Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cold front with postfrontal stratus was just north of the Red River mid afternoon. The main forecast problem is how long the low clouds will hang in over the Big Country Monday, which will affect high temperatures. It appears the NAM12 has the best handle on the low clouds this afternoon, so went with its colder and more cloudy solution Monday for the Big Country where stratus dissipates mid/late afternoon. A pair of troughs will cross the region, sending a couple of cold fronts south towards our area.
232 PM CST SUN JAN 17 2016 THE 20Z SURFACE ANALYSIS AND IR/VISIBLE SATELLITE IMAGERY INDICATED THAT THE ARCTIC COLD FRONT WAS MOVING SOUTHEAST THROUGH WESTERN KENTUCKY AND EXTENDING SOUTHWEST THROUGH NORTHERN ARKANSAS. AHEAD OF THE COLD FRONT ACROSS THE FORECAST AREA. TO THE LOW-MID 40S IN NORTHERN ALABAMA UNDER MOSTLY SUNNY SKIES. THE SHORT TERM MODELS ARE FAIRLY SIMILAR INVOLVING THE SOUTHEAST MOVEMENT OF THE COLD FRONT. THE COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA TONIGHT BETWEEN THE 06Z-09Z TIME FRAME. WITH A FEW SCATTERED FLURRIES POSSIBLE ALONG AND SLIGHTLY ON EITHER SIDE OF THE COLD FRONT. BITTERLY COLD AIR WILL FOLLOW THE PASSAGE OF THE COLD FRONT BY EARLY MONDAY. AS HIGH TEMPS ON MLK DAY WILL STRUGGLE TO MAKE IT TO AROUND OR SLIGHTLY ABOVE FREEZING.
1116 AM CST SUN JAN 17 2016 ONLY MADE SOME MINOR ADJUSTMENTS TO THE HIGH TEMPERATURES FOR TODAY FOR THE SOUTHWESTERN PORTIONS OF THE AREA. A WEAK COLD FRONT WILL MOVE INTO CENTRAL TEXAS AND POSSIBLY THE NORTHERN HILL COUNTRY EARLY MONDAY. SLIGHTLY WARMER ACROSS SOUTHERN AREAS TOMORROW.
BUT THE REST OF THE HIGHLIGHTS LOOK GOOD FOR MUCH OF TODAY. UPDATED FOR WINDS BLOWING VERY STRONG OVER THE RIDGES ESPECIALLY THE SAN JUANS. A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA ON MON. BRINGING INCREASED WARMER AIR ALOFT AND INCREASED STABILITY.
1059 AM EST SUN JAN 17 2016 PERIODIC SNOW SHOWERS AND MUCH COLDER TEMPERATURES ARE EXPECTED THROUGH EARLY IN THE WEEK AFTER THE PASSAGE OF A COLD FRONT LATER TODAY. SNOW SHOWERS ARE EXPECTED TO MOVE INTO THE RGN LATE THIS MRNG INTO THE AFTN WITH THE APPROACH AND PASSAGE OF A COLD FRONT. WITH TERRAIN ENHANCED SNOW IN THE RIDGES. COLD TEMPS AND WINDS SHOULD RESULT IN ADVISORY LVL WIND CHILLS IN THE RIDGES TONIGHT ALSO. AN UPPER LOW/TROF IS PROGGED TO TRACK ACRS ONTARIO INTO THE NE CONUS MON AND TUE. SNOW SHOWERS SHOULD TAPER OFF TUE WITH BUILDING HIGH PRESSURE. ADVISORY LVL WIND CHILLS ARE EXPD TO CONTINUE ACRS THE HIGHER TERRAIN AREAS THRU TUE MRNG.
1140 AM EST SUN JAN 17 2016 A CHILLY RAIN WILL END THIS AFTERNOON AS A LOW PRESSURE SYSTEM OFFSHORE SCOOTS RAPIDLY AWAY FROM THE REGION.
120 PM EST SUN JAN 17 2016 PERIODIC SNOW SHOWERS AND MUCH COLDER TEMPERATURES ARE EXPECTED THROUGH EARLY IN THE WEEK AFTER THE PASSAGE OF A COLD FRONT LATER TODAY. SNOW SHOWERS ARE EXPECTED TO MOVE INTO THE RGN LATE THIS MRNG INTO THE AFTN WITH THE APPROACH AND PASSAGE OF A COLD FRONT. WITH TERRAIN ENHANCED SNOW IN THE RIDGES. COLD TEMPS AND WINDS SHOULD RESULT IN ADVISORY LVL WIND CHILLS IN THE RIDGES TONIGHT ALSO. AN UPPER LOW/TROF IS PROGGED TO TRACK ACRS ONTARIO INTO THE NE CONUS MON AND TUE. SNOW SHOWERS SHOULD TAPER OFF TUE WITH BUILDING HIGH PRESSURE. ADVISORY LVL WIND CHILLS ARE EXPD TO CONTINUE ACRS THE HIGHER TERRAIN AREAS THRU TUE MRNG.
354 PM EST SUN JAN 17 2016 LOW PRESSURE HAS MOVED OFF THE SOUTHEAST COAST THIS AFTERNOON. A STRONG COLD FRONT OVER THE OHIO VALLEY WILL ALSO BE MOVING EAST TONIGHT.
THE WELL ADVERTISED ARCTIC COLD FRONT WAS APPROACHING THE OHIO RIVER AT MID MORNING.
1222 PM EST SUN JAN 17 2016 COLD AND DRY CANADIAN HIGH PRESSURE WILL BUILD SOUTH INTO OUR REGION FOR EARLY TO MID WEEK. TEMPERATURES MAY REACH THE LOWER 40S NORTH. A DRY NORTHWEST FLOW WILL OCCUR BETWEEN THE PRESSURE RIDGE IN THE MIDWEST AND LOW PRESSURE LIFTING NORTHEASTWARD WELL OFF THE NORTHEAST COAST. TEMPERATURES WILL FALL INTO THE LOWER 30S AND UPPER 20S IN MANY LOCATIONS OVERNIGHT. A DRY REINFORCING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA MONDAY.
LATEST SURFACE ANALYSIS PLACES A COLD FRONT ROUGHLY HALFWAY THROUGH THE STATE AT THIS TIME WITH CLOUDS DEVELOPING ALONG AND BEHIND THE BOUNDARY. HIGH PRESSURE MOVING ACROSS THE AREA MONDAY AND MONDAY NIGHT.
MAY SEE SOME PATCHY HAZE OVER PORTIONS OF THE LOWER/MID RIO GRANDE VALLEY AROUND THE SUNRISE HOURS MONDAY MORNING. OVERNIGHT LOWS TONIGHT WILL DIP INTO THE LOWER/MID 40S FOR MUCH OF THE FORECAST AREA EXCEPT UPPER 40S TO NEAR 50 AT THE COAST.
THE LOW LEVEL AIR MASS WILL REMAIN SUFFICIENTLY DRY TO KEEP ANY PRECIPITATION FROM GETTING INTO ALABAMA.
THESE CLOUDS ARE ASSOCIATED WITH A WEAK WAVE ROTATING SOUTHWARD ON BACKSIDE OF UPPER LOW.
HIGH PRESSURE CURRENTLY OVER THE PLAINS WILL SPREAD OVER THE GREAT LAKES TONIGHT AND MONDAY. VERY COLD AIR ALOFT ASSOCIATED WITH AN UPPER LEVEL TROUGH WILL LINGER INTO MONDAY MORNING.
A COLD FRONT WILL MOVE IN TONIGHT AND NORTHWEST WINDS WILL INCREASE SOME AND MAY GUST UP TO 20 KTS AT TIMES.
THE HIGH PRESSURE RIDGE AXIS REMAINS IN THE PLAINS WITH LOW PRESSURE EXTENDING INTO THE EASTERN LAKES.
TEMPERATURES WILL STILL DROP INTO THE LOWER 20S TONIGHT WITH STRONG COLD AIR ADVECTION.
HIGH PRESSURE ACROSS AREA WILL RESULT IN DRY LOW TO MID LVL AIR.
A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA ON MON. BRINGING INCREASED WARMER AIR ALOFT AND INCREASED STABILITY.
THE WELL ADVERTISED ARCTIC COLD FRONT WAS APPROACHING THE OHIO RIVER AT MID MORNING. THE DAY STARTS OFF WITH LOW-LEVEL MOISTURE FINALLY PULLING EASTWARD, WITH IFR/MVFR CIGS DISSIPATING THIS MORNING AND A BRIEF PERIOD OF CLR/SCT CLOUDS BEFORE A DRY COLD FRONT PUSHES THROUGH THE MID STATE THIS EVENING.
AND STILL EXPECT TO SEE OVERNIGHT LOWS RANGE FROM THE LOWER TO MID 30S WELL INLAND TO THE LOWER TO MID 40S ALONG THE COAST.
WITH HIGH CIRRUS TO START STREAMING IN LATER TODAY AHEAD OF A TROF DIGGING OUT WEST. AS COLDER AIR CONTINUES TO ADVECT IN LOOKING AT AFTERNOON HIGHS REACHING INTO THE LOW TO MID 50S THIS AFTERNOON.
AS HIGH PRESSURE BUILDS INTO THE WESTERN GREAT LAKES REGION.
CONFIDENCE IN HOW FAR EAST WARMER TEMPERATURES CAN PUSH IS QUITE LOW. SOME FREEZING RAIN MAY OCCUR AT KHLN AND KHVR.
135 PM MST SUN JAN 17 2016 HIGH PRESSURE OVER THE WESTERN STATES WILL FLUCTUATE IN STRENGTH BUT OVERALL KEEP ANY WEATHER SYSTEMS TO THE NORTH OF ARIZONA.
Again freezing fog canbe an issue again early Monday morning, reducing visibility in some areas. A quick return to southerly surface winds and increase in insolation by midday Monday, aiding to a bump in temperatures wellabove freezing on the higher elevation western counties. Cold highs in the low 30s are all that can be expected on the lower plains(Hays to medicine Lodge).
This feature is interacting with an arctic cold front creating frontogenetic forcing within the 850-700mb layer.
154 PM EST WED DEC 30 2015 HIGH PRESSURE OVER LABRADOR WILL MOVE EAST THIS AFTERNOON. WEAK LOW PRESSURE WILL CROSS THE REGION TONIGHT.
The region remains influenced by low pressure systems so cloud cover and light snow have been falling and will continue to fall (mainly in western Montana) until drier air moves in. A ridge of high pressure will build over the northern Rockies, leading to a very stable pattern. The combination of a low pressure centered in southern Idaho and another in eastern Montana have caused persistent low cloud cover and light snow in much of north central Idaho and western Montana.
EXPECT HIGHS FROM THE LOWER TO MID 40S NE AR TO LOWER 50S NE MS. A LOW PRESSURE CENTER WILL DEVELOP ALONG THE FRONT ON THURSDAY.
WATER VAPOR IMAGERY THIS MORNING SHOWED AN UPPER LOW CENTER AND TROUGH ACROSS S ID AND JORDAN VALLEY WHICH WERE DIGGING SOUTH TO SSE. UNUSUALLY STRONG 1040+ MB HIGH PRESSURE DUE IN THURS/FRI.
344 PM EST WED DEC 30 2015 HIGH PRESSURE, SITTING TO THE EAST, WILL REMAIN IN CONTROL FOR A COUPLE MORE DAYS.
BROAD TROUGH AXIS SWINGS THROUGH OUR CWA TONIGHT FROM NW TO SE. BUT I WOULD NOT BE SURPRISED TO HEAR OF A FEW REPORTS OF AROUND 2 INCHES ALONG RIDGES OR UNDER NARROW BANDS.
ESP IN WRN CWA THOUGH THANKFULLY BUFKIT SUPPORTS ANY VRY LGT PRECIP WOULD BE FROZEN AND NOT FREEZING.
THE SE WILL HAVE THE HIGHEST POPS - BUT ONLY THE LOWEST LIKELY VALUES POSSIBLE /55-60PCT/ DUE TO UNCERTAINTY OF THE WEAK NE-SW BANDS AND THE AMOUNT OF FALLING MOISTURE WHICH CAN REACH THE SFC. SFC TEMPS REMAIN ABOVE FREEZING - EVEN IN WARREN/MCKEAN/ELK COS UNTIL CLOSE TO SUNRISE. THE WRLY FLOW IN THE LOW LAYERS MEANS THE 45-50F LAKE WATER SFC TEMPS COME INTO PLAY AND -8C 8H TEMPS YIELD A DIFF OF ROUGHLY 18C. WILL JUST MENTION A MINOR ACCUM IN THE FAR NW DURING THE DAY AS TEMPS HANG CLOSE TO OR MAYBE JUST BELOW FREEZING.
DRY WEATHER CONDITIONS ARE EXPECTED THROUGH THE DAY FOR THE REMAINDER OF THE DISTRICT AS HIGH PRESSURE BUILDS OFF OF THE WEST COAST. DRY CONDITIONS ARE EXPECTED OVER THE ENTIRE REGION BY THIS EVENING THROUGH NEW YEARS DAY AND INTO THE BEGINNING OF THE WEEKEND AS THE RIDGE SHIFTS TOWARD THE COAST. POSSIBLE FREEZING FOG IN THE NORTH BAY NEAR KSTS TOMORROW MORNING. SFO BRIDGE APPROACH.
DRY WEATHER CONDITIONS ARE EXPECTED THROUGH THE DAY FOR THE REMAINDER OF THE DISTRICT AS HIGH PRESSURE BUILDS OFF OF THE WEST COAST. DRY CONDITIONS ARE EXPECTED OVER THE ENTIRE REGION BY THIS EVENING THROUGH NEW YEARS DAY AND INTO THE BEGINNING OF THE WEEKEND AS THE RIDGE SHIFTS TOWARD THE COAST. A COLD FRONT IS APPROACHING FROM THE NORTH THIS MORNING. SFO BRIDGE APPROACH.
AS COLDER AIR ARRIVES LATE TONIGHT PRECIP WILL TRANSITION TO SNOW SHOWERS ACROSS THE RIDGES. OTHER THAN LINGER SNOW SHOWERS IN THE RIDGES IN THE MORNING. DRY THURSDAY WITH COLD ADVECTION TO CONTINUE THROUGH THE DAY AS HIGH PRESSURE NOSES INTO THE UPPER OHIO VALLEY.
TEMPERATURES THURSDAY WILL BE COOLER EAST BUT A LITTLE WARMER SOUTHWEST.
BROAD, SLOW-MOVING UPPER-LEVEL TROUGH WILL KEEP MIX OF MAINLY VFR/MVFR CONDITIONS OVER CENTRAL AND SOUTHWEST MT TODAY. WARANAUSKAS /ISSUED 430 AM MST WED DEC 30 2015/ AN UPPER LEVEL TROUGH ENCOMPASSES MUCH OF THE CENTRAL AND WESTERN CONUS WITH AN UPPER LEVEL RIDGE AMPLIFYING FROM OFF THE WEST COAST NORTH INTO NW CANADA THIS MORNING. BROAD CYCLONIC CIRCULATION WITHIN THE TROUGH CENTERED OVER EASTERN MT WILL GRADUALLY SHIFT EAST INTO ND TODAY WITH MOIST NORTHERLY FLOW CONTINUING TO PRODUCE MAINLY LIGHT SNOW SHOWER ACTIVITY ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST THROUGH THIS AFTERNOON WHILE SOME DRIER AIR WORKS S FROM AB INTO NW PORTIONS OF THE FORECAST AREA.
A BROAD UPPER LEVEL TROUGH OF LOW PRESSURE OVER MUCH OF THE WESTERN TWO THIRDS OF THE COUNTRY WILL PREVAIL WITH SEVERAL DISTURBANCES ROUNDING THE BASE. TOWARD LATE WEEK AN UPPER LOW WILL FORM OVER CALIFORNIA AND NEVADA WITH AN ADVANCING UPPER TROUGH MOVING EAST. EXTENDING FROM AN UPPER LOW OVER CANADA. TEMPERATURES WILL BE COLD BUT ABOVE FREEZING WHERE THE RAINFALL IS EXPECTED AND WILL KEEP LIQUID MENTIONED. TOWARD MID WEEK RAIN CHANCES RETURN AS UPPER LEVEL RIDGE AXIS SHIFTS TO THE EAST AND SHORT WAVE TROUGH OF LOW PRESSURE FROM THE SOUTHERN ROCKIES AND INTO SOUTH TEXAS RETURNS.
302 PM CST WED DEC 30 2015 FAIRLY QUIET WEATHER IN THE SHORT TERM AS ZONAL FLOW SETS ACROSS THE PLAINS ON THE SOUTH SIDE OF ANOTHER WEAK TROUGH MOVING THROUGH THE NORTHERN CONUS. IT WILL PROBABLY BE A CHILLY NIGHT TONIGHT WITH DECREASING CLOUDS AND WEAK HIGH PRESSURE SETTLING OVERHEAD. WEAK RIDGING ALOFT DEVELOPS EARLY IN THE PERIOD WITH MORE OF A NORTHERLY SURFACE COMPONENT TO THE WIND.
NOT MUCH IS LEFTOVER FOR THE THE HIGHER MOUNTAINS SUCH AS THE GORE AND SAWATCH RANGES. TROUGH DROPPING SOUTH ACROSS THE FORECAST AREA GETS PINCHED OFF WITH WESTERN ENERGY FORMING A CLOSED LOW OVER WESTERN NEVADA. THE LOW IS EXPECTED TO LIFT NNE ACROSS OREGON.
A BROAD UPPER TROUGH NOTED ACROSS MUCH OF THE U. OUTSIDE OF BRECKENRIDGE WHERE STRATUS AND FOG HAS HELD THAT AREA IN THE UPPER 30S. THE FREEZING FOG THAT PERSISTED THROUGH MIDDAY ACROSS THE FAR WESTERN COUNTIES HAS EASED MOSTLY OUT OF THE AREA. WILL INTRODUCE FOG AND FREEZING FOG ACROSS MUCH OF THE WESTERN CWA LATE TONIGHT AND THROUGH THURSDAY MORNING. IF THE THERMAL PROFILE WERE TO COOL TOWARD THE COOLER WET-BULB PROFILE.
342 PM EST WED DEC 30 2015 COLDER AIR WILL BE DRAWN INTO THE LOWER LEVELS BEHIND LOW PRESSURE AS IT PULLS AWAY THIS EVENING AND EARLY THURSDAY. ACTIVITY SHOULD TAPER OFF AFTER ABOUT NOON TOMORROW AS HIGH PRESSURE EXPANDING INTO THE WESTERN GREAT LAKES CRASHES INVERSION HEIGHTS AND BRINGS SOME DRIER AIR IN THE MID-LEVELS (DECREASING POTENTIAL FOR ICE NUCLEI). COOLER AIR WILL REMAIN ENTRENCHED OVER THE AREA TOMORROW. KEEPING TEMPERATURES CLOSER TO SEASONAL NORMALS IN THE LOW/MID 30S. THIS WILL OCCUR IN ADVANCE OF A LARGER UPPER TROUGH THAT WILL DROP DOWN FROM CENTRAL CANADA. BUT ASSOCIATED COLD FRONT WILL DROP H925 TEMPS TO AROUND -10C AND H850 TEMPS TO -15C. THIS WILL BRING A COOLER AND BREEZY START TO THE NEW YEAR.
9AM TEMPS ARE ALREADY WARMER THAN YESTERDAYS HIGH TEMPS NEAR THE COAST. 48 THE SURFACE PRESSURE GRADIENT IS TIGHTENING THIS MORNING AS A LOW PRESSURE SYSTEM DEVELOPS ABOUT 100 MILES EAST OF PORT ISABEL ALONG A NEARLY STATIONARY FRONTAL BOUNDARY. A SMALL CRAFT ADVISORY WILL BE ISSUED OVER THE OFFSHORE WATERS DURING THE DAY TODAY AS SUSTAINED 20-25 KT WINDS ARE ANTICIPATED IN THE WAKE OF A RE- ENFORCING COLD FRONT WILL MOVE OFF THE COAST THIS MORNING.
329 PM EST WED DEC 30 2015 WEAK LOW PRESSURE WILL MOVE NORTHEAST THROUGH THE AREA THIS EVENING WITH A COLD FRONT CROSSING TONIGHT.
349 PM CST WED DEC 30 2015 BROAD UPPER TROF OVER THE WRN AND CNTL CONUS CONTINUES TO PRODUCE SWLY FLOW ALOFT OVER OUR AREA. SHALLOW HIGH PRES RIDGES SOUTH ACRS OK INTO NE TX WHILE A QUASI-STATIONARY FRONT CONTINUES TO SIT FURTHER SE ACRS THE NRN AND WRN GULF.
GUIDANCE DOES INDICATE YET ANOTHER MID-LVL VORT/TROUGH PIVOTING NORTHEAST ACROSS THE REGION LATE TONIGHT. AND WILL SLOWLY FALL INTO THE LOW/MID 20S OVERNIGHT AS A RESULT OF THE THICK CLOUD COVER. WEAK TROUGH PIVOTS EAST THUR MORNING. OTHERWISE TEMPS MAY END UP HOLDING IN THE LOW 20S FOR MANY LOCATIONS.
SINCE I AM UNSURE ABOUT THE NORTHERN EXTENT OF THE -FZDZ HAVE OPTED TO INCLUDE FREEZING FOG AND MENTION IN HWO PRODUCTS FOR THE TIME BEING. 05Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED LARGE TROUGH ACROSS THE NORTHERN ROCKIES WITH SHORT WAVE TROUGH EMBEDDED IN LARGER FLOW MOVING OVER THE CWA. ALTHOUGH WITH A SERIES OF WEAK SHORT WAVE TROUGH EMBEDDED IN THE FLOW CANNOT SAY FOR SURE THAT IT WILL BE COMPLETELY DRY.
AND THURSDAY SOME PATCHY ZL WAS OBSERVED ACROSS THE FAR NORTH EARLY THIS MORNING AS MID LEVEL DRYING WAS WORKING INTO A NEARLY STATIONARY WEAK UPPER LOW OVER THE NORTHERN GREAT LAKES REGION. MID LEVELS SHOULD OVERALL SATURATE AGAIN TODAY AS A SHORT WAVE OVER THE CENTRAL PLAINS IS EJECTED FROM THE BROAD WESTERN STATES TROUGH. PROGS PHASE THIS APPROACHING TROUGH WITH THE STALLED LOW OVER THE NORTHERN GREAT LAKES REGION. AN 850 TROUGH WITH SUBTLE WIND SHIFT SLOWLY DRIFTS OVER EASTERN HALF OF THE STATE TODAY BEFORE DRIFTING EAST THIS EVENING. ANTICIPATE THE HIGHER AMOUNTS/POP OVER EAST CENTRAL WISCONSIN TODAY. WEAK TROUGHING DURING THIS TIME MAY CONTINUE TO PRODUCE FLURRIES AND PATCHY FREEZING DRIZZLE AT TIMES.
106 PM EST WED DEC 30 2015 LOW PRESSURE PRESSURE MOVES TO THE SOUTH AND EAST OF WEST THIS AFTERNOON AND EARLY TONIGHT. HIGH PRESSURE WITH DRIER AND COLDER AIR WILL FILTER IN FOR THE REMAINDER OF THE WEEK WITH PERIODS OF SNOW SHOWERS IN THE MOUNTAINS. WEAK LOW PRESSURE WILL LIFT OUT OF THE SOUTHEAST TODAY. WITH THE TRACK OF THE LOW JUST TO OUR SE BY LATE THIS AFTERNOON. COLDER AIR AND RIDGING STARTS TO MOVE IN AFTER MIDNIGHT AND ANY LEFT OVER SHOWERS MAY MIX OR CHANGE OVER TO SNOW SHOWERS TOWARDS DAWN IN THE HIGHER ELEVATIONS OF THE WV MOUNTAINS. DESPITE BEING UNDER HIGH PRESSURE.
1210 PM EST WED DEC 30 2015 LOW PRESSURE WILL BRING SCATTERED RAIN SHOWERS THIS AFTERNOON. MEAN WESTERLY FLOW THROUGH 850MB AND LOW INVERSION HEIGHTS WILL ALLOW ONLY CHANCE TO SLIGHT CHANCE POPS FOR RAIN SHOWERS TO SNOW SHOWERS OVERNIGHT ACROSS I-80 AND IN THE RIDGES.
AN ELONGATED MID/UPPER TROUGH STRETCHING ACROSS THE NORTHERN CONUS IS PROGGED TO SHEAR EASTWARD THROUGH THE REMAINDER OF THE WEEK WHILE A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WESTERN CONUS. THIS RIDGE WILL BEGIN TO EDGE EASTWARD ALLOWING TEMPERATURES TO MODERATE SLOWLY ACROSS THE CENTRAL PLAINS STATES. THIS WILL HELP BOOST TEMPERATURES INTO THE LOWER OR MIDDLE 40S TUE-WED. A MID/UPPER TROUGH IS PROGGED TO BUILD OVER THE SOUTHWEST EARLY IN THE WEEK EJECTING ACROSS THE PLAINS TOWARD MID-WEEK.
TONIGHT THROUGH THURSDAY IMAGERY SHOWS BROAD LW TROF ACROSS MOST OF THE CONUS TODAY EXCEPT FOR THE SERN US. WEAK HIGH P ACROSS THE WEST AND A RELATIVELY WEAK P GRAD BETWEEN THE TWO KEEPING WINDS ON THE LOW SIDE. ONLY A WEAK SFC TROF FROM NERN WY INTO S CNTRL MT. AND AN INVERTED TROF INTO S CNTRL/SERN WY. WILL CONTINUE SMALL PRECIP/SNOWFALL CHANCES THROUGH MAINLY THURSDAY MORNING AROUND THE FA WITH ONLY OCCASIONAL LIGHT SNOW/FLURRIES ACROSS THE HIGHER TERRAIN OF WY. WITH AN INCH OR TWO MAX OVR THE BIG HORN MOUNTAINS AND GENERALLY LESS THAN A HALF AN INCH OVR THE LOWER ELEVATIONS.
301 PM EST WED DEC 30 2015 UNSEASONABLY WARM WEATHER ALONG WITH THE CHANCE FOR SHOWERS WILL CONTINUE THROUGH THURSDAY AS A COLD FRONT STALLS NEAR THE FORECAST AREA.
AN UPPER LEVEL LOW OVER EASTERN MT CONTINUES TO SLOWLY SHIFT EAST AT THIS TIME. LINGERING MOISTURE ASSOCIATED WITH THIS LOW IS KEEPING SOME -SN GOING ACROSS PARTS OF CENTRAL AND SOUTHWEST MONTANA. MARTIN /ISSUED 430 AM MST WED DEC 30 2015/ AN UPPER LEVEL TROUGH ENCOMPASSES MUCH OF THE CENTRAL AND WESTERN CONUS WITH AN UPPER LEVEL RIDGE AMPLIFYING FROM OFF THE WEST COAST NORTH INTO NW CANADA THIS MORNING. BROAD CYCLONIC CIRCULATION WITHIN THE TROUGH CENTERED OVER EASTERN MT WILL GRADUALLY SHIFT EAST INTO ND TODAY WITH MOIST NORTHERLY FLOW CONTINUING TO PRODUCE MAINLY LIGHT SNOW SHOWER ACTIVITY ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST THROUGH THIS AFTERNOON WHILE SOME DRIER AIR WORKS S FROM AB INTO NW PORTIONS OF THE FORECAST AREA.
AND FOR THURSDAY THE HIGHEST POPS AND QPF WILL BE CONFINED TO THE SOUTHERN COUNTIES.
LOW CLOUDS ARE CREATING AREAS OF FREEZING FOG IN THE UPSLOPE REGIONS OF CENTRAL AND NORTHEAST OREGON.
211 PM EST WED DEC 30 2015 UNSEASONABLY WARM WEATHER ALONG WITH THE CHANCE FOR SHOWERS WILL CONTINUE THROUGH THURSDAY AS A COLD FRONT STALLS NEAR THE FORECAST AREA.
MEDIUM BROAD UPPER TROUGH REMAINS ACROSS THE WRN AND CNTRL PORTION OF THE US. NEXT VORT COMING OUT OF THIS TROUGH WORKS THROUGH IL OVERNIGHT. MEDIUM NOT MUCH CHANGE AT THE SURFACE WITH STILL A PRESSURE GRADIENT BETWEEN DEPARTED LOW AND PLAINS HIGH PRESSURE.
316 PM EST WED DEC 30 2015 A WAVE OF LOW PRESSURE WILL LIFT NORTHEAST THROUGH THE MID ATLANTIC REGION ALONG A SLOW MOVING FRONT.
AFTER SHOWERS CLEAR OUT CEILINGS WILL REMAIN IN THE LOW TO MID LEVELS.
1245 PM EST WED DEC 30 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW SPLIT FLOW OVER NAMERICA WITH THE SRN STREAM FEATURING A TROF THAT DOMINATES MOST OF THE W HALF OF THE CONUS. BROAD TROUGHING OVER THE EAST HALF OF CANADA WILL ALLOW FOR WNW TO NW FLOW TO CONTINUE ACROSS THE GREAT LAKES. A SHARPER EMBEDDED TROUGH AXIS WILL CROSS THE CWA THURSDAY NIGHT. BEHIND THE TROUGH THURSDAY NIGHT.
305 PM CST WED DEC 30 2015 A WEAK UPPER LEVEL LOW OVER UPPER PENINSULA MICHIGAN WILL GRADUALLY SHIFT EAST THROUGH TONIGHT. THE WEAK NORTHWEST FLOW NEAR IRON AND ASHLAND COUNTIES WILL CONTINUE TO SUPPORT ENOUGH LOW LEVEL MOISTURE FOR LIGHT SNOW AND FREEZING DRIZZLE THROUGH EARLY THIS EVENING. AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE NORTHLAND EARLY THURSDAY. FOLLOWED BY A COLD FRONT IN THE AFTERNOON. WEAK UPPER LEVEL TROF IN NW FLOW WILL BE OVERHEAD AT THE BEGINNING OF THE PERIOD.
TEMPERATURES ABOVE FREEZING THIS AFTERNOON HELPING TO MELT SNOW AND INCREASE MOISTURE AT THE SURFACE. /ISSUED 553 AM CST WED DEC 30 2015/ AREAS OF FOG AND FREEZING FOG WILL RESULT IN LOW VISIBILITIES AT THE TERMINALS EARLY THIS MORNING. THE WARMER TEMPERATURES HAVE ALSO MOSTLY KEPT FREEZING FOG AT BAY. WE EXPECT AT LEAST PATCHY FREEZING FOG TO DEVELOP ACROSS MUCH OF THE AREA AND WE/VE ADDED A MENTION TO THE FORECAST. A HIGH PRESSURE RIDGE WILL EXTEND FROM ERN KS/WRN MO SOUTHWEST THROUGH WEST TEXAS.
Stratus expected to lower quickly again just after sunset, with freezing fog again possibly affecting aviation operations at GCK and DDC as soon as 03z, as suggested by NAM guidance. The upper level trough that was crossing western Kansas earlier this morning will move quickly northeast into the Upper Great Lakes region as the next in a series of upper level disturbances crosses the Central Rockies and moves out into the Western High Plains.
TEMPS ARE IN THE LOW 50S ACROSS THE TN VALLEY WHICH IS CLOSE TO NORMAL VALUES FOR THIS WARM DECEMBER. THIS IS ASSOCIATED WITH A SMALL COLD FRONT THAT COULD PRODUCE ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS THIS AFTERNOON. THIS WILL MOVE ACROSS OUR SOUTHEASTERN COUNTIES WHERE WARMER TEMPS AND SOME ISENTROPIC LIFT ARE PRESENT ALLOWING FOR THE HIGHEST POPS AND ISOLATED THUNDERSTORMS TO REMAIN IN THE FORECAST THERE. ALSO INCREASED TEMPS AHEAD OF THE FRONT BY A DEGREE AS HOURLY TRENDS WERE SLIGHTLY BEHIND CURRENT OBS AND BREAK IN CLOUD COVER MAY GIVE A QUICK ADDITIONAL BOOST BEFORE COOLER AIR FILTERS IN.
Areas of light snow is coming to an end for the Central Panhandle Mountains and Camas Prairie with the departing upper level trough with drier air aloft moving in. Main issue now is the stratus and freezing fog. Satellite and web cams show stratus to be more prevalent with only patchy freezing fog over most of the area. Freezing fog is most favored where clearing skies occurring (at least briefly) overnight. Freezing fog has been removed from the Waterville Plateau. as drier air aloft tries to work its way into the area on the back side of an exiting upper trough.
423 PM EST WED DEC 30 2015 UNSEASONABLY WARM WEATHER ALONG WITH THE CHANCE FOR SHOWERS WILL CONTINUE THROUGH THURSDAY AS A COLD FRONT STALLS NEAR THE FORECAST AREA.
337 PM EST WED DEC 30 2015 A WEAK LOW PRESSURE SYSTEM WILL BRING LIGHT WINTRY MIX TONIGHT. ESPECIALLY OVER THE HIGHER TERRAIN. AREA OF CONFLUENCE MOVING INTO THE NORTH COUNTRY FROM THE SOUTHWEST AS A TROUGH/WAVE ALOFT MOVES OVER THE NORTHERN GREAT LAKES INTO SOUTHWESTERN ONTARIO. AREAS EAST OF THE GREENS AND PORTIONS OF THE ADIRONDACKS/ADJACENT FOOTHILLS CAN EXPECT SOME SLEET AND POSSIBLY POCKETS OF FREEZING RAIN. THIS TREND CONTINUES EASTWARD AND EXPECT MOST AREAS TO BE LIGHT SNOW SHOWERS BY 12Z THURSDAY, AT WHICH TIME THE MOISTURE ASSOCIATED WITH THE TROUGH/WAVE WILL BE EXITING EASTERN VT. AS WE REMAIN UNDER THE LARGE SCALE UPPER TROUGH, SNOW SHOWERS WILL CONTINUE TO BE A POSSIBILITY.
138 PM EST WED DEC 30 2015 LOW PRESSURE WILL BRING SCATTERED RAIN SHOWERS THIS AFTERNOON. MEAN WESTERLY FLOW THROUGH 850MB AND LOW INVERSION HEIGHTS WILL ALLOW ONLY CHANCE TO SLIGHT CHANCE POPS FOR RAIN SHOWERS TO SNOW SHOWERS OVERNIGHT ACROSS I-80 AND IN THE RIDGES.
130 PM EST WED DEC 30 2015 A WEAK LOW PRESSURE SYSTEM WILL CROSS THE REGION TODAY. TEMPERATURES SHOULD PUSH INTO THE LOWER 40S FOR MOST AREAS SOUTH OF LAKE ONTARIO WHILE EAST OF THE LAKE HIGHS WILL BE IN THE MID TO UPPER 30S. BEHIND THE TROUGH PASSAGE THIS EVENING. INITIALLY SHOWERS COULD START AS RAIN OR A RAIN SNOW MIX OVER THE LOWER ELEVATIONS BUT THEN SHOULD TRANSITION TO ALL SNOW EARLY THURSDAY MORNING. THE HIGHER ELEVATIONS OF THE SOUTHERN TIER AND THE TUG HILL WILL BE THE FIRST TO MAKE THE TRANSITION TO SOME WET SNOW OVERNIGHT. OUTSIDE OF THE HIGHER ELEVATIONS. WESTERLY FLOW LAKE EFFECT SNOWS SHOULD RAMP UP DURING THE PERIOD AS COLDER AIR SETTLES OVER THE EASTERN GREAT LAKES WITH THE LONGWAVE TROUGH.
HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 30S IN SOUTHERN MICHIGAN TO AROUND 40 NEAR THE OHIO RIVER.
OUR OFFICE HAS RECEIVED REPORTS OF FREEZING DRIZZLE ACROSS THE IRON AND ASHLAND COUNTIES AREA. IT MAY BE THIS LAYER IS WARM ENOUGH TO ALLOW SUPERCOOLED WATER VAPOR TO SUFFICIENTLY CONDENSE INTO FREEZING DRIZZLE. HAVE ADDED PATCHY FREEZING DRIZZLE ACROSS IRON AND ASHLAND COUNTIES THROUGH THE AFTERNOON.