT ENOUGH MIXING LATE THIS MORNING/EARLY AFTERNOON TO HELP SCOUR
OUT SOME OF THE LOW CLOUDS GIVEN SHALLOW NATURE OF LOW LEVEL
MOISTURE...PER 12Z KAPX SOUNDING. LATEST REGION VISIBLE SATELLITE
IMAGERY ALREADY SHOWING SIGNS OF THIS WITH SOME CLEARING NOTED OVER
CENTRAL LAKE MICHIGAN AND EASTERN WISCONSIN WITH SMALLER CLEAR
PATCHES ROTATING ACROSS NORTHERN MICHIGAN. NOT EXPECTING A WHOLE LOT
OF SUN BY ANY MEANS WITH MID AND HIGH LEVEL MOISTURE RAPIDLY
APPROACHING FROM CENTRAL PLAINS DEVELOPING STORM SYSTEM. AS FOR
PRECIPITATION...LOCAL RADAR SHOWING DRY CONDITIONS AT THIS TIME
ACROSS THE AREA. WILL MAINTAIN CHANCE WORDING THROUGH EARLY
AFTERNOON AS DECENT MOISTURE (12Z LOCAL SOUNDING HAD PWAT OF 0.90
INCHES) MAY HELP KICK OFF LIGHT RAIN SHOWERS. HOWEVER...AM EXPECTING
MOST AREAS TO REMAIN DRY UNTIL BETTER SLUG OF MOISTURE APPROACHES
FROM THE SOUTH THIS AFTERNOON. THUNDERSTORM POTENTIAL APPEARS
MINIMAL GIVEN LACK OF SIGNIFICANT SOLAR ISOLATION AND WARM SECTOR
REMAINING SOUTH OF THE REGION. ISOLATED ELEVATED CONVECTION IS
POSSIBLE LATER THIS AFTERNOON OVER THE NORTHERN LOWER AS DYNAMICS
INCREASE AHEAD OF APPROACHING SHORTWAVE. MEAGER MID LEVEL LAPSE
RATES OF UNDER 6 C/KM WOULD ARGUE OTHERWISE BUT GIVEN OVERALL
DYNAMICS OF SYSTEM WILL CONTINUE TO MENTION. SPC DAY 1 SEVERE
OUTLOOK STILL HAS AREAS SOUTHEAST OF A LINE EXTENDING FROM
HARRISVILLE TO CADILLAC HIGHLIGHTED IN SLIGHT RISK FOR LATE THIS
AFTERNOON AND EVENING. OVERALL KINEMATICS OF SYSTEM RATHER
IMPRESSIVE WITH 0-6KM BULK SHEAR VALUES OF 60-70KTS AND 500MB
WINDSPEED APPROACHING 60-65KTS IN THIS AREA. THERMODYNAMICS LESS
THAN FAVORABLE WITH MODIFIED SOUNDINGS SHOWING ONLY 200-500 J/KG ML
CAPE USING A SURFACE PARCEL OF 71/57. WHILE ISOLATED SEVERE THREAT
IS POSSIBLE GIVEN ABOVE KINEMATICS...FEEL LACK OF INSTABILITY WILL
PREVENT SIGNIFICANT DEEP MOIST CONVECTION FROM TAPPING THESE WINDS.
BEST CHANCE FOR SEVERE WEATHER APPEARS TO BE NEAR SAGINAW BAY IF
WARM SECTOR CAN PUSH THAT FAR NORTH.
MSB
&&
.PREV DISCUSSION ISSUED AT 610 AM EDT SAT SEP 23 2006
SFC/RUC/SATELLITE/RADAR AND UPPER AIR ANALYSIS SHOWING STACKED LOW
PRESSURE IN SRN MN WITH DEEP SOUTHERLY FLOW OVER NRN MI AND SEVERAL
VORTICITY MAXIMA ROTATING AROUND THE SYSTEM/UPPER MIDWEST. AXIS OF
HIGHEST H8-H7 THETA-E STRETCHES UP INTO NRN MICHIGAN BUT GREATEST
MOISTURE LIES WELL SOUTH...INTO THE OHIO RIVER VALLEY. RADAR SHOWS
FAIRLY QUIET WEATHER OVER NRN MICHIGAN AS AXIS OF H8-H7
FRONTOGENETICAL FORCING HAS SHIFTED NORTH...AND DRY SLOT HAS MOVED
IN OVERHEAD. THIS HAS RESULTED IN COOLING OF THE LOW LEVELS
PROMPTING THE DEVELOPMENT OF WIDESPREAD STRATUS AND LIGHT FOG. WE DO
HAVE SOME SHOWERS AND ISOLATED STORMS THAT WERE MOVING NNE UP LAKE
MICHIGAN IN A REGION OF STEEP H8-H5 LAPSE RATES OF 6.5 TO 7.0 C/KM
ALONG A WEAKISH H8 LLJ OF 25 KTS AND H8 THETA-E GRADIENT. FURTHER
UPSTREAM IN KANSAS/OKLAHOMA...ADDITIONAL SHORTWAVE ENERGY HAS
PRODUCED LOW PRESSURE AND SHOWERY WEATHER.
FORECAST CONCERNS...PRECIP TRENDS THROUGH SUNDAY AND POTENTIAL FOR
SEVERE WEATHER THIS AFTERNOON AND EVENING. WINDS OVER THE LAKES
BECOME A CONCERN MAINLY BEGINNING SUNDAY AFTERNOON.
TODAY AND TONIGHT...ALTHOUGH DRY SLOT HAS MOVED IN OVERHEAD...THE
ATMOSPHERE IS STILL RATHER MOIST...AND WEAKISH H8 LLJ OF 20-25KTS
AND STEEP MID LEVEL LAPSE RATES WILL RESULT IN ISOLATED
THUNDERSTORMS WITH SCATTERED SHOWERS EARLY THIS MORNING ALONG WITH
AREAS OF FOG. STILL REMAINS A TOUGH CALL FOR WHAT ENSUES FOR THE
LATE MORNING THROUGH THE AFTERNOON...AS MODELS DIFFER ON SOME OF THE
FINER DETAILS. HOWEVER...THE GENERAL IDEA REMAINS THE SAME. UPPER
LOW IN MN OPENS UP AS A POSITIVELY TILTED WAVE AND EJECTS INTO INTO
THE FAR WESTERN GREAT LAKES BY LATE THIS AFTERNOON. THE SFC LOW FROM
OKLAHOMA DEEPENS FURTHER AND RIDES NE INTO CENTRAL LOWER BY 00Z.
NAM-WRF NOT AS FAST WITH THIS EVOLUTION AS THE GFS (6HRS
SLOWER)...AND SLIGHTLY FURTHER SOUTH THAN THE GFS...BUT DOES AGREE
WITH THIS SOLUTION. AM TAKING A MIDDLE OF THE ROAD FORECAST
HERE...AND AM EXPECTING A MOISTURE PUSH AND MASS CONVERGENCE TO
ARRIVE LATE IN THE AFTERNOON PER ONGOING FORECAST WITH THE ARRIVAL
OF THE SFC LOW. RAIN SHOWERS WILL BREAK OUT ACROSS NRN LOWER
GENERALLY SOUTH OF M-32. UNTIL THEN...HAVE A FEELING THAT THINGS MAY
BE RATHER QUIET...AS MID LEVEL LAPSE RATES BECOME LESS FAVORABLE
THROUGH THE DAY WITH AN APPARENT LACK OF A LIFTING MECHANISM.
HOWEVER...THE SHORTWAVES ROUNDING THE UPPER LOW ATTM...AND THE FACT
THAT THE ATMOSPHERE IS SO MOIST KEEPS ME FROM TAKING OUT THE CHANCE
FOR SHOWERS. AS FAR AS THUNDER AND SEVERE POTENTIAL...LOW CLOUDS AND
FOG WILL CERTAINLY KEEP ANY INSTABILITY FROM DEVELOPING EARLY ON.
MODELS SOUNDINGS DO NOT SUGGEST THAT THIS LOW LEVEL MOISTURE IS TOO
DEEP...BUT MORNING 12Z UPPER AIR LAUNCH WILL TELL THE STORY. WITH AN
EXPECTATION THAT THERE WILL BE AT LEAST SOME CLEARING BY
AFTERNOON...AND MODIFYING SOUNDINGS FOR MLCAPE WITH A 71/57 PARCEL
LEADS TO ONLY 200-500 J/KG. THIS IS NOT SO GREAT FOR DEEP
CONVECTION. THEREFORE...EVEN THOUGH 0-6KM BULK SHEAR IS A WHOPPING
60-70KTS FOR THE AFTERNOON...THE ABSENCE OF DEEP CONVECTION WILL
PREVENT SEVERE THUNDERSTORMS FROM OCCURRING. THE ONLY REAL CHANCE
WOULD BE CONFINED TO THOSE AREAS CLOSEST TO THE SAGINAW BAY...IN
ARENAC/GLADWIN COUNTIES SUCH AS PORTRAYED IN LATEST SPC DAY 1
OUTLOOK. WILL GO FOR SCATTERED THUNDERSTORMS HERE...OTHERWISE CAN
ONLY SEE GOING WITH ISOLATED THUNDERSTORMS FOR THIS AFTERNOON AND
FIRST HALF OF THE EVENING IN NRN LOWER DUE TO THE MINIMAL
INSTABILITY. STORMS SHOULD BE MORE PREVALENT DOWNSTATE AND ACROSS
THE LOWER MISSISSIPPI AND OHIO RIVER VALLEYS. THE SFC LOW PRESSURE
WORKS ACROSS LOWER MICHIGAN TONIGHT AND CONTINUES TO DEEPEN.
CONVERGENCE INCREASES FURTHER AS COLD FRONT SWEEPS ACROSS THE REGION
OVERNIGHT. WRAP-AROUND MOISTURE IN MID LEVEL DEFORMATION ZONE WILL
PRODUCE WHAT COULD BE UP TO AN INCH OF PRECIP ACROSS PORTIONS OF FAR
NRN LOWER AND EASTERN UPPER MICHIGAN...BEFORE SWEEPING SE AND
THROUGH THE SAGINAW BAY AREA MORE QUICKLY OVERNIGHT. HAVE INCREASED
RAIN CHANCES TO CATEGORICAL FOR ALL AREAS TONIGHT. THERE MAY BE A
BREAK IN THE ACTION ACROSS THE SAGINAW BAY REGION BETWEEN PRECIP
FROM SFC LOW EARLY THIS EVENING AND WRAP-AROUND PRECIPITATION
OVERNIGHT AS A DRY SLOT MAY TRY AND SNEAK IN FOR A PERIOD OF TIME.
SUNDAY AND SUNDAY NIGHT...AT LEAST SCATTERED RAIN SHOWERS WILL STILL
BE ONGOING ACROSS MAINLY NORTHEAST LOWER SUNDAY MORNING...BUT BY
AFTERNOON THE SFC LOW PULLS FAR ENUF EAST THAT ALL MOISTURE AND
FORCING IS DRAGGED AWAY FOR SOME CLEARING TO ENTER THE PICTURE.
NAM-WRF WANTS TO KEEP SCATTERED SHOWERS IN FOR MOST OF THE AFTERNOON
AND THIS PORTION OF THE FORECAST COULD SEE SOME TIMING DETAILS
HAMMERED OUT IN SUBSEQUENT FORECAST ISSUANCES. THE MAIN WEATHER FOR
THESE TIME PERIODS WILL BE THE COLD ADVECTION...INCREASED NORTHWEST
WINDS AND OVER LAKE INSTABILITY THAT DEVELOPS. H8 TEMPS WILL HAVE
FALLEN FROM 11C TO 1-3C BY SUNDAY AFTERNOON. HIGH TEMPERATURES WILL
LIKELY ONLY GET TO THE MIDDLE 50S TO LOWER 60S WITH WINDS GUSTING TO
AROUND 20 MPH AT TIMES IN THE AFTERNOON. OVER THE LAKES IT WILL BE A
DIFFERENT STORY AS OVER LAKE INSTABILITY WILL BE AROUND THROUGH THE
NIGHT DUE TO THE WARMER LAKE WATERS. WILL LIKELY SEE 20-30KT RANGE
GUSTS...STRONGEST GUSTS WITH FROPA. TOO EARLY AT THIS TIME TO ISSUE
SMALL CRAFT ADVISORIES...BUT FULLY EXPECT THEM IN ENSUING FORECASTS.
WITH SUCH COLD H8 TEMPS COMING DOWN...HAVE TO CONSIDER LAKE EFFECT
RAIN SHOWERS...HOWEVER THE AIR MASS LOOKS TO DRY TOO MUCH THROUGH
SUNDAY EVENING...AND THERE COULD BE AS LITTLE AS JUST SCATTERED LAKE
EFFECT CLOUDS. FOR THE OVERNIGHT HOURS...WE WILL HAVE A SECONDARY
PUSH OF COLDER AIR/FRONT THAT THE NAM IS NOW JUMPING ON TO SOME
EXTENT. 1000-850MB WINDS WILL BE MORE OUT OF THE WEST WITH DELTA T'S
13-14C. THIS DIRECTION MAY ALLOW WHITEFISH POINT TO GET CLIPPED WITH
SOME WEAK LAKE EFFECT...BUT THIS WIND REGIME AFFECTS MORE OF NRN
LOWER. WE MAY HAVE TO EVENTUALLY CONSIDER A CHANCE FOR RAIN SHOWERS
BETWEEN GRAND TRAVERSE BAY AND THE STRAITS FOR LATE SUNDAY NIGHT AND
POSSIBLY INTO MONDAY.
NO OTHER CHANGES TO THE FORECAST.   SMD
&&
.APX...WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE ALBANY NY
1037 AM EDT SAT SEP 23 2006
.SHORT TERM /REST OF TODAY/...
THIS UPDATE IS BASED ON THE KENX AND NEIGHBORING RADAR TRENDS AS
WELL AS THE LATEST 40KM RUC.  THE MAIN THRUST OF THERMAL ADVECTION
RAINFALL WITH THE THERMAL TROUGH IS CLEARING THE NE CORNER OF THE
FCST AREAS /SRN VT AND THE LAKE GEORGE REGION/ AT THIS TIME.
SCATTERED SHOWER ACTIVITY THAT HAS PERSISTED IN THE I-88  TO I-90
CORRIDOR IS TIED TO A WEAK H500 IMPULSE. WE HAVE DECIDED TO KEEP
LIKELY VALUES FOR SHOWERS NORTH OF THE CAPITAL DISTRICT AND
BERKSHIRES UP TO 18Z...THEN CHANCE VALUES THEREAFTER UP TO 22Z.  WE
ALSO WILL KEEP A CHANCE OF SHOWERS IN FOR THE NRN CATSKILLS...ERN
MOHAWK VALLEY...CAPITAL DISTRICT AND BERKSHIRES UNTIL 18Z TOO.
SLIGHT CHANCE VALUES SOUTH OF THE CAPITAL DISTRICT...WE WILL
CONTINUE FROM THE LATE MORNING FORWARD. WE ALSO BUMPED MAX TEMPS
DOWN A CATEGORY /3 DEGREES/ FOR THE BULK OF THE FCST AREA. TEMPS
WILL BE STEADY OR RISE AFTER 22Z.
THE MAIN WARM FRONT WITH AN EMBEDDED SHORTWAVE WILL MOVE N/NE INTO
NY AND NEW ENGLAND AFTER 22Z WITH ELEVATED CONVECTION A GOOD
POSSIBILITY WITH SHOWALTER VALUES OF -1 TO -3C AND MLCAPE VALUES OF
200-500 J/KG BASED ON THE GFS MODEL SOUNDINGS FOR THE OVERNIGHT
PERIOD.
UPDATE...WASULA
&&
.PREV DISCUSSION...
 /ISSUED 327 AM EDT SAT SEP 23 2006/
SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION THIS
MORNING...BRINING SHOWERS. THEN A BREAK IN THE PRECIPITATION WILL
OCCUR DURING THE AFTERNOON AND INTO THE EVENING...BEFORE THE NEXT
BATCH OF RAIN ARRIVES LATE TONIGHT ASSOCIATED WITH A STRENGTHENING
LOW PRESSURE SYSTEM MOVING NORTHEAST THROUGH THE CENTRAL GREAT
LAKES. AS THE SURFACE LOW CONTINUES TO PROGRESS NORTHEASTWARD INTO
SOUTHERN CANADA ON SUNDAY...A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL SWEEP THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND DURING
THE AFTERNOON. SHOWERS AND THUNDERSTORMS AND WINDY CONDITIONS WILL
AFFECT MOST OF THE REGION AS THE FRONT MOVES THROUGH...WITH SOME
THUNDERSTORMS POSSIBLY BECOMING SEVERE SOUTH AND EAST OF THE CAPITAL
REGION. DRIER AND COOLER CONDITIONS WILL MOVE IN FOR EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH MONDAY/...
AN ACTIVE COUPLE DAYS OF WEATHER IN STORE...COMPLETE WITH
RAIN...INCREASING HUMIDITY LEVELS...WARM TEMPS...THUNDERSTORMS AND
WIND. WHILE THE ENTIRE WEEKEND WILL NOT BE A WASHOUT...THERE WILL BE
A FEW DOSES OF INCLEMENT WEATHER.
THIS MORNING...WARM ADVECTION/ISENTROPIC LIFT PRODUCING OCCASIONAL
LIGHT SHOWERS ACROSS THE AREA. HOWEVER...THIS FORCING WILL LIFT
NORTH OF THE AREA BY AFTN...LEAVING MAINLY DRY CONDITIONS FOR THE
REST OF THE DAY INTO THE EVENING. THERE WILL STILL BE PLENTY OF
CLOUDS AROUND...WITH A NOTICEABLE INCREASE IN DEWPOINTS. DUE TO
CLOUD COVER...TEMPS WILL BE HELD DOWN JUST BELOW 70 IN THE VALLEYS
TODAY.
TONIGHT...WE WILL LIKELY REMAIN DRY UNTIL LATE EVENING/EARLY SUNDAY
MORNING. THEN THE NEXT BATCH OF RAIN MOVES IN FROM THE SOUTH AND
WEST ASSOCIATED WITH A SURGE OF ISENTROPIC LIFT TIED TO AN
IMPRESSIVE DEEPENING SFC CYCLONE LIFTING NE THRU THE CENTRAL GREAT
LAKES REGION. WILL ADD MENTION OF THUNDER...WITH SOME ELEVATED
INSTABILITY SEEN ON FORECAST SOUNDINGS IN THE MID LEVELS. IT WILL BE
MILD NIGHT...WITH CLOUDS/RAIN AND LOW LEVEL MOISTURE ASSOC WITH S/SW
FLOW.
SUNDAY WILL BE THE MOST ACTIVE AND CHANGEABLE DAY IN THE SHORT TERM.
THE AFOREMENTIONED SFC CYCLONE IS FORECAST TO LIFT NE THRU SE
ONTARIO AND SOUTHERN QUEBEC...WITH A TRAILING COLD FRONT BLASTING
THRU EASTERN NEW YORK/WESTERN NEW ENG DURING THE EARLY TO MID AFTN.
THERE ARE A COUPLE DIFFERENT CONCERNS. THE FIRST IS THE SEVERE
THUNDERSTORM POTENTIAL. CHOSE TIMING CLOSEST TO THE GFS...WHICH
BRINGS THE COLD FRONT THRU MUCH EARLIER THAN THE WRF/NAM. EARLY TO
MID AFTN TIMING OF CFROPA WILL PLAY A BIG ROLE IN DETERMINING WHICH
AREAS HAVE THE GREATEST SEVERE POTENTIAL. AS OF NOW IT APPEARS AREAS
TO THE SOUTH AND EAST OF THE CAPITAL REGION WILL BE AT RISK. THIS IS
WHERE THE MOST INSTABILITY WILL HAVE A CHANCE TO BUILD. FORECAST
CAPE VALUES ARE MODEST AT BEST AROUND 300-500 J/KG...HOWEVER THERE
WILL BE LOW LEVEL CONVERGENCE ALONG THE FRONT...TO GO ALONG WITH A
VERY STRONG AND IMPRESSIVE WIND FIELD THROUGHOUT THE DEPTH OF THE
TROPOSPHERE. THIS WILL LIKELY BE A HIGH SHEAR/LOW INSTABILITY
EVENT...WITH THE POTENTIAL FOR DAMAGING WIND GUSTS. MAINLY
UNIDIRECTIONAL 0-6 KM BULK SHEAR VALUES OF 40-55 KTS COME AS NO
SURPRISE SINCE 850 MB WINDS ARE FORECAST TO BE AROUND 50 KTS...WITH
700 MB WINDS NEAR 65 KTS! ANOTHER FAVORABLE FACTOR WILL BE SFC
DEWPOINTS RISING INTO THE MID TO UPPER 60S.
THE OTHER CONCERN BESIDES SEVERE THUNDERSTORMS IS THE POTENTIAL FOR
STRONG...GUSTY WEST TO NORTHWEST WIND BEHIND THE COLD FRONT. COLD
AIR ADVECTION WILL LEAD TO STRONG MIXING WITH SOME BREAKS OF
SUNSHINE LIKELY. WINDS GUSTS OF 40-50 MPH WILL BE POSSIBLE DURING
THE LATTER HALF OF THE AFTN AND EARLY EVENING. WE MAY END UP NEEDING
A WIND ADVISORY...BUT TOO EARLY TO ISSUE JUST YET. WILL CONTINUE TO
MENTION THREAT IN HWO. ALSO POST CFROPA...TEMPS WILL SPIKE DUE TO
THE MIXING AND NEAR DRY ADIABATIC LAPSE RATES FOR A FEW HOURS. THIS
WILL ALLOW TEMPS TO RISE INTO THE MID TO UPPER 70S FROM ALBANY
SOUTHWARD.
THE THREAT OF RAIN WILL DIMINISH CONSIDERABLY BY EVENING...WITH
NORTHWEST FLOW REGIME BECOMING ESTABLISHED. MONDAY WILL FEATURE DRY
CONDITIONS WITH MUCH COOLER TEMPS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
NO CHANGES TO THE GOING FORECAST PAST MONDAY. AFTER A REINFORCING
SHOT OF COOL AIR EARLY TUESDAY...HIGH PRESSURE WILL BUILD IN AND
TAKE CONTROL OF THE WEATHER WED INTO THUR. IT APPEARS THE NEXT LOW
PRESSURE SYSTEM WILL APPROACH THE AREA OF FRI...BRINGING THE NEXT
SIGNIFICANT CHANCE OF RAIN.
AVIATION...
CEILINGS ARE FORECAST TO LOWER IN THE PREDAWN HOURS TO AROUND 3000
FEET MSL WHICH WILL RESULT IN MVFR OVER THE VALLEYS WITH AREAS OF
IFR OVER THE HIGHER TERRAIN...WITH CEILINGS SLIGHTLY BELOW 2000 FEET
MSL SHORTLY AFTER DAYBREAK AND VISIBILITY 4 TO 5 MILES IN RAIN
SHOWERS. WINDS WILL GENERALLY BE FROM THE SOUTH 7 TO 14 KNOTS. THE
LOW CLOUDS ARE LIKELY TO BECOME SCATTERED IN LATE AFTERNOON BUT WILL
BECOME BROKEN AROUND 5000 FEET EARLY THIS EVENING ALONG WITH LIGHT
FOG FORMING. THE OVERCAST WILL LOWER TO AROUND 1000 FEET BY LATER
THIS EVENING WITH WIDESPREAD LIGHT FOG RESULTING IN WIDESPREAD IFR
CONDITIONS OVER THE REGION TONIGHT...WITH WINDS AT THE SURFACE CALM
OR NEARLY SO.
FIRE WEATHER...
CONDITIONS FOR IGNITION WILL CONTINUE TO BE UNFAVORABLE WITH
SCATTERED SHOWERS MOVING INTO THE REGION IN THE PREDAWN HOURS.
SEVERAL HOURS OF RAIN LATER THIS MORNING WILL RESULT IN HIGH FUEL
MOISTURE. A BRIEF PERIOD OF PARTLY SUNNY WEATHER MAY OCCUR LATER
THIS AFTERNOON WHILE THE REGION IS IN THE WARM SECTOR BUT CLOUDINESS
IS EXPECTED TO INCREASE THIS EVENING WITH OVERNIGHT RH VALUES CLOSE
TO 100 PERCENT IN WIDESPREAD LIGHT FOG. AS THE COLD FRONT APPROACHES
AND PASSES THROUGH THE REGION ON SUNDAY THUNDERSTORMS ARE LIKELY TO
DEVELOP AND BRING A THREAT OF CLOUD TO GROUND LIGHTNING ALTHOUGH
HEAVY RAIN WITH THE STORMS SHOULD MINIMIZE THE THREAT OF FIRE. SOME
DRYING OF GROUND FUELS MAY BE EXPECTED FOLLOWING THE FRONTAL PASSAGE
WITH BRISK WESTERLY WINDS 10 TO 15 MPH...PARTLY SUNNY SKIES...AND
AFTERNOON RH VALUES OF 40 TO 50 PERCENT.
HYDROLOGY...
NO HYDRO PROBLEMS EXPECTED ON THE RIVERS THE NEXT SEVERAL DAYS. A
WARM FRONT WILL BRING A PERIOD OF LIGHT RAIN TO THE FORECAST AREA
SATURDAY MORNING INTO THE EARLY AFTERNOON. RAINFALL AMOUNTS OVER THE
HYDRO SERVICE AREA WILL BE A TENTH OF AN INCH TO A THIRD OF AN INCH
TODAY. THE REGION WILL GET INTO A WARM SECTOR LATE SATURDAY
AFTERNOON INTO SUNDAY MORNING. A COLD FRONT AND A STRONG SURFACE
CYCLONE MOVING NORTH OF THE SAINT LAWRENCE RIVER VALLEY SUNDAY
MORNING...WILL BRING SOME HEAVY SHOWERS AND THUNDERSTORMS TO THE
REGION. STRONG MOISTURE CONVERGENCE AHEAD OF THE FRONT...COUPLED
WITH DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES IN THE
1.50-2.00" RANGE WILL CAUSE SOME LOCALLY HEAVY DOWNPOURS...AND WITH
THEM A POTENTIAL FOR FLOODING OF POORLY DRAINED ROADS AND PARKING
AREAS. RAPID RISES TO NEAR BANKFULL MAY OCCUR ON SOME STREAMS. THE
PASSAGE OF THE COLD FRONT WILL BE FOLLOWED BY COOLER AND DRIER
WEATHER FOR THE FIRST FEW DAYS OF THE UPCOMING WEEK.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NY...NONE.
VT...NONE.
&&
$$
</PRE></TT></td>   ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1023 AM EDT SAT SEP 23 2006
.SHORT TERM /TODAY/...TEMPS WARMING NICELY THIS MORNING WITH
READINGS NEAR 80 DEGREES OVER THE COASTAL PLAIN AS OF 10 AM.
AFTERNOON HIGHS IN THE MID/UPPER 80S LOOKS ON TRACK. HAVE INCREASED
DEWPOINT GRIDS SLIGHTLY TO REFLECT CURRENT TRENDS. THE NAM...GFS AND
RUC ALL INDICATE SOME PRECIP DEVELOPING THIS AFTERNOON MAINLY OVER
SOUTHERN SECTIONS. THIS IS LIKELY A RESULT OF SOME SEA BREEZE
DEVELOPMENT GIVEN STRONG INLAND HEATING. FORECAST SOUNDINGS INDICATE
SOME DECENT INSTABILITY ACROSS THE AREA AS WELL SO WILL ADD A 20 POP
FOR THIS AFTERNOON. REST OF FORECAST ON TRACK.
&&
.AVIATION...INCREASED DEWPOINTS WITH SOUTHERLY FLOW LEADING TO
MORE IN THE WAY OF CLOUDINESS TODAY. GENERALLY MID AND HIGH LEVEL
CLOUDS...BUT SOME OCCASIONAL MVFR CEILINGS IN LOWER STRATOCUMULUS
WILL BE AROUND OVER THE NEXT COUPLE OF HOURS. AFTER THAT...ANTICIPATE
VFR CONDITIONS WITH BROKEN CEILINGS IN THE 5K RANGE.
&&
.MARINE...STILL SEEING 4 TO 6 FT COMBINED SEAS WITH UP TO 13
SECOND WAVE PERIODS AS EASTERLY SWELL CONTINUES ON AREA WATERS.
WILL UPDATE MARINE FCST TO REMOVE MORNING WORDING AND TWEAK WINDS
A LITTLE...BUT OVERALL FCST REMAINS LARGELY UNCHANGED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ152-154.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR AMZ150-
     156-158.
&&
$$
SHORT TERM...WINGENROTH
LONG TERM...WINGENROTH
AVIATION...COLLINS
MARINE...COLLINS
</PRE></TT></td>   nc
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE WILMINGTON NC
750 AM EDT SAT SEP 23 2006
.UPDATE...
ADDED REQUIRED HEADLINES TO APPROPRIATE ZONES FOR HIGH RIP CURRENT
RISK TODAY. ALSO ADDED SLIGHT CHANCE OF SHOWERS TO THE COASTAL
WATERS EXCEPT N OF CAPE FEAR AND GIVEN CURRENT BUOY DATA...ADDED
SMALL CRAFT EXERCISE CAUTION STATEMENT FOR TODAY.
&&
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
SFC HIGH PRESSURE OVER NORTHEAST/MIDATL STATES WILL SINK SSE
TODAY. REMAINDER OF THE BL WILL FOLLOW SUIT LEADING TO A DEEP
LAYER OF WARM AND MOIST S TO SWRLY FLOW. AS SUCH A WARM AND MUGGY
AFTERNOON IS EXPECTED THIS FIRST DAY OF FALL AND CU DEVEL SHOULD
BE FAIRLY ROBUST. WEAK SHOWER ACTIVITY JUST OFFSHORE FROM WRN
BRUNSWICK AND OFF OF SC....A COMBO OF WEAK LLJ AND CONV
AXIS...WILL PROBABLY DIMINISH WITHIN A FEW HRS OF SUNRISE. THIS
IDEA IS SUPPORTED BY THE RUC, WHICH HAS RECENTLY INITIALIZED WITH
THE ACTIVITY PRETTY WELL. AND ALTHOUGH A LAST MINUTE DECISION TO
INCLUDE THEM MAY BE MADE FOR NOW THEY WILL LIKELY ONLY MERIT A
NOWCAST OR TWO...IF EVER MAKING IT ONSHORE THAT IS.
WITH CONTINUED WARM AND MOIST ADVECTION OVERNIGHT EXPECT GRADUAL INC
IN MIDLVL CLOUDS AND A MUGGY NIGHT. FLOW SHOULD BE PARALLEL
ENOUGH TO THE COAST THAT IF OFFSHORE SHOWERS REDEVEL THEY SHOULD
REMAIN OVER WATER. BL APPEARS TO STAY MIXED ENOUGH TO PRECLUDE
MUCH FOG DEVEL EVEN IF THE MID CLOUDS STAY JUST TO OUR NW, WHICH
IS A POSSIBILITY SINCE THE OVERALL EVOLUTION OF THE SUNDAY/MONDAY
PATTERN APPEARS SLOWER THAN PREV THOUGHT.
ACCORDINGLY...POPS HAVE BEEN TRIMMED SUNDAY TO SHOW SLOWER TIMING.
MOST OF THE DAY SHOULD BE MUGGY WITH MORE ROBUSTLY INCREASING MID
LVL CLOUDS. LATER IN THE AFTERNOON POPS WILL STILL BE RISING AS
THE COLD FRONT NEARS...AND THE SEA BREEZE MAY EVEN MAKE A
CONTRIBUTION ALTHOUGH THE SYNOPTIC FLOW WILL KEEP IT FROM MOVING
INLAND VERY FAR OR VERY QUICKLY.
IF THE GFS TIMING IS CORRECT THEN POPS SHOULD START RAMPING UP
QUICKLY AOA 03Z MONDAY (MAYBE A BIT SOONER W) AS DEEP ASCENT
OVERSPREADS THE AREA. THE ASCENT IS DEEP BUT NOT TERRIBLY STRONG
SO MODERATE RAIN WILL BE POSSIBLE DUE TO A DEEP NEARLY SATURATED
LAYER BUT ANY HEAVY RAIN SHOULD BE CONFINED TO LOCALIZED POCKETS OF
CONVECTION. THE FRONT WILL PROGRESSING ACRS THE AREA AT THIS TIME
AND SHOULD ROUGHLY PARALLEL THE COAST AND BE JUST OFFSHORE AOA 12Z
MON.
THE EASTERNMOST COUNTIES WILL HAVE A TOUGH TIME SHAKING RAIN
CHANCES THROUGH MOST OF MONDAY. AS THE TROUGH THAT DROVE THE FRONT
INTO THE AREA ALREADY BEGINS LIFTING OUT A POTENT SHORTWAVE
LAGGING BEHIND WILL BEING TO MOVE IN FROM THE WEST. ACCORDING TO
THE GFS THE TROP WILL BE FOLDING DOWN TO ABOUT 500MB OVER ATL BY
MONDAY AFTERNOON WITH THIS FEATURE. THIS WILL RESULT IN FAIRLY STRONG
VERTICAL MOTION OVER THE ERN CAROLINAS. MOST OF THIS STRONG ASCENT
WILL BE OCCURRING OVER THE DEEP STABLE BL OVER WRN ZONES BUT
COASTAL COUNTIES MAY STILL HAVE A SHALLOW ENOUGH STABLE LAYER FOR
SOME ELEVATED MOISTURE AND INSTABILITY AND COULD SEE ANOTHER ROUND
OF APPRECIABLE RAINFALL. SHOULD THE BOUNDARY BE JUST A BIT
FARTHER TO THE EAST MOST OF THE RAIN WILL REMAIN OFFSHORE. TOO
EARLY TO IRON OUT THE DETAILS.
&&
.AVIATION...
PROBLEMATICAL FORECAST THIS MORNING...ESPECIALLY AT FLO
WHICH IS NOW EXPERIENCING VLIFR CONDITIONS FOR VSBY AND CIG. HAVE NO
GOOD EXPLANATION WHY IT HAS GONE SO LOW HERE...NEITHER GUIDANCE NOR
CLIMO NOR THE SYNOPTIC SITUATION WOULD SUGGEST THIS SCENARIO. REST
OF THE TAFS ARE BEHAVING. RADAR HAS PATCHES OF LIGHT SHOWER ACTIVITY
MOVING ASHORE BEFORE DISSIPATING SOUTH OF CAPE FEAR WHICH IS LEADING
TO TEMPO MVFR FOR CIGS AT CRE AND MYR. PATCHY MVFR FOG ELSEWHERE
THIS MORNING EXCEPT FOR ILM WHICH SEEMS TO LIE JUST OUTSIDE OF THE
BEST MOISTURE TAP.
&&
.MARINE...
LONG PERIOD SWELL FROM DISTANT TROPICAL CYCLONE HELENE
CONTINUES TO IMPACT THE COASTAL WATERS. SWELLS ABOUT 4 FT WITH A
PERIOD OF 15 SECONDS OUT AT 41013 ACCORDING TO SPECTRAL PLOTS. WITH
TIGHTENING SOUTHERLY GRADIENT OVER THE COASTAL WATERS WIND DRIVEN
WAVES HAVE ALSO INCREASED...LEADING TO COMBINED SEAS OF 5 FT AT
41013 AND AROUND 4 FT CLOSER TO SHORE. BASED ON LATEST FROM TPC ON
HELENE...EXPECT SIGNIFICANT CONTRIBUTION TO COMBINED SEAS FROM THE
SWELL COMPONENT TO CONTINUE INTO THE WEEKEND...ALTHOUGH IT LOOKS
LIKE WE HAVE ALREADY SEEN ITS PEAK. PRESENT SHADOWING EFFECT OF
SWELL ENERGY FOR WATERS WEST OF CAPE FEAR DUE TO FRYING PAN SHOALS
WILL BECOME LESS OF A FACTOR DURING THE DAY TODAY AS SWELL ENERGY
DECREASES. WINDS AND SEAS WILL PICK UP AGAIN SUNDAY IN ADVANCE OF
COLD FROPA SET FOR EARLY MONDAY. MAY SEE SCA CRITERIA MET FOR SEAS
SUNDAY NIGHT IN THE OUTER REACHES OF OUR NC WATERS. STUCK WITH THE
GFS FOR MOST OF THE FORECAST EXCEPT FOR THE FIRST COUPLE OF PERIOD.
AS NOTED BY OPC...THE GFS IS SUPPORTED BY THE ECMWF AND BY THE
LATEST HPC MEDIUM RANGE FORECASTER GUIDANCE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SHORT TERM...MBB/RJD
AVIATION...REK
MARINE...REK/RJD
</PRE></TT></td>   nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
312 PM EDT SAT SEP 23 2006
.SHORT TERM...
TONIGHT AND SUNDAY
TOTAL CONVECTIVE FAILURE CONTINUES THIS AFTERNOON AS EXPANSIVE
STRATUS DECK CONTINUES TO SEVERELY LIMIT SOLAR INSOLATION AND
DESTABILIZATION. 18Z OBJECTIVE RUC MESOANALYSIS SHOWING MLCAPE
PRACTICALLY NIL ACROSS THE CWA. CONVECTIVE OUTFLOW AND ONGOING
CONVECTION OVER THE LOWER OHIO VALLEY HAS ALSO DISRUPTED SOUTHERLY
MOISTURE CONVEYOR. THIRDLY...WAVE OF LOW PRESSURE WHICH ALL MODEL
GUIDANCE DEVELOPS ALONG FRONTAL BOUNDARY IS STILL NOWHERE TO BE
FOUND PER 18Z MSAS ANALYSIS. HAND 12Z MESOANALYSIS SHOWED A LARGE
CONVECTIVE BUBBLE HIGH OVER THE REGION IN WHICH LOW PRESSURE WAVE
WAS FORECAST TO DEVELOP...WHICH HAS LIKELY INHIBITED ITS DEVELOPMENT
THUS FAR.
FOR TONIGHT...NO SHORT RANGE MODEL GUIDANCE HAS A DECENT HANDLE ON
ONGOING COVERAGE OF PRECIPITATION. WILL SIMPLY USE EXTRAPOLATION OF
OBSERVATIONAL DATA FOR THE FIRST PERIOD OF THE FORECAST. THIS MEANS
A SLOWER FROPA THAN ANY MODEL INDICATES...AND MUCH LESS COVERAGE/QPF
WRT RAIN. REMOVED ALL MENTION OF SEVERE WEATHER WITH EARLIER UPDATE
AND THIS STILL LOOKS GOOD GIVEN TOTAL LACK OF THERMODYNAMICS.
KINEMATICS ARE EXTREME...HOWEVER WITHOUT INSTABILITY NO ORGANIZED
CONVECTIVE UPDRAFTS WILL FORM. WILL GO WITH LIKELY POPS FOR THIS
EVENING...THEN TAPER TO CHANCE OVERNIGHT AS PRIMARY MOISTURE PLUME
SHIFTS EAST AND OCCLUDED FRONT SLOWLY CROSSES THE CWA.
ON SUNDAY OCCLUDED FRONT CONTINUES EAST OF THE CWA WITH MID LEVEL
DRY SLOT BRIEFLY PUNCHING INTO THE CWA IN THE MORNING. SECONDARY
FROPA ENTERS THE NW CORNER OF THE CWA DURING THE MORNING THEN
SPREADS SE THROUGH THE AFTERNOON WITH ATTENDANT MID LEVEL WAVE
PROVIDING WEAK LIFT. WILL RETAIN LOW CHANCE POPS CWA WIDE...WITH
HIGHER CHANCE N/NW ZONES WHERE AIR BECOMES JUST COLD ENOUGH FOR A
LIMITED LAKE EFFECT RESPONSE.
&&
.LONG TERM...
SUNDAY NIGHT THROUGH SATURDAY.
GOING FORECAST APPEARS ON TRACK WITH LITTLE CHANGE...THOUGH CONCERN
WITH FORECAST THU INTO SATURDAY WITH RESPECT TO POTENTIAL
INSTABILITY SHOWERS. LATEST GFS APPEARS OVERDONE WITH HUDSON BAY
VORTEX AT F84 PER COMPARE WITH ENSEMBLE MEMBERS. GFS CONTINUES
AGRESSSIVE WITH NORTHERN STREAM DIVING A WAVE IN BASE OF MEAN TROF
TO DEVELOP END OF WEEK CUTOFF OVER GREAT LAKES LATE THURSDAY/FRIDAY
WITH ASSOCIATED M29C COLD POOL INTO CWA FRI/SAT. HOWEVER WITH
GEM/ECMWF AND EVEN GFS FLATTENING WESTERN RIDGE WITH APPROACH OF
GULF OF AK SYSTEM...HESITATE TO ADOPT GFS SOLUTION OVER GREAT LAKES
AT THIS TIME.
&&
.AVIATION...
MAJOR OVERHAUL NECESSARY FROM PREVIOUS TAF ISSUANCE TO FOCUS MORE ON
LOW CIGS THAN TSRA. CONVECTIVE FAILURE EVIDENT TODAY WITH LOW/MID
LEVEL MOISTURE CONVEYOR EFFECTIVELY CUTOFF BY ONGOING CONVECTION AND
OUTFLOWS OVER THE LOWER OHIO VALLEY. EXPANSIVE CLOUD COVER HAS
ELIMINATED POTENTIAL INSTABILITY. ILL-FATED TEMPO TSRA GROUPS WHICH
WERE ADDED 18 HOURS BEFORE THE EVENT HAVE BEEN REMOVED ALTOGETHER
WITH NO CONVECTIVE MENTION AT ALL. MAIN FOCUS FOR 18Z TAFS REVOLVES
AROUND LOW CIGS. LOW STRATUS LOCKED IN AND EXPANSIVE CIRRUS SHIELD
IS PREVENTING MUCH SUNSHINE FROM PENETRATING TO STRATUS DECK. SEE
LITTLE REASON WHY MVFR CIGS WONT CONTINUE THROUGH THE REST OF THE
DAY. CIGS BECOME MORE UNCERTAIN TONIGHT FOLLOWING OCCLUDED FRONTAL
PASSAGE. SOME SUGGESTION BY UPSTREAM TRENDS THAT CIGS WILL IMPROVE
FOLLOWING FRONT...HOWEVER MODEL GUIDANCE WOULD SUGGEST A
CONTINUATION OF LOW CIGS FOLLOWING FRONT. FOR NOW WILL GO WITH
PERSISTENCE AND KEEP CIGS IN MVFR CATEGORY THROUGH THE END OF THE
TAF PERIOD AND MONITOR UPSTREAM TRENDS FOR 00Z ISSUANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM/AVIATION...HITCHCOCK
LONG TERM...MURPHY
</PRE></TT></td>   in
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
530 PM EDT SAT SEP 23 2006
.SHORT TERM... TONIGHT AND SUNDAY
MAIN FCST ISSUES ARE REDEVELOPMENT OF MORE WIDESPREAD RAIN THIS
EVENING AND THEN DIMINISHING TRENDS LATE TONIGHT/SUN MORNING.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THAT THE MIDLEVEL LOW OVER
THE NRN PLAINS YESTERDAY HAS WEAKENED AND OPENED UP WITH OVERALL
TROF ORIENTATION POSITIVELY TILTED ACROSS THE CNTRL TO SW CONUS.
SHORTWAVE THAT WAS OVER CO/UT YESTERDAY IS RACING NE INTO THE GREAT
LAKES REGION. AT THE SFC...BROAD LOW PRES COVERS SE MN/WI/NW IL. A
NEW LOW PRES CENTER HAS YET TO BECOME WELL-DEFINED IN RESPONSE TO
THE SHORTWAVE APPROACHING THE GREAT LAKES. MEANWHILE...A SFC TROF
CONTINUES TO SLOW SAG SE ACROSS UPPER MI. STIFF NE WINDS ARE
OCCURRING N OF THE TROF ACROSS LAKE SUPERIOR...ESPECIALLY THE W PART
WHERE WINDS HAVE BEEN GUSTING TO GALE FORCE AT TIMES. SCT TSRA...
SOME PRODUCING SMALL HAIL...DEVELOPED ACROSS THE CNTRL/ERN FCST AREA
THIS AFTN AS THERE WERE ENOUGH BREAKS IN THE CLOUD COVER TO INCREASE
INSTABITY. MODIFIED LAPS SOUNDING EARLY THIS AFTN FOR SFC T/TD OF
70/59F INDICATED UPWARDS OF 1000J/KG.
THERE IS LITTLE CHANGE TO PREVIOUS THINKING FOR TONIGHT/SUN.
COUPLING OF THE INCREASING MID/UPPER LEVEL FORCING SHOWN BY QVECTOR
CONVERGENCE OVERTOP LOW-LEVEL FRONTOGENESIS SHOULD CONTINUE TO LEAD
TO AN EXPANSION OF PCPN ACROSS UPPER MI THIS EVENING. PCPN SHOULD
BECOME FOCUSED ALONG 850MB TROF THAT IS MOVING S ACROSS UPPER MI.
EXPECT TSRA OVER THE CNTRL/E TO END BY MID EVENING AS INSTABILITY
DIMINISHES. PCPN SHOULD THEN END FAIRLY QUICKLY FROM NW TO SE LATE
TONIGHT THRU EARLY SUN MORNING AS SYSTEM IS PROGRESSIVE. ON
SUNDAY...EXPECT IMPROVING SKY CONDITION TO PARTLY SUNNY AS SUGGESTED
BY RH TIME SECTIONS. ALSO VIS SATELLITE IMAGERY INDICATES AN
INCREASING AREA OF MOSTLY SUNNY SKIES TO THE NW OF LAKE SUPERIOR...
SUPPORTING THE IDEA OF DECREASING CLOUD COVER HERE DURING THE DAY.
.LONG TERM... 00Z MON THROUGH 00Z SUNDAY...
LATEST NAM/GFS GUIDANCE SHOWS TROUGH PASSING OVER THE NORTHERN HALF
OF THE CWA EARLY MONDAY MORNING...KEPT IN SLIGHT CHANCE FOR PRECIP
ON MONDAY MORNING WITH A BETTER CHANCE OVER EASTERN LAKE
SUPERIOR...WOULDN'T BE SURPRISED IF MOST OF THE FA REMAINED DRY AS
BEST FORCING REMAINS OVER LAKE SUPERIOR. TUESDAY LOOKS LIKE A NICE
DAY AHEAD OF WEDNESDAY'S WEATHER. MAX TEMPS IN THE UPPER 60S AREN'T
OUT OF THE QUESTION WITH SOUTHERLY WINDS/PARTLY CLOUDY SKIES.
DECIDED TO KEEP FCST DRY...DESPITE THE NAM CREATING WARM FRONTAL
PRECIP DURING THE DAY ON TUESDAY AS ONLY THE LATEST...12Z...RUN HAS
ANY PRECIP OVER THE FA...THE BETTER CHANCE FOR RAIN IS ON
WEDNESDAY...THE QUESTION IS NOT IF BUT WHEN. FRONTAL TIMING HAS BEEN
TRICKY GIVEN LACK OF MODEL TO MODEL CONSISTENCY. THOUGH THE MODELS
THEMSELVES HAVE BEEN PRETTY CONSISTENT...WITH THE EXCEPTION OF LAST
NIGHTS GFS RUN...00Z...AS THIS RUN BROUGHT THE LOW DIRECTLY OVER
LAKE SUPERIOR AROUND 00Z ON THURSDAY. WITH THAT SAID THE LAST TWO
RUNS HAVE TRENDED NORTH WITH THE LOW TRACK AS WELL AS A STRONGER LOW
PRESSURE CENTER...AND KEEPING THE LOW JUST NORTH OF THE LAKE BY 00Z
THURSDAY. NOT TO BE OUTDONE...THE ECMWF HAS MAINTAINED A QUICKER
SOLUTION...BRINGING THE LOW AND ASSOCIATED CLD FNT THROUGH AROUND
12Z WEDNESDAY. AS A RESULT...FRONTAL PASSAGE TIMING IS A COMPROMISE
BETWEEN 12Z GFS/UKMET/ECMWF/HPC GUIDANCE. WENT WITH A FRONTAL
PASSAGE AROUND 18Z. DID INCREASE POPS FOR WEDNESDAY AFTN TO 40.
FUTURE SHIFTS...STILL TOO MUCH UNCERTAINTY TO GO SCATTERED/LIKELY.
AHEAD OF THIS FRONT WINDS COULD INCREASE TO NEAR GALE FORCE OVER THE
EAST HALF OF LAKE SUPERIOR...THEN MODEST WINDS BEHIND IT...15-25
KT...THEN TAPERING OFF ON THURSDAY. THINGS COOL OFF A BIT BEHIND
WEDNESDAYS FRONTAL PASSAGE. WITH HIGHS ON THURSDAY PROBABLY ONLY
GETTING IN THE LOW 50S. KEPT POST FRONTAL PRECIP IN FOR AREAS NEAR
AND AROUND LAKE SUPERIOR. FROM THURSDAY NIGHT INTO FRIDAY
MORNING...1000-700/850-700/1000-500 THICKNESS VALUES SUPPORT SNOW OR
SOME TYPE OF MIXED PRECIP. BUT THE MOST IMPORTANT LOW LEVEL
THICKNESS...1000-850MB IS STILL TOO WARM TO CONSIDER ADDING SNOW/MIX
TO FCST. HIGH PRESSURE TRIES TO BUILD IN THURSDAY NIGHT/FRI
MORNING...HOWEVER BOTH THE ECMWF/GFS DEVELOP SOME TYPE OF LOW
PRESSURE SYSTEM OVER THE CENTRAL GREAT LAKES WHICH IS KEEPING THIS
HIGH FROM BUILDING TO FAR TO THE WEST. THE LATEST ENSEMBLE FCST FOR
THE FRI/SAT TIME FRAME...HAS UPPER LEVEL TROUGHING OVER THE GREAT
LAKES AND A BROAD HIGH PRESSURE RIDGE OVER THE WEST EXTENDING INTO
THE SOUTHERN PORTION OF THE YUKON TERRITORY. THIS SUPPORTS ECMWF/GFS
GUIDANCE...THOUGH DUE TO UNCERTAINTY OPTED TO ONLY KEEP PRECIP IN
CENTRAL AND EASTERN LAKE SUPERIOR AREAS THROUGH 12Z FRIDAY. JUST
MINOR CHANGES MADE TO TEMP/DWPT FCSTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
ROLFSON(SHORT TERM)/PEARSON(LONG TERM)
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
340 PM EDT SAT SEP 23 2006
.SHORT TERM DISCUSSION...19Z SATELLITE/SURFACE/AND RUC ANALYSIS
INDICATING VERTICALLY STACKED LOW OVER SOUTHWEST MINNESOTA BEGINNING
TO OPEN UP AND EJECT EAST AS 120+ KNOT 300MB JET STREAK AND
SHORTWAVE ROUNDS BASE OFF TROUGH. AT THE SURFACE...1001MB LOW
CENTERED OVER WEST CENTRAL WISCONSIN WITH A SECONDARY WAVE OF LOW
PRESSURE RIDING UP FRONTAL ZONE IN MISSOURI. ILL DEFINED WARM FRONT
STRETCHES EAST/WEST FROM ALPENA TO TRAVERSE CITY. REGIONAL RADARS
SHOWING EXPANDING AREA OF SHOWERS MOVING NORTHEAST ACROSS CENTRAL
LAKE MICHIGAN INTO NORTHERN ILLINOIS IN REGION OF INCREASING MID
LEVEL DEFORMATION. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
OCCURING ACROSS THE CENTRAL AND WESTERN U.P. AND PARTS OF THE
NORTHERN LOWER WHERE AFTERNOON CLEARING HELPED GENERATE SOME SURFACE
BASED INSTABILITY. FORECAST CONCERNS THROUGH SUNDAY CENTER ON
PRECIPITATION TRENDS THROUGH EARLY SUNDAY AFTERNOON ALONG WITH
INCREASING MARINE WINDS.
TONIGHT...SHOWERS WILL CONTINUE TO SPREAD NORTH AND OVERSPREAD THE
AREA THIS EVENING AS ISENTROPIC ASCENT INCREASES AHEAD OF PLAINS
SYSTEM. ISOLATED THUNDER NOT OUT OF THE QUESTION THIS EVENING WITH
LINGERING INSTABILITY GIVEN AFTERNOON CLEARING THAT OCCURRED ACROSS
THE AREA. MODIFIED 12Z KAPX SOUNDING WITH A TEMPERATURE/DEWPOINT OF
68/58 RESPECTIVELY DOES SHOW NEARLY 850J/KG MEAN LAYER CAPE.
ALTHOUGH KINEMATICS WILL BE ON THE INCREASE THIS EVENING WITH 0-6KM
BULK SHEAR VALUES APPROACHING 60-70KTS AND 500MB WINDSPEED OF OVER
60KTS...AGREE WITH LATEST SPC DAY ONE OUTLOOK THAT KEEPS SEVERE
THREAT JUST SOUTH OF THE AREA IN REGION OF BETTER SURFACE BASED
INSTABILITY AND WHERE BEST MASS CONVERGENCE ON NOSE OF LOW LEVEL JET
RESIDES. BY LATER TONIGHT...SURFACE WAVES OVER MISSOURI AND
WISCONSIN CONGEAL TO ONE PRIMARY LOW CENTER. STILL SOME SUBTLE
DIFFERENCES WITH OVERALL STRENGTH AND LOCATION OF LOW WITH GFS MOST
AGGRESSIVE AND FASTEST SHOWING 992MB LOW NEAR GEORGIAN BAY BY 06Z.
NAM LESS AGGRESSIVE SHOWING MORE DIFFUSE PRESSURE FIELD WITH 997MB
LOW OVER SOUTHER LAKE HURON AT SAME TIME. UKMET OFFERS A NICE
COMPROMISE WITH 995MB LOW OVER SOUTHERN LAKE HURON AND WILL SIDE
WITH THIS SOLUTION. THIS PLACES MUCH OF THE NORTHWEST LOWER AND
EASTERN U.P. IN DEFORMATION AXIS IN NORTHWEST QUADRANT OF SYSTEM.
WILL HAVE CATEGORICAL COVERAGE OF SHOWERS IN THIS AREA.
ELSEWHERE...NUMEROUS SHOWERS ARE EXPECTED AS SYSTEM PASSES THROUGH.
SUNDAY...DEFORMATION AXIS QUICKLY PIVOTS OFF TO THE SOUTHEAST SUNDAY
MORNING AND EARLY AFTERNOON AND WILL CONTINUE TO TAILOR POPS IN THIS
FASHION. FORCING MOVES FAR ENOUGH EAST BY LATER SUNDAY AFTERNOON TO
DRY OUT CONDITIONS. 850MB TEMPERATURES FALL THROUGHOUT THE DAY
REACHING 1-2C BY MID AFTERNOON PRODUCING DELTA T/S OF 15C.
HOWEVER...MID LEVELS QUICKLY DRY OUT WITH SIGNIFICANT INVERSION
PRESENT AT 850MB. SO EXPECTING NOTHING MORE THAN SOME LAKE EFFECT
CLOUDS TO STREAM OFF THE LAKES. CAA ADVECTION WILL KEEPS
TEMPERATURES FROM RECOVERING MUCH WITH HIGHS EXPECTED ONLY IN THE
UPPER 50S TO LOW 60S.
MARINE...INCREASING OVER LAKE INSTABILITY AND TIGHTENING PRESSURE
GRADIENT SHOULD LEAD TO SCA CRITERIA CONDITIONS BEGINNING SUNDAY
MORNING AND CONTINUING THROUGH THE DAY FOR NEARSHORE WATERS OF
NORTHERN LAKE MICHIGAN AND FROM 5 NM EAST OF THE MACKINAC BRIDGE TO
STURGEON PT ALONG NORTHERN LAKE HURON. WILL HOIST SCA FOR THESE
AREAS BEGINNING AT 9Z AND RUNNING THROUGH 21Z ON SUNDAY.
MSB
REMAINDER OF THE FORECAST (SUNDAY NIGHT THROUGH NEXT SATURDAY)...AS
AUTUMN COMMENCES THERE WILL BE PLENTY OF SYSTEMS TO KEEP AN EYE ON
WITH A FAST FLOW ALOFT. THE MAIN LONG TERM CONCERNS WILL BE POPS AND
HIGH TEMPERATURES THROUGH THE PERIOD.
SUNDAY NIGHT...DRY AIR (MEAN 900-700 MB RH UNDER 40 PERCENT)
CONTINUES TO FILTER INTO THE REGION ALONG WITH ABUNDANT DOWNWARD
MOTION BEHIND DEPARTING WAVE. THEREFORE DESPITE INCREASING OVER LAKE
INSTABILITY (850 MB/LAKE DELTA TS BETWEEN 15 AND 18) WILL NOT
INCLUDE POPS AS IT APPEARS THAT IT WILL BE TOO DRY TO PRODUCE
NORTHWEST FLOW LAKE EFFECT RAIN SHOWERS. LOWS GENERALLY IN THE LOWER
AND MIDDLE 40S EXPECTED.
MONDAY...NORTHWEST FLOW ALOFT WITH 850 MB TEMPERATURES BETWEEN PLUS
2 AND 4 C WITH A SHORT WAVE MOVING THROUGH THE FLOW ACROSS SOUTHEAST
ONTARIO. IT/S A CLOSE CALL AS TO HOW FAR SOUTH MOISTURE FROM THIS
WAVE WILL BE WITH VARYING MODEL SOLUTIONS. FOR NOW WILL CONTINUE
WITH FARTHER NORTH SCENARIO PER THE UKMET/NAM AND LIMIT LOW CHANCE
POPS TO ACROSS CHIPPEWA COUNTY. HIGHS ARE EXPECTED TO BE IN THE
LOWER AND MIDDLE 60S.
MONDAY NIGHT AND TUESDAY...HEIGHTS SLOWLY RISE WITH WARMER AIR
MOVING IN AT 850 MB (PLUS 8 TO PLUS 12 C). OVERALL PARTLY CLOUDY
CONDITIONS EXPECTED WITH LOWS MONDAY NIGHT IN THE LOWER AND MIDDLE
40S AGAIN AND HIGHS TUESDAY IN THE MIDDLE 60S FOR THE MOST PART.
WEDNESDAY AND THURSDAY...SOME TIMING ISSUES WITH THE NEXT IN THE
SERIES OF SYSTEMS. MODEL TRENDS HAVE BEEN TO SLOW DOWN UPSTREAM
SURFACE COLD FRONT. THEREFORE...HAVE LOWERED POPS TO LOW CHANCE ON
WEDNESDAY AS WELL AS RAISE HIGHS WELL INTO THE 60S. HIGHER CHANCE
POPS LOOK TO BE WEDNESDAY NIGHT (WITH THE FRONTAL PASSAGE) WITH
CONTINUED CHANCE POPS ON THURSDAY DUE TO POSSIBLE LAKE EFFECT.
FRIDAY AND SATURDAY...EXTENDED MODELS ARE HINTING AT THE DEVELOPMENT
OF A COLD TROUGH AND ASSOCIATED SURFACE LOW DEVELOPMENT ACROSS THE
EASTERN LAKES. FOR NOW WILL COOL DOWN TEMPERATURES INTO THE 50S FOR
HIGHS BUT NOT ADD POPS JUST YET. INSTEAD WILL CONTINUE WITH
CONTINUITY/OFFICE CONSENSUS BUT IF MODEL TRENDS CONTINUE POPS WILL
LIKELY HAVE TO BE ADDED BY LATER SHIFTS.
SULLIVAN
&&
.APX...WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
109 PM EDT SAT SEP 23 2006
.AVIATION...
THUNDERSTORMS ARE EXPECTED TO HAVE AN IMPACT ON AVIATION
OPERATIONS AT ALL TERMINALS OVER THE NEXT 12 HOURS. LOW CEILINGS
WILL CONTINUE TO PREVAIL...DOING NO BETTER THAN MVFR THROUGH THIS
TAF PERIOD. CONCERNING VISIBILITIES...A BRIEF PERIOD OF
IMPROVEMENT WILL BE POSSIBLE THIS AFTERNOON...PRIOR TO THE ONSET
OF WIDESPREAD CONVECTIVE ACTIVITY. THEREAFTER...LOW VISIBILITIES
WILL PREVAIL...FLUCTUATING BETWEEN IFR AND MVFR...AND AS LOW AS
LIFR IN THE VICINITY OF HEAVY DOWNPOURS IN THUNDERSTORMS.
THE MAIN CHALLENGE IS TIMING BOTH THE ONSET AND DURATION OF
THUNDERSTORM ACTIVITY. CANNOT COMPLETELY RULE OUT A HEAVY SHOWER OR
ISOLATED THUNDERSTORM OVER THE NEXT COUPLE OF HOURS...BUT MAIN
ACTIVITY WILL ARRIVE LATER IN THE DAY...SO SEE NO REASON TO DEVIATE
FROM THE PREVIOUS TIMING OF THUNDERSTORM ACTIVITY...WITH THE MOST
LIKELY PERIOD COINCIDING WITH THE MAXIMUM HEATING OF THE DAY. THIS
TIMING WILL ALSO COINCIDE WITH MAX SURFACE CONVERGENCE AND MAX UPPER
LEVEL DIVERGENCE WHICH WILL BE QUITE FAVORABLE FOR THUNDERSTORM
ACTIVITY ACROSS SOUTHEAST LOWER MICHIGAN DURING THE LATE AFTERNOON
AND EARLY EVENING HOURS.
FOLLOWING THE THUNDERSTORM ACTIVITY...LIGHT SHOWERS AND/OR
DRIZZLE/FOG WILL BE POSSIBLE THROUGH THE EVENING HOURS...THUS WILL
MAINTAIN LOW CEILINGS/VISIBILITIES. COOLER AIR WILL ALSO BEGIN TO
FILTER INTO THE REGION...FURTHER EXTENDING THE PERIOD OF LOW
CEILINGS. VISIBILITIES SHOULD IMPROVE TO VFR SHORTLY AFTER SUNRISE
ON SUNDAY.
&&
.PREV DISCUSSION...ISSUED 1215 PM EDT SAT SEP 23 2006
UPDATE...
THE THREAT OF SEVERE WEATHER CONTINUES FOR LATE THIS AFTERNOON INTO
THIS EVENING. 15Z SURFACE ANALYSIS SHOWS THE STRONGEST SURFACE
PRESSURE FALLS EXTENDING FROM WESTERN TENNESSEE TO SOUTHWEST
ILLINOIS ALONG THE WARM FRONT. THE TEMPERATURE AT PADUCAH KENTUCKY
CLIMBED FROM 68 TO 75 IN TWO HOURS AS THE FRONT STARTED TO COME
THROUGH. THE TREND OVER THE NEXT SEVERAL HOURS SHOULD BE FOR
PRESSURE TO CONTINUE FALLING OVER SOUTHWEST ILLINOIS AND AHEAD OF
THIS WARM FRONTAL BOUNDARY AS THIS FEATURE LIFTS NORTH. PRESSURE
FALLS AT THE SURFACE WILL BE IN RESPONSE TO A STRONG SHORTWAVE
MOVING THROUGH THE UPPER LEVEL TROUGH CURRENTLY SEEN ON WATER VAPOR
OVER NEBRASKA AND KANSAS. THE UPPER LEVEL CLOSED CIRCULATION OVER
EASTERN SOUTH DAKOTA IS STARTING TO OPEN AND THE WHOLE UPPER LEVEL
TROUGH AXIS IS EXPECTED TO PIVOT AND MOVE EASTWARD. AT THE
SURFACE...THE LOW OVER SOUTHERN ILLINOIS WILL TRACK NORTHEAST AHEAD
OF THE SHORTWAVE WITH BOTH THE 12Z NAM AND RUC INDICATING A PATH
FROM SOUTH BEND TO SOUTHERN LAKE HURON EARLY THIS EVENING. THIS
TRACK WILL LIKELY BRING THE SURFACE WARM FRONT INTO EXTREME
SOUTHEAST MICHIGAN WITH THUNDERSTORMS ACTIVITY ALSO POSSIBLE ALONG
THE COLD FRONT WITH STRONG DYNAMICAL FORCING. A MODIFIED NAM
SOUNDING AT DETROIT DURING THIS TIME WITH A SURFACE PARCEL OF 75/67
YIELDS 1200 J/KG OF CAPE WITH LITTLE IF ANY CONVECTIVE INHIBITION.
TEMPERATURES NEAR THE OHIO BORDER ARE ALREADY IN THE LOW 70S WITH
DEWPOINTS IN THE MID 60S. STRATUS HAS STARTED TO THIN BUT WILL
EXPECT CLOUDS TO THICKEN AGAIN AS LOW LEVEL THETA-E ADVECTION
INCREASES ACROSS SOUTHEAST MICHIGAN THIS AFTERNOON. ANY SHOWERS OR
THUNDERSTORMS THAT DEVELOP ALONG THIS ADVECTION WILL LIKELY REMAIN
ELEVATED WITH THE MOST FAVORABLE TIME FOR SEVERE STORMS STILL LATE
THIS AFTERNOON INTO THIS EVENING. MODELS STILL GENERALLY IN
AGREEMENT SHOWING STRONG OMEGA BETWEEN 21-00Z AS WELL AS A COUPLED
UPPER LEVEL JET. IF STORMS ARE ABLE TO BECOME SURFACE BASED BY EARLY
EVENING...SEVERE THREAT WILL BE FOCUSED SOUTH OF I-69 WITH STRONG
WIND GUSTS AND TORNADOS CONTINUING TO BE THE MAIN THREAT. FORECAST
GENERALLY ON TRACK AND HAVE RAISED POPS FOR EARLY AFTERNOON ACROSS
OUR SOUTHERN COUNTIES.
SHORT TERM...TODAY AND TONIGHT ISSUED 352 AM EDT SAT SEP 23 2006
THE CURRENT WATER VAPOR IMAGE SHOWS A POSITIVELY TILTED LONG WAVE
TROUGH EXTENDING FROM THE UPPER GREAT LAKES TO THE SOUTHERN ROCKIES.
THE 07Z SURFACE ANALYSIS SHOWS A LOW OVER MINNESOTA WITH AN OCCLUDED
FRONT EXTENDING INTO THE SOUTHERN PLAINS. A WARM FRONT IS ALSO
LOCATED ACROSS CENTRAL ILLINOIS AND INDIANA AND A SECONDARY SURFACE
LOW IS LOCATED NEAR THE TEXAS/OKLAHOMA BORDER. SHORT WAVE ENERGY
NEAR THE BASE OF THE LONG WAVE TROUGH OVER THE SOUTHERN ROCKIES IS
FORECAST TO LIFT INTO THE MIDWEST TODAY AND PHASE WITH THE CLOSED
LOW CURRENTLY OVER THE NORTHERN PLAINS. THE UPPER TROUGH AXIS IS
THEN FORECAST TO SWING THROUGH THE GREAT LAKES REGION LATE TONIGHT.
THE 00Z MODEL SUITE FORECAST STRONG UPPER LEVEL JET COUPLING
DEVELOPING ACROSS THE SOUTHERN GREAT LAKES REGION LATE IN THE
AFTERNOON AND PERSISTING THROUGH THE EVENING. THIS ALONG WITH THE
MID LEVEL HEIGHT FALLS WILL LEAD TO WIDESPREAD SHOWERS AND
THUNDERSTORMS THIS EVENING.
THE 00Z MODEL SUITE STILL HAVE SOME DIFFERENCES IN TIMING AND TRACK
OF THE ASSOCIATED SURFACE LOW NOW OVER TEXAS INTO THE SOUTHERN GREAT
LAKES REGION TONIGHT. THE UKMET...WRFHEMI AND GLOBAL TAKE THE LOW
JUST SOUTHEAST OF DETROIT OVERNIGHT AND FOCUS THE HIGHER INSTABILITY
SOUTH OF THE STATE. THE NAM...AND TO SOME EXTEND THE GFS...TAKES THE
LOW ACROSS SOUTHERN LOWER MI THIS EVENING. ALL OF THE 00Z MODEL
SUITE HAD SOME INITIALIZATION PROBLEMS WITH THE HEIGHT FIELDS
UPSTREAM. GIVEN THE STRONG UPPER JET COUPLING OVER THE SOUTHERN
LAKES THIS EVENING...PREFER THE NAM SURFACE LOW TRACK. THE NAM ALSO
HAD A GOOD HANDLE ON THE STRENGTH AND POSITION OF THE LOW AS OF 06Z.
THE FORECAST AREA IS IN A SLIGHT RISK FOR SEVERE WEATHER
TODAY...WHICH WILL BE MORE LIKELY THIS EVENING AS STRONGER MID LEVEL
FORCING MOVES INTO THE REGION. GIVEN THE STRONGLY SHEARED
ENVIRONMENT...0-6KM SHEAR OF 40-50 KNOTS...THE SEVERE POTENTIAL
WILL RELY ON HOW MUCH INSTABILITY CAN BE REALIZED. THE EXTENSIVE
STRATUS DECK ACROSS THE AREA THIS MORNING WILL LIFT INTO A BROKEN
STRATO CU FIELD BY AFTERNOON. SO SUNSHINE WILL BE VERY LIMITED
TODAY. IF AFTERNOON TEMPS REACH THE MID 70S...MODIFIED NAM
SOUNDINGS WITH LOWER 60 DEWPOINTS SHOW 0-1KM MIXED LAYER CAPE
APPROACHING 1000 J/KG. GIVEN THE 50-60KT MID LEVEL WINDS AND
EXPECTED BACKED SURFACE FLOW AHEAD OF THE APPROACHING LOW...STORM
TYPE IS EXPECTED TO BE SUPERCELLULAR WITH DAMAGING WINDS AND
TORNADOES THE PRIMARY SEVERE WEATHER HAZARDS.
SOME DRYER MID LEVEL AIR HAS MOVED ACROSS THE FORECAST AREA THIS
MORNING IN THE WAKE OF LAST EVENINGS CONVECTION. THUS UNTIL THE
STRONGER MID LEVEL FORCING ARRIVES AFTER 21Z...POPS WILL BE FAIRLY
LOW THIS MORNING AND AFTERNOON. WEAK SHORT WAVES EMBEDDED WITHIN THE
SOUTHWEST FLOW ALOFT AND INCREASING UPPER JET FORCING WILL SUPPORT
ISOLATED TO SCATTERED POPS THROUGH 21Z. AN INCREASE IN 850MB THETA E
LATE THIS MORNING AND AFTERNOON SHOULD ALSO SUPPORT SCATTERED
CONVECTION ALONG AND SOUTH OF I-94 THROUGH THE AFTERNOON.
LONG TERM...SUNDAY THROUGH FRIDAY
SURFACE LOW WILL LIFT THROUGH THE LOWER GREAT LAKES AND UP THE ST
LAWRENCE VALLEY ON SUNDAY...LEAVING SOME DEGREE OF TROUGHING BACK
ACROSS THE CENTRAL GREAT LAKES. 00Z NAM REVERSED ITS EARLIER TREND
AND IS NOT A BIT FASTER TAKING THE LOW OUT OF THE REGION...WITH THE
GFS ALREADY FASTER AND CONTINUING TO ACCELERATE. WITH THE FASTER
CONSENSUS AND OVERALL TREND...DO NOT NECESSARILY BUY THE SHARP
SURFACE TROUGH THE NAM LINGERS ACROSS SOUTHEAST MICHIGAN. HOWEVER
SOME DEGREE OF LOW-LEVEL CYCLONIC FLOW AND CONVERGENCE CAN BE
EXPECTED WITH THE COLD ADVECTION BEHIND THE SYSTEM. WILL CARRY
LIKELY POPS ACROSS LAKE HURON DURING THE MORNING...OTHERWISE
SCATTERED SHRA DURING THE AFTERNOON WITH SOME DIURNAL ENHANCEMENT TO
LAPSE RATES/INSTABILITY.
NAM ALSO CONTINUES TO TREND TOWARD THE GFS SOLUTION WITH THE NEXT
SHORTWAVE DIGGING OUT OF NORTHERN CANADA MONDAY/MONDAY NIGHT. WITH
THE FASTER APPROACH AND STRONGER/MORE DEFINED SHORTWAVE...WE WILL
NOT SEE AS MUCH OF A PROLONGED PERIOD OF COLD NORTHERLY FLOW. MIXED
LAYER FLOW BACKS AROUND TO THE WEST/SOUTHWEST ON MONDAY...WITH THE
LOW-LEVEL THERMAL TROUGH WEAKENING/SHIFTING DOWNSTREAM...LIMITING
LAKE EFFECT POTENTIAL. HOWEVER THIS WILL BE OFFSET BY INCREASING
SYNOPTIC LIFT AHEAD OF THE SHORTWAVE...WITH ENHANCED LOW-LEVEL
CONVERGENCE ALONG THE SURFACE TROUGH. AM CONCERNED THAT THE GFS IS
TOO STRONG WITH THE SHORTWAVE...AND CONSEQUENTLY DIVES IT TOO FAR
SOUTHWEST ACROSS THE CENTRAL GREAT LAKES. CONSENSUS WOULD OTHERWISE
SUPPORT PRECIP TO THE EAST ACROSS LAKE HURON/ONTARIO. IF THE
STRONGER GFS SOLUTION PANS OUT...WOULD NEED TO CARRY A CHANCE SHRA
LATE MONDAY/MONDAY NIGHT ACROSS SOUTHEAST MICHIGAN. AS IT STANDS
MOISTURE MAY BE RATHER LIMITED...BUT WILL INCREASE SKY COVER MONDAY
NIGHT. THEREFORE WILL ALSO RAISE MINS A COUPLE DEGREES WITH
ADDITIONAL CLOUDS/WEAK WARM ADVECTION.
ADDITIONAL DIFFERENCES DEVELOP WITH THE NEXT LONGWAVE SYSTEM THAT
DIGS ACROSS THE PLAINS TUESDAY/WEDNESDAY AND AMPLIFIES ACROSS THE
GREAT LAKES BY THURSDAY. 00Z GFS HAS TRENDED SLOWER WITH THIS SYSTEM
CRESTING THE WESTERN RIDGE...AND AMPLIFIES IT FARTHER WEST...LEADING
TO A MUCH SLOWER TIMING INTO THE GREAT LAKES. OTHER 12Z MODELS WERE
PRETTY SIMILAR AND CONSISTENT WITH THE EVOLUTION OF THE SYSTEM.
TEMPTED TO LEAVE THE FORECAST AS IS FOR NOW GIVEN THIS BREAK FROM
CONTINUITY...TO SEE WHETHER THE NEXT RUN SETTLES DOWN ON A SIMILAR
SOLUTION. A QUICK LOOK AT THE 00Z ECMWF SHOWS A SIMILAR TREND...MORE
AMPLIFIED AND ABOUT 12 HOURS SLOWER THAN THE 12Z RUN. IT LOOKS LIKE
THERE IS SOMETHING IN THE 00Z INITIALIZATION THAT BOTH THE GFS/ECMWF
LATCHED ONTO TO AFFECT THEIR SOLUTIONS. WE WILL SEE IF THIS FEATURE
HOLDS INTO THE 12Z RUNS...WHICH WOULD LEAD TO A SLOWER ONSET BUT
MORE PROLONGED PERIOD OF POPS THROUGH THE END OF THE WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CONSIDINE
LONG TERM....BRAVENDER
AVIATION...SHULER
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
</PRE></TT></td>   mi
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE ALBANY NY
1257 PM EDT SAT SEP 23 2006
CORRECTED HEADER
.SHORT TERM /REST OF THIS AFTERNOON/...
ANOTHER QUICK UPDATE TO IMPROVE THE ZONE FORECAST WORDING BASED ON
THE 1730Z KENX RADAR.  THE SHOWERS HAVE ENDED OVER THE MAJORITY OF
THE FCST AREA WITH SOME LINGERING SHOWERS OVER THE SRN ADIRONDACKS.
WE HAVE TAKEN THE POPS OUT PRIOR TO 22Z/6 PM SOUTH OF THE CAPITAL
DISTRICT AND KEPT SLIGHT CHANCE OR LOW CHANCE VALUES IN FROM THE
CAPITAL DISTRICT NORTH. THE MAIN WARM FRONT HAS REACHED WRN NY AND
WRN PA. ANOTHER BATCH OF RAIN IS ORGANIZING OVER S-CNTRL PA AND MD
FOR TONIGHT.
SHORT TERM UPDATE...WASULA
&&
.PREV DISCUSSION...
 /ISSUED 1037 AM EDT SAT SEP 23 2006/
SHORT TERM /REST OF TODAY/...
THIS UPDATE IS BASED ON THE KENX AND NEIGHBORING RADAR TRENDS AS
WELL AS THE LATEST 40KM RUC.  THE MAIN THRUST OF THERMAL ADVECTION
RAINFALL WITH THE THERMAL TROUGH IS CLEARING THE NE CORNER OF THE
FCST AREAS /SRN VT AND THE LAKE GEORGE REGION/ AT THIS TIME.
SCATTERED SHOWER ACTIVITY THAT HAS PERSISTED IN THE I-88  TO I-90
CORRIDOR IS TIED TO A WEAK H500 IMPULSE. WE HAVE DECIDED TO KEEP
LIKELY VALUES FOR SHOWERS NORTH OF THE CAPITAL DISTRICT AND
BERKSHIRES UP TO 18Z...THEN CHANCE VALUES THEREAFTER UP TO 22Z.  WE
ALSO WILL KEEP A CHANCE OF SHOWERS IN FOR THE NRN CATSKILLS...ERN
MOHAWK VALLEY...CAPITAL DISTRICT AND BERKSHIRES UNTIL 18Z TOO.
SLIGHT CHANCE VALUES SOUTH OF THE CAPITAL DISTRICT...WE WILL
CONTINUE FROM THE LATE MORNING FORWARD. WE ALSO BUMPED MAX TEMPS
DOWN A CATEGORY /3 DEGREES/ FOR THE BULK OF THE FCST AREA. TEMPS
WILL BE STEADY OR RISE AFTER 22Z.
THE MAIN WARM FRONT WITH AN EMBEDDED SHORTWAVE WILL MOVE N/NE INTO
NY AND NEW ENGLAND AFTER 22Z WITH ELEVATED CONVECTION A GOOD
POSSIBILITY WITH SHOWALTER VALUES OF -1 TO -3C AND MLCAPE VALUES OF
200-500 J/KG BASED ON THE GFS MODEL SOUNDINGS FOR THE OVERNIGHT
PERIOD.
UPDATE...WASULA
PREV DISCUSSION...
 /ISSUED 327 AM EDT SAT SEP 23 2006/
SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION THIS
MORNING...BRINING SHOWERS. THEN A BREAK IN THE PRECIPITATION WILL
OCCUR DURING THE AFTERNOON AND INTO THE EVENING...BEFORE THE NEXT
BATCH OF RAIN ARRIVES LATE TONIGHT ASSOCIATED WITH A STRENGTHENING
LOW PRESSURE SYSTEM MOVING NORTHEAST THROUGH THE CENTRAL GREAT
LAKES. AS THE SURFACE LOW CONTINUES TO PROGRESS NORTHEASTWARD INTO
SOUTHERN CANADA ON SUNDAY...A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL SWEEP THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND DURING
THE AFTERNOON. SHOWERS AND THUNDERSTORMS AND WINDY CONDITIONS WILL
AFFECT MOST OF THE REGION AS THE FRONT MOVES THROUGH...WITH SOME
THUNDERSTORMS POSSIBLY BECOMING SEVERE SOUTH AND EAST OF THE CAPITAL
REGION. DRIER AND COOLER CONDITIONS WILL MOVE IN FOR EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH MONDAY/...
AN ACTIVE COUPLE DAYS OF WEATHER IN STORE...COMPLETE WITH
RAIN...INCREASING HUMIDITY LEVELS...WARM TEMPS...THUNDERSTORMS AND
WIND. WHILE THE ENTIRE WEEKEND WILL NOT BE A WASHOUT...THERE WILL BE
A FEW DOSES OF INCLEMENT WEATHER.
THIS MORNING...WARM ADVECTION/ISENTROPIC LIFT PRODUCING OCCASIONAL
LIGHT SHOWERS ACROSS THE AREA. HOWEVER...THIS FORCING WILL LIFT
NORTH OF THE AREA BY AFTN...LEAVING MAINLY DRY CONDITIONS FOR THE
REST OF THE DAY INTO THE EVENING. THERE WILL STILL BE PLENTY OF
CLOUDS AROUND...WITH A NOTICEABLE INCREASE IN DEWPOINTS. DUE TO
CLOUD COVER...TEMPS WILL BE HELD DOWN JUST BELOW 70 IN THE VALLEYS
TODAY.
TONIGHT...WE WILL LIKELY REMAIN DRY UNTIL LATE EVENING/EARLY SUNDAY
MORNING. THEN THE NEXT BATCH OF RAIN MOVES IN FROM THE SOUTH AND
WEST ASSOCIATED WITH A SURGE OF ISENTROPIC LIFT TIED TO AN
IMPRESSIVE DEEPENING SFC CYCLONE LIFTING NE THRU THE CENTRAL GREAT
LAKES REGION. WILL ADD MENTION OF THUNDER...WITH SOME ELEVATED
INSTABILITY SEEN ON FORECAST SOUNDINGS IN THE MID LEVELS. IT WILL BE
MILD NIGHT...WITH CLOUDS/RAIN AND LOW LEVEL MOISTURE ASSOC WITH S/SW
FLOW.
SUNDAY WILL BE THE MOST ACTIVE AND CHANGEABLE DAY IN THE SHORT TERM.
THE AFOREMENTIONED SFC CYCLONE IS FORECAST TO LIFT NE THRU SE
ONTARIO AND SOUTHERN QUEBEC...WITH A TRAILING COLD FRONT BLASTING
THRU EASTERN NEW YORK/WESTERN NEW ENG DURING THE EARLY TO MID AFTN.
THERE ARE A COUPLE DIFFERENT CONCERNS. THE FIRST IS THE SEVERE
THUNDERSTORM POTENTIAL. CHOSE TIMING CLOSEST TO THE GFS...WHICH
BRINGS THE COLD FRONT THRU MUCH EARLIER THAN THE WRF/NAM. EARLY TO
MID AFTN TIMING OF CFROPA WILL PLAY A BIG ROLE IN DETERMINING WHICH
AREAS HAVE THE GREATEST SEVERE POTENTIAL. AS OF NOW IT APPEARS AREAS
TO THE SOUTH AND EAST OF THE CAPITAL REGION WILL BE AT RISK. THIS IS
WHERE THE MOST INSTABILITY WILL HAVE A CHANCE TO BUILD. FORECAST
CAPE VALUES ARE MODEST AT BEST AROUND 300-500 J/KG...HOWEVER THERE
WILL BE LOW LEVEL CONVERGENCE ALONG THE FRONT...TO GO ALONG WITH A
VERY STRONG AND IMPRESSIVE WIND FIELD THROUGHOUT THE DEPTH OF THE
TROPOSPHERE. THIS WILL LIKELY BE A HIGH SHEAR/LOW INSTABILITY
EVENT...WITH THE POTENTIAL FOR DAMAGING WIND GUSTS. MAINLY
UNIDIRECTIONAL 0-6 KM BULK SHEAR VALUES OF 40-55 KTS COME AS NO
SURPRISE SINCE 850 MB WINDS ARE FORECAST TO BE AROUND 50 KTS...WITH
700 MB WINDS NEAR 65 KTS! ANOTHER FAVORABLE FACTOR WILL BE SFC
DEWPOINTS RISING INTO THE MID TO UPPER 60S.
THE OTHER CONCERN BESIDES SEVERE THUNDERSTORMS IS THE POTENTIAL FOR
STRONG...GUSTY WEST TO NORTHWEST WIND BEHIND THE COLD FRONT. COLD
AIR ADVECTION WILL LEAD TO STRONG MIXING WITH SOME BREAKS OF
SUNSHINE LIKELY. WINDS GUSTS OF 40-50 MPH WILL BE POSSIBLE DURING
THE LATTER HALF OF THE AFTN AND EARLY EVENING. WE MAY END UP NEEDING
A WIND ADVISORY...BUT TOO EARLY TO ISSUE JUST YET. WILL CONTINUE TO
MENTION THREAT IN HWO. ALSO POST CFROPA...TEMPS WILL SPIKE DUE TO
THE MIXING AND NEAR DRY ADIABATIC LAPSE RATES FOR A FEW HOURS. THIS
WILL ALLOW TEMPS TO RISE INTO THE MID TO UPPER 70S FROM ALBANY
SOUTHWARD.
THE THREAT OF RAIN WILL DIMINISH CONSIDERABLY BY EVENING...WITH
NORTHWEST FLOW REGIME BECOMING ESTABLISHED. MONDAY WILL FEATURE DRY
CONDITIONS WITH MUCH COOLER TEMPS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
NO CHANGES TO THE GOING FORECAST PAST MONDAY. AFTER A REINFORCING
SHOT OF COOL AIR EARLY TUESDAY...HIGH PRESSURE WILL BUILD IN AND
TAKE CONTROL OF THE WEATHER WED INTO THUR. IT APPEARS THE NEXT LOW
PRESSURE SYSTEM WILL APPROACH THE AREA OF FRI...BRINGING THE NEXT
SIGNIFICANT CHANCE OF RAIN.
AVIATION...
CEILINGS ARE FORECAST TO LOWER IN THE PREDAWN HOURS TO AROUND 3000
FEET MSL WHICH WILL RESULT IN MVFR OVER THE VALLEYS WITH AREAS OF
IFR OVER THE HIGHER TERRAIN...WITH CEILINGS SLIGHTLY BELOW 2000 FEET
MSL SHORTLY AFTER DAYBREAK AND VISIBILITY 4 TO 5 MILES IN RAIN
SHOWERS. WINDS WILL GENERALLY BE FROM THE SOUTH 7 TO 14 KNOTS. THE
LOW CLOUDS ARE LIKELY TO BECOME SCATTERED IN LATE AFTERNOON BUT WILL
BECOME BROKEN AROUND 5000 FEET EARLY THIS EVENING ALONG WITH LIGHT
FOG FORMING. THE OVERCAST WILL LOWER TO AROUND 1000 FEET BY LATER
THIS EVENING WITH WIDESPREAD LIGHT FOG RESULTING IN WIDESPREAD IFR
CONDITIONS OVER THE REGION TONIGHT...WITH WINDS AT THE SURFACE CALM
OR NEARLY SO.
FIRE WEATHER...
CONDITIONS FOR IGNITION WILL CONTINUE TO BE UNFAVORABLE WITH
SCATTERED SHOWERS MOVING INTO THE REGION IN THE PREDAWN HOURS.
SEVERAL HOURS OF RAIN LATER THIS MORNING WILL RESULT IN HIGH FUEL
MOISTURE. A BRIEF PERIOD OF PARTLY SUNNY WEATHER MAY OCCUR LATER
THIS AFTERNOON WHILE THE REGION IS IN THE WARM SECTOR BUT CLOUDINESS
IS EXPECTED TO INCREASE THIS EVENING WITH OVERNIGHT RH VALUES CLOSE
TO 100 PERCENT IN WIDESPREAD LIGHT FOG. AS THE COLD FRONT APPROACHES
AND PASSES THROUGH THE REGION ON SUNDAY THUNDERSTORMS ARE LIKELY TO
DEVELOP AND BRING A THREAT OF CLOUD TO GROUND LIGHTNING ALTHOUGH
HEAVY RAIN WITH THE STORMS SHOULD MINIMIZE THE THREAT OF FIRE. SOME
DRYING OF GROUND FUELS MAY BE EXPECTED FOLLOWING THE FRONTAL PASSAGE
WITH BRISK WESTERLY WINDS 10 TO 15 MPH...PARTLY SUNNY SKIES...AND
AFTERNOON RH VALUES OF 40 TO 50 PERCENT.
HYDROLOGY...
NO HYDRO PROBLEMS EXPECTED ON THE RIVERS THE NEXT SEVERAL DAYS. A
WARM FRONT WILL BRING A PERIOD OF LIGHT RAIN TO THE FORECAST AREA
SATURDAY MORNING INTO THE EARLY AFTERNOON. RAINFALL AMOUNTS OVER THE
HYDRO SERVICE AREA WILL BE A TENTH OF AN INCH TO A THIRD OF AN INCH
TODAY. THE REGION WILL GET INTO A WARM SECTOR LATE SATURDAY
AFTERNOON INTO SUNDAY MORNING. A COLD FRONT AND A STRONG SURFACE
CYCLONE MOVING NORTH OF THE SAINT LAWRENCE RIVER VALLEY SUNDAY
MORNING...WILL BRING SOME HEAVY SHOWERS AND THUNDERSTORMS TO THE
REGION. STRONG MOISTURE CONVERGENCE AHEAD OF THE FRONT...COUPLED
WITH DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES IN THE
1.50-2.00" RANGE WILL CAUSE SOME LOCALLY HEAVY DOWNPOURS...AND WITH
THEM A POTENTIAL FOR FLOODING OF POORLY DRAINED ROADS AND PARKING
AREAS. RAPID RISES TO NEAR BANKFULL MAY OCCUR ON SOME STREAMS. THE
PASSAGE OF THE COLD FRONT WILL BE FOLLOWED BY COOLER AND DRIER
WEATHER FOR THE FIRST FEW DAYS OF THE UPCOMING WEEK.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NY...NONE.
VT...NONE.
&&
$$
</PRE></TT></td>   ny
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE ALBANY NY
1238 PM EDT SAT SEP 23 2006
.SHORT TERM /REST OF TONIGHT/...
ANOTHER QUICK UPDATE TO IMPROVE THE ZONE FORECAST WORDING BASED ON
THE 1730Z KENX RADAR.  THE SHOWERS HAVE ENDED OVER THE MAJORITY OF
THE FCST AREA WITH SOME LINGERING SHOWERS OVER THE SRN ADIRONDACKS.
WE HAVE TAKEN THE POPS OUT PRIOR TO 22Z/6 PM SOUTH OF THE CAPITAL
DISTRICT AND KEPT SLIGHT CHANCE OR LOW CHANCE VALUES IN FROM THE
CAPITAL DISTRICT NORTH. THE MAIN WARM FRONT HAS REACHED WRN NY AND
WRN PA. ANOTHER BATCH OF RAIN IS ORGANIZING OVER S-CNTRL PA AND MD
FOR TONIGHT.
SHORT TERM UPDATE...WASULA
&&
.PREV DISCUSSION...
 /ISSUED 1037 AM EDT SAT SEP 23 2006/
SHORT TERM /REST OF TODAY/...
THIS UPDATE IS BASED ON THE KENX AND NEIGHBORING RADAR TRENDS AS
WELL AS THE LATEST 40KM RUC.  THE MAIN THRUST OF THERMAL ADVECTION
RAINFALL WITH THE THERMAL TROUGH IS CLEARING THE NE CORNER OF THE
FCST AREAS /SRN VT AND THE LAKE GEORGE REGION/ AT THIS TIME.
SCATTERED SHOWER ACTIVITY THAT HAS PERSISTED IN THE I-88  TO I-90
CORRIDOR IS TIED TO A WEAK H500 IMPULSE. WE HAVE DECIDED TO KEEP
LIKELY VALUES FOR SHOWERS NORTH OF THE CAPITAL DISTRICT AND
BERKSHIRES UP TO 18Z...THEN CHANCE VALUES THEREAFTER UP TO 22Z.  WE
ALSO WILL KEEP A CHANCE OF SHOWERS IN FOR THE NRN CATSKILLS...ERN
MOHAWK VALLEY...CAPITAL DISTRICT AND BERKSHIRES UNTIL 18Z TOO.
SLIGHT CHANCE VALUES SOUTH OF THE CAPITAL DISTRICT...WE WILL
CONTINUE FROM THE LATE MORNING FORWARD. WE ALSO BUMPED MAX TEMPS
DOWN A CATEGORY /3 DEGREES/ FOR THE BULK OF THE FCST AREA. TEMPS
WILL BE STEADY OR RISE AFTER 22Z.
THE MAIN WARM FRONT WITH AN EMBEDDED SHORTWAVE WILL MOVE N/NE INTO
NY AND NEW ENGLAND AFTER 22Z WITH ELEVATED CONVECTION A GOOD
POSSIBILITY WITH SHOWALTER VALUES OF -1 TO -3C AND MLCAPE VALUES OF
200-500 J/KG BASED ON THE GFS MODEL SOUNDINGS FOR THE OVERNIGHT
PERIOD.
UPDATE...WASULA
PREV DISCUSSION...
 /ISSUED 327 AM EDT SAT SEP 23 2006/
SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD THROUGH THE REGION THIS
MORNING...BRINING SHOWERS. THEN A BREAK IN THE PRECIPITATION WILL
OCCUR DURING THE AFTERNOON AND INTO THE EVENING...BEFORE THE NEXT
BATCH OF RAIN ARRIVES LATE TONIGHT ASSOCIATED WITH A STRENGTHENING
LOW PRESSURE SYSTEM MOVING NORTHEAST THROUGH THE CENTRAL GREAT
LAKES. AS THE SURFACE LOW CONTINUES TO PROGRESS NORTHEASTWARD INTO
SOUTHERN CANADA ON SUNDAY...A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL SWEEP THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND DURING
THE AFTERNOON. SHOWERS AND THUNDERSTORMS AND WINDY CONDITIONS WILL
AFFECT MOST OF THE REGION AS THE FRONT MOVES THROUGH...WITH SOME
THUNDERSTORMS POSSIBLY BECOMING SEVERE SOUTH AND EAST OF THE CAPITAL
REGION. DRIER AND COOLER CONDITIONS WILL MOVE IN FOR EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH MONDAY/...
AN ACTIVE COUPLE DAYS OF WEATHER IN STORE...COMPLETE WITH
RAIN...INCREASING HUMIDITY LEVELS...WARM TEMPS...THUNDERSTORMS AND
WIND. WHILE THE ENTIRE WEEKEND WILL NOT BE A WASHOUT...THERE WILL BE
A FEW DOSES OF INCLEMENT WEATHER.
THIS MORNING...WARM ADVECTION/ISENTROPIC LIFT PRODUCING OCCASIONAL
LIGHT SHOWERS ACROSS THE AREA. HOWEVER...THIS FORCING WILL LIFT
NORTH OF THE AREA BY AFTN...LEAVING MAINLY DRY CONDITIONS FOR THE
REST OF THE DAY INTO THE EVENING. THERE WILL STILL BE PLENTY OF
CLOUDS AROUND...WITH A NOTICEABLE INCREASE IN DEWPOINTS. DUE TO
CLOUD COVER...TEMPS WILL BE HELD DOWN JUST BELOW 70 IN THE VALLEYS
TODAY.
TONIGHT...WE WILL LIKELY REMAIN DRY UNTIL LATE EVENING/EARLY SUNDAY
MORNING. THEN THE NEXT BATCH OF RAIN MOVES IN FROM THE SOUTH AND
WEST ASSOCIATED WITH A SURGE OF ISENTROPIC LIFT TIED TO AN
IMPRESSIVE DEEPENING SFC CYCLONE LIFTING NE THRU THE CENTRAL GREAT
LAKES REGION. WILL ADD MENTION OF THUNDER...WITH SOME ELEVATED
INSTABILITY SEEN ON FORECAST SOUNDINGS IN THE MID LEVELS. IT WILL BE
MILD NIGHT...WITH CLOUDS/RAIN AND LOW LEVEL MOISTURE ASSOC WITH S/SW
FLOW.
SUNDAY WILL BE THE MOST ACTIVE AND CHANGEABLE DAY IN THE SHORT TERM.
THE AFOREMENTIONED SFC CYCLONE IS FORECAST TO LIFT NE THRU SE
ONTARIO AND SOUTHERN QUEBEC...WITH A TRAILING COLD FRONT BLASTING
THRU EASTERN NEW YORK/WESTERN NEW ENG DURING THE EARLY TO MID AFTN.
THERE ARE A COUPLE DIFFERENT CONCERNS. THE FIRST IS THE SEVERE
THUNDERSTORM POTENTIAL. CHOSE TIMING CLOSEST TO THE GFS...WHICH
BRINGS THE COLD FRONT THRU MUCH EARLIER THAN THE WRF/NAM. EARLY TO
MID AFTN TIMING OF CFROPA WILL PLAY A BIG ROLE IN DETERMINING WHICH
AREAS HAVE THE GREATEST SEVERE POTENTIAL. AS OF NOW IT APPEARS AREAS
TO THE SOUTH AND EAST OF THE CAPITAL REGION WILL BE AT RISK. THIS IS
WHERE THE MOST INSTABILITY WILL HAVE A CHANCE TO BUILD. FORECAST
CAPE VALUES ARE MODEST AT BEST AROUND 300-500 J/KG...HOWEVER THERE
WILL BE LOW LEVEL CONVERGENCE ALONG THE FRONT...TO GO ALONG WITH A
VERY STRONG AND IMPRESSIVE WIND FIELD THROUGHOUT THE DEPTH OF THE
TROPOSPHERE. THIS WILL LIKELY BE A HIGH SHEAR/LOW INSTABILITY
EVENT...WITH THE POTENTIAL FOR DAMAGING WIND GUSTS. MAINLY
UNIDIRECTIONAL 0-6 KM BULK SHEAR VALUES OF 40-55 KTS COME AS NO
SURPRISE SINCE 850 MB WINDS ARE FORECAST TO BE AROUND 50 KTS...WITH
700 MB WINDS NEAR 65 KTS! ANOTHER FAVORABLE FACTOR WILL BE SFC
DEWPOINTS RISING INTO THE MID TO UPPER 60S.
THE OTHER CONCERN BESIDES SEVERE THUNDERSTORMS IS THE POTENTIAL FOR
STRONG...GUSTY WEST TO NORTHWEST WIND BEHIND THE COLD FRONT. COLD
AIR ADVECTION WILL LEAD TO STRONG MIXING WITH SOME BREAKS OF
SUNSHINE LIKELY. WINDS GUSTS OF 40-50 MPH WILL BE POSSIBLE DURING
THE LATTER HALF OF THE AFTN AND EARLY EVENING. WE MAY END UP NEEDING
A WIND ADVISORY...BUT TOO EARLY TO ISSUE JUST YET. WILL CONTINUE TO
MENTION THREAT IN HWO. ALSO POST CFROPA...TEMPS WILL SPIKE DUE TO
THE MIXING AND NEAR DRY ADIABATIC LAPSE RATES FOR A FEW HOURS. THIS
WILL ALLOW TEMPS TO RISE INTO THE MID TO UPPER 70S FROM ALBANY
SOUTHWARD.
THE THREAT OF RAIN WILL DIMINISH CONSIDERABLY BY EVENING...WITH
NORTHWEST FLOW REGIME BECOMING ESTABLISHED. MONDAY WILL FEATURE DRY
CONDITIONS WITH MUCH COOLER TEMPS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
NO CHANGES TO THE GOING FORECAST PAST MONDAY. AFTER A REINFORCING
SHOT OF COOL AIR EARLY TUESDAY...HIGH PRESSURE WILL BUILD IN AND
TAKE CONTROL OF THE WEATHER WED INTO THUR. IT APPEARS THE NEXT LOW
PRESSURE SYSTEM WILL APPROACH THE AREA OF FRI...BRINGING THE NEXT
SIGNIFICANT CHANCE OF RAIN.
AVIATION...
CEILINGS ARE FORECAST TO LOWER IN THE PREDAWN HOURS TO AROUND 3000
FEET MSL WHICH WILL RESULT IN MVFR OVER THE VALLEYS WITH AREAS OF
IFR OVER THE HIGHER TERRAIN...WITH CEILINGS SLIGHTLY BELOW 2000 FEET
MSL SHORTLY AFTER DAYBREAK AND VISIBILITY 4 TO 5 MILES IN RAIN
SHOWERS. WINDS WILL GENERALLY BE FROM THE SOUTH 7 TO 14 KNOTS. THE
LOW CLOUDS ARE LIKELY TO BECOME SCATTERED IN LATE AFTERNOON BUT WILL
BECOME BROKEN AROUND 5000 FEET EARLY THIS EVENING ALONG WITH LIGHT
FOG FORMING. THE OVERCAST WILL LOWER TO AROUND 1000 FEET BY LATER
THIS EVENING WITH WIDESPREAD LIGHT FOG RESULTING IN WIDESPREAD IFR
CONDITIONS OVER THE REGION TONIGHT...WITH WINDS AT THE SURFACE CALM
OR NEARLY SO.
FIRE WEATHER...
CONDITIONS FOR IGNITION WILL CONTINUE TO BE UNFAVORABLE WITH
SCATTERED SHOWERS MOVING INTO THE REGION IN THE PREDAWN HOURS.
SEVERAL HOURS OF RAIN LATER THIS MORNING WILL RESULT IN HIGH FUEL
MOISTURE. A BRIEF PERIOD OF PARTLY SUNNY WEATHER MAY OCCUR LATER
THIS AFTERNOON WHILE THE REGION IS IN THE WARM SECTOR BUT CLOUDINESS
IS EXPECTED TO INCREASE THIS EVENING WITH OVERNIGHT RH VALUES CLOSE
TO 100 PERCENT IN WIDESPREAD LIGHT FOG. AS THE COLD FRONT APPROACHES
AND PASSES THROUGH THE REGION ON SUNDAY THUNDERSTORMS ARE LIKELY TO
DEVELOP AND BRING A THREAT OF CLOUD TO GROUND LIGHTNING ALTHOUGH
HEAVY RAIN WITH THE STORMS SHOULD MINIMIZE THE THREAT OF FIRE. SOME
DRYING OF GROUND FUELS MAY BE EXPECTED FOLLOWING THE FRONTAL PASSAGE
WITH BRISK WESTERLY WINDS 10 TO 15 MPH...PARTLY SUNNY SKIES...AND
AFTERNOON RH VALUES OF 40 TO 50 PERCENT.
HYDROLOGY...
NO HYDRO PROBLEMS EXPECTED ON THE RIVERS THE NEXT SEVERAL DAYS. A
WARM FRONT WILL BRING A PERIOD OF LIGHT RAIN TO THE FORECAST AREA
SATURDAY MORNING INTO THE EARLY AFTERNOON. RAINFALL AMOUNTS OVER THE
HYDRO SERVICE AREA WILL BE A TENTH OF AN INCH TO A THIRD OF AN INCH
TODAY. THE REGION WILL GET INTO A WARM SECTOR LATE SATURDAY
AFTERNOON INTO SUNDAY MORNING. A COLD FRONT AND A STRONG SURFACE
CYCLONE MOVING NORTH OF THE SAINT LAWRENCE RIVER VALLEY SUNDAY
MORNING...WILL BRING SOME HEAVY SHOWERS AND THUNDERSTORMS TO THE
REGION. STRONG MOISTURE CONVERGENCE AHEAD OF THE FRONT...COUPLED
WITH DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES IN THE
1.50-2.00" RANGE WILL CAUSE SOME LOCALLY HEAVY DOWNPOURS...AND WITH
THEM A POTENTIAL FOR FLOODING OF POORLY DRAINED ROADS AND PARKING
AREAS. RAPID RISES TO NEAR BANKFULL MAY OCCUR ON SOME STREAMS. THE
PASSAGE OF THE COLD FRONT WILL BE FOLLOWED BY COOLER AND DRIER
WEATHER FOR THE FIRST FEW DAYS OF THE UPCOMING WEEK.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NY...NONE.
VT...NONE.
&&
$$
</PRE></TT></td>   ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
235 PM CDT SAT SEP 23 2006
.DISCUSSION...THE MAIN CONCERN IN THE SHORT TERM IS THE CONV
POTENTIAL LATE TONIGHT INTO SUNDAY. ALTHOUGH BOTH THE NAM AND THE
GFS ARE IN REASONABLE AGREEMENT ON THE OVERALL TIMING OF THE
FRONT...BIG DIFFERENCES SHOW UP IN THE POPS AND OVERALL QPF VALUES.
THE GFS QPF FIELDS LOOK TO HAVE SOME CONV FEEDBACK ISSUES THROUGH
12Z TOMORROW AND PAINT A LARGE CIRCULAR BULLSEYE OF VERY HIGH VALUES
OVER THE CRP AND NORTHERN BRO CWAS. THIS LOOKS SOMEWHAT SUSPICIOUS
AND AM FAVORING THE MORE CONSERVATIVE AND REASONABLE NAM FIELDS.
THE HIGHER GFS QPF VALUES APPEAR TO BE DUE TO AN OVERDEVELOPED 500
MB VORT MAX MOVING OVER DEEP SOUTH TEXAS EARLY TOMORROW MORNING. THE
GFS 500 MB VORTICITY FIELD EARLY IN THE PERIOD APPEARS TO BE THE
OUTLIER IN COMPARISON TO THE RUC/NAM AND ECMWF SOLUTIONS WHICH
INDICATE SOME PVA BUT BROADER AND WEAKER. ALTHOUGH THE GFS APPEARS
TO BE TOO AGGRESSIVE IN OVERALL QPF FIELDS...THE ATMS IN PLACE OVER
DEEP SOUTH IS VERY MOIST WITH A 12Z BRO PWAT OF AROUND 2.13 INCHES.
WITH THE COLD FRONT APPROACHING THE REGION LATER TONIGHT AND
SUNDAY...GOOD UVV WILL INTERACT WITH THIS DEEP MOISTURE TO SPREAD
CONV OVER THE REGION ON SUNDAY. BECAUSE OF THE APPARENT CONV
FEEDBACK PROBLEMS IN THE GFS...HAVE GONE WITH A BLEND OF THE MET AND
MAV GUIDANCE FOR POPS IN THE SHORT TERM WITH THE RAIN CHCS
DIMINISHING ON MONDAY AS DRIER AIR BUILDS INTO THE REGION. DUE TO
THE HIGH PWATS THAT WILL PERSIST OVER THE REGION...WILL INCLUDE A
MENTION OF LOCALLY HEAVY RAINFALL IN THE CURRENT ZFP WORDING AS THE
LASTEST QPF OUTLOOKS FROM HPC PLACES ROUGHLY 1 TO 2 INCH AMOUNTS FOR
TOTAL AREAL COVERAGE WITHIN THE BRO CWA THROUGH 12Z MONDAY.  ALSO
THE LATES QPFERD DISC PLACES THE BEST POTENTIAL FOR EXCESSIVE
RAINFALL THROUGH TOMORROW EVENING JUST NORTH OF THE BRO CWA.  SINCE
THE FFG FROM THE WGRFC FOR THE BRO CWA SHOWS THE 6 HOURLY FLASH
FLOOD GUIDANCE GENERALLY FROM 4.5 TO 5.5 INCHES FOR THE
CWA...BELIEVE THAT THE SOIL CONDITIONS WITHIN THE CWA CAN HANDLE THE
CURRENTLY PROGGED QPF VALUES AT THIS TIME WITHOUT ANY SERIOUS
FLOODING PROBLEMS. SO WILL NOT POST ANY FLOOD WATCHES FOR THE REGION
AT THIS TIME. HOWEVER...THIS SITUATION WILL NEED TO BE CLOSELY
MONITORED THROUGH THE EVENING AND OVERNIGHT HOURS IN CASE THE
SYNOPTIC SITUATION CHANGES SIGNIFICANTLY. FOR TEMPERATURES... HAVE
GONE WITH A BLEND OF THE MAV AND MET NUMBERS AS BELIEVE THAT THE
WARMER MET GUIDANCE IS A LITTLE TOO WARM.  FOR THE LONGER
RANGE...BROAD 500 MB RIDGING PREVAILS FROM TUESDAY THROUGH THURSDAY
WHICH WILL MAINTAIN AT OR ABOVE NORMAL TEMPS AND ZERO POPS.  ANOTHER
STRONG AND DEEPLY DIGGING 500 MB TROFFING WILL PUSH INTO THE CENTRAL
AND EASTERN PORTIONS OF THE LOWER 48 STATES LATER THIS UPCOMING WEEK
AND THIS FEATURE PULLS ANOTHER STRONG COLD FRONT THROUGH THE REGION
NEXT FRIDAY. OVERALL MOISTURE VALUES AHEAD OF THIS FRONT ARE A
LITTLE MORE LIMITED SO WILL GO WITH ONLY 20 TO 30 % FOR THE REGION
AFTER FRIDAY. THANKS CRP FOR THE COORD!
&&
.MARINE...TCOON OBS REPORT S WINDS AT 20 TO 30 MPH AND BUOY020
REPORTED SSE WINDS AT AROUND 20 KTS AND SEAS AT 9 FT. THE TIGHT
PRESSURE GRADIENT OVER THE REGION WILL MAINTAIN ADVISORY CONDITIONS
OVER THE LOWER TEXAS COASTAL WATERS TODAY. THE GRADIENT WILL RELAX
OVERNIGHT AS A COLD FRONT MOVES INTO SOUTH TEXAS. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS WILL PREVAIL SUNDAY AHEAD OF THE
FRONT AS IT MIGRATES SOUTH INTO AND THROUGH THE REGION. MODERATE TO
STRONG NORTH TO NORTHEAST WINDS IN THE WAKE OF THE FRONT WILL
PRODUCE ADVISORY CONDITIONS INTO MONDAY. HIGH PRESSURE SHIFTS EAST
BY TUESDAY WITH SOUTHEAST WINDS PREVAILING THROUGH THE FORECAST.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THIS AFTERNOON WITH GUSTY S
WINDS PRODUCING LGT CHOP BLO 5KFT. ISOLD TO SCT CONVECTION WILL
BEGIN MOVE FROM NW INTO THE CWA AFTER MIDNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  81  86  73  86  71 /  30  60  40  30   0
BROWNSVILLE          80  87  71  86  69 /  30  60  40  30   0
HARLINGEN            78  87  71  86  68 /  30  60  40  30   0
MCALLEN              76  87  69  88  68 /  30  60  40  30   0
RIO GRANDE CITY      76  87  67  89  66 /  40  60  40  30   0
SOUTH PADRE ISLAND   81  86  77  86  72 /  30  60  40  30   0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
SCA GMZ130-132-135 THROUGH 01Z.
SCA GMZ150-155 THROUGH 05Z.
SCA GMZ170-175 THROUGH SUNDAY MORNING..
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT:
HTTP://WWW.SRH.NOAA.GOV/BRO
SYNOPTIC/GRIDS....60
MARINE/AVIATION...55
MESO...VEGA
</PRE></TT></td>   tx