Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 11/26/11
AREA FORECAST DISCUSSION
NWS TAUNTON MA
430 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE FROM THE TENNESSEE VALLEY TO THE MID ATLANTIC STATES
WILL PROVIDE SOUTHERN NEW ENGLAND WITH DRY WEATHER THROUGH THE
WEEKEND WITH WARMING TEMPERATURES. LOW PRESSURE OUT OF THE GREAT
LAKES WILL MOVE TO THE MID ATLANTIC COAST LATE SUNDAY NIGHT...THEN
WILL MOVE SLOWLY MOVE ACROSS THE REGION MONDAY INTO TUESDAY. A COLD
FRONT WILL TRAIL THROUGH TUESDAY NIGHT. ANOTHER FRONT MAY APPROACH
THE REGION LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
410 PM UPDATE...
THE ONLY REMAINING LOW CLOUDS WERE OVER SOUTHERN NEW HAMPSHIRE AND
NORTH OF ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS
HANGING AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A
SIGNIFICANT PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. CLEAR SKIES
EXPECTED OVER THE REST OF SOUTHERN NEW ENGLAND AS STRONG HIGH
PRESSURE FROM THE TN VALLEY TO THE MID ATLANTIC INFLUENCES OUR
WEATHER. USED MAVMOSGUID BIAS CORRECTED GRIDS FOR LOWS TONIGHT.
LOWERED THEM BY A FEW DEGREES IN NORTHERN CHESHIRE COUNTY WHERE
HIGHS TODAY REMAINED IN THE 30S. WITH CLEARING SKIES AND LIGHT WINDS
THERE...IT COULD DROP TO MID 20S. ELSEWHERE EXPECTING LOWS IN THE
UPPER 20S TO MID 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...HIGH PRESSURE WITH CONTINUED WARMING TREND ALOFT
AND AT THE SURFACE. LIGHT WINDS AND ABUNDANT SUNSHINE EXPECTED.
TEMPERATURES AT 925 MB CLIMB TO 10-13C ON BOTH NAM AND GFS. USED
MAVMOS GUIDANCE WITH BIAS ADJUSTMENT WHICH YIELDS 60 TO 64 ACROSS
CT...MUCH OF RI...AND INTERIOR SE MA. LOWER TO MID 50S IN SOUTHERN
NH AND NW MA.
FRIDAY NIGHT...CLEAR SKIES AND LIGHT WINDS MAY ALLOW FOR
TEMPERATURES TO RADIATE DOWN TO PURE MAVMOS LEVELS WHICH WERE 5 TO
10 DEGREES LOWER THAN THE BIAS CORRECTED ONES. HOWEVER...AM OPTING
FOR A BLEND OF THE TWO SINCE WE WILL BE IN AN ANOMALOUSLY WARM
PATTERN. LOWS MAINLY IN THE MID 30S TO NEAR 40 BUT COOLER IN
NORTHWESTERN AREAS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODEL DISCUSSION AND PREFERENCES...
HIGH CONFIDENCE CONTINUES FOR THE FORECAST THIS WEEKEND AS STRONG
HIGH PRES BUILDS ALONG THE EASTERN SEABOARD.
BEYOND SUNDAY...THE FORECAST BECOMES VERY MUDDY TO SAY THE LEAST.
INDIVIDUAL OP MODEL SOLUTIONS HAVE VEERED IN THEIR OWN DIRECTIONS...
LEAVING A LOT TO TRY TO FIGURE OUT FOR SENSIBLE WEATHER AND TEMP
REGIME...ESPECIALLY WITH APPROACH OF LOW AND ASSOCIATED FRONT EARLY
NEXT WEEK. EVEN HPC CHANGED THEIR COURSE FOR THIS AFTERNOON/S MEDIUM
RANGE ISSUANCE. DID LEAN TOWARD HPC SOLUTION WHICH WENT TOWARD THE
GEFS ENSEMBLE MEANS...BUT THIS ONLY PLACES THE LOW IN BETWEEN THE
FAR NE 12Z OP GFS AND FAR SW ECMWF. NEEDLESS TO SAY...CONFIDENCE IS
VERY LOW FOR THE MON-WED TIMEFRAME /AT LEAST/.
SATURDAY-SUNDAY...
SPRING LIKE WEATHER WILL CONTINUE AS HIGH PRES OFF THE MID ATLC/SE
U.S. COAST. THIS WILL PUMP MILD AIR UP INTO THE REGION...WITH MODEL
850 HPA TEMPS ON THE ORDER OF +9C TO AS HIGH AS +11C SATURDAY AND
EVEN INTO SUNDAY. EXPECT MAINLY CLEAR SKIES ON SATURDAY...THEN
QUESTIONS IN PLACE AS TO WHETHER CLOUDS START TO MOVE IN DURING
SUNDAY. IN ANY EVENT...WITH RECORD HIGHS AT OUR FOUR MAJOR CLIMATE
SITES MAINLY IN THE MID-UPPER 60S...MAY SEE MAX TEMPS ON SATURDAY
/AND MAYBE SUNDAY TOO/ GETTING CLOSE TO RECORD LEVELS. HAVE INCLUDED
LIST OF RECORDS AND DATES IN CLIMATE SECTION BELOW.
SUNDAY NIGHT TO TUESDAY...
AS MENTIONED ABOVE...VERY LITTLE FORECAST CONFIDENCE DURING THIS
TIMEFRAME. FOR NOW...CONTINUED TO CARRY INCREASING POPS SUNDAY
NIGHT...WITH LIKELY POPS INTO WESTERN AREAS AFTER MIDNIGHT. LOOKS
LIKE BEST SHOT OF PRECIP COULD OCCUR MONDAY INTO MONDAY NIGHT. LOW
PRES ALONG THIS FRONT MAY ENHANCE THE RAINFALL ALONG WITH GOOD
TROPICAL CONNECTION UP THE COAST ON LONG S-SE FETCH. CONTINUED WITH
VERY MILD TEMPS THROUGH MONDAY NIGHT...RUNNING AT LEAST 10-15 DEGS
ABOVE SEASONAL NORMALS...THEN MAY START TO TRIM BACK AS FRONT COULD
PUSH E DURING TUESDAY. HAVE TRENDED TO END CHANCE POPS FROM W-E TUE
NIGHT.
WEDNESDAY...
A SECOND FRONT MAY PUSH ACROSS BY WED MORNING...SO MAY SEE SHOT OF
COOLER AIR WORKING IN ON W WINDS. TIMING IS HIGHLY UNCERTAIN...
THOUGH. DID NOT GO NEARLY AS COLD AS MOS GUIDANCE...PRETTY MUCH
LOWERED TEMPS A BIT FROM THE PREV FORECAST. MAY BE A BIT BREEZY
ESPECIALLY ALONG THE COAST DURING THE DAY.
THURSDAY...
WITH SUCH LOW CONFIDENCE...REALLY UNCERTAIN OF WEATHER FOR THIS
PERIOD. AT THIS POINT...HAVE CARRIED DRY WEATHER WITH SEASONABLE
TEMPS.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
410 PM UPDATE...
REST OF THIS AFTERNOON AND EVENING...THE ONLY REMAINING MVFR
CEILINGS AROUND 2000-2500 FT WERE OVER SOUTHERN NH AND NORTH OF
ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS HANGING AROUND
MUCH LONGER THAN THE OTHER MODELS. THINK A SIGNIFICANT PORTION OF IT
WILL CLEAR OUT AFTER SUNDOWN. ELSEWHERE HIGH CONFIDENCE VFR WITH
CLEAR SKIES.
TONIGHT...HIGH CONFIDENCE VFR WITH CLEAR SKIES EXCEPT POSSIBLE
POCKETS OF MVFR CEILINGS CONTINUING IN THE MONADNOCKS OF SOUTHERN
NH. THIS SHOULD REMAIN TO THE WEST OF MHT...MODERATE CONFIDENCE OF
THAT.
FRIDAY... HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
KBOS TERMINAL...
HIGH CONFIDENCE VFR THROUGH FRIDAY. THERE WILL BE SCT-BKN CLOUDS
IN THE 2000-2500 FT RANGE THROUGH ABOUT 01Z NOT TOO FAR TO THE
NORTH OF LOGAN INTL.
FRIDAY NIGHT...HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...HIGH CONFIDENCE FOR VFR CONDITIONS. MAY SEE LOCAL
MVFR-IFR VSBYS IN PATCHY FOG LATE SAT NIGHT.
SUNDAY...MODERATE CONFIDENCE FOR MAINLY VFR. MID TO HIGH LEVEL
CLOUDS MAY MOVE IN FROM WEST TO EAST. MAY SEE LOCAL MVFR-IFR VSBYS
IN PATCHY FOG EARLY SUN MORNING.
SUNDAY NIGHT-MONDAY NIGHT...LOW CONFIDENCE. EXPECT VFR CIGS EARLY
SUN NIGHT...THEN MVFR CIGS/VSBYS IN DEVELOPING SHOWERS. MAY SEE
PERIODS OF IFR CONDITIONS LATE SUNDAY NIGHT-MONDAY WITH POCKETS OF
HEAVY RAIN POSSIBLE. ALSO MAY SEE IFR VSBYS IN PATCHY FOG LATE
NIGHTS ON SUN AND MON.
TUESDAY...LOW CONFIDENCE. AREAS OF MVFR CIGS/VSBYS IN SHOWERS EARLY
DURING THE DAY...THEN SHOULD SLOWLY IMPROVE LATE TUESDAY-TUESDAY
NIGHT FROM W-E...BUT TIMING IS HIGHLY SUSPECT.
&&
.MARINE...
TONIGHT AND FRIDAY...
SEAS HAVE BEEN STEADILY SUBSIDING THROUGHOUT THE AFTERNOON
BUT STILL REMAIN AT 5 TO 6 FEET ACROSS THE EASTERN OUTER WATERS.
HAVE CONTINUED THE SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS FOR
WATERS NORTH OF CAPE COD THROUGH 7 PM AND FOR THE WATERS OFF OF
CAPE COD AND SE OF NANTUCKET THROUGH 10 PM. EXPECTING ALL WATERS
TO BE BELOW THRESHOLDS BY AROUND 10 PM. PREFERRED WNAWAVE GRIDS TO
SWANNAM OR SWANGFS BECAUSE IT KEEPS SEAS HIGHER JUST TO THE EAST
OF OUR MARINE FORECAST AREA.
MODELS INDICATE THAT THERE WILL BE AN INCREASING PRESSURE GRADIENT
OVER THE SOUTHERN COASTAL WATERS ON FRIDAY AFTERNOON. THIS CAUSES
WEST TO SOUTHWEST WINDS TO GUST TO AROUND 20 KT AND
CORRESPONDINGLY THE SEAS WILL BEGIN TO INCREASE BACK TO AROUND
5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN OUTER WATERS.
SMALL CRAFT ADVISORIES WILL AGAIN BE NEEDED FOR SOMEWHAT ROUGH SEAS.
FRIDAY NIGHT...CONDITIONS WILL REMAIN RATHER STEADY-STATE WITH SEAS
NEAR 5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN WATERS. COULD
HAVE W TO SW WIND GUSTS TO 15 TO 20 KT OVER ALL COASTAL WATERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY-SUNDAY...W-SW WINDS MAY GUST CLOSE TO 20 KT DURING THE DAY
SAT...THEN WILL BACK TO S ON SUN. SEAS MAY LINGER AT 5-6 FT EARLY
SATURDAY ACROSS THE SOUTHERN OUTER WATERS...THEN SHOULD SUBSIDE.
SUNDAY NIGHT...S-SE WINDS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA.
SEAS WILL BUILD BACK UP TO AROUND 5 FT ON THE SOUTHERN OPEN WATERS
MAINLY AFTER MIDNIGHT.
MONDAY...EXPECT SE WINDS GUSTING TO 25 KT FOR A TIME DURING THE
DAY...THEN SHIFT TO SW AND SHOULD DIMINISH MON NIGHT. SEAS MAY BUILD
UP TO 8 FEET OR GREATER...THOUGH SUSPECT WNA WAVEWATCH MODEL MAY BE
TOO HIGH USING THE GFS MODEL WHICH HAS STRONGEST GRADIENT AND LOW
PASSING CLOSE TO THE WATERS.
TUESDAY...W-SW WINDS MAY GUST TO 20 KT. SEAS STILL FORECASTED AROUND
8 FT BUT SHOULD SUBSIDE IF THEY REACH THAT HIGH.
&&
.TIDES/COASTAL FLOODING...
HAVE ISSUED ANOTHER COASTAL FLOOD STATEMENT FOR POSSIBLE POCKETS
OF MINOR COASTAL FLOODING OR SPLASHOVER NEAR THE TIME OF THE
FRIDAY MORNING HIGH TIDE...MAINLY BETWEEN 9 AM AND NOON.
ALTHOUGH WE WILL HAVE HIGHER ASTRONOMICAL TIDES THAN TODAY...WE WILL
HAVE LOWER SEAS AND AN OFFSHORE WIND WHICH SHOULD PREVENT ANYTHING
SIGNIFICANT FROM OCCURRING. MRPSSE GUIDANCE GAVE -0.5 FT SURGE
DUE TO THE OFFSHORE WINDS. WE CAPPED THESE AT NO LESS THAN -0.2 FT
JUST IN CASE THERE WAS SOME RESIDUAL LEFTOVER FROM TODAY.
&&
.CLIMATE...
WITH VERY MILD AIR WORKING UP THE COAST THIS WEEKEND...SEVERAL OF
THE FOUR MAJOR CLIMATE LOCATIONS MAY APPROACH RECORD HIGHS. HERE IS
A LIST OF THE RECORDS...
NOV 26 SAT NOV 27 SUN
BOSTON 67/1946 AND PREV 72/1896
WORCESTER 64/1895 66/1896
PROVIDENCE 67/2001 66/1946
BRADLEY 65/1979 64/1976
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EST THIS
EVENING FOR ANZ250-251.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EST THIS
EVENING FOR ANZ254-255.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON FRIDAY TO 5
AM EST SATURDAY FOR ANZ256.
&&
$$
SYNOPSIS...EVT/GAF
NEAR TERM...GAF
SHORT TERM...GAF
LONG TERM...EVT/GAF
AVIATION...EVT/GAF
MARINE...EVT/GAF
TIDES/COASTAL FLOODING...GAF
CLIMATE...EVT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
415 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE FROM THE TENNESSEE VALLEY TO THE MID ATLANTIC STATES
WILL PROVIDE SOUTHERN NEW ENGLAND WITH DRY WEATHER THROUGH THE
WEEKEND WITH WARMING TEMPERATURES. A COLD FRONT WILL SLOWLY MOVE
TOWARD THE REGION SUNDAY NIGHT...MOVING OFFSHORE LATE TUESDAY OR
TUESDAY NIGHT. ANOTHER FRONT MAY PUSH ACROSS THE REGION DURING THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
410 PM UPDATE...
THE ONLY REMAINING LOW CLOUDS WERE OVER SOUTHERN NEW HAMPSHIRE AND
NORTH OF ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS
HANGING AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A
SIGNIFICANT PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. CLEAR
SKIES EXPECTED OVER THE REST OF SOUTHERN NEW ENGLAND AS STRONG
HIGH PRESSURE FROM THE TN VALLEY TO THE MID ATLANTIC INFLUENCES
OUR WEATHER. USED MAVMOSGUID BIAS CORRECTED GRIDS FOR LOWS
TONIGHT. LOWERED THEM BY A FEW DEGREES IN NORTHERN CHESHIRE COUNTY
WHERE HIGHS TODAY REMAINED IN THE 30S. WITH CLEARING SKIES AND
LIGHT WINDS THERE...IT COULD DROP TO MID 20S. ELSEWHERE EXPECTING
LOWS IN THE UPPER 20S TO MID 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY... HIGH PRESSURE WITH CONTINUED WARMING TREND ALOFT AND AT
THE SURFACE. LIGHT WINDS AND ABUNDANT SUNSHINE EXPECTED.
TEMPERATURES AT 925 MB CLIMB TO 10-13C ON BOTH NAM AND GFS. USED
MAVMOS GUIDANCE WITH BIAS ADJUSTMENT WHICH YIELDS 60 TO 64 ACROSS
CT...MUCH OF RI...AND INTERIOR SE MA. LOWER TO MID 50S IN SOUTHERN
NH AND NW MA.
FRIDAY NIGHT... CLEAR SKIES AND LIGHT WINDS MAY ALLOW FOR
TEMPERATURES TO RADIATE DOWN TO PURE MAVMOS LEVELS WHICH WERE 5 TO
10 DEGREES LOWER THAN THE BIAS CORRECTED ONES. HOWEVER...AM OPTING
FOR A BLEND OF THE TWO SINCE WE WILL BE IN AN ANOMALOUSLY WARM PATTERN.
LOWS MAINLY IN THE MID 30S TO NEAR 40 BUT COOLER IN NORTHWESTERN
AREAS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* ABOVE AVERAGE AND DRY WEATHER FOR THE WEEKEND
* PRECIP CHANCES INCREASING BEGINNING NEXT WEEK
* TEMPS WILL BE CLOSE TO AVERAGE LATER IN THE WEEK
CONFIDENCE...
ANOTHER TRICKY FORECAST FOR THIS MORNING AS MODEL SPREAD CONTINUES
TO BE QUITE LARGE. HAVE HIGH CONFIDENCE IN THE FORECAST FOR SATURDAY
AND EVEN INTO SUNDAY. ALSO CONFIDENCE IS INCREASING THAT TEMPS FOR
SAT THROUGH TUESDAY WILL BE ABOVE SEASONABLE AVERAGE AS SOUTHWEST
FLOW CONTINUES TO DOMINATE THE REGION. VERY LOW CONFIDENCE ON TIMING
OF PRECIP ON MONDAY THROUGH WEDNESDAY AS MODELS ARE STRUGGLING WITH
THE MEDIUM RANGE. IN THE EXTENDED PORTION OF THE
FORECAST...CONFIDENCE IS INCREASING THAT TEMPS WILL BE CLOSE TO OR
BELOW AVERAGE. HOWEVER HAVE HIGH UNCERTAINTY ON CHANCE OF
PRECIPITATION. FOR NOW LEFT THURSDAY DRY...BUT DEPENDING ON MODEL
SOLUTION PRECIP MAY NEED TO BE INSERTED.
FRIDAY PM - SATURDAY...
ALL SHORT RANGE MODELS ARE CONSISTENT FOR THE BEGINNING PERIODS OF
THIS FORECAST. HIGH PRESSURE WILL SET UP ACROSS THE CAROLINAS AND
EVENTUALLY BE PUSHED OFF SHORE BY A STOUT TROUGH DIGGING THROUGH THE
CENTER CONUS BY SUNDAY.
WITH THE HIGH PRESSURE SOUTH OF THE REGION...WESTERLY WINDS WILL SET
UP ACROSS SOUTHERN NEW ENGLAND. THIS WILL HELP INCREASE TEMPS AT
LEAST 10F ABOVE AVERAGE. WITH A GOOD AMOUNT OF WAA...850MB TEMPS
WILL INCREASE TO 8-10C. MID TO HIGH LEVEL CLOUDS WILL STREAM THROUGH
THE NORTHERN HALF OF THE AREA...WHICH COULD EFFECT HOW MUCH THE
REGION MIXES OUT. LOW TEMPS FOR THIS PORTION OF THE FORECAST WILL BE
MILD...REACHING THE MID 40S ALONG THE COAST WITH THE UPPER 30S TO
LOW 40S IN THE INTERIOR.
SUNDAY - TUESDAY...
THIS IS THE POINT WHERE ALL MODELS DIVERGE FROM EACH OTHER. THE GFS
KEEPS THE LONGWAVE TROUGH INTACT WITH A CUTOFF LOW MOVING ACROSS THE
GREAT LAKES. WHERE AS THE ECMWF IS PERSISTENT ON KEEPING A CUTOFF LOW
ACROSS THE TX/LA BORDER. WITH THIS CUTOFF LOW...AN UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE THE GREAT LAKES AND INTO THE
NORTHEAST. EITHER WAY BOTH MODEL SOLUTIONS BRING PRECIP TO THE
REGION LATE SUNDAY NIGHT AND INTO MONDAY. THE QUESTION IS JUST HOW
MUCH AND THE EXACT TIMING. THE GFS HAS BEEN THE MOST CONSISTENT FROM
RUN TO RUN...AND BEING LESS DRAMATIC WITH THE POTENTIAL OF A CUT OFF
LOW. THE ECMWF HAS ALSO BEEN CONSISTENT WITH A CUT OFF LOW IN LA/TX
REGION...AS WELL AS CONTINUING TO BE MORE PROGRESSIVE. WITH ALL THE
UNCERTAINTY IN HAND...TRENDED TOWARDS THE GFS ENSEMBLES AS WELL AS
HPC.
STOUT SOUTHERLY WINDS WILL BE BREEZY ON SUNDAY AHEAD OF A SURFACE
TROUGH. EXPECT PRECIP TO BEGIN FROM WEST TO EAST IN THE LATE
MORNING/EARLY AFTERNOON ON SUNDAY AS SURFACE LOW PASSES ACROSS
SOUTHERN NEW ENGLAND BY MONDAY AFTERNOON. TEMPS WILL BEGIN TO
DECLINING BACK TO AVERAGE BY TUESDAY. BEST TIME FRAME FOR PRECIP WILL
BE EARLY MONDAY MORNING. STILL SOME UNCERTAINTY ON TIMING AND
AMOUNTS. STAY TUNE FOR FURTHER FORECAST ON THIS SYSTEM.
WEDNESDAY - THURSDAY...
WITH THE SPREAD OF THE MODELS INCREASING...THIS PORTION OF THE
FORECAST REMAINS LOW CONFIDENCE. THE MORE AMPLIFIED...CUT OFF
LOW...ECMWF KEEPS THE AREA WET AS THE LOW PRESSURE SYSTEM GETS
KICKED BACK UP INTO THE LONG WAVE PATTERN AND MOVES ACROSS THE
REGION. WHERE AS THE GFS KEEPS THE AREA DRY UNTIL AN UPPER LEVEL
DISTURBANCE PUSHES THROUGH ON BY LATE THURSDAY...INDICATING PERHAPS
A COASTAL STORM. BECAUSE OF THE VERY LOW CONFIDENCE...KEPT THE POPS
FORECAST LOW AND TRENDED TOWARDS A COOLER TEMPERATURE SOLUTION.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
410 PM UPDATE...
REST OF THIS AFTERNOON AND EVENING... THE ONLY REMAINING MVFR
CEILINGS AROUND 2000-2500 FT WERE OVER SOUTHERN NH AND NORTH OF
ROUTE 2 IN NORTHERN MA. THE RUC SHOWS THIS CLOUDINESS HANGING
AROUND MUCH LONGER THAN THE OTHER MODELS. THINK A SIGNIFICANT
PORTION OF IT WILL CLEAR OUT AFTER SUNDOWN. ELSEWHERE HIGH
CONFIDENCE VFR WITH CLEAR SKIES.
TONIGHT... HIGH CONFIDENCE VFR WITH CLEAR SKIES EXCEPT POSSIBLE
POCKETS OF MVFR CEILINGS CONTINUING IN THE MONADNOCKS OF SOUTHERN
NH. THIS SHOULD REMAIN TO THE WEST OF MHT... MODERATE CONFIDENCE
OF THAT.
FRIDAY... HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
KBOS TERMINAL...
HIGH CONFIDENCE VFR THROUGH FRIDAY. THERE WILL BE SCT-BKN CLOUDS
IN THE 2000-2500 FT RANGE THROUGH ABOUT 01Z NOT TOO FAR TO THE
NORTH OF LOGAN INTL.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
FRIDAY NIGHT...HIGH CONFIDENCE VFR WITH CLEAR OR MOSTLY CLEAR SKIES.
SATURDAY...HIGH CONFIDENCE FOR VFR CONDITIONS.
SATURDAY NIGHT-SUNDAY...HIGH CONFIDENCE FOR MAINLY VFR. MID TO HIGH
LEVEL CLOUDS WILL MOVE IN FROM WEST TO EAST. MAY SEE LOCAL MVFR-IFR
VSBYS IN PATCHY FOG LATE SAT NIGHT/SUN MORNING.
SUNDAY NIGHT-MONDAY...MODERATE CONFIDENCE. EXPECT VFR CIGS EARLY SUN
NIGHT...THEN MVFR CIGS/VSBYS IN DEVELOPING SHOWERS. MAY SEE LOCAL
IFR VSBYS IN FOG SUN NIGHT-MON MORNING.
&&
.MARINE...
410 PM UPDATE...
TONIGHT...
SEAS HAVE BEEN STEADILY SUBSIDING THROUGHOUT THE AFTERNOON
BUT STILL REMAIN AT 5 TO 6 FEET ACROSS THE EASTERN OUTER WATERS.
HAVE CONTINUED THE SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS FOR
WATERS NORTH OF CAPE COD THROUGH 7 PM AND FOR THE WATERS OFF OF
CAPE COD AND SE OF NANTUCKET THROUGH 10 PM. EXPECTING ALL WATERS
TO BE BELOW THRESHOLDS BY AROUND 10 PM. PREFERRED WNAWAVE GRIDS TO
SWANNAM OR SWANGFS BECAUSE IT KEEPS SEAS HIGHER JUST TO THE EAST
OF OUR MARINE FORECAST AREA.
MODELS INDICATE THAT THERE WILL BE AN INCREASING PRESSURE GRADIENT
OVER THE SOUTHERN COASTAL WATERS ON FRIDAY AFTERNOON. THIS CAUSES
WEST TO SOUTHWEST WINDS TO GUST TO AROUND 20 KT AND
CORRESPONDINGLY THE SEAS WILL BEGIN TO INCREASE BACK TO AROUND
5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN OUTER WATERS.
SMALL CRAFT ADVISORIES WILL AGAIN BE NEEDED FOR SOMEWHAT ROUGH SEAS.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...
FRIDAY NIGHT...CONDITIONS WILL REMAIN RATHER STEADY-STATE WITH
SEAS NEAR 5 TO 6 FEET OVER THE SOUTHERN AND SOUTHEASTERN WATERS.
COULD HAVE W TO SW WIND GUSTS TO 15 TO 20 KT OVER ALL COASTAL
WATERS.
SATURDAY - SATURDAY NIGHT...
HIGH PRESSURE WILL SET UP ACROSS THE CAROLINAS KEEPING THE WATERS IN
A WEST TO SOUTHWESTERLY FLOW. GOOD MIXING ACROSS THE WATERS WILL
HELP BUILD SEAS TO ABOVE SCA...ESPECIALLY ACROSS THE OUTER WATERS.
AFTER SUNSET ON SATURDAY...BOTH SEAS AND WIND WILL RELAX BELOW SCA.
SUNDAY - MONDAY...
SURFACE TROUGH WILL APPROACH THE REGION ON SUNDAY...INCREASING
SOUTHERLY WINDS TO 20 KTS. EXPECT SEAS TO BEGIN TO BUILD ABOVE 5FT
STARTING ON THE SOUTHERN OUTER WATERS AND EVENTUALLY INCREASING
ACROSS ALL WATERS BY MONDAY. SURFACE LOW PRESSURE SYSTEM WILL
APPROACH THE REGION BY MONDAY ALLOWING FOR WINDS TO SWITCH FROM A
STOUT SOUTHERLY DIRECTION TO THE WEST. HAVE HIGH CONFIDENCE THAT A
SCA WILL BE NEEDED DURING THIS TIMEFRAME FOR THE OUTER WATERS AND
ALONG THE COASTS.
&&
.TIDES/COASTAL FLOODING...
HAVE ISSUED ANOTHER COASTAL FLOOD STATEMENT FOR POSSIBLE POCKETS
OF MINOR COASTAL FLOODING OR SPLASHOVER NEAR THE TIME OF THE
FRIDAY MORNING HIGH TIDE...MAINLY BETWEEN 9 AM AND NOON.
ALTHOUGH WE WILL HAVE HIGHER ASTRONOMICAL TIDES THAN TODAY...WE WILL
HAVE LOWER SEAS AND AN OFFSHORE WIND WHICH SHOULD PREVENT ANYTHING
SIGNIFICANT FROM OCCURRING. MRPSSE GUIDANCE GAVE -0.5 FT SURGE
DUE TO THE OFFSHORE WINDS. WE CAPPED THESE AT NO LESS THAN -0.2 FT
JUST IN CASE THERE WAS SOME RESIDUAL LEFTOVER FROM TODAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 7 PM EST THIS
EVENING FOR ANZ250-251.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EST THIS
EVENING FOR ANZ254-255.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON FRIDAY TO 5
AM EST SATURDAY FOR ANZ256.
&&
$$
SYNOPSIS...GAF/DUNTEN
NEAR TERM...GAF
SHORT TERM...GAF
LONG TERM...DUNTEN
AVIATION...GAF/DUNTEN
MARINE...GAF/DUNTEN
TIDES/COASTAL FLOODING...GAF
AREA FORECAST DISCUSSION
NWS ALBANY NY
402 PM EST THU NOV 24 2011
.SYNOPSIS...
THE WEATHER PATTERN WILL BE TRANQUIL FOR THIS HOLIDAY WEEKEND AS
HIGH PRESSURE REMAINS IN CONTROL ACROSS THE EASTERN SEABOARD.
TEMPERATURES WILL SLOWLY MODERATE TO ABOVE NORMAL AS SOUTHERLY
WINDS INCREASE. THE NEXT CHANCE FOR SHOWERS ARRIVES LATE SUNDAY
INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
STRATUS DECK WAS ALONG THE I90 CORRIDOR AS OF 19Z. THIS CLOUD DECK
CONTINUES TO SLOWLY ERODE AND MIGRATE NORTHWARD THIS AFTERNOON.
NCEP MODEL SUITE AND HOURLY RUC13 LOW LEVEL RH FIELDS SUGGEST THIS
STRATUS DECK SHOULD CONTINUE TO LIFT NORTHWARD AND ERODE FURTHER.
MEANWHILE...WARM ADVECTION ALOFT AND ITS ASSOCIATED HIGH AND SOME
MID LEVEL CLOUDS ARE QUICKLY MOVING ACROSS NEW ENGLAND AND
PORTIONS OF UPSTATE NEW YORK. THIS TOO IS EXPECTED TO SLIDE
OFFSHORE TONIGHT LEAVING BEHIND A PTCLOUDY-MOCLEAR SKIES.
BASED ON CURRENT DEWPOINTS...MOS TEMPERATURES LOOK A BIT COOL AND
HAVE FOLLOWED WARMER OVERNIGHT TRENDS WITHIN THE LAV/LAMP
GUIDANCE.
LARGE AREA OF HIGH PRESSURE...CENTERED OVER THE SOUTHEAST
CONUS...WILL BE THE DOMINANT PLAYER FOR THIS NEAR TERM AND INTO
THE SHORT TERM.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THIS LARGE AREA OF HIGH PRESSURE WILL KEEP THE WEATHER QUIET EAST
OF THE MISSISSIPPI RIVER THROUGH THIS SHORT TERM PERIOD. IN
FACT...RATHER PRONOUNCED WEST-SOUTHWEST FLOW ALONG WITH MILD MID
LEVEL TEMPS WILL RESULT IN TEMPERATURES CLIMBING TOWARD OR
EXCEEDING 10 DEGREES ABOVE CLIMATOLOGY /IN ADDITION...DOWNSLOPING
MAY ENHANCE THESE TEMPS INTO THE VALLEY LOCATIONS/. THE ONLY
COMPLICATION COULD BE SOME OVERNIGHT SHALLOW BR/FG AND A POTENTIAL
FOR SOME LOW LEVEL STRATUS DEVELOPMENT. IN ADDITION...WITH THE
ONGOING WARM ADVECTION...SOME HIGH AND MID LEVEL CLOUD COVER MAY
MOVE ACROSS THE SKY THOUGH THIS PERIOD. EITHER WAY...THE WEATHER
SHOULD HAVE MINIMAL IMPACT TO HOLIDAY WEEKEND TRAVELS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ACTIVE WEATHER PATTERN EXPECTED THROUGH THE LONG TERM...BUT MODEL
GUIDANCE HAS DIFFERING SOLUTIONS...SO CONFIDENCE IS LOW. WENT WITH
HPC GUIDANCE.
SFC LOW APPROACHING FROM THE GREAT LAKES REGION SUNDAY MORNING. 12Z
GFS...ECMWF AND GFSENSEMBLE MEMBERS HAVE NOT AGREED UPON A
TRACK...SPEED...OR QPF AMOUNTS. ECMWF HAS THE MORE PROGRESSIVE AND
NORTHERLY TRACK OF SFC LOW...WITH THE COLD FRONT AND PRECIP
ASSOCIATED WITH THE LOW MOVING THROUGH THE FA LATE SUNDAY THROUGH
LATE MONDAY...WITH QPF AMOUNTS AROUND HALF AN INCH OR LESS.
ASSOCIATED UPPER LEVEL POSITIVELY TILTED TROUGH REMAINS OPEN IN
ECMWF.
MEANWHILE...GFS DEVELOPS A CLOSE LOW WITHIN THE UPPER LEVEL TROUGH.
AS THIS TROUGH APPEARS TO HAVE A NEUTRAL TILT...GFS KEEPS IT SLOW
MOVING OVER THE GREAT LAKES REGION...WHERE THE UPPER LEVEL LOW
PRESSURE CENTER REFORMS FURTHER NORTH SUNDAY NIGHT. THE TROUGH
BECOMES NEGATIVELY TILTED BEFORE A PIECE OF SOUTHERLY ENERGY BREAKS
OFF...TRAVELING TOWARDS THE OBX AHEAD OF THE MAIN TROUGH...BY
TUESDAY NIGHT. QPF AMOUNTS UP TO 2 INCHES WITH THE GFS.
CHANCE FOR PRECIP POSSIBLE THROUGH TUESDAY NIGHT/WEDNESDAY WITH GFS
ENSEMBLE MEMBERS SLOWLY MOVE SFC LOW NORTHWARD TOWARDS JAMES BAY.
ALL GUIDANCE SHOW HIGH PRESSURE BUILDING IN JUST SOUTH OF THE
REGION...BUT NO AGREEMENT ON WHEN OR FOR HOW LONG. HPC HAS HIGH
PRESSURE WEDNESDAY INTO THURSDAY.
TEMPS ABOUT 10 DEGREES ABOVE NORMAL TO START THE PERIOD...TRENDING
COOLER TO ABOUT NORMAL BY THE END OF THE PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD ENDING
AT 18Z FRIDAY. STRATOCUMULUS HAVE LIFTED NORTH OF KPOU AND WILL
LIFT NORTH OF KALB BY 19Z. KGFL WILL CONTINUE TO HAVE
STRATOCUMULUS WITH MVFR CONDITIONS FOR THE REMAINDER OF THE AFT.
SKIES WILL BE MAINLY SKC OR SCT250 TONIGHT WITH SOME FOG PSBL AT
KGFL AND KPOU WITH MAINLY MVFR CONDITIONS EXPECTED AFT 07Z. ON
FRIDAY SKC CONDITIONS ARE EXPECTED AT THE TAF SITES AFT 12Z AS A
LARGE RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
EXPECT WINDS WILL REMAIN SOUTH AT 3-5 KTS THROUGH THE REMAINDER OF
THIS AFT...BECOME LIGHT AND VARIABLE TONIGHT...AND SOUTH AT 4-6
KTS FRI MRNG.
OUTLOOK...
FRIDAY AFT-SAT NIGHT...VFR. NO SIG WX.
SUN...MAINLY VFR. INCREASING CLDS. CHC -SHRA LATE.
SUN NIGHT-MON...MVFR/IFR IN RAIN AND MIST.
&&
.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH MOST OF THE LONG HOLIDAY WEEKEND
AS HIGH PRESSURE DOMINATES. OUR NEXT CHANCES FOR WET WEATHER WILL
RETURN LATE IN THE WEEKEND INTO EARLY NEXT WEEK AS A LOW PRESSURE
SYSTEM APPROACHES AND MOVES ACROSS THE REGION. THERE IS MUCH
UNCERTAINTY WITH REGARDS TO THE SYSTEM AS THERE IS A LARGE SPREAD
IN THE MODEL GUIDANCE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
2011 HAS MOVED UP INTO FIFTH PLACE FOR WETTEST YEARS ON RECORD
FOR ALBANY NEW YORK.
WETTEST YEARS - ALBANY NY - SINCE 1820
1) 55.78 INCHES 1871
2) 55.81 INCHES 1870
3) 51.83 INCHES 1850
4) 49.80 INCHES 1827
5) 49.75 INCHES THROUGH NOVEMBER 23ND
6) 49.37 INCHES 1878
7) 48.35 INCHES 1843
8) 48.22 INCHES 1848
9) 47.79 INCHES 2008
10) 47.72 INCHES 2005
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...KGM
AVIATION...11
HYDROLOGY...BGM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1259 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO DECREASE ON THE WATERS THIS MORNING.
THE SCA FLAG FOR THE DELAWARE BAY AND THE NORTHERN COASTAL WATERS
HAVE BEEN TAKEN DOWN. SEAS REMAIN UP ACROSS THE SOUTHERN COASTAL
WATERS...SO THE FLAG WILL CONTINUE THERE INTO THE MID-AFTERNOON. A
FEW GUSTS UP TO 25 KTS STILL MAY OCCUR ON THE WATERS THIS
AFTERNOON...BUT THE TREND CONTINUES DOWNWARD AS HIGH PRESSURE
BUILDS IN. SUB SCA CONDITIONS EXPECTED TONIGHT INTO FRIDAY AND
WINDS WILL BACK AROUND TO W THEN SW.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE UPPER DELAWARE BAY HAS EXPIRED. HIGH TIDE IS
OCCURRING AT PHILADELPHIA PRESENTLY AND WILL TAKE A FEW HOURS MORE
TO REACH THE UPPER PORTIONS OF THE DELAWARE RIVER. THE CFW FOR
THOSE AREAS WILL BE TAKEN DOWN AT 3 PM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
PAZ071.
NJ...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NJZ018-019.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1016 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS AND SEAS CONTINUE TO DECREASE ON THE WATERS THIS MORNING.
THE SCA FLAG FOR THE DELAWARE BAY AND THE NORTHERN COASTAL WATERS
HAVE BEEN TAKEN DOWN. SEAS REMAIN UP ACROSS THE SOUTHERN COASTAL
WATERS...SO THE FLAG WILL CONTINUE THERE INTO THE MID-AFTERNOON. A
FEW GUSTS UP TO 25 KTS STILL MAY OCCUR ON THE WATERS THIS
AFTERNOON...BUT THE TREND CONTINUES DOWNWARD AS HIGH PRESSURE
BUILDS IN. SUB SCA CONDITIONS EXPECTED TONIGHT INTO FRIDAY AND
WINDS WILL BACK AROUND TO W THEN SW.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
925 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING. HOWEVER TEMPERATURES WITH THE
PREVIOUS FORECAST ARE ON TRACK TODAY WITH SLIGHT ALTERATIONS
BASED ON 14Z METAR OBS. RAISED VISIBILITY A BIT ON THIS UPDATE ALSO
BASED OFF OF 14Z OBS. PREVIOUS FORECASTER THINKING BELOW STILL
LOOKS GOOD SO FEW CHANGES MADE OVERALL ATTM. A VERY NICE
THANKSGIVING DAY IS AHEAD OF US!
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS
THE SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED
ON THE ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT
1500 UTC ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC
ACROSS THE SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...GAINES/HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
909 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD AIR ADVECTION IS ENDING...AND THE MOISTURE TRAPPED UNDER
THE INVERSION IS MIXING OUT. THE MOISTURE MAY BE TOUGHER TO SCOUR
OUT OF THE HIGHER TERRAIN...AND THIS MAY HAVE TO BE ACCOUNTED FOR
IN THE MORNING FORECAST.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN
SOME HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE
BEST PART OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST
AREA NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND
SHOULD DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR
ADVECTION ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS TODAY...BUT FOR THE
MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY. 850 MB TEMPERATURES
SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS CLOSE TO THE MOS
BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CFW FOR THE OCEAN AREAS HAS BEEN CANCELLED WITH THE HIGH TIDE
HAVING PASSED. MINOR TIDAL FLOODING LEVELS WERE REACHED ALONG THE
SHORE AREAS.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
630 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LOWER CLOUD DECK CONTINUES TO SHRINK AWAY EARLY THIS
MORNING...WITH THE LAST VESTIGES OVER THE SOUTHERN POCONOS AND
SOUTHERN NEW JERSEY AND DELAWARE. THE COLD AIR ADVECTION IS
ENDING...AND THE MOISTURE TRAPPED UNDER THE INVERSION IS MIXING OUT.
THE MOISTURE MAY BE TOUGHER TO SCOUR OUT OF THE HIGHER TERRAIN...AND
THIS MAY HAVE TO BE ACCOUNTED FOR IN THE EARLY MORNING FORECAST.
ELSEWHERE...THE LOWER CLOUDS SHOULD DISSIPATE BEFORE SUNRISE.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN SOME
HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE BEST PART
OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST AREA
NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND SHOULD
DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR ADVECTION
ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS JUST AFTER
SUNRISE...BUT FOR THE MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY.
850 MB TEMPERATURES SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS
CLOSE TO THE MOS BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE
DOES NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT
1500 UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE
GALE WARNING WILL BE RUN UNTIL ABOUT 1500 UTC ON THE DELAWARE BAY
(AND IT MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
A FEW POINTS HAVE REACHED THE MINOR TIDAL FLOODING BENCHMARK ALONG
THE OCEANFRONT THIS MORNING (SANDY HOOK AND ATLANTIC CITY ARE
ALREADY THERE...AND CAPE MAY AND LEWES DELAWARE SHOULD FOLLOW
SHORTLY). THE DEPARTURES DECREASED AS HIGH TIDE APPROACHED (WHICH
IS TYPICAL IN AN NON-SURGE TIDE)...BUT STILL ENOUGH FOR MINOR
TIDAL FLOODING.
TIDE DEPARTURES ON THE UPPER DELAWARE BAY AND TIDAL PORTION OF
THE DELAWARE HAVE INCREASED STEADILY THIS MORNING. THE FACT THAT
WE WOULD ONLY NEED ABOUT ONE-HALF TO THREE-QUARTERS OF A FOOT OF
DEPARTURE FROM PREDICTED (WE ARE JUST ABOUT THERE NOW) SUGGESTS
THAT MINOR TIDAL FLOODING WILL OCCUR THERE AS WELL. BASED ON THE
ABOVE...AND THE RATE OF INCREASE OF DEPARTURES...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY AND TIDAL
SECTION OF THE DELAWARE RIVER.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
PAZ070-071.
NJ...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>019-021.
DE...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR DEZ003-
004.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES
MARINE...HAYES
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
300 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO OUR REGION THIS THANKSGIVING
THURSDAY AND DOMINATE OUR WEATHER INTO SUNDAY. A COLD FRONT...
APPROACHING FROM THE WEST...WILL MOVE SLOWLY ACROSS OUR REGION
SUNDAY NIGHT INTO MONDAY. LOW PRESSURE MAY DEVELOP ON THE FRONT
ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY NORTHWARD MONDAY
NIGHT INTO TUESDAY NIGHT. MORE LOW PRESSURE IS POSSIBLE DURING
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LOWER CLOUD DECK CONTINUES TO SHRINK AWAY EARLY THIS
MORNING...WITH THE LAST VESTIGES OVER THE SOUTHERN POCONOS AND
SOUTHERN NEW JERSEY AND DELAWARE. THE COLD AIR ADVECTION IS
ENDING...AND THE MOISTURE TRAPPED UNDER THE INVERSION IS MIXING OUT.
THE MOISTURE MAY BE TOUGHER TO SCOUR OUT OF THE HIGHER TERRAIN...AND
THIS MAY HAVE TO BE ACCOUNTED FOR IN THE EARLY MORNING FORECAST.
ELSEWHERE...THE LOWER CLOUDS SHOULD DISSIPATE BEFORE SUNRISE.
CONVECTIVE TEMPERATURES ARE OUT OF REACH TODAY...AND OTHER THAN SOME
HIGH CLOUDINESS THIS MORNING...SKIES SHOULD BE SUNNY. THE BEST PART
OF THE SURFACE PRESSURE GRADIENT IS OVER THE FORECAST AREA
NOW...AND SOME GUSTINESS LINGERS. THE GUSTINESS TO THE WIND SHOULD
DROP BACK EARLY THIS MORNING AS THE LAST OF THE COLD AIR ADVECTION
ENDS.
IT IS POSSIBLE THERE COULD BE SOME GUSTINESS JUST AFTER
SUNRISE...BUT FOR THE MOST PART WINDS SHOULD NOT BE AN ISSUE TODAY.
850 MB TEMPERATURES SUPPORT HIGHS IN THE MID 50S TODAY...WHICH IS
CLOSE TO THE MOS BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
BUILDING MID LEVEL RIDGING SHOULD KEEP ANY HIGH AND MID LEVEL CLOUDS
NORTH OF THE AREA TONIGHT...AND SKIES SHOULD BE CLEAR. AS THE HIGH
REACHES NORTH CAROLINA TONIGHT...THE GRADIENT WILL BACK OFF.
HOWEVER...WINDS MAY NOT BECOME COMPLETELY CALM OUTSIDE OF PROTECTED
AREAS...AS THE GRADIENT WOULD SUPPORT WEST WINDS LESS THAN 10 MPH.
THE ABOVE SCENARIO WOULD SUPPORTS LOWS NEAR THE MOS BLEND IN THE
URBAN AREAS AND PLACES WITH EXPOSURE. FOR PROTECTED AREAS (INCLUDING
THE PINE BARRENS IN NEW JERSEY)...LOWS WERE DROPPED A FEW DEGREES
FROM THE MOS MEAN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A QUIESCENT PERIOD OF WEATHER IS SHAPING UP FOR THE NORTHERN MID
ATLANTIC AREA FRIDAY INTO SUNDAY. THE MODELS HAVE LATCHED ONTO A
COLD FRONT WHICH LOOKS LIKE IT WILL AFFECT OUR AREA MAINLY SUNDAY
NIGHT INTO MONDAY. THEN...MODEL PERFORMANCE HAS SEEMINGLY
DETERIORATED OVER THE PAST 24 TO 48 HOURS, WITH RUN-TO-RUN AND
INTERMODEL INCONSISTENCY AND CHANGEABILITY. WITH NO CLEAR
SIGNALS...IT WAS DECIDED TO JUST USE A BROAD BRUSH OF CHANCE
PROBABILITIES FOR SHOWERS THROUGH THE MONDAY THROUGH WEDNESDAY
PERIOD, WITH A MODERATE TO HIGH AMOUNT OF CLOUDINESS. THE GFS EVEN
PAINTS SOME TYPE OF RAIN/SNOW EVENT WEDNESDAY NIGHT INTO THURSDAY.
LATER MODEL ITERATIONS WILL BE NEEDED TO GAIN MORE CLARITY ON THIS
PERIOD.
SO...HPC TEMPERATURES WERE USED AS A STARTING POINT FOR HIGHS AND
LOWS, WITH SOME MODIFICATIONS FOR LOCAL EFFECTS AND CLIMATOLOGY. A
GENERAL COOLING TREND SHOULD OCCUR THROUGH THE LONG TERM PERIOD...
WITH HIGHS IN THE MID 50S AND LOWER 60S OVER THE WEEKEND, DROPPING
TO THE 40S TO NEAR 50 BY WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO PROVIDE US WITH FINE VFR
FLYING CONDITIONS FRIDAY INTO...OR PERHAPS THROUGH MOST OF...SUNDAY.
A COLD FRONT MOVING IN FROM THE WEST SUNDAY NIGHT WILL MOVE EASTWARD
THROUGH OUR AREA. HOWEVER, A SUCCESSION OF LOWS COULD AFFECT OUR
REGION AND PERHAPS BRING LOWER CONDITIONS AT TIMES INTO THE EARLY OR
EVEN MIDDLE PORTION OF NEXT WEEK. MODEL GUIDANCE HAS BEEN CHANGING
AND INCONSISTENT...SO LITTLE IN THE WAY OF CONFIDENCE CAN BE SHOWN
UNTIL THE MODELS START TO OFFER BETTER AGREEMENT AND RUN-TO-RUN
CONSISTENCY. LOWER CEILINGS AND/OR VISIBILITIES IN SHOWERS/RAIN AND
FOG MAY OCCUR THROUGH MUCH OF THE SUNDAY NIGHT THROUGH WEDNESDAY
TIME PERIOD, THOUGH.
&&
.MARINE...
WINDS HAVE DROPPED BELOW GALE FORCE IN GUSTS JUST ABOUT EVERYWHERE
EARLY THIS MORNING. THE GUSTINESS SHOULD LOSE ITS EDGE WITH THE END
OF THE COLD AIR ADVECTION...SO THE GALE WARNING WILL BE REPLACED BY
A SMALL CRAFT ADVISORY WITH THE EARLY MORNING PACKAGE.
THE GRADIENT REMAINS IN PLACE MOST OF THE DAY...AND AT A GLANCE DOES
NOT APPEAR TO SUPPORT SMALL CRAFT WINDS ANYWHERE AFTER ABOUT 1500
UTC. THEREFORE...THE SMALL CRAFT ADVISORY THAT REPLACES THE GALE
WARNING WILL BE RUN UNTIL ABOUT 1400 UTC ON THE DELAWARE BAY (AND IT
MAY NOT EVEN BE NEEDED THAT LONG).
OVER THE OCEAN WATERS...SEAS ARE STILL RUNNING 5 TO 9 FEET...WITH
THE HIGHEST SEAS ACROSS THE SOUTHERN WATERS. WHILE WINDS SHOULD DROP
BELOW SMALL CRAFT LEVELS IN GUSTS BY 1500 UTC...THE SEAS ACROSS THE
SOUTHERN WATERS MAY TAKE LONGER TO SORT THEMSELVES OUT. BASED ON THE
ABOVE...THE SMALL CRAFT ADVISORY WILL BE RUN THROUGH ABOUT 1500 UTC
ACROSS THE NORTHERN OCEAN WATERS...AND ABOUT 1800 UTC ACROSS THE
SOUTHERN OCEAN WATERS.
AFTER THIS...THE GRADIENT LOOKS TO SUPPORT WINDS AROUND 15 KNOTS ON
THE OCEAN FOR THE REST OF TODAY INTO TONIGHT. WINDS ACROSS THE
DELAWARE BAY WILL BE SLIGHTLY LOWER...BUT PROBABLY DO NOT DROP BELOW
10 KNOTS...AS THE GRADIENT LOOKS TO SUPPORT WINDS OF THESE SPEEDS.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR MARINE
AREA FRIDAY THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST,
A COLD FRONT WILL APPROACH FROM THE WEST SUNDAY. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THESE TWO SYSTEMS...AND THIS WILL MEAN
A GOOD CHANCE OF SHOWERS AS WELL AS INCREASING SOUTH TO SOUTHEAST
WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY. A SERIES OF LOW
PRESSURE SYSTEMS COULD AFFECT OUR AREA THROUGH THE EARLY AND MIDDLE
PORTIONS OF NEXT WEEK...BUT MODEL GUIDANCE HAS BECOME TOO CHANGEABLE
AND INCONSISTENT TO OFFER ANY KIND OF SPECIFICS. ADVISORY CONDITIONS
ARE LIKELY AT SOME POINT...AND EVEN GALE CONDITIONS MAY OCCUR FOR A
TIME...IN THE SUNDAY NIGHT TO MID WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
TIDE DEPARTURES HAVE RISEN A BIT EARLY THIS MORNING...EVEN AS WINDS
HAVE SHIFTED TO THE NORTH. IT COULD BE THAT AN EKMAN SPIRAL HAS
DEVELOPED ON THE OCEAN WATERS...WHICH PRODUCES A NET MASS TRANSPORT
OF WATER TO THE SHORE. THIS COULD ACCOUNT FOR THE TIDE DEPARTURES
RUNNING BETWEEN THREE-QUARTERS AND ONE AND ONE-QUARTER FEET ABOVE
PREDICTED EARLY THIS MORNING.
THE HIGH ASTRONOMICAL TIDES WILL BRING THE HIGH TIDE CYCLE WITH
ONE-HALF FOOT OF THE MINOR TIDAL FLOODING BENCHMARK WITHOUT ANY
RESIDUAL TIDE EFFECTS. GIVEN WHAT IS GOING ON NOW...AS WELL AS THE
PREPONDERANCE OF TIDE MODEL GUIDANCE...A COASTAL FLOOD ADVISORY WILL
BE ISSUED FOR THE OCEAN...RARITAN BAY AND THE BACK BAYS FOR THE
MORNING HIGH TIDE.
TIDE DEPARTURES ARE CURRENTLY NEGATIVE ACROSS THE DELAWARE BAY AND
TIDAL DELAWARE RIVER. THE TIDE MODEL GUIDANCE BRINGS BOTH OF THESE
LOCATIONS CLOSE TO THE MINOR TIDAL FLOODING BENCHMARK LATER THIS
MORNING AND EARLY THIS AFTERNOON. FOR NOW...WILL WATCH TRENDS AND
ISSUE A COASTAL FLOOD STATEMENT IF IT APPEARS AS THOUGH IT MAY BE
CLOSE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
DE...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR DEZ003-
004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ450-
451.
SMALL CRAFT ADVISORY UNTIL 8 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...
NEAR TERM...HAYES
SHORT TERM...HAYES
LONG TERM...
AVIATION...HAYES/
MARINE...HAYES/
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
149 AM EST THU NOV 24 2011
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE TENNESSEE VALLEY LATE THIS EVENING
WILL BUILD INTO THE REGION AND DOMINATE OUR WEATHER THROUGH THE
WEEKEND. A COLD FRONT, APPROACHING FROM THE WEST, WILL MOVE SLOWLY
ACROSS OUR REGION SUNDAY NIGHT AND MONDAY. LOW PRESSURE MAY
DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY
NORTH MONDAY NIGHT INTO TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM,
WITH A REINFORCING SHOT OF COLD AIR, WILL APPROACH FROM THE
NORTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STUBBORN STRATOCUMULUS TRAPPED UNDER THE INVERSION IN THE
COLD AIR ADVECTION IS FINALLY BREAKING UP. A BATCH REMAINS ACROSS
THE SOUTHERN POCONOS...AND THIS ONE COULD TAKE SOME TIME TO BREAK
MORE WITH THE UPSLOPE FLOW. THE BATCH OVER SOUTHERN NEW JERSEY AND
SOUTHERN DELAWARE SHOULD CONTINUE TO BREAK UP AS DRIER AIR IS
ENTRAINED INTO THE LOWER LEVELS.
THE BEST SURFACE PRESSURE GRADIENT IS ACROSS THE FORECAST AREA
EARLY THIS MORNING...AND WINDS REMAIN AT OR ABOVE 10 MPH IS MOST
PLACES. THERE IS STILL SOME GUSTINESS OUT THERE EARLY THIS
MORNING...AS LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT.
AMDAR SOUNDINGS SHOWED 32 TO 35 KNOTS OF WINDS AT THE TOP OF IN
THE INVERSION...SO THERE COULD BE SOME GUSTINESS FOR THE NEXT HOUR
OR TOW. AFTER THAT...THE GUSTINESS SHOULD ABATE...BUT MOST PLACES
PROBABLY KEEP A STEADY NORTH TO NORTHWEST WIND OVERNIGHT.
LOW TEMPERATURES APPEAR TO BE IN LINE...AND LITTLE CHANGE WAS
NEEDED FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE CONTINUES TO MOVE INTO OUR REGION TOMORROW HELPING US
TO MAINTAIN THE NORTHWESTERLY WINDS AND CLEAR SKIES. THE PRESSURE
GRADIENT WILL BEGIN TO SLACKEN EVEN MORE TOMORROW AND DEEP MIXING
APPEARS OUT THE QUESTION SO GUSTS SHOULD NOT BE AN ISSUE...AROUND 15
KNOTS OR LESS. IT IS CERTAINLY GOING TO BE ONE GORGEOUS
THANKSGIVING DAY.
HAPPY THANKSGIVING!!!!
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A LARGE HIGH PRESSURE SYSTEM, CENTERED JUST TO OUR SOUTH, WILL
MOVE SLOWLY EAST TO A POSITION JUST OFF THE NORTH CAROLINA COAST
ON SATURDAY. THIS SYSTEM WILL SUPPLY US WITH FAIR AND RELATIVELY
MILD WEATHER THROUGH THE WEEKEND. WILL SEE PLENTY OF SUNSHINE
FRIDAY AND SATURDAY. CLOUDS WILL BEGIN TO INCREASE SUNDAY AS THE
HIGH MOVES OFF TO THE EAST AND A COLD FRONT APPROACHES FROM THE
WEST. THERE COULD BE A FEW LIGHT SHOWERS SPREADING INTO OUR
NORTHWEST SECTIONS LATE IN THE DAY. DAYTIME HIGHS FRIDAY THROUGH
SUNDAY WILL BE IN THE MID 50S TO MID 60S. OVERNIGHT LOWS WILL BE
MAINLY IN THE 30S THURSDAY NIGHT AND IN THE MID 30S TO MID 40S
FRIDAY NIGHT AND SATURDAY NIGHT. RAIN IS LIKELY SUNDAY NIGHT AND
MONDAY AS THE COLD FRONT CROSSES THE REGION. LOW PRESSURE WILL
THEN DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE
NORTH. THIS COULD MORE RAIN TO OUR AREA MONDAY NIGHT INTO TUESDAY
NIGHT. WITH CLOUDS AND RAIN, HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE SLIGHTLY LOWER THAN OVER THE WEEKEND, WITH READINGS IN
THE UPPER 40S AND 50S. BY WEDNESDAY, ANOTHER FRONT WILL BE
APPROACHING FROM THE NORTHWEST, AS AN UPPER TROUGH MOVES EAST
FROM THE GREAT LAKES. THIS FRONT WILL USHER IN A REINFORCING
SHOT OF COLD AIR BUT WILL BE MOISTURE STARVED. LOOKS LIKE THE
MOST WE COULD GET WOULD BE SCATTERED SHOWERS. HIGH TEMPERATURES
WEDNESDAY WILL BE IN THE 40S TO LOWER 50S.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
THE HIGH PRESSURE SYSTEM TO OUR SOUTH WILL CONTINUE TO PROVIDE US
WITH GOOD VFR FLYING CONDITIONS WELL INTO SUNDAY. A COLD FRONT
MOVING IN FROM THE WEST AND A LOW DEVELOPING ON THIS FRONT, ONCE
IT MOVES JUST OFF TO OUR EAST, WILL BRING OUR NEXT ROUND OF
INCLEMENT WEATHER SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK.
LOWER CIGS/VSBYS IN RAIN AND FOG CAN BE EXPECTED FOR MUCH OF
THAT TIME PERIOD.
&&
.MARINE...
WITH THE COLD FRONT NOW TO OUR EAST AND HIGH PRESSURE TRYING TO NOSE
IN FROM THE WEST THE SURFACE PRESSURE GRADIENT WILL REALLY TIGHTEN
UP TONIGHT. NORTHERLY TO NORTHWESTERLY WINDS WILL BEGIN TO REALLY
HOWL WITH MULTIPLE HOURS OF GALE FORCE GUSTS EXPECTED TONIGHT. SEAS
WILL ALSO REMAIN QUITE ELEVATED TONIGHT IN THE WAKE OF THE STRONGER
NNW FLOW RUNNING AROUND 6 FEET.
THE GALE WARNING IS STILL IN AFFECT FOR ALL OUR COASTAL ZONES
THROUGH 09Z...THAT REMAINS UNCHANGED. AFTER THAT TIME PERIOD THE
GUSTS DROP INTO SMALL CRAFT RANGE FOR A FEW MORE HOURS FOLLOWED BY
SMALL CRAFT FOR HAZARDOUS SEAS BEING A POSSIBILITY.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR WATERS
THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST, A COLD FRONT
WILL APPROACH FROM THE WEST. THE PRESSURE GRADIENT WILL TIGHTEN
BETWEEN THESE TWO SYSTEMS. THIS WILL MEAN INCLEMENT WEATHER WITH
INCREASING S TO SE WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY.
LOW PRESSURE IS THEN FORECAST TO DEVELOP ON THE FRONT ONCE IT MOVES
OFF THE EAST COAST. DEPENDING ON THE TIMING AND LOCATION OF THE LOW,
ADVISORY OR GALE CONDITIONS COULD OCCUR IN THE SUNDAY NIGHT TO MID
WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
TIDE DEPARTURES HAVE RISEN A BIT EARLY THIS MORNING...EVEN AS WINDS
HAVE SHIFTED TO THE NORTH. IT COULD BE THAT AN EKMAN SPIRAL HAS
DEVELOPED ON THE OCEAN WATERS...WHICH PRODUCES A NET MASS TRANSPORT
OF WATER TO THE SHORE. THIS COULD ACCOUNT FOR THE TIDE DEPARTURES
RUNNING BETWEEN THREE-QUARTERS AND ONE AND ONE-QUARTER FEET ABOVE
PREDICTED EARLY THIS MORNING.
THE HIGH ASTRONOMICAL TIDES WILL BRING THE HIGH TIDE CYCLE WITH
ONE-HALF FOOT OF THE MINOR TIDAL FLOODING BENCHMARK WITHOUT ANY
RESIDUAL TIDE EFFECTS. GIVEN WHAT IS GOING ON NOW...AS WELL AS THE
PREPONDERANCE OF TIDE MODEL GUIDANCE...A COASTAL FLOOD ADVISORY WILL
BE ISSUED FOR THE OCEAN...RARITAN BAY AND THE BACK BAYS FOR THE
MORNING HIGH TIDE.
TIDE DEPARTURES ARE CURRENTLY NEGATIVE ACROSS THE DELAWARE BAY AND
TIDAL DELAWARE RIVER. THE TIDE MODEL GUIDANCE BRINGS BOTH OF THESE
LOCATIONS CLOSE TO THE MINOR TIDAL FLOODING BENCHMARK LATER THIS
MORNING AND EARLY THIS AFTERNOON. FOR NOW...WILL WATCH TRENDS AND
ISSUE A COASTAL FLOOD STATEMENT IF IT APPEARS AS THOUGH IT MAY BE
CLOSE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 5 AM TO 9 AM EST THIS MORNING FOR
NJZ012>014-020-022>027.
DE...COASTAL FLOOD ADVISORY FROM 5 AM TO 9 AM EST THIS MORNING FOR
DEZ003-004.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...GIGI/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...RPW
AVIATION...HAYES/RPW
MARINE...GIGI/HEAVENER/RPW
TIDES/COASTAL FLOODING...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1213 AM EST THU NOV 24 2011
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE TENNESSEE VALLEY LATE THIS EVENING
WILL BUILD INTO THE REGION AND DOMINATE OUR WEATHER THROUGH THE
WEEKEND. A COLD FRONT, APPROACHING FROM THE WEST, WILL MOVE SLOWLY
ACROSS OUR REGION SUNDAY NIGHT AND MONDAY. LOW PRESSURE MAY
DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE SLOWLY
NORTH MONDAY NIGHT INTO TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM,
WITH A REINFORCING SHOT OF COLD AIR, WILL APPROACH FROM THE
NORTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STUBBORN STRATOCUMULUS TRAPPED UNDER THE INVERSION IN THE
COLD AIR ADVECTION IS FINALLY BREAKING UP. A BATCH REMAINS ACROSS
THE SOUTHERN POCONOS...AND THIS ONE COULD TAKE SOME TIME TO BREAK
MORE WITH THE UPSLOPE FLOW. THE BATCH OVER SOUTHERN NEW JERSEY AND
SOUTHERN DELAWARE SHOULD CONTINUE TO BREAK UP AS DRIER AIR IS
ENTRAINED INTO THE LOWER LEVELS.
THE BEST SURFACE PRESSURE GRADIENT IS ACROSS THE FORECAST AREA
EARLY THIS MORNING...AND WINDS REMAIN AT OR ABOVE 10 MPH IS MOST
PLACES. THERE IS STILL SOME GUSTINESS OUT THERE EARLY THIS
MORNING...AS LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT.
AMDAR SOUNDINGS SHOWED 32 TO 35 KNOTS OF WINDS AT THE TOP OF IN
THE INVERSION...SO THERE COULD BE SOME GUSTINESS FOR THE NEXT HOUR
OR TOW. AFTER THAT...THE GUSTINESS SHOULD ABATE...BUT MOST PLACES
PROBABLY KEEP A STEADY NORTH TO NORTHWEST WIND OVERNIGHT.
LOW TEMPERATURES APPEAR TO BE IN LINE...AND LITTLE CHANGE WAS
NEEDED FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE CONTINUES TO MOVE INTO OUR REGION TOMORROW HELPING US
TO MAINTAIN THE NORTHWESTERLY WINDS AND CLEAR SKIES. THE PRESSURE
GRADIENT WILL BEGIN TO SLACKEN EVEN MORE TOMORROW AND DEEP MIXING
APPEARS OUT THE QUESTION SO GUSTS SHOULD NOT BE AN ISSUE...AROUND 15
KNOTS OR LESS. IT IS CERTAINLY GOING TO BE ONE GORGEOUS
THANKSGIVING DAY.
HAPPY THANKSGIVING!!!!
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A LARGE HIGH PRESSURE SYSTEM, CENTERED JUST TO OUR SOUTH, WILL
MOVE SLOWLY EAST TO A POSITION JUST OFF THE NORTH CAROLINA COAST
ON SATURDAY. THIS SYSTEM WILL SUPPLY US WITH FAIR AND RELATIVELY
MILD WEATHER THROUGH THE WEEKEND. WILL SEE PLENTY OF SUNSHINE
FRIDAY AND SATURDAY. CLOUDS WILL BEGIN TO INCREASE SUNDAY AS THE
HIGH MOVES OFF TO THE EAST AND A COLD FRONT APPROACHES FROM THE
WEST. THERE COULD BE A FEW LIGHT SHOWERS SPREADING INTO OUR
NORTHWEST SECTIONS LATE IN THE DAY. DAYTIME HIGHS FRIDAY THROUGH
SUNDAY WILL BE IN THE MID 50S TO MID 60S. OVERNIGHT LOWS WILL BE
MAINLY IN THE 30S THURSDAY NIGHT AND IN THE MID 30S TO MID 40S
FRIDAY NIGHT AND SATURDAY NIGHT. RAIN IS LIKELY SUNDAY NIGHT AND
MONDAY AS THE COLD FRONT CROSSES THE REGION. LOW PRESSURE WILL
THEN DEVELOP ON THE FRONT ALONG THE MID ATLANTIC COAST AND MOVE
NORTH. THIS COULD MORE RAIN TO OUR AREA MONDAY NIGHT INTO TUESDAY
NIGHT. WITH CLOUDS AND RAIN, HIGH TEMPERATURES MONDAY AND TUESDAY
WILL BE SLIGHTLY LOWER THAN OVER THE WEEKEND, WITH READINGS IN
THE UPPER 40S AND 50S. BY WEDNESDAY, ANOTHER FRONT WILL BE
APPROACHING FROM THE NORTHWEST, AS AN UPPER TROUGH MOVES EAST
FROM THE GREAT LAKES. THIS FRONT WILL USHER IN A REINFORCING
SHOT OF COLD AIR BUT WILL BE MOISTURE STARVED. LOOKS LIKE THE
MOST WE COULD GET WOULD BE SCATTERED SHOWERS. HIGH TEMPERATURES
WEDNESDAY WILL BE IN THE 40S TO LOWER 50S.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE LAST OF THE LARGE STRATOCUMULUS CLOUD DECK THAT GOT TRAPPED
UNDER THE INVERSION IN THE COLD AIR ADVECTION IS FINALLY BREAKING UP
EARLY THIS MORNING. THE LAST OF THE MVFR CEILINGS APPEARS TO NOW BE
GONE AT KABE...AND KACY MAY TRY TO HOLD ONTO MVFR CEILINGS THROUGH
0630 UTC OR SO. OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE
OVERNIGHT.
THE BEST PRESSURE GRADIENT REMAINS OVER THE AREA EARLY THIS
MORNING...BUT THE GUSTINESS HAS BECOME CONFINED TO SOUTHERN NEW
JERSEY...WHERE KMIV AND KACY ARE STILL GUSTING. LATE EVENING AMDAR
SOUNDINGS SHOWED 32 TO 35 KNOTS AT THE TOP OF THE INVERSION ACROSS
THE REGION. THIS COULD ALLOW KMIV AND KACY TO GUST THROUGH 0800 UTC
OR SO. THE LATEST HRRR MODEL RUN SUGGESTS THAT THE NORTHERLY
GRADIENT REMAINS IN PLACE THROUGH 1200 UTC...SO WINDS PROBABLY DO
NOT GO CALM EARLY THIS MORNING.
AS SURFACE HIGH PRESSURE BUILDS TOWARD THE REGION TODAY...WINDS WILL
BACK WITH TIME. THE BEST GRADIENT SHOULD BE THIS MORNING...WITH SOME
SLACKENING THIS AFTERNOON. ANY GUSTINESS WOULD BE THIS MORNING...AS
THE LAST OF THE COLD AIR ADVECTION WINDS ITSELF OUT. THE 0600 UTC
TERMINAL FORECASTS DO NOT CONTAIN GUSTS...BUT THIS CAN BE REVISITED
LATER. AT MOST...GUSTS PROBABLY TOP OUT NEAR 15 KNOTS. CONVECTIVE
TEMPERATURES ARE WELL OUT OF REACH TODAY...SO VFR CONDITIONS SHOULD
CONTINUE THROUGHOUT THE DAY.
WINDS SHOULD DROP OFF FAIRLY QUICKLY THIS EVENING AS THE LAST OF THE
GRADIENT DROPS OFF. HIGH PRESSURE AT THE SURFACE AND IN THE MID
LEVEL SHOULD RESULT IN CLEAR SKIES. THE AIRMASS LOOKS TO BE TOO DRY
FOR EVEN PATCHY FOR LATE TONIGHT AND EARLY FRIDAY MORNING.
OUTLOOK...
THE HIGH PRESSURE SYSTEM TO OUR SOUTH WILL CONTINUE TO PROVIDE US
WITH GOOD VFR FLYING CONDITIONS WELL INTO SUNDAY. A COLD FRONT
MOVING IN FROM THE WEST AND A LOW DEVELOPING ON THIS FRONT, ONCE
IT MOVES JUST OFF TO OUR EAST, WILL BRING OUR NEXT ROUND OF
INCLEMENT WEATHER SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK.
LOWER CIGS/VSBYS IN RAIN AND FOG CAN BE EXPECTED FOR MUCH OF
THAT TIME PERIOD.
&&
.MARINE...
WITH THE COLD FRONT NOW TO OUR EAST AND HIGH PRESSURE TRYING TO NOSE
IN FROM THE WEST THE SURFACE PRESSURE GRADIENT WILL REALLY TIGHTEN
UP TONIGHT. NORTHERLY TO NORTHWESTERLY WINDS WILL BEGIN TO REALLY
HOWL WITH MULTIPLE HOURS OF GALE FORCE GUSTS EXPECTED TONIGHT. SEAS
WILL ALSO REMAIN QUITE ELEVATED TONIGHT IN THE WAKE OF THE STRONGER
NNW FLOW RUNNING AROUND 6 FEET.
THE GALE WARNING IS STILL IN AFFECT FOR ALL OUR COASTAL ZONES
THROUGH 09Z...THAT REMAINS UNCHANGED. AFTER THAT TIME PERIOD THE
GUSTS DROP INTO SMALL CRAFT RANGE FOR A FEW MORE HOURS FOLLOWED BY
SMALL CRAFT FOR HAZARDOUS SEAS BEING A POSSIBILITY.
OUTLOOK...
HIGH PRESSURE TO OUR SOUTH WILL BRING QUIET CONDITIONS TO OUR WATERS
THROUGH THE WEEKEND. AS THE HIGH MOVES OFF TO THE EAST, A COLD FRONT
WILL APPROACH FROM THE WEST. THE PRESSURE GRADIENT WILL TIGHTEN
BETWEEN THESE TWO SYSTEMS. THIS WILL MEAN INCLEMENT WEATHER WITH
INCREASING S TO SE WINDS AND BUILDING SEAS SUNDAY NIGHT AND MONDAY.
LOW PRESSURE IS THEN FORECAST TO DEVELOP ON THE FRONT ONCE IT MOVES
OFF THE EAST COAST. DEPENDING ON THE TIMING AND LOCATION OF THE LOW,
ADVISORY OR GALE CONDITIONS COULD OCCUR IN THE SUNDAY NIGHT TO MID
WEEK TIME FRAME.
&&
.TIDES/COASTAL FLOODING...
THE CONSENSUS OF THE LATEST GUIDANCE PRODUCTS (STEVENS, MDL AND
THE BOFS FAMILY) GIVES TIDAL DEPARTURES THAT WOULD JUST TOUCH
MINOR TIDAL FLOODING LEVELS ALONG THE OCEANFRONT. MOST OF THE
FORECAST DEPARTURES ARE LESS THAN HALF A FOOT AS THE BULK OF THE
TIDE ISSUES HAVE TO DO WITH THE ASTRONOMICAL SPRING TIDE
ASSOCIATED WITH THE NEW MOON. BECAUSE OVERALL WAVE ACTION IS NOT
EXPECTED TO BE UNUSUALLY HIGH AND NO RAIN IS EXPECTED, WE HAVE
DECIDED TO ISSUE A COASTAL FLOOD STATEMENT VS AN ADVISORY. THE
FORECAST NORTH WINDS ARE CAUSING SOME OF THE HIGHER GUIDANCE TIDAL
DEPARTURES AT SANDY HOOK AND LEWES.
FARTHER UP IN DELAWARE BAY AND THE TIDAL DELAWARE RIVER, THE WIND
DIRECTION SHOULD ASSIST. OVERALL TIDAL DEPARTURES HAVE TO BE
GREATER THAN AT THE SHORE, GENERALLY AROUND THREE-QUARTERS OF A
FOOT. THE ONE CAVEAT THAT WE WILL HAVE TO WATCH IS THE BELOW FLOOD
STAGE RIVER CREST NOW WORKING ITS WAY DOWN THE DELAWARE RIVER.
ALONG CHESAPEAKE BAY, NO TIDAL PROBLEMS ARE BEING REPORTED WITH
THE CURRENT HIGH TIDE CYCLE AND DEPARTURES ARE ALREADY DECREASING.
THE OVERALL NORTHWEST TO NORTH WINDS SHOULD HELP CONTINUE DRAIN IT
AND LOWER DEPARTURES INTO THURSDAY MORNING.
ASTRONOMICAL HIGH TIDES WITH THE CURRENT NEW MOON SPRING TIDE
CYCLE WILL PEAK ON FRIDAY MORNING. CURRENT EXPECTATIONS ARE FOR
THE WIND DIRECTION TO BE LESS FAVORABLE AND BY THEN THE DELAWARE
RIVER FRESH WATER CREST WILL ALSO BE THROUGH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...GIGI/HAYES/HEAVENER
SHORT TERM...HEAVENER
LONG TERM...RPW
AVIATION...HAYES/RPW
MARINE...GIGI/HEAVENER/RPW
TIDES/COASTAL FLOODING...GIGI
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
900 PM EST Fri Nov 25 2011
.UPDATE...
01Z water vapor and H4 RUC analysis shows an amplified upper level
pattern across the CONUS this evening. Main features of note are an
increasingly energetic trough ejecting out of the inter-mountain
west, followed downstream by broad ridging over the Gulf of Mexico
and eastern third of the nation. The influence of this ridging aloft
is quite evident on the KTLH 26/00Z sounding profile in the form of
a well defined subsidence inversion at approx 800mb. The profile
above this level is quite dry. The subsidence acting on some low
level Atlantic moisture below this level is helping to produce
SCT-BKN stratacu over portions of the area this evening. No worries
though, these are "fair weather clouds" and our Friday evening/night
will be rain free.
At the surface,
Strong 1027mb high pressure centered near the Carolina coast
continues to ridge back westward over the forecast area. Our
position on the southern side of the ridge axis is providing a
general easterly flow, which is supplying the low level Atlantic
moisture mentioned above. Temperatures are mild this late evening
with most stations reporting upper 50s to lower 60s. Low
temperatures tonight are forecast to reach the upper 40s to middle
50s. Will not make any significant changes at this point, however
if these BKN clouds at 5-6kft hold for much of the night, then
locations underneath may end up several degrees warmer.
Saturday,
Looking at the latest guidance packages, don`t see any major changes
needed to the previous forecast. Upper ridge axis will be sliding
eastward through the day in response to potent upper level troughing
approaching the middle/lower MS valley. However, the ridge axis will
not exit our area until late in the day and will help provide a very
pleasant start to the weekend. Forecast will show a mix of sun and
clouds with afternoon temps reaching the lower to middle 70s.
Sunday/Monday,
Beginning to finally see better agreement amongst the global
guidance suite with respect to the evolution of the upper trough to
our west. With the parent energy now onshore and being sampled well,
this agreement should only increase with the next few model
runs...hopefully. The GFS which had been a bit of an outlier with
its much more progressive trough passage Sunday/Sunday night, has
now come into alignment with the less progressive closed low
solutions from both the ECMWF and Canadian. While model details are
still disputed, it is apparent that a big change in our weather is
upcoming by the early portion of next week. With the GFS now cutting
off, and slower in its eastward progress, the higher PoPs on Sunday
(especially over the eastern zones) may need to be pushed back
toward Sunday night or even Monday. In fact, latest guidance
consensus would suggest a rather low chance of rain during the
daylight hours of Sunday to the east of Albany and Tallahassee.
Upper low and associated surface front will then cross over the area
during the early portion of next week, bringing much colder/cloudier
and showery conditions to the forecast. In other words, enjoy the
pleasant weather on tap for Saturday.
&&
.AVIATION...
Latest satellite imagery and sfc obs showing VFR BKN deck pushing
across the region and beginning to affect area terminals. The VFR
cigs are forecast to impact all terminals overnight and through
Saturday. The CIGS should prevent significant fog development
overnight...with the possible exception of KVLD.
&&
.MARINE...
Winds over the coastal waters will occasionally flirt with
cautionary levels through Saturday night while slowly veering
around to a more southerly direction. The next big concern for
marine interests will begin Sunday as a cold front approaches from
the west. Winds will increase from the south and seas are expected
to increase up to 8 feet in offshore zones and 3 to 6 feet for
coastal zones by Sunday afternoon. Most of this wave action is
expected to be in a 8 second swell from the southwest. Elevated seas
are likely to remain over the waters even after the cold front
passes on Sunday night as stiff northwesterly winds behind the front
will keep conditions at advisory levels. Seas are expected to
decrease again on Monday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 48 74 52 75 43 / 10 10 30 80 30
Panama City 53 70 57 72 44 / 10 20 50 80 30
Dothan 48 72 53 71 41 / 10 10 60 80 30
Albany 48 73 52 72 43 / 10 10 40 80 30
Valdosta 49 76 51 75 44 / 10 20 20 80 50
Cross City 49 77 54 78 43 / 10 20 10 30 50
Apalachicola 56 71 60 75 47 / 10 20 40 80 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Update...Mroczka
Aviation...Camp
Marine...Mroczka/Lericos
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
843 PM EST FRI NOV 25 2011
UPDATE...
CLOUDS HAVE DEVELOPED AND ARE RAPIDLY SPREADING ACROSS THE WESTERN
TWO THIRDS OF CENTRAL GEORGIA AND MORNING NORTH. DEWPOINTS ARE ALSO
INCREASING ACROSS CENTRAL GEORGIA WITH READINGS ALREADY IN THE LOWER
50S. DEWPOINTS HAVE RISEN INTO THE LOWER 40S AS FAR NORTH AS FFC.
LATEST RUC HAS DEWPOINTS CONTINUING TO RISE ACROSS THE REST OF NORTH
GEORGIA. WITH THE HIGHER DEWPOINTS AND CLOUDS...TEMPS WILL NEED TO
BE ADJUSTED UPWARDS FOR OVERNIGHT LOWS TONIGHT. NO OTHER CHANGES
PLANNED.
&&
.PREV DISCUSSION...
..STRONG COLD FRONT TO PUSH INTO THE AREA SUNDAY...
SHORT TERM /TONIGHT THROUGH SUNDAY/...
/ISSUED 230 PM EST FRI NOV 25 2011/
HAS BEEN A STELLAR POST THANKSGIVING DAY ACROSS THE AREA AS HIGH
PRESSURE PARKED ALONG THE ATLANTIC COAST HAS ALLOWED FOR SLIGHT
MODIFICATION OF THE AIRMASS IN PLACE. MID TO UPPER 60S VALUES HAVE
BEEN THE RESULT WITH EXTREME SOUTHERN TIER ALREADY BREAKING THE 70
DEGREE MARK. CONVERGENT ATLANTIC FLOW OFF THE SE GEORGIA COAST IS
ALLOWING FOR STRATO CU DEVELOPMENT WHICH IS INFRINGING UPON MY
SOUTHEAST MOST COUNTIES AT THIS HOUR. MIXING PROCESSES AND LOSS OF
DAYTIME HEATING WILL DICTATE CONTINUED MOSTLY SUNNY/CLEAR
CONDITIONS FOR THE SHORT TERM PERIOD.
MAIN FOCUS IN THE SHORT TERM WILL BE STRONG SOUTHERN STREAM
SHORTWAVE OVER THE FOUR CORNERS AREA WHICH IS COMING INTO PHASE
WITH PACIFIC SHORTWAVE. MODELS IN GOOD AGREEMENT THROUGH THE FIRST
24 TO 36 HOURS OF THE FORECAST PERIOD IN SHOWING THE DEVELOPMENT
OF A SHARP FULL LATITUDE TROUGH THAT WILL EXTEND FROM CANADA
THROUGH MUCH OF CENTRAL MEXICO BY SATURDAY EVENING. AHEAD OF THIS
FEATURE...CONDITIONS TO REMAIN TRANQUIL LOCALLY WITH JUST SOME
ISENTROPICALLY INDUCED CLOUDS DEVELOPING OVERNIGHT TONIGHT AND
PERSISTING INTO SATURDAY. COULD SEE SOME SPRINKLES DEVELOP FROM
THIS AS WRF SHOWS BUT EXPECT COVERAGE AND CHANCES TO BE TOO LOW
FOR GRID INCLUSION AT THIS TIME. WILL BE A TOUGH CALL ON TIMING OF
BREAK UP OF LOW CLOUDS BUT SHOULD SEE ENOUGH TO REALIZE GOOD
WARMING AND WILL CONTINUE TO LEAN HEAVILY TOWARD THE WARM SIDE OF
GUIDANCE.
SHOWERS WILL MOVE INTO THE NORTHWEST ZONES JUST PRIOR TO 12Z
SUNDAY WHICH IS THE EXACT POINT MODELS BEGIN TO DIVERGE IN A BIG
WAY. 12Z ECMWF COMING IN CONTINUES TO CLOSE OFF UPPER LOW OVER THE
LOWER MISSISSIPPI VALLEY AND DEVELOPS A CORRESPONDING SURFACE LOW
FROM EASTERN ALABAMA THROUGH NORTHWEST GA THROUGH 12Z MON. THIS
EFFECTIVELY PUTS THE BRAKES ON PRECIP SHIELD WITH ACTIVITY NOT
PROGRESSING THROUGH THE REMAINDER OF THE CWA UNTIL 18Z MONDAY WITH
SIGNIFICANT WRAP AROUND THEREAFTER THROUGH WED. GFS CONTINUES TO
BE MORE PROGRESSIVE BUT HAS SLOWED SIGNIFICANTLY WITH THE LATEST
RUN. BASICALLY CHOSE A BLEND WHICH IS CLOSE TO THE 09Z SREF WHICH
IS NOT AS FAST AS THE 12Z NAM12. THIS DELAYS ONSET OF PRECIP UNTIL
SUNDAY AFTERNOON FOR MOST AREAS AND KEEPS HIGH POPS IN THROUGH
SUNDAY EVENING. OF COURSE IF ECMWF TURNS OUT TO BE
RIGHT...ADDITIONAL SIGNIFICANT CHANGES WILL NEED TO BE MADE WRT
TIMING. WHAT WE ARE CONFIDENT IN IS THE HIGH POPS FOR THE AREA AND
HAVE GONE WITH CATEGORICAL FOR MOST AREAS EVEN THROUGH TIMING IS
AN ISSUE.
DEESE
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
/ISSUED 230 PM EST FRI NOV 25 2011/
UNCERTAINTY CONTINUES INTO NEXT WEEK AS EVEN THE GFS NOW SHOWS
SOME WRAP AROUND POTENTIAL FOR THE AREA MONDAY EVENING INTO THE
OVERNIGHT HOURS. 850 TEMPS GO TO -4C TO -6C DURING THIS TIMEFRAME
BUT MAY TAKE A WHILE FOR SURFACE WET BULBS DROP SIGNIFICANTLY.
NEWEST ECMWF HAS MORE POTENTIAL TUE INTO TUE NIGHT BUT DEPENDS ON
LOW DEEPENING SIGNIFICANTLY ALOFT. GIVEN ENORMOUS
DIFFERENCES...WILL JUST ADVERTISE 10 TO 15 POPS FOR NOW AND KEEP
AS LIQUID FOR ANOTHER RUN. WITH SOME LESSENING OF DIFFERENCES THIS
RUN...WE MAY SEE ADDITIONAL AGREEMENT WITH SUBSEQUENT RUNS
ALLOWING FOR MORE CONFIDENCE WITH FORECAST.
DEESE
&&
.AVIATION...
00Z UPDATE...
MID LEVEL CLOUDS MOVING UP FROM SOUTHERN GEORGIA. EXPECT THIS TO
LOWER OVERNIGHT AND MOVE INTO ATL SITES BY 7Z AND PROVIDE
BORDERLINE MVFR/IFR CIGS IN THE MORNING. WILL SEE BKN-OVC CLOUDS
BUT CONFIDENCE IS LOW WITH THE EXACT HEIGHT. LARGE DIFFERENCES IN THE
MODELS TOMORROW...BUT OVERALL MAY SEE SOME IMPROVEMENT IN CIG
HEIGHTS LATE IN THE AFTERNOON. WINDS WILL REMAIN EASTERLY
OVERNIGHT AND BECOME SE TO SSE DURING THE DAY SATURDAY. COULD SEE
SOME VSBY RESTRICTIONS ON VSBY AT NORMAL TROUBLE SITES...AHN AND
MCN IN THE MORNING.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ON WINDS. MEDIUM CONFIDENCE ON CIGS AFTER 10Z. LOW
CONFIDENCE ON CIG HEIGHTS.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 38 65 50 64 / 0 10 10 70
ATLANTA 46 67 53 58 / 0 10 10 100
BLAIRSVILLE 36 57 48 55 / 0 10 10 90
CARTERSVILLE 39 64 53 56 / 0 10 30 100
COLUMBUS 45 69 56 62 / 0 10 10 100
GAINESVILLE 43 62 50 57 / 0 10 10 90
MACON 41 70 53 67 / 0 10 5 90
ROME 39 64 52 55 / 0 10 60 100
PEACHTREE CITY 37 68 52 60 / 0 10 10 100
VIDALIA 48 73 56 73 / 0 10 0 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
202 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE WEST TONIGHT AND
PERSIST THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL AFFECT THE
REGION EARLY NEXT WEEK...FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO NOTEWORTHY CHANGES WERE MADE THIS THE EARLY MORNING UPDATE.
FRESHENED UP HOURLY GRIDS TO ACCOUNT FOR FALLING TEMPS AND
DEWPOINTS. OTHERWISE...GOING FORECAST IS IN GOOD SHAPE.
LAKE WINDS...WINDS AT BOTH PINEVILLE AND PINOPOLIS INDICATE WINDS
ARE SOLIDLY WITHIN LAKE WIND ADVISORY THRESHOLDS. ALTHOUGH WINDS
SHOULD PEAK WITHIN THE NEXT FEW HOURS...IT WILL TAKE SOMETIME FOR
SPEEDS TO DIMINISH. A LAKE WIND ADVISORY WILL CONTINUE FOR LAKE
MOULTRIE UNTIL 6 AM.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL CONTINUE TO PUSH OFFSHORE ON THURSDAY
AS RIDGING BUILDS INTO THE REGION FROM THE WEST. THE UPPER LEVEL
RIDGE WILL THEN PREVAIL OVER THE SOUTHEASTERN STATES THROUGH
SATURDAY. AT THE SURFACE...EXPANSIVE HIGH PRESSURE WILL PERSIST
ACROSS THE MID-ATLANTIC REGION AND SOUTHEAST STATES THROUGH
FRIDAY...THEN BEGIN TO SHIFT OFFSHORE ON SATURDAY.
STRONG SUBSIDENCE AND A LACK OF ANY SIGNIFICANT MOISTURE WILL RESULT
IN RAIN FREE CONDITIONS AND MAINLY CLEAR SKIES INTO FRIDAY.
THEN...AS THE LOW LEVEL FLOW BECOMES MORE ONSHORE SOUTH OF THE
SURFACE HIGH...AN INCREASE IN CLOUD COVER IS EXPECTED INTO THE START
OF THE WEEKEND...ESPECIALLY ACROSS SOUTHEAST GEORGIA. TEMPERATURES
WILL BE SLIGHTLY BELOW NORMAL ON THURSDAY...MODERATE TO NEAR NORMAL
ON FRIDAY...THEN BECOME SLIGHTLY ABOVE NORMAL BY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT SHOWING A BLOCKING
RIDGE DEVELOPING OVER THE WESTERN ATLANTIC BY THE END OF THE
WEEKEND...RESULTING IN THE DEVELOPMENT OF A HIGHLY AMPLIFIED UPPER
LEVEL TROUGH NEAR THE MISSISSIPPI VALLEY. MODELS THEN SHOW A CLOSED
UPPER LEVEL LOW DEVELOPING SOMEWHERE OVER THE SOUTHEAST STATES EARLY
IN THE WEEK...BUT THERE IS SIGNIFICANT SPREAD IN THE MODELS WITH
RESPECT TO THE LOCATION AND PROGRESSION OF THE UPPER LEVEL
LOW...WITH THE 23/00Z GFS MORE PROGRESSIVE THAN THE 23/00Z ECMWF AND
CANADIAN. THIS LEADS TO A RATHER LOW CONFIDENCE FORECAST...BUT WILL
FAVOR THE GFS SOLUTION WHICH IS IN LINE WITH HPC THINKING. AS A
RESULT...A COLD FRONT IS EXPECTED TO APPROACH FROM THE WEST LATE IN
THE WEEKEND...PUSHING THROUGH THE AREA SUNDAY NIGHT INTO MONDAY AS
THE TROUGH AXIS TAKES ON A NEGATIVE TILT. A GOOD MOISTURE FEED AHEAD
OF THE FRONT SHOULD RESULT IN A SOLID CHANCE OF SHOWERS ACROSS MUCH
OF THE AREA...WITH PERHAPS A FEW STRONG THUNDERSTORMS ACCOMPANYING
THE FRONT ITSELF. DRIER CONDITIONS ARE EXPECTED TUESDAY AND
WEDNESDAY AS THE FRONT SHIFTS OFFSHORE AND THE UPPER LOW LIFTS
NORTHWARD. ABOVE NORMAL TEMPERATURES LATE IN THE WEEKEND WILL FALL
BELOW NORMAL IN WAKE OF THE COLD FRONT.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS AT BOTH SITES THROUGH 06Z FRIDAY. GUSTS AT KCHS HAS
DIMINISHED AND THIS WILL CONTINUE THROUGH THE PREDAWN HOURS. HAVE
MAINTAINED LLWS MENTION AT BOTH SITES AS 35 KT WINDS AREN/T TOO FAR
OFF THE DECK. WINDS WILL TURN TO MORE NE AFTER SUNRISE AND THERE
MAY EVEN BE SOME LOW END GUSTS THROUGH LATE MORNING AS THE HIGH
CONTINUES TO BUILD IN FROM THE WEST. OTHERWISE...CLOUD FREE
CONDITIONS WILL PREVAIL WITH NE FLOW INTO TONIGHT.
EXTENDED AVIATION OUTLOOK...SUB-VFR CONDITIONS POSSIBLE SUN/MON IN
SCATTERED SHOWERS AND T-STORMS.
&&
.MARINE...
SMALL CRAFT ADVISORIES CONTINUE FOR ALL MARINE LEGS. BUOY
OBSERVATIONS AND RADAR DATA INDICATE THE INITIAL WIND SURGE
CONTINUES TO WORK SOUTH. A SPECIAL MARINE WARNING HAS BEEN ISSUED
ALONG AND AHEAD OF THE LEADING LEDGE TO COVER GUSTS TO 35-40 KT
FOR LESS THAN 2 HOURS. INCOMING RUC DATA SUGGEST MARGINAL GALES
MAY OCCUR BEHIND THE WIND SURGE FOR SEVERAL MORE HOURS WITH
BOUNDARY LAYER WINDS FORECAST TO BE RIGHT AT 35 KNOTS. MODIS WATER
TEMPERATURE DATA INDICATE SEA SURFACE TEMPERATURES ARE IN THE
UPPER 60S TO LOWER 70S BEYOND 40 NM...SO GALES COULD CERTAINLY
OCCUR IN THE WARMER WATERS WERE MORE VIGOROUS MIXING WILL OCCUR.
HOWEVER...PER COORDINATION WITH WFO JAX...HAVE OPTED TO HOLD WINDS
AT 25-30 KT FOR NOW SINCE THE EVENT LOOKS MARGINAL AND HANDLE
WITH A STRONG SMALL CRAFT ADVISORY. A GALE WARNING MAY STILL BE
NEEDED...BUT CONFIDENCE IS NOT GREATER THAN 80 PERCENT ATTM.
THURSDAY THROUGH MONDAY...IMPROVING CONDITIONS ARE EXPECTED ON
THURSDAY AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE
NORTHWEST. WINDS AND SEAS SHOULD FALL BELOW SMALL CRAFT ADVISORY
CRITERIA FOR ALL NEAR SHORE WATERS BY THE END OF THE DAY
THURSDAY...BUT A FAVORABLE FETCH WILL KEEP SEAS ELEVATED ABOVE
ADVISORY CRITERIA ACROSS THE OUTER GEORGIA WATERS THROUGH FRIDAY
AFTERNOON.
THE AREA OF HIGH PRESSURE WILL PREVAIL OVER THE REGION INTO THE
WEEKEND...WITH A COLD FRONT THEN EXPECTED TO APPROACH FROM THE WEST
LATE IN THE WEEKEND AND PUSH OFFSHORE EARLY NEXT WEEK. ADDITIONAL
SMALL CRAFT ADVISORIES ARE POSSIBLE OVER PORTIONS OF THE WATERS IN
ASSOCIATION WITH THIS FRONT.
&&
.TIDES/COASTAL FLOODING...
GIVEN THE UPCOMING PERIGEAN SPRING TIDES THERE IS A PRETTY GOOD
CHANCE OF EXCEEDING COASTAL FLOOD ADVISORY CRITERIA DURING THE
MORNING HIGH TIDES THURSDAY THROUGH AT LEAST SATURDAY. WITH THE
ASTRONOMICAL PREDICTED VALUES RIGHT AT 7.0 FT IN CHARLESTON HARBOR
THURSDAY THROUGH SATURDAY MORNINGS...ONLY A NEUTRAL OR HIGHER
ANOMALY WILL BE NECESSARY FOR MINOR COASTAL FLOODING. THIS APPEARS
QUITE LIKELY GIVEN THE VEERING WIND PROFILE LATE TONIGHT THROUGH
THURSDAY. LATER SHIFTS MAY NEED TO ISSUE A COASTAL FLOOD ADVISORY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ330-
352.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ354.
SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR AMZ374.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CST THU NOV 24 2011
.DISCUSSION...
ISSUED 300 PM CST THU NOV 24 2011
INITIAL CONCERN WILL BE POSSIBLE REDEVELOPMENT OF LOW STRATUS
CLOUDS TONIGHT INTO FRIDAY MORNING. THEN ATTENTION TURNS TO THE
ONSET OF RAIN LATE FRIDAY NIGHT THROUGH SATURDAY AND THE ARRIVAL
OF COLDER AIR FOR MUCH OF THE EXTENDED FORECAST.
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT.
CHALLENGING FORECAST FOR TONIGHT IN TERMS OF CLOUDS AND RESULTANT
LOW TEMPS. THE ONLY MODELS THAT SEEM TO HAVE A DECENT HANDLE ON
THE LOW LEVEL MOISTURE ARE THE HRRR AND SPC 4KM WRF. BOTH OF THEM
ARE INDICATING CLOUD REDEVELOPMENT ACROSS CENTRAL IL AND EVEN
SURROUNDING PORTIONS OF IL. THE NAM AND GFS SOUNDINGS SHOW A LOW
LEVEL SATURATION AS WELL...BUT SHALLOW. FORECAST WIND TRAJECTORY
FLOWS INDICATE WE SHOULD SEE THE SW RETURN FLOW ORIGINATING WHERE
STRATUS CLOUDS ARE LINGERING THIS AFTERNOON IN MO/AR. A TIGHTER
PRESSURE GRADIENT WOULD TYPICALLY KEEP WINDS UP AT NIGHT...BUT THE
LOW LEVEL INVERSION LOOKS TO BE PLENTY STRONG ENOUGH TO PREVENT
MIXING OVERNIGHT. WILL FORECAST CLOUDS TO REFORM...AND KEEP LOW
TEMPS A COUPLE DEGREES WARMER THAN GUIDANCE.
CLEARING SHOULD COME QUICKER ON FRIDAY AS MORE PROMINENT MIXING
WILL OCCUR UNDER A MUCH STRONGER SFC PRESSURE GRADIENT. PLENTY OF
DRY AIR ALOFT WILL AID IN CLOUD EROSION. WINDY CONDITIONS ARE
EXPECTED WITH SSW GUSTS OVER 30 MPH. TEMPS WILL RESPOND IN KIND AS
WAA FLOWS PUSH 850 MB TEMPS UP NEAR 12C. THAT COUPLED WITH ADDITIONAL
SUNSHINE SHOULD PUT HIGHS INTO THE L-M 60S.
BROAD SCALE ISENTROPIC LIFT AHEAD OF THE NEXT COLD FRONT WILL HELP
PRIME THE ATMOSPHERE FOR RAIN TO DEVELOP W OF THE IL RIVER AFTER
MIDNIGHT FRIDAY NIGHT. HOWEVER...BASED ON FORECAST CONDENSATION
PRESSURE DEFICITS /CPD/...IT STILL APPEARS WE WILL HAVE A 5-7 HOUR
WINDOW OF STEADY RAINS AS THE FRONT PROGRESSES EASTWARD DURING THE
DAY ON SATURDAY. WE WILL CONTINUE WITH CATEGORICAL POPS WEST IN
THE MORNING AND EAST IN THE AFTERNOON. SOME SHOWERS MAY LINGER IN
THE EVENING ACROSS THE EAST...SO WILL CONTINUE WITH CHANCE POPS AS
SUBSIDENT FLOWS BEGIN TO SHUT DOWN MEASURABLE PRECIP.
COLD AIR WILL RETURN ON BRISK NW WINDS SAT NIGHT. MOST OF THE
PRECIP SHOULD COME TO AN END BEFORE THE AIR COLUMN GETS COLD
ENOUGH FOR SNOW. HOWEVER...WE CAN NOT RULE OUT SOME FLURRIES
POSSIBLE AFTER MIDNIGHT SAT NIGHT. BY 12Z SUNDAY...ANOTHER WAVE OF
ISENTROPIC LIFT AND LOW CPD/S IS INDICATED AS THE UPPER TROUGH MOVES
ACROSS IL. ENOUGH RESIDUAL MOISTURE MAY BE PRESENT FOR A FEW LIGHT
RAIN/SNOW SHOWERS AFTER MIDNIGHT...AND FLURRIES NORTH/SPRINKLES
SOUTH ON SUNDAY.
BY SUNDAY NIGHT...ALL PRECIP SHOULD COME TO AN END FROM THIS
SYSTEM...AS THE UPPER TROUGH AXIS FINALLY SLIDES EAST.
LONG TERM...MONDAY THROUGH THURSDAY.
THE EXTENDED FORECAST SHOWS PERSISTENT COLD CONDITIONS AS A CUT
OFF LOW POSSIBLY DEVELOPS ACROSS THE SOUTHERN OHIO RIVER VALLEY.
THERE HAS BEEN A WIDE VARIETY OF SOLUTIONS FROM THE MODELS ON THIS
CUT OFF FEATURE...WITH THE ECMWF AND THE CANADIAN THE MAIN ONES
SHOWING THIS FEATURE. THE ECMWF BEING A BIT MORE PRONOUNCED AND
SLOWER THAN THE CANADIAN. THE GFS KEEPS A PROGRESSIVE PATTERN WITH
NORTHWEST FLOW AND A DRY FRONTAL PASSAGE ON MONDAY NIGHT/TUESDAY
ACROSS IL. DESPITE THE DIFFERING SOLUTIONS...THE OVERALL SENSIBLE
WEATHER LOOKS TO BE ON THE CHILLY SIDE WITH PERIODICALLY BREEZY
CONDITIONS.
SHIMON
&&
.AVIATION...
ISSUED 1142 AM CST THU NOV 24 2011
LOW CLOUDS WILL CONTINUE TO STEADILY ERODE FROM WEST TO EAST
ACROSS CENTRAL ILLINOIS THIS AFTERNOON. SATELLITE TIMING TOOLS
INDICATE SKIES BECOMING MOSTLY CLEAR AT KPIA AND KSPI BY
19Z...THEN FURTHER EAST TO KCMI BY 21Z. AFTER A PERIOD OF CLEAR
SKIES AT ALL TERMINALS LATE THIS AFTERNOON/EVENING...THE BIG
QUESTION BECOMES WHETHER THE LOW CLOUDS/FOG WILL RETURN LATER
TONIGHT. 12Z NAM FORECAST SOUNDINGS ARE SHOWING THE STRONG
SUBSIDENCE INVERSION REMAINING IN PLACE...WITH SATURATION
OCCURRING BELOW 950MB AFTER 03Z. DESPITE SOME DECENT MIXING/DRYING
THIS AFTERNOON...AM HARD PRESSED TO IGNORE THESE SOUNDINGS AS WELL
AS SIMPLE PERSISTENCE. AS A RESULT...HAVE BROUGHT CEILINGS BACK
DOWN BELOW 1000FT AT ALL TAF SITES AFTER 05Z. IN ADDITION...A
DEVELOPING JET STREAK ABOVE THE INVERSION WILL LEAD TO LOW-LEVEL
WIND SHEAR OVERNIGHT. HAVE INCLUDED 35 TO 40KT OF SHEAR AT 2000FT
ACCORDINGLY. THE LOW CLOUDS WILL MIX OUT BY MID-MORNING
FRIDAY...ALLOWING GUSTY S/SW WINDS TO MIX DOWN TO THE SURFACE
AFTER 15Z.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS NEAR 1000 FT SCATTERING/CLEARING 21-22Z FROM WEST.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 20Z...
STRATUS STARTING TO ERODE MORE QUICKLY FROM THE WEST AND SHOULD BE
REACHING RFD NEXT HOUR OR SO AND THE NE IL AIRPORTS 21-22Z AND
SOON AFTER AT GYY. STILL HAVE SOME CONCERN THAT FEW-SCT LOW CLOUDS
WILL LINGER AS SUNSET APPROACHES BUT HAVE SLIGHTLY BETTER
CONFIDENCE THAT VFR WILL PERSIST SO HAVE ADJUSTED TAFS
ACCORDINGLY. LOW CONFIDENCE REMAINS IN POTENTIAL FOR LOW
STRATUS/IFR TO REDEVELOP SOMETIME THIS EVENING OR TONIGHT.
FROM 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN CIGS SCATTERING/CLEARING 21-22Z.
* LOW-MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING...MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
229 PM CST
STRONG SOUTHWEST WINDS AND WIND GUSTS HAVE DEVELOPED ACROSS THE LAKE
DUE TO THE TIGHT PRESSURE GRADIENT OVER THE REGION. WIND GUSTS TO 30
KT WITH OCCASIONAL GUSTS TO 35 KT GALES CAN BE EXPECTED THROUGH
THIS EVENING OVER THE OPEN WATERS. AT THE MOMENT NO GALE GUSTS HAVE BEEN
REPORTED...MOST LIKELY DUE TO THE STUBBORN LOW LEVEL STRATUS DECK
OVER THE LAKE. HOWEVER...THE POSSIBILITY OF SEEING GUSTS TO 35 KT
GALES REMAINS THROUGH THIS EVENING. WITH ONLY OCCASIONAL GALE GUSTS
EXPECTED...DECIDED TO HOLD OFF ON GALE RELATED HEADLINES. GUST TO
30 KT WILL PERSIST ON FRIDAY BUT NOT ANTICIPATING ANY GALES. LOW
PRESSURE OVER MINNESOTA MOVES OVER LAKE MICHIGAN ON SATURDAY AND
THE LOWS COLD FRONT SWINGS THROUGH LATE ON SATURDAY. THE LOW
ITSELF WILL REMAIN IN THE GREAT LAKES REGION THROUGH MONDAY BEFORE
MERGING INTO A LARGER LOW OVER EASTERN MANITOBA. WINDS WILL TURN
OUT OF THE NORTHWEST BEHIND THE LOW WITH NO SIGNIFICANT GUSTS TO
MENTION. LOOKING INTO NEXT WEEK...A CANADIAN HIGH SINKS SOUTH FROM
ALBERTA INTO THE CENTRAL PLAINS ON TUESDAY. THE HIGH THEN MOVES
OVER THE EASTERN HALF OF THE US...LEADING TO LIGHT WEST TO
NORTHWEST WINDS THROUGH THE EXTENDED.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS NEAR 1000 FT SCATTERING/CLEARING 21-22Z FROM WEST.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 20Z...
STRATUS STARTING TO ERODE MORE QUICKLY FROM THE WEST AND SHOULD BE
REACHING RFD NEXT HOUR OR SO AND THE NE IL AIRPORTS 21-22Z AND
SOON AFTER AT GYY. STILL HAVE SOME CONCERN THAT FEW-SCT LOW CLOUDS
WILL LINGER AS SUNSET APPROACHES BUT HAVE SLIGHTLY BETTER
CONFIDENCE THAT VFR WILL PERSIST SO HAVE ADJUSTED TAFS
ACCORDINGLY. LOW CONFIDENCE REMAINS IN POTENTIAL FOR LOW
STRATUS/IFR TO REDEVELOP SOMETIME THIS EVENING OR TONIGHT.
FROM 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN CIGS SCATTERING/CLEARING 21-22Z.
* LOW-MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING...MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1214 PM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS AROUND 700 FT LIFTING SLIGHTLY TO NEAR 1000 FT THEN
EXPECTED TO SCATTER TOWARDS ROUGHLY 22-23Z.
* POTENTIAL FOR IFR/LIFR CIGS TO REDEVELOP THIS EVENING AND
OVERNIGHT...THEN SCATTERING MID MORNING FRIDAY.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 18Z...
IFR AND LOWER STRATUS CONTINUES ACROSS THE TERMINALS EARLY THIS
AFTERNOON. SATELLITE TRENDS SHOW THE WESTERN EDGE OF THE STRATUS
THINNING AND ERODING FROM NEAR DBQ TO JUST EAST OF GBG DOWN TO
NEAR SPI AT 1745Z AND WORKING ITS WAY EAST. STRONG LOW LEVEL
INVERSION REMAINS IN PLACE WHICH WILL LIKELY MAKE IT MORE
DIFFICULT FOR THE CLEARING TO QUICKLY WORK EAST...ESPECIALLY BY
LATE AFTERNOON BUT AM THINKING THAT THE TAF SITES WILL BE ABLE TO
SCATTER LATE THIS AFTERNOON. HOW QUICKLY THIS OCCURS IS NOT QUITE
CERTAIN. UNTIL THEN CLOUD BASES LOOK TO REMAIN FAIRLY STEADY WITH
SOME MINIMAL INCREASE INTO MID AFTERNOON...WITH A MORE NOTABLE
INCREASE IN BASES POSSIBLE AS SCATTERING OCCURS...THOUGH BASES
WOULD LIKELY REMAIN BELOW 1500 FT. SOUTHWEST WINDS WILL CONTINUE
TO BE GUSTY THOUGH GUSTS MAY BE ERRATIC IN FREQUENCY.
ASSUMING SCATTERING/CLEARING CAN OCCUR BY EVENING THE NEXT
CHALLENGE WILL BE IF IFR/LIFR CEILINGS CAN RETURN OVERNIGHT.
INVERSION WILL REMAIN IN PLACE AND LOW LEVEL MOISTURE SHOULD
REMAIN HIGH...ESPECIALLY GIVEN THAT SCATTERING WILL HAPPEN CLOSER
TO DARK LIMITING THE CHANCE FOR DRIER AIR TO MIX DOWN. CONFIDENCE
IS LOW SO WILL CONTINUE WITH THE TREND OF EARLIER FORECASTS TO
BRING IFR BACK TO THE TERMINALS LATER THIS EVENING. THE INVERSION
SHOULD HAVE A BETTER TIME MIXING OUT LATER FRIDAY MORNING ALLOWING
ANY IFR TO CLEAR OUT BY MIDDAY OR SO. SOUTHWEST WINDS WILL REMAIN
BREEZY TONIGHT WITH GUSTS INCREASING TO AROUND 25 KT...IF NOT
SLIGHTLY HIGHER FRIDAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILINGS LIFTING TO NEAR 1000 FT THIS AFTERNOON.
* MEDIUM CONFIDENCE CEILINGS WILL SCATTER OUT...LOW-MEDIUM
CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM-HIGH CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* HIGH CONFIDENCE IN WINDS INCREASING OFF THE DECK LATE THIS
EVENING BUT LOW-MEDIUM CONFIDENCE THAT STRONG LLWS WILL DEVELOP.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1021 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS AROUND 700 FT SLOWLY LIFTING TO AROUND 1000 FT SOMETIME
EARLY THIS AFTERNOON...POTENTIAL FOR SCATTERING LATE THIS
AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 16Z...
IFR/LIFR STRATUS CONTINUES ACROSS THE TERMINALS WITH IFR VSBY AS
WELL. STILL EXPECT THAT BASES WILL GRADUALLY LIFT THIS AFTERNOON
WITH VSBY ALSO IMPROVING. THE TWO MAIN CHALLENGES IS HOW HIGH
BASES WILL GET THIS AFTERNOON AND THEY WILL SCATTER ACROSS ANY OF
THE TERMINALS. LATEST SATELLITE TRENDS SHOW THINNING/ERODING OF
STRATUS ALONG THE MISSISSIPPI RIVER FROM SOUTH OF ST. LOUIS
NORTHWARD TOWARDS THE QUAD CITIES AND EXPECT THIS EROSION TO
SPREAD EASTWARD. LATEST AIRCRAFT SOUNDINGS CONTINUE TO SHOW VERY
STRONG LOW LEVEL INVERSION OVER THE LOCAL AREA WHICH WILL ACT TO
KEEP CLOUDS IN PLACE AND LIMIT THE EASTERN EXTENT OF CLEARING INTO
THE AFTERNOON. THAT SAID...THINK AREAS SOUTH AND WEST OF THE
TERMINALS WILL SCATTER/CLEAR INTO EARLY AFTERNOON BUT INVERSION
MAY TRAP ENOUGH MOISTURE TO DEVELOP NEW STRATOCU AS HEATING
COMMENCES. FOR THE TERMINALS...THERE IS A CHANCE THAT SCATTERING
WILL OCCUR MID/LATE AFTERNOON BUT HAVE LIMITED CONFIDENCE THAT
THIS WILL OCCUR SO WILL MAKE LITTLE CHANGE TO THE TAF BEYOND 20Z
FOR NOW.
FROM 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IFR CIGS WILL LIFT TO LOW MVFR EARLY THIS
AFTERNOON...LOW CONFIDENCE ON TIMING AND IF CIGS WILL LIFT TO
MUCH ABOVE 1000 FT.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
817 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 700 FT SLOWLY LIFTING INTO THE AFTERNOON AND MAY
REACH MVFR EARLY THIS AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS TO AROUND 20 KT.
* POTENTIAL FOR LLWS TONIGHT.
MDB
//DISCUSSION...UPDATED 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IFR CIGS WILL LIFT TO LOW MVFR EARLY THIS
AFTERNOON...LOW CONFIDENCE ON TIMING AND IF CIGS WILL LIFT TO
MUCH ABOVE 1000 FT.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
601 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR/LIFR CIGS LIFTING TO LOW MVFR THIS AFTERNOON.
* IFR/LIFR CIGS REDEVELOPING THIS EVENING AND OVERNIGHT.
* PERIODS OF GUSTY SOUTHWEST WINDS.
* POTENTIAL FOR LLWS TONIGHT. CMS
//DISCUSSION...UPDATED 12Z...
VERY LARGE AREA OF IFR/LIFR CIGS EXTENDS FROM THE GREAT LAKES
SOUTH TO THE ARKLATEX THIS MORNING. LOCALLY THESE CLOUDS ARE
TRAPPED UNDER A VERY STRONG INVERSION JUST A FEW THOUSAND FEET
ALOFT AND IT WILL LIKELY BE UNTIL AT LEAST EARLY THIS AFTERNOON
BEFORE THESE CLOUDS POTENTIALLY SHOW SOME BREAKS OR SCATTER OUT.
WHILE CIGS SHOULD SLOWLY DIURNALLY LIFT THROUGH IFR INTO LOW MVFR
THIS AFTERNOON...CONFIDENCE ON TIMING AND SPECIFIC HEIGHTS IS LOW.
THE INVERSION ALOFT BECOMES EVEN STRONGER TONIGHT AND WITH LOW
LEVEL MOISTURE STILL STREAMING NORTH...SHOULD CLOUDS SCATTER OUT
THEY SHOULD QUICKLY REDEVELOP BY LATE EVENING/EARLY FRIDAY
MORNING. THOUGH THE INVERSION DOES MIX OUT RATHER QUICKLY AFTER
SUNRISE FRIDAY MORNING. VISIBILITIES HAVE GENERALLY BEEN IN THE
2-4SM RANGE MOST AREAS AND NOT EXPECTING ANYTHING MUCH LOWER THAN
THAT...AT LEAST NOT ANYTHING WIDESPREAD. THE VIS SHOULD IMPROVE
THROUGH THE MORNING BUT LIKELY DROP BACK INTO MVFR THIS EVENING
AND OVERNIGHT.
DESPITE THE LOW INVERSION...WINDS HAVE GUSTED IN THE 15-20KT
RANGE DURING THE EARLY MORNING HRS AND EXPECT GUSTS IN THIS RANGE
FOR MUCH OF THE DAY...WITH THE POTENTIAL FOR SOME HIGHER GUSTS
DURING THE AFTERNOON SHOULD LOW CLOUDS SCATTER OUT. GRADIENT
REMAINS TIGHT THROUGH THE NIGHT AND LOW LEVEL WINDS ALOFT INCREASE
TO 40-45 KTS BY 2KFT...THUS THE POTENTIAL FOR LLWS. HAVE OPTED TO
LEAVE THIS OUT OF THIS FORECAST SINCE IT IS QUITE POSSIBLE SURFACE
WINDS WILL BE GUSTY AND CONFIDENCE REGARDING MEETING LLWS CRITERIA
IS LOW. CMS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE LIFR/IFR CIGS WILL LIFT TO LOW MVFR BY EARLY
AFTERNOON...LOW CONFIDENCE ON TIMING.
* LOW CONFIDENCE LOW MVFR CIGS WILL SCATTER OUT THIS AFTERNOON.
* MEDIUM CONFIDENCE IFR CIGS WILL REDEVELOP THIS EVENING AND
PERSIST INTO MID MORNING FRIDAY.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE REGARDING LLWS TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. CHANCE OF SHRA.
SATURDAY...MVFR WITH IFR POSSIBLE. PERIODS OF RAIN DURING THE DAY.
CHANCE OF SHRA/SHSN SATURDAY NIGHT.
SUNDAY...MVFR POSSIBLE. CHANCE OF SHRA/SHSN.
MONDAY THROUGH WEDNESDAY...VFR. CMS
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 10Z...
* IFR/LIFR CIGS THROUGH MID/LATE MORNING.
* GUSTY SOUTHWEST WINDS THROUGH THE PERIOD...PRIMARILY THIS
AFTERNOON.
* LLWS POTENTIAL TONIGHT. CMS
//DISCUSSION...UPDATED 06Z...
STRATUS DECK CONTINUES TO SPREAD ACROSS THE REGION AND WILL BE
OVER ALL TERMINALS WITHIN THE NEXT HOUR. CIGS QUICKLY DROPPED
FROM LOW END MVFR TO HIGH TO MIDDLE RANGE IFR. VERY STRONG
SUBSIDENCE INVERSION NOTED ON THE 00Z RAOB OUT OF DVN...AND WOULD
EXPECT THE STRATUS DECK TO REMAIN THROUGH THE MORNING HOURS. WARM
AIR ADVECTION WILL BEGIN TO RAMP UP AND BOUNDARY LAYER FLOW WILL
ALSO INCREASE INTO THE MORNING...AND IT IS THEN THAT THE CLOUDS
SHOULD LIFT AND THEN BEGIN TO ERODE. INTO THE AFTERNOON
HOURS...EFFICIENT MIXING WILL ALLOW GUSTS IN THE AFTERNOON TO
REACH INTO THE LOWER 20KT RANGE AND WILL LAST UNTIL SUN DOWN. AS
GUSTS FALL OFF...THE POTENTIAL EXISTS FOR LLWS INTO THE EVENING
HOURS. FORECAST SOUNDINGS SHOWING ROUGHLY 40KT AT 02KFT...JUST
FLIRTING WITH CRITERIA. FOR NOW...WILL WITHHOLD ANYTHING IN THE
ORD TAFOR.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 10Z...
* HIGH CONFIDENCE IFR/LIFR CIGS WILL PERSIST THROUGH MID/LATE
MORNING.
* MEDIUM CONFIDENCE CIGS WILL LIFT/SCATTER OUT THIS AFTERNOON...
LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE IN MEETING LLWS CRITERIA TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...VFR
* SATURDAY...RA. MVFR LIKELY WITH IFR POSSIBLE
* SUNDAY THROUGH TUESDAY...MVFR. SHRA WITH POSSIBLE RASN OVERNIGHT
SHEA
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 AM CST THU NOV 24 2011
.DISCUSSION...
320 AM CST
LOW CLOUDS CAN BE A WILDCARD DURING WARM AIR ADVECTION DURING THIS
TIME OF YEAR...AND INDEED THE WIDESPREAD STRATUS HAS ENVELOPED THE
AREA TO START OUT THANKSGIVING. THE ENVIRONMENT FAVORABLE FOR THIS
AND HOW LONG IT WILL HAMPER WARMING TODAY...AND WHETHER OR NOT IT
REDEVELOPS TONIGHT TO START FRIDAY...ARE THE PRIMARY CHALLENGES
THIS MORNING. THIS IS FOLLOWED BY THE FRONTAL TIMING AND RAIN ON
SATURDAY AND THE COLD AIR AND SNOW SHOWER CHANCES BEHIND IT.
SYNOPSIS...THE EXPANSIVE STRATUS BANK LINES UP WELL THE LOW-LEVEL
RIDGE THIS MORNING...FROM TEXARKANA NORTHEAST TO THE GREAT LAKES.
AS OF EARLY THIS MORNING...THE FORECAST AREA IS ABOUT 150 MILES
FROM THE NEAREST UPSTREAM SCATTERING IN NORTHEAST MO. ACCORDING TO
AN EARLY MORNING ACARS SOUNDING AT RFD...THE CLOUD DEPTH IS AROUND
800 FT THICK OR SO...WHICH LIKELY SPEAKS FOR MUCH OF THE AREA.
WHILE THAT IS NOT VERY DEEP...THE INVERSION STRENGTH IS
IMPRESSIVE...WITH TEMPERATURES CLIMBING 16F IN ABOUT 1200 FT. THAT
PRESENTS THE CHALLENGE TO ALLOW MIXING TO REALLY GET GOING TODAY.
SURFACE TEMPERATURES AND DEW POINTS ARE BASICALLY HOLDING STEADY
38 TO 42 AND SHOULD THROUGH MID-MORNING. SOUTHWEST WINDS NEAR 10
MPH HAVE ALLEVIATED ANY DENSE FOG CONCERNS.
TODAY...MANY OF THE SHORT TERM MODELS AND ASSOCIATED MOS HAVE
GENERALLY STRUGGLED WITH THE LOW CLOUD DEPICTION. A FEW THAT HAVE
HAD A GENERAL IDEA INCLUDE THE HRRR AND THE SPC 4KM WRF...AS WELL
AS THE MOISTURE IN THE RUC 0-500M LAYER. THE THEME OF BASICALLY NO
IMPROVEMENT THROUGH 10 AM IS SEEN IN ALL OF THESE. THE HRRR AND
WRF THEN WANT TO SHOW MAJOR IMPROVEMENT. FORECAST SOUNDINGS ON
THE RUC CONTINUE TO SHOW AN AGGRESSIVE INVERSION HOWEVER...AND
ITS LOW LEVEL MOISTURE IS SLOWER TO IMPROVE...BASICALLY TOWARDS
3 PM. INEVITABLY SOME HOLES WILL DEVELOP IN THE CLOUD SHIELD AND
TO PRECISELY INDICATE WHERE IS CHALLENGING MORE THAT A COUPLE
HOURS IN ADVANCE. IT WOULD SEEM BY LATE MORNING INTO EARLY
AFTERNOON THESE SHOULD INCREASE...ESPECIALLY OVER THE SOUTHERN AND
WESTERN FORECAST AREA. THE CHICAGOLAND AREA MAY BE THE LAST PART
OF THE CWA TO CLEAR SIMPLY DUE TO THE TRAJECTORIES OF DRY AIR FROM
THE DISTANT SOUTHWEST. HAVE TAKEN TEMPS DOWN SOME...WEIGHING
GREATLY TOWARDS THE COOLER GUIDANCE. THE 24.06 NAM IS SEVERAL
DEGREES COOLER THAN ITS PRIOR RUN...AN INDICATION COOLER IS LIKELY
THE WAY TO GO. NORMAL DIURNAL CLIMBS THIS TIME OF YEAR ARE AROUND
15 DEGREES...AND GIVEN CLOUDS FORECAST FOR OVER HALF THE DAYLIGHT
HOURS...HAVE CLIMBS CLOSER TO 6-7 DEGREES. OVERALL...THE
CONFIDENCE IS LOW FOR A PERIOD ONE FORECAST...BUT THE THEME OF
COOLER THAN ORIGINALLY THOUGHT SHOULD HOLD TRUE. FOR MORE ON WHERE
TODAYS HIGHS WILL FALL OUT FOR THANKSGIVING CLIMATOLOGY...PLEASE
SEE THE CLIMATE DISCUSSION BELOW.
TONIGHT AND FRIDAY...THE 24.00 NAM LOW-LEVEL PARCEL TRAJECTORIES
OVER THE LOCAL AREA FOR FRIDAY MORNING ORIGINATE IN THE AIR MASS
IN AR/SOUTHERN MO AT PRESENT. THAT AREA IS ALSO UNDER THE STRATUS
BLANKET...WHICH IS CONCERNING. THERE WILL BE AN EVEN STRONGER LOW-
LEVEL WIND COMPONENT TONIGHT WHICH SHOULD AT LEAST HELP TO KEEP
THINGS MORE TURBULENT AND MORE CLOUD AREAS AS OPPOSED TO A
WIDESPREAD BLANKET...IF CLOUDS DO REDEVELOP. THE NAM 0-500M
MOISTURE FIELDS AND SOUNDINGS INDICATE THE POTENTIAL...THOUGH MORE
IMPROVED THAN THIS MORNING. SO HAVE AT LEAST INCREASED SKY COVER
BY QUITE A BIT GIVEN THE PERSISTENCE OF THE CLOUDS TO EXPAND THE
PAST COUPLE NIGHTS. ANY CLOUDS SHOULD MOVE ON OR BREAK UP QUICKER
ON FRIDAY MORNING...BEING REPLACED BY CIRRUS IN THE NORTH.
TEMPERATURES STILL ARE ON PAR FOR MAINLY MID-UPPER 50S TO LOWER
60S FROM NORTH TO SOUTH.
FRIDAY NIGHT AND SATURDAY...A STRONG UPPER TROUGH APPROACHING
BRITISH COLUMBIA TODAY WILL BE OUR WEATHER-MAKER IN THIS PERIOD AS
IT NEGATIVELY TILTS AND DIGS INTO THE UPPER MIDWEST. THE SUITE OF
MODEL GUIDANCE CONTINUES TO SHOW SIZABLE DIFFERENCES IN THE
SURFACE COLD FRONTAL TIMING FOR SATURDAY...WHICH WOULD DICTATE
WHEN DURING SATURDAY THE HIGHEST POPS NEED TO BE FORECAST. WHAT
GUIDANCE DOES AGREE ON IS GOOD QG FORCING...MOISTURE RETURN...AND
FOCUS FOR RAIN. PRECIPITABLE WATERS INCREASE UP TO NEAR ONE INCH
ON THE GFS/NAM IN A NARROW TONGUE AHEAD OF THE FRONT. THE BEST
TIMING FOR RAIN STILL APPEARS TO BE DURING THE DAY SATURDAY...AND
HAVE FURTHER TAPERED POPS ON FRIDAY NIGHT PRIOR TO MIDNIGHT. WHILE
RAIN IS FAVORED ACROSS MUCH OF THE AREA ON SATURDAY...THIS DOES
LOOK TO BE MORE OF A HIGH POP/LOW QPF EVENT. THE 24.03 SREF QPF
CONFIDENCE FOR SATURDAY IS ONLY 40 PERCENT FOR 0.25 OR GREATER OF
AN INCH...AND THAT IS IN THE FAR SOUTH. IN THE ABSENCE OF THUNDER
OR PRECIPITATION TYPE ISSUES...THE SREF TENDS TO HANDLE SUCH
LOWER-END QPF CONFIDENCE FORECASTS WELL. AFTER A VERY MILD FRIDAY
NIGHT...TEMPERATURES WILL GO NOWHERE ON SATURDAY...CLIMBING ONLY A
COUPLE DEGREES POSSIBLY IN THE MORNING BEFORE GRADUALLY COMING
DOWN...AND THEN QUICKLY DOWN AFTER THE FRONTAL PASSAGE. THAT
PASSAGE IS RIGHT NOW FAVORED TO BE IN THE AFTERNOON. SATURDAY
NIGHT WOULD LOOK TO HAVE SCATTERED SHOWERS IF ANYTHING...POSSIBLY
WITH SOME LIGHT SNOW MIXED IN AS THE COLUMN CONTINUES TO COOL.
SUNDAY AND BEYOND...HAVE OVERALL TRENDED SLIGHTLY DRIER DURING
THIS TIME AS MODELS CONTINUE TO INDICATE A QUICKER PROGRESSION OF
THE UPPER LOW...EVEN THOUGH THERE ARE CONTINUED SIGNS IT MAY CUT
OFF...LIKE ON THE 24.00 EC. SUNDAY WILL STILL SEE CYCLONIC FLOW
IT APPEARS...AND HAVE GONE ABOVE THE MODEL BLEND FOR SKY COVER AND
SHOWER CHANCES. THERE IS AN INCREASINGLY BETTER SIGNAL FOR LAKE
ENHANCED SHOWERS INTO NORTHWEST INDIANA...WHICH COULD BE SNOW
SHOWERS BASED ON THE FORECAST SOUNDINGS. THE NEARLY DRY ADIABATIC
LAPSE RATES BASED ON THE COLD AIR ADVECTION OVER THE LAKE...THE
LOW-LEVEL MOISTURE...AND CONVERGENCE ALL FAVOR AT LEAST SOME
ENHANCED CHANCES FOR SHOWERS. MORE OF AN INFLUENCE OF THE NORTHERN
STREAM JET IS EXPECTED IN OUR AREA AS OPPOSED TO THIS LOW BY
MONDAY AND TUESDAY. SO COOLER /NEAR NORMAL/ TEMPERATURES ARE
FORECAST WITH POTENTIALLY SOME SMALL CHANCES FOR SHOWERS...BUT
BELOW MENTIONABLE AT THIS TIME.
&&
.CLIMATE...
215 AM CST
FORECAST HIGHS FOR TODAY DO POSSESS A RANGE OF SEVERAL DEGREES OF
UNCERTAINTY BECAUSE OF THE LOW CLOUDS. RIGHT NOW...THE COOLING
TREND IN THE FORECAST HAS TAKEN THIS BELOW A TOP TEN WARMEST
THANKSGIVING. IT IS STILL POSSIBLE HOWEVER...THOUGH A SMALL
CHANCE. FRIDAY HIGH TEMPERATURES ARE STILL FORECAST SEVERAL
DEGREES BELOW RECORD HIGHS FOR LONG TERM CLIMATE SITES. THOSE
RECORDS FOR NOVEMBER 25TH ARE 65 IN 2008 FOR ORD...AND 64 IN 1915
FOR RFD. IT IS UNLIKELY THESE WILL BE REACHED. EVEN AFTER THE COLD
FRONT ON SATURDAY...TEMPERATURES ONLY FALL BACK TO NEAR NORMAL.
CHICAGO HAS ONLY SEEN TWO DAYS THIS MONTH WHERE THE DEPARTURE FROM
NORMAL WAS COOLER THAN -1. A COUPLE DAYS MORE ARE POSSIBLE BY THE
END OF THE MONTH BUT THATS IT IN WHAT LOOKS TO SURELY BE A WARMER
THAN NORMAL MONTH BY AT LEAST A COUPLE DEGREES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* IFR CIGS THROUGH MID/LATE MORNING.
* GUSTY SOUTHWEST WINDS THROUGH THE PERIOD...PRIMARILY THIS
AFTERNOON.
* LLWS POTENTIAL TONIGHT. CMS
//DISCUSSION...UPDATED 06Z...
STRATUS DECK CONTINUES TO SPREAD ACROSS THE REGION AND WILL BE
OVER ALL TERMINALS WITHIN THE NEXT HOUR. CIGS QUICKLY DROPPED
FROM LOW END MVFR TO HIGH TO MIDDLE RANGE IFR. VERY STRONG
SUBSIDENCE INVERSION NOTED ON THE 00Z RAOB OUT OF DVN...AND WOULD
EXPECT THE STRATUS DECK TO REMAIN THROUGH THE MORNING HOURS. WARM
AIR ADVECTION WILL BEGIN TO RAMP UP AND BOUNDARY LAYER FLOW WILL
ALSO INCREASE INTO THE MORNING...AND IT IS THEN THAT THE CLOUDS
SHOULD LIFT AND THEN BEGIN TO ERODE. INTO THE AFTERNOON
HOURS...EFFICIENT MIXING WILL ALLOW GUSTS IN THE AFTERNOON TO
REACH INTO THE LOWER 20KT RANGE AND WILL LAST UNTIL SUN DOWN. AS
GUSTS FALL OFF...THE POTENTIAL EXISTS FOR LLWS INTO THE EVENING
HOURS. FORECAST SOUNDINGS SHOWING ROUGHLY 40KT AT 02KFT...JUST
FLIRTING WITH CRITERIA. FOR NOW...WILL WITHHOLD ANYTHING IN THE
ORD TAFOR.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE IFR CIGS WILL PERSIST THROUGH MID/LATE MORNING.
* MEDIUM CONFIDENCE CIGS WILL LIFT/SCATTER OUT THIS AFTERNOON...
LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/GUSTS.
* LOW CONFIDENCE IN MEETING LLWS CRITERIA TONIGHT. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...VFR
* SATURDAY...RA. MVFR LIKELY WITH IFR POSSIBLE
* SUNDAY THROUGH TUESDAY...MVFR. SHRA WITH POSSIBLE RASN OVERNIGHT
SHEA
&&
.MARINE...
300 AM CST
WINDS HAVE BEEN A LITTLE SLOW TO INCREASE THIS MORNING DESPITE A
FAIRLY TIGHT PRESSURE GRADIENT AND STRONG FLOW ALOFT IN PLACE. WITH
TWO SEPARATE AREAS OF LOW PRESSURE TO THE NORTH AND NORTHWEST OF THE
LAKE AND A RIDGE OF HIGH PRESSURE JUST TO THE SOUTHEAST...STRONG
SOUTHERLY FLOW CONTINUES TO USHER IN WARMER AIR TO THE NORTH.
BELIEVE THIS IS WHAT MAY BE CAUSING THIS SLOW INCREASE IN WIND SPEED
AS A SLIGHTLY MORE STABLE LAKE MAY BE IN PLACE THAN WHAT CURRENT
GUIDANCE IS INDICATING. NONETHELESS...WINDS WILL CONTINUE TO
INCREASE TODAY AS THIS TIGHT PRESSURE GRADIENT REMAINS AND FLOW
ALOFT INCREASES. PERSISTENT SOUTHWEST WINDS TO 30 KT CAN BE EXPECTED
INTO FRIDAY FOR BOTH THE NORTH AND SOUTH HALF OF LAKE MICHIGAN. HAVE
LEFT OUT ANY MENTION OF GALES FOR THE LAKE THIS FORECAST
ISSUANCE...BUT DO THINK THERE MAY BE BRIEF PERIODS OF HIGHER WINDS
AROUND GALES LATE THIS AFTERNOON AND EARLY EVENING MAINLY FOR THE
NORTH HALF OF THE LAKE. ALTHOUGH DO FEEL THAT THIS WILL BE SPORADIC
AND BRIEF...THUS LEAVING ANY MENTION OF GALES OUT OF THE CURRENT
FORECAST. SOUTHWEST WINDS WILL SLOWLY BEGIN TO DIMINISH FRIDAY NIGHT
INTO SATURDAY...BUT WILL BECOME MORE WESTERLY ON SATURDAY AS AN AREA
OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY PUSH ACROSS THE
LAKE. THEN A PERIOD OF WEST TO NORTHWEST WINDS CAN BE EXPECTED INTO
THE START OF NEXT WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
352 PM EST THU NOV 24 2011
.SHORT TERM...
TONIGHT THROUGH FRIDAY NIGHT
BROAD SW UPPER FLOW REMAINS IN PLACE OVER THE REGION WITH SFC
PRESSURE FALLS CONTINUING OVER THE UPPER MIDWEST IN RESPONSE TO A
PROGRESSING NORTHERN STREAM TROUGH. A STAUNCH INVERSION REMAINS IN
PLACE PER A SIG WAA REGIME...WITH TRAPPED MOISTURE IN THE BL.
INSOLATION AND ENSUED MIXING PROCESSES ARE WORKING TO BREAK THE
PERSISTENT CLOUD DECK UP...AND SOME SUN WILL BE POSSIBLE IN AREAS
THIS AFTERNOON. HOWEVER...DIURNAL BL COOLING WILL LIKELY SUPPORT
RE-SATURATION WITH THE CLOUD LAYER FILLING BACK IN...THIS BEING THE
MAIN FORECAST CHALLENGE. TEMPS HAVE STRUGGLED TO RISE ACROSS THE FA
GIVEN CLOUD COVER...BUT POSITIVE THERMAL ADVECTION HAS ALLOWED FOR
SOME RECOVERY AS LL WIND INCREASES PER HIGHER LATITUDE PRESSURE
FALLS. SYNOPTIC EVOLUTION IN THE PERIOD WILL FEATURE CENTRAL PLAINS
PHASING OF THE PAC NW AND SW CONUS UPPER TROUGHS...WITH A WAA REGIME
CONTINUING THROUGH THE PERIOD AHEAD OF THE LL TROUGH REFLECTION.
HEIGHT RISES COMBINED WITH A DIRTY TYPE RIDGE RIDDLED WITH LOW
AMPLITUDE IMPULSES WILL SUPPORT INCREASING CIRRUS ON FRIDAY. MUCH
WARMER WEATHER IS IN STORE FRIDAY GIVEN A TREND TO MOSTLY SUNNY
CONDITIONS AND WARM THERMAL FIELDS IN THE SFC TO H925 LAYER.
RAOB AND TAMDAR ANALYSIS CONFIRM A SATURATED LAYER IN THE
H975-H95 LAYER...WITH LOCAL CLOUD LAYER SOURCE BACK TRAJECTORY
SAMPLING A LARGE PORTION OF THE STRATUS LAYER IN PLACE OVER THE
LOWER MISSISSIPPI VALLEY. BULK OF DRY AIR PUSH ASSOCIATED WITH
REFLECTED LL FLOW WILL REMAIN NORTH OF THE REGION...WITH H975-H95
FLOW REMAINING SOUTHERLY OVERNIGHT. RUC13 AND NAM12 BOTH SUGGEST
RE-SATURATION OF THIS LAYER...WHICH IS VERY REASONABLE GIVEN CLOUD
LAYER TRAJECTORIES/A SHARP BL TOP INVERSION/AND AMPLE LL MOISTURE IN
THE BL. HENCE...EXPECTING CLOUDS TO FILL BACK IN THIS EVENING.
INCREASING NOCTURNAL LLJ AND ASSOCIATED TURBULENT MIX DOWN MAY
SUPPORT SOME CLOUD BREAK UP LATE IN THE NIGHT...ESP ACROSS THE
NORTHWEST WHERE H95 GEOSTROPHIC FLOW INCREASES TO OVER 35 KNOTS.
CLOUD LAYER FLOW WILL VEER SW TOWARD DAWN AND HELP SUPPORT THE
ADVECTION OF HIGH PLAINS SOURCE DRIER AIR...WITH CLEARING OF CIGS
THROUGH LATE MORNING. PHASING UPPER TROUGH WITH SLOW EAST ADVECTION
WILL DELAY ANY PRECIP CHANCES UNTIL SATURDAY GIVEN CONTINUED DRY
DEEP LAYER FLOW WITH THE BULK OF ALL SYSTEM GENERATED ASCENT
REMAINING WELL NORTH AND WEST OF THE REGION.
NO SIG CHANGE TO TEMPS. CLOUDS AND MIXED LL FLOW WILL SUPPORT A
RELATIVELY MILD NIGHT TONIGHT AND FRIDAY...WITH LOWS IN THE
40S...COOLEST READINGS TONIGHT. CLEARING LL STRATUS/WARM THERMAL
FIELDS/AND GENEROUS MIXING WILL SUPPORT HIGHS INTO THE 50S...WITH
SOME LOWER 60S POSSIBLE ACROSS THE SW THIRD FRIDAY.
&&
.LONG TERM...
SATURDAY THROUGH THURSDAY. PRIMARY FOCUS ON DY3 PRECIP TIMING AND
INTRO RASN MIX LATE SAT NIGHT TO PRIMARY FZN PTYPE ON SUN...IN LES
REGN. LARGE DISCREPANCIES IN MID RANGE...HOWEVER FAVOR NAM/GFS/SREF
DVLPG GRTLKS CUTOFF DY3 AS OPPOSED TO ECMWF/GEM TAKING FAR SRN
DIXIE/GOMEX CUTOFF. GIVEN RAMPED NRN STREAM FLOW ACRS ENTIRE PACIFIC
TO JAPAN GTE 150 KTS PER SAT DERIVED WINDS...AIDED BY COMPLEX BC TO
ALEUTIANS VORTEX. STRONG/DEEP CAA IN MERIDONAL FLOW AS UL RIDGE FM
SOCAL BUILDS TOWARD SRN CANADA 12 UTC SUN. ADNLY NO ENSEMBLE GFS
MEMBERS TAKE STRONG SRN CUTOFF APPROACH. NAM/GFS BUFKIT WET BULB
PROFILES WOULD SUGGEST THAT PTYPE CHANGEOVER MAY BE COMPLETE TO FZN
ACRS NRN/NWRN CWA LATE SAT NIGHT...BUT GIVEN ALL LIQUID PRIOR FCST
WL ATTEMPT TO START TREND. SOME ACCUM PSBL IN LES REGN SUN...THOUGH
EXTRM DISCREPANCIES IN CBL FLOW AS EXPECTED AT F72-84. ATTENDENT SFC
LOW SHOULD BEGIN LIFTOUT MON WITH CONTINUATION OF PROGRESSIVE NRN
STREAM FLOW AND IN COLLAB WITH MI NEIGHBORS HAVE AXED PRIOR LOW CHC
MENTION MON-TUE NIGHT. FEW CHANGES OTHERWISE...APPEARS NEXT NRN
STREAM TROF DIGS INTO WRN GRTLKS/UPR MSVLY PER GEFS ON DY7 WITH
POTNL CHC SHSN THEREAFTER.
&&
.AVIATION.../18Z TAFS/
IFR CIGS WILL REMAIN IN PLACE FOR MOST OF THE DAY GIVEN TRAPPED LL
MOISTURE UNDER A STAUNCH INVERSION. SCOURING OF THIS CLOUD DECK IS
ONGOING ACROSS WESTERN IL AND THIS IS EXPECTED TO SLOWLY SPREAD
INTO THE AREA LATE THIS AFTERNOON AND EVENING PER NEGATIVE THETA-E
ADV INTO THE SATURATED CLOUD LAYER. HENCE...EXPECT A SW-NE IFR-
VFR TREND IN TAFS...ESP WESTERN HALF. THIS PROCESS MAY SEE A DELAY
GIVEN DIURNAL BL COOLING THIS EVENING...ESP EASTERN AREAS.
HOWEVER...ONCE THE EXPECTED NOCTURNAL LLJ DEVELOPS IN RESPONSE TO
UPSTREAM PRESSURE FALLS...ANY REMAINING LOW CIGS SHOULD DISSIPATE
BY LATE TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...JC
LONG TERM...MURPHY
AVIATION...JC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1244 PM EST THU NOV 24 2011
.AVIATION.../18Z TAFS/
IFR CIGS WILL REMAIN IN PLACE FOR MOST OF THE DAY GIVEN TRAPPED LL
MOISTURE UNDER A STAUNCH INVERSION. SCOURING OF THIS CLOUD DECK IS
ONGOING ACROSS WESTERN IL AND THIS IS EXPECTED TO SLOWLY SPREAD
INTO THE AREA LATE THIS AFTERNOON AND EVENING PER NEGATIVE THETA-E
ADV INTO THE SATURATED CLOUD LAYER. HENCE...EXPECT A SW-NE IFR-
VFR TREND IN TAFS...ESP WESTERN HALF. THIS PROCESS MAY SEE A DELAY
GIVEN DIURNAL BL COOLING THIS EVENING...ESP EASTERN AREAS.
HOWEVER...ONCE THE EXPECTED NOCTURNAL LLJ DEVELOPS IN RESPONSE TO
UPSTREAM PRESSURE FALLS...ANY REMAINING LOW CIGS SHOULD DISSIPATE
BY LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1053 AM EST THU NOV 24 2011/
UPDATE...
STAUNCH LL INVERSION IN PLACE PER RAOB/TAMDAR ANALYSIS WITH WAA
REGIME ONGOING ACROSS THE FA. LL MOISTURE REMAINS TRAPPED BELOW
THE INVERSION BASE...WHICH IS JUST ABOVE H95...AND INCREASING FLOW
WILL LIKELY BE TOO LITTLE TO SUPPORT MIX OUT OF STRATUS TODAY.
SATELLITE CONFIRMS STRATUS DECK STRETCHING BACK TO TX...AND GIVEN
LOW SUN ANGLE AND A RE-ENFORCING INVERSION PER WAA...HAVE UPDATED
SKY GRIDS TO HOLD CLOUDY MENTION THROUGH THE DAY. THE POTENTIAL
FOR A FEW BREAKS LINGERS ACROSS THE NW THIRD GIVEN THE INCREASED
POTENTIAL FOR TURBULENT BL TOP MIXING...ALBEIT SMALL ATTM.
OTHERWISE...EVEN WITH THE LACK OF STRONG INSOLATION TEMPS WILL
CONTINUE TO CLIMB THROUGH AFTERNOON GIVEN SIG WAA. HOWEVER...MOST
AREAS WILL FALL SHORT OF 50...SAVE THE NW WHERE THERMAL ADVECTION
WILL BE THE STRONGEST.
PREV DISCUSSION... /ISSUED 411 AM EST THU NOV 24 2011/
SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION/UPDATE...JC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1053 AM EST THU NOV 24 2011
.UPDATE...
STAUNCH LL INVERSION IN PLACE PER RAOB/TAMDAR ANALYSIS WITH WAA
REGIME ONGOING ACROSS THE FA. LL MOISTURE REMAINS TRAPPED BELOW
THE INVERSION BASE...WHICH IS JUST ABOVE H95...AND INCREASING FLOW
WILL LIKELY BE TOO LITTLE TO SUPPORT MIX OUT OF STRATUS TODAY.
SATELLITE CONFIRMS STRATUS DECK STRETCHING BACK TO TX...AND GIVEN
LOW SUN ANGLE AND A RE-ENFORCING INVERSION PER WAA...HAVE UPDATED
SKY GRIDS TO HOLD CLOUDY MENTION THROUGH THE DAY. THE POTENTIAL
FOR A FEW BREAKS LINGERS ACROSS THE NW THIRD GIVEN THE INCREASED
POTENTIAL FOR TURBULENT BL TOP MIXING...ALBEIT SMALL ATTM.
OTHERWISE...EVEN WITH THE LACK OF STRONG INSOLATION TEMPS WILL
CONTINUE TO CLIMB THROUGH AFTERNOON GIVEN SIG WAA. HOWEVER...MOST
AREAS WILL FALL SHORT OF 50...SAVE THE NW WHERE THERMAL ADVECTION
WILL BE THE STRONGEST.
&&
.PREV DISCUSSION... /ISSUED 635 AM EST THU NOV 24 2011/
AVIATION...
STRATUS HAS ENVELOPED ENTIRE AREA WITH IFR CONDITIONS AT BOTH TAF
SITES. AMDAR SOUNDINGS AND PIREPS INDICATE MOISTURE DEPTH ABOUT 1KFT
WITH DRY AIR ABOVE. VERY STRONG INVERSION OF NEARLY 15 DEGREES SEEN
IN ONE AMDAR SOUNDING EARLIER THIS MORNING. WILL BE DIFFICULT TO MIX
THIS MOISTURE OUT BUT WIND FIELD HAS INCREASED AND YEILDS SOME HOPE
FOR AFTERNOON BREAKS. HOWEVER...HRRR RUNS FOR LOW CLOUD PRODUCT HAS
BEEN HANDLING THIS STRATUS VERY WELL AND CONTINUES TO SHOW ONLY A
SMALL CONTRACTION OF STRATUS WITH FEW BREAKS THROUGH LATE AFTERNOON.
THEREFORE HAVE SHOWN ONLY SLIGHT IMPROVEMENTS IN CIGS TODAY BUT VIS
SHOULD IMPROVE TO P6SM WITH WIND LATER THIS MORNING. SIMILAR
CONDITIONS TONIGHT SO EXPECT STRATUS TO FILL BACK IN. WINDS WILL BE
INCREASING THROUGH THE NIGHT IN LOWER LEVELS SO POSSIBLE THIS COULD
HELP MIX STRATUS LAYER LATE TONIGHT.
SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
UPDATE...JC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
635 AM EST THU NOV 24 2011
.AVIATION...
STRATUS HAS ENVELOPED ENTIRE AREA WITH IFR CONDITIONS AT BOTH TAF
SITES. AMDAR SOUNDINGS AND PIREPS INDICATE MOISTURE DEPTH ABOUT 1KFT
WITH DRY AIR ABOVE. VERY STRONG INVERSION OF NEARLY 15 DEGREES SEEN
IN ONE AMDAR SOUNDING EARLIER THIS MORNING. WILL BE DIFFICULT TO MIX
THIS MOISTURE OUT BUT WIND FIELD HAS INCREASED AND YEILDS SOME HOPE
FOR AFTERNOON BREAKS. HOWEVER...HRRR RUNS FOR LOW CLOUD PRODUCT HAS
BEEN HANDLING THIS STRATUS VERY WELL AND CONTINUES TO SHOW ONLY A
SMALL CONTRACTION OF STRATUS WITH FEW BREAKS THROUGH LATE AFTERNOON.
THEREFORE HAVE SHOWN ONLY SLIGHT IMPROVEMENTS IN CIGS TODAY BUT VIS
SHOULD IMPROVE TO P6SM WITH WIND LATER THIS MORNING. SIMILAR
CONDITIONS TONIGHT SO EXPECT STRATUS TO FILL BACK IN. WINDS WILL BE
INCREASING THROUGH THE NIGHT IN LOWER LEVELS SO POSSIBLE THIS COULD
HELP MIX STRATUS LAYER LATE TONIGHT.
&&
.SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5
TO 15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
&&
.LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
411 AM EST THU NOV 24 2011
.SHORT TERM...
AS FEARED...POTENTIAL WRINKLES IN TERMS OF STRATUS AND FOG CAME TO
FRUITION OVERNIGHT AND ARE CAUSE FOR SIGNIFICANT CHANGES TO SHORT
TERM FORECAST GRIDS. 11-3.9 MICRON SATELLITE IMAGE SHOWS LARGE AREA
OF STRATUS ACROSS THE MS AND OH RIVER VALLEY REGIONS AND QUICKLY
EXPANDING NORTHEAST ACROSS OUR AREA AS OF 08Z. 1000MB SW FLOW OF 5
TO 10 KNOTS AIDING IN MOVING STRATUS NORTHEAST. THE ENTIRE SHORT
TERM FORECAST HINGES ON WHAT THIS STRATUS DECK DOES OVER NEXT 24
HOURS AND HENCE THE SHORT TERM PROBLEM OF THE DAY.
NAM12 AND RUC HAVE SOME CLUE THAT STRATUS EXISTS BUT HRRR SEEMS TO
HAVE BEST HANDLE BY FAR. MOS GUIDANCE HAS NO CLUE WITH CLOUD COVER
CATEGORIES MAINLY CLEAR THROUGH THE PERIOD AND EVEN LAMP GUIDANCE AS
OF 08Z HAS NO INDICATION. THUS MOS TEMPS NOT CLOSE TODAY FOR
OPTIMISTIC 50S UNLESS CLOUD COVER ERODES QUICKLY WHICH IS DOUBTFUL
AT THIS TIME. NAM12 BUFKIT SOUNDINGS SHOW SATURATED SURFACE TO 1KFT
LAYER WITH STRONG INVERSION AND VERY DRY AIR ABOVE. WHILE YESTERDAYS
MODEL RUNS MIXED THE LOWER LEVELS...LATEST RUNS ARE MUCH STRONGER
WITH INVERSION AND SLIGHTLY DEEPER WITH MOIST LAYER LEADING TO
LITTLE MIXING UNTIL LATE AFTERNOON. LATEST HRRR LOW CLOUD PRODUCT
HAD STRATUS AREA NAILED AT INITIATION AND KEEPS IT LOCKED THROUGH
ITS VALID PERIOD WHICH IS MID AFTERNOON. HRRR 2M TEMPS ALSO REMAIN
IN UPPER 30S AND LOWER 40S THROUGH MID AFTERNOON. ALSO SOME CONCERN
FOR DRIZZLE FOR A FEW HOURS AFTER SUNRISE AS TURBULENT MIXING OF
SHALLOW CLOUD TOPS OFTEN LEADS TO PERIOD OF LIGHT
PRECIPITATION...ESPECIALLY WHEN SUB CLOUD LAYER IS MOIST WITH BR OR
FOG. HAVE ADDED A CHANCE FOR DRIZZLE TO ACCOUNT FOR THIS POSSIBILITY
THROUGH MID MORNING.
A LOOK BACK AT SATELLITE TRENDS ON WEDNESDAY REVEALED VERY LITTLE
MIXING OF STRATUS AND THUS CONCERNED FOR SIMILAR TREND TODAY INTO
TONIGHT. SUBTLE DIFFERENCE TODAY WILL BE INCREASING WINDS IN THE
1000-925MB LAYER... ESPECIALLY ABOVE 950MB WITH 40 TO 50 KNOTS
DEVELOPING LATE TONIGHT. HOWEVER...THIS WILL BE JUST ABOVE INVERSION
AND MAY NOT BE ENOUGH TO MIX OUT LOWER STRATUS DECK GIVEN STRONG
INVERSION IN PLACE. 1000MB WINDS LOOK TO INCREASE BUT ONLY IN THE 5 TO
15 KNOT RANGE WITH LIGHTER WINDS UPSTREAM WHERE STRATUS COULD
REDEVELOP AND AGAIN ADVECT BACK IN.
AFTER MUCH COLLABORATION HAVE OPTED FOR CLOUDY CONDITIONS THROUGH
EARLY AFTERNOON WITH A SUBTLE OPTIMISTIC TRANSITION TO PARTLY CLOUDY
MID TO LATE AFTERNOON. KEPT SKY COVER IN PARTLY CLOUDY RANGE TONIGHT
WITH UNCERTAINTY CONTINUING AS TO DEGREE OF REDEVELOPMENT IF WE
ACTUALLY DO BREAK OUT THIS AFTERNOON. STRONGER FLOW ON FRIDAY AHEAD
OF NEXT SYSTEM SUGGEST ANY REMAINING STRATUS WOULD MIX OUT MID TO
LATE MORNING.
TEMPS OBVIOUSLY WILL BE IMPACTED SIGNIFICANTLY WITH THIS STRATUS.
HAVE LOWERED HIGHS TODAY SEVERAL DEGREES BUT LIKELY NOT NEARLY
ENOUGH IF CLOUDS PERSIST ALL DAY. HAVE TO RESPECT PARTIAL CLEARING
IN AFTERNOON SO DID NOT GO AS LOW AS COLDEST MODEL BLENDS. 06Z NAM12
KEEPING TEMPS IN 30S ALL AREAS TODAY. MINS TONIGHT NOW HEAVILY
DEPENDENT ON ACTUAL MAX TEMPS TODAY BUT EXPECT LITTLE DROP OFF WITH
DECENT GRADIENT AND CLOUD POTENTIAL. KEPT TEMPS IN LOW TO MID 40S
TONIGHT. HIGHS ON FRIDAY STILL LOOK TO BE NEAR 60 WITH BETTER MIXING
BUT CONCERNS CONTINUE FOR LINGERING STRATUS IN THE MORNING.
&&
.LONG TERM.../SATURDAY THROUGH WEDNESDAY/
FEW SIG CHANGES TO LONG TERM WITH MODEL TURMOIL STILL ABUNDANT
THROUGH THE PERIOD. ARRIVAL OF TROUGH FROM THE WEST AND ASSOCIATED
PRECIP STILL NOT MUCH CLEARER WITH NAM/GFS SPREADING RAIN ACROSS THE
AREA MID MORNING WEST INTO AFTERNOON EAST VS ECMWF MORE QUICK
AFTERNOON ARRIVAL WEST TO EAST. THESE FASTER SOLUTIONS ALSO PUSHES
PRECIP OUT AFTER 6Z SUN IN WESTERN AREAS. THINK COMPROMISE STILL
NEEDED IN MODELS...MEANING GENERALLY SAME FORECAST FOR SAT/SAT NGT.
TEMPS STILL GOING TO BE TRICKY BUT WITH INCREASING MID/HIGH CLOUDS
THINK THEY WILL BE KEPT IN CHECK ESPECIALLY WEST. HAVE INCREASED SKY
COVER TO REFLECT FASTER CLOUD ARRIVAL.
ECMWF ONLY MODEL THAT STARTS PROGRESSIVE SUNDAY WITH GFS/GEFS/GEM
ALL SHOWING CLOSED UPPER LOW ACROSS THE GREAT LAKES /IN VARYING
LOCATIONS/. WITH TIME...ECMWF AND GEM CONTINUE A DEPICTION OF RAPID
DEEPENING OF UPPER LOW AND MAJOR TRANSLATION SOUTHWARD IN ENERGY.
GFS/GEFS HOLD WITH NORTHERN INFLUENCE BEING STRONGER. NEXT TROUGH
WILL MOVE INTO THE AREA MONDAY NIGHT INTO TUESDAY AND INTERACT WITH
CLOSED LOW WHEREVER IT MAY BE. THINK THERE WILL BE AT LEAST A
DECENT SHOT FOR PRECIP UNDER THE UPPER LOW WITH COOL NW FLOW ACROSS
THE LAKE AND SYNOPTIC MSTR STILL ACROSS THE AREA. IN
ADDITION...PIECE OF ENERGY SHOULD ROTATE ACROSS THE AREA ON SUNDAY.
WILL MAINTAIN MID RANGE CHC POPS FOR NOW WITH POSSIBLE INCREASE TO
LIKELY WITH TIME. BASED ON THERMAL PROFILES...HAVE OPTED TO THROW IN
MIX MENTION FOR THE DAY AS 1000-850 MB VALUES DROP TO NEAR OR BELOW
1300 M.
HAVE ONLY MADE MINOR TWEAKS TO POPS FROM CR INIT TO PLACE HIGHER
EMPHASIS ON PAST VS PRESENT WITH SLIGHTLY HIGHER POPS. WHILE AN
OUTLIER...IF ECMWF SOLUTION OF UPPER LOW EVENTUALLY WORKING NORTH
TOWARDS THE AREA MON NGT INTO TUES NGT BODES TRUE...COULD BE RATHER
WET. ECMWF HAS BEEN VERY VARIABLE OF LATE...BUT NO WORSE THAN SOME
OF THE OTHERS LEADING TO AT LEAST CONSIDERATION OF THE SCENARIO.
REGARDLESS OF SOLUTIONS...NORMAL TO BELOW NORMAL TEMPS WILL BE IN
STORE SUNDAY AND BEYOND.
&&
.AVIATION...
STRATUS DECK CONTINUES TO ADVECT RAPIDLY NORTHEAST OUT OF CENTRAL
ILLINOIS AND INDIANA. THIS SHOULD OVERSPREAD TERMINAL SITES AROUND
07Z AT KSBN AND 08Z AND KFWA BASED ON LATEST EXTRAPOLATION FROM
SATELLITE. CIGS GENERALLY IN THE 4-8HFT RANGE WITH VIS BETWEEN 1 AND
2SM. HAVE TRENDED TAFS TO THIS RANGE. MODELS NOT HANDLING STRATUS
AREA WELL BUT NAM BUFKIT HINTED AT IT LAST NIGHT AND DOES SHOW
SATURATED LOWER LEVELS BELOW VERY STRONG INVERSION AT BOTH TAF
SITES. CONCERN IS NAM12 SOUNDINGS NOW SHOW SATURATED LOWER LEVELS
PERSISTING THROUGH MUCH OF THE DAY UNTIL VERY LATE AFTERNOON WHEN
MIXING FINALLY DRIES OUT LOWER LEVELS. GIVEN TRENDS ON WEDNESDAY OF
SLOW ERODING STRATUS HAVE TRENDED TAFS TO A MORE PESSIMISTIC NATURE
WITH SLOWER EROSION OF LOW CLOUD DECK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
627 AM CST THU NOV 24 2011
.AVIATION...
IFR TO LIFR CONDITIONS IN FOG AND LOW CLOUDS CONTINUE TO BLANKET
REGION EARLY THIS AM. CLOUD TRENDS THE MAIN CHALLENGE DURING
THE TAF CYCLE. IT APPEARS LITTLE CHG THROUGH MID MORNING WITH
WIDESPREAD IFR/LIFR CONDITIONS. HOWEVER BY LATE AM AND THIS AFTN
EXPECT INCREASED MIXING WITH GUSTY S/SW WINDS 15-25 KTS TO ERODE
LOW CLOUDS FROM WEST TO EAST RESULTING IN VFR CONDITIONS. THIS
SCENARIO SUPPORTED BY LAST SEVERAL RUNS OF RUC BACKUP FLIGHT RULES
PRODUCT AND HRRR LOW LEVEL CLOUD PRODUCT. TNGT WITH LOW LEVEL
MOISTURE STILL STREAMING TOWARD AREA AND LOW LEVEL INVERSION
STRENGTHENING BELIEVE STRATUS WITH IFR TO LIFR CONDITIONS WILL
REDEVELOP OVER AREAS THAT MANAGE TO CLEAR OUT TDY. THIS ALSO
DEPICTED BY RUC BACKUP MODEL FLIGHT RULES PRODUCT. MAY HAVE TO
WATCH FOR LLWS LATER TNGT AS SOME MODELS INCREASE WINDS TO AROUND
40 KTS IN 1500-2000 FT AGL... BUT BEING MARGINAL WITH POTENTIAL
GUSTY SLY SFC WINDS HAVE LEFT OUT MENTION.
&&
.PREV DISCUSSION... /ISSUED 335 AM CST THU NOV 24 2011/
SYNOPSIS...
SFC HIGH CENTERED OVER THE TN/OH VLYS EARLY THIS AM. MOIST LOW LEVEL
RETURN FLOW (SFC DEWPTS IN 40S) ON WESTERN AND SOUTHERN PERIPHERY OF
HIGH WITH 11-3.9 MICRON SATL IMAGERY SHOWING LARGE AREA OF LOW
CLOUDS WITHIN THIS MOIST AXIS. SOME FOG ALSO FOUND OVER REGION BUT
MAINLY LIGHT (2-6SM) DUE TO BLANKET OF LOW CLOUDS AND ALSO S/SW WINDS
OF 5-10 KTS KEEPING BL MIXED JUST ENOUGH.
SHORT TERM...TODAY AND TONIGHT...
ANOTHER DIFFICULT FCST REVOLVING AROUND SKY COVER TRENDS WITH HUGE IMPACT
ON TEMPS. COMPOUNDING DIFFICULTY IS THAT IT/S HARD TO FIND MODEL DOING
WELL IN CAPTURING COVERAGE/EXTENT OF LOW CLOUDS. OBSERVED SOUNDINGS
SHOW MOISTURE TO BE VERY SHALLOW ON THE ORDER OF 20 MB OR SO IN DEPTH
BUT BELOW VERY STRONG LOW LEVEL INVERSION. IT IS EXPECTED THOUGH THAT
MIXING TO INCREASE TDY AIDED BY STRENGTHENING SFC PRESSURE GRADIENT
WITH DEVELOPING GUSTY S/SW WINDS. THIS SHOULD BE SUFFICIENT TO TAP LARGE
AMOUNTS OF DRY AIR NEAR BASE OF INVERSION TO BEGIN EROSION PROCESS/
CLEARING TREND LATER THIS AM THROUGH AFTN. HIGHEST CONFIDENCE OF SEEING
CLEARING TDY IS ACROSS W/SW SECTIONS BEING IN CLOSER PROXIMITY TO
BACK EDGE OF STRATUS. LOWEST CONFIDENCE OF ANY CLEARING OF IS ACROSS NW IL
COUNTIES WHERE MOIST LOW LEVEL PARCEL TRAJECTORIES ARE AIMED. THE
HRRR LOW CLOUD PRODUCT... WHICH DID REALLY WELL YSTDY WITH STRATUS...
SUPPORTS THIS IDEA OF BEST CLEARING POTENTIAL W/SW OF MISSISSIPPI RVR TDY
AND HAVE TAILORED FCST CLOSELY TOWARD THIS SCENARIO. OBVIOUSLY AS CLOUDS
GO TDY... SO GO TEMPS. LOOKING BACK YSTDY TO OUR WEST NOTICED THAT AREAS
KEPT STRATUS THROUGH 18Z BEFORE DECREASING SAW HIGHS GENERALLY IN RANGE
OF 47-55 DEGS WITH U50S NEAR KC METRO. WENT WITH THIS GENERAL RANGE FOR MOST
OF CWA BEING COOLEST NW IL... AND WARMEST SE IA INTO NORTHEAST MO WHERE HAVE
SOME U50S/NR 60 DEGS. OF COURSE IF STRATUS HOLDS AND WHERE THAT DOES
OCCUR WILL SEE TEMPS ONLY GO UP 3-5 DEGS FOR HIGHS GENERALLY MID 40S.
IF CLEARING BUSTS OPEN EARLIER THEN WITH GUSTY S/SW WINDS WOULD SEE MORE
AREAS NR 60 OR IN THE 60S FOR HIGHS AND POSSIBLY NEARING RECORDS. SHOULD THIS
OCCUR MOST LIKELY WRN/SRN CWA.
TNGT... WENT WITH GENERAL IDEA THAT ANY CLEARING TO FILL BACK IN WITH
STRATUS WITH MOIST LOW LEVEL SFC PARCEL TRAJECTORIES STILL AIMED AT REGION.
THIS ALSO SUPPORTED BY BACKUP RUC MODEL AVIATION FLIGHT CATEGORIES PRODUCT
WHICH SHOWS IFR CONDITIONS BLOSSOMING THROUGHOUT REGION. GIVEN THIS AND
SLY WINDS AROUND 10 KTS WITH SOME GUSTS STAYED AT OR ABOVE WARMEST GUIDANCE
FOR LOWS... WITH WIDESPREAD L/M 40S. SOME FOG POSSIBLE BUT MAINLY LIGHT
(2-6SM) DUE TO CLOUDS AND SOUTH WINDS AROUND 10 KTS WITH SOME GUSTS.
.05..
LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
FORECAST FOCUS ON RAIN FRIDAY NIGHT AND SATURDAY OTHERWISE MAINLY A
CHILLY BUT DRY PERIOD.
FRIDAY...EXPECTING A WARM DAY IN THE BRISK SOUTHERLY FLOW AS TROUGH
DIVES INTO THE NORTHERN ROCKIES AND ANOTHER LIFTS INTO THE SOUTHERN
ROCKIES. MAX TEMPS IN THE 60 TO 65 RANGE ROUGHLY SOUTH OF HIGHWAY 30
WITH 55 TO 60 TO THE NORTH. THESE TEMPS BASED ON INCREASING CLOUD
COVER AS THE DAY PROGRESSES. BUT IF THERE IS MORE SUNSHINE THEN
TEMPS MAY BE SOMEWHAT HIGHER. HOWEVER A BIG PROBLEM COULD BE STRATUS
FORMING UNDER THE STRENGTHENING INVERSION EARLY FRIDAY THAT IF
LINGERS TOO LONG WOULD PUT A BIG DENT INTO THE WARM TEMPS. BASED ON
THIS CURRENT FORECAST RECORD HIGHS ARE NOT IN JEOPARDY. SEE CLIMATE
SECTION BELOW. PREVIOUS SHIFT HAD REMOVED MENTION OF RAIN FOR FRIDAY
AND BASED ON LATEST DATA THIS STILL LOOKS GOOD. SHOULD HAVE SOUTH
WINDS GUSTING TO AROUND 30 MPH.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE 00Z ECM HAS SLOWED THE
PHASING OF THE TWO STREAMS AND KEEPS MUCH OF THE CWA DRY FRIDAY
EVENING...AND IN FACT KEEPS OUR FAR EASTERN CWA TOTALLY DRY FRIDAY
NIGHT. OTHERWISE WILL GRADUALLY WORK THE LIKELY POPS EASTWARD AS
MOST OF THE OPERATIONAL MODELS PAINT A WET NIGHT. RAINY DAY ON
SATURDAY MOST OF THE CWA EXCEPT OUR WESTERN CWA WHERE WE WILL HAVE A
CHANCE. TIMING THE ENDING OF THE RAIN VARIES UPON THE MODELS AND
LATER SHIFTS MAY NEED TO ADJUST. WIDESPREAD 0.20 TO 0.40 INCH RAIN
AMOUNTS STILL APPEAR LIKELY. ANY RAIN THAT CHANGES TO SNOW SHOWERS
AT THE TAIL END OF THIS EVENT BY SATURDAY NIGHT LOOKS SHORT-LIVED
AND UNEVENTFUL AS OF NOW. BACK TO REALITY AS MUCH COLDER AIR RETURNS
ON SATURDAY WITH STRONG COLD ADVECTION. MAX TEMPS ONLY IN THE MID
40S TO LOWER 50S...ALONG WITH NORTHWEST WINDS GUSTING OVER 30 MPH
ADDING TO THE CHILL. A RATHER WET AND RAW DAY ON SATURDAY.
SUNDAY THROUGH WEDNESDAY...INTERESTING THAT THE PAST COUPLE OF RUNS
OF THE ECM SHOWED EITHER A PROGRESSIVE TROUGH MOVING ACROSS THE
EASTERN UNITED STATES EARLY NEXT WEEK...OR A CLOSED LOW FORMING WELL
TO OUR EAST. AMAZINGLY THE 00Z RUN NOW IS DEPICTING THE CLOSED LOW
FARTHER TO THE WEST FORMING IN THE GULF STATES AND MOVING INTO THE
OHIO VALLEY. THE PRECIPITATION JUST GRAZES OUR FAR SE CWA. THE
GFS/GEM INDICATE A DIGGING TROUGH IN THE EASTERN STATES KEEPING THE
PRECIPITATION WELL EAST OF THE DVN CWA. BASICALLY FOR THE PAST 7
DAYS THE GFS/ECM HAVE BEEN ERRATIC AND SHOWING A LOT OF FLIP-
FLOPPING. THEREFORE THE EXTENDED REMAINS LOW CONFIDENCE. OTHER THAN
A SLIGHT CHANCE OF SNOW SHOWERS EAST OF THE MS RIVER ON SUNDAY THE
EXTENDED INDICATES DRY AND CHILLY WEATHER FOR NOW.
IF THE ECM IS CORRECT THE RECORD COLD ARCTIC AIR THAT HAS BEEN
BUILDING IN ALASKA THE PAST SEVERAL WEEKS WILL BE GETTING CLOSER AND
CLOSER THE FIRST WEEK OF DECEMBER. FAIRBANKS HAS NOT BEEN ABOVE ZERO
FOR THE PAST 10 DAYS. THE ARCTIC OSCILLATION IS ALSO FORECAST TO
START GOING NEGATIVE DURING THAT TIME. THIS MAY ALSO INCREASE THE
POTENTIAL FOR A SNOWSTORM.
.HAASE..
CLIMATE...
RECORD HIGHS FOR NOVEMBER 24...
MOLINE.........66 IN 1966
CEDAR RAPIDS...63 IN 1931
DUBUQUE........63 IN 1931
BURLINGTON.....68 IN 1915
RECORD HIGHS FOR NOVEMBER 25...
MOLINE.........67 IN 1896
CEDAR RAPIDS...68 IN 1896
DUBUQUE........65 IN 1896
BURLINGTON.....68 IN 1915
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
335 AM CST THU NOV 24 2011
.SYNOPSIS...
SFC HIGH CENTERED OVER THE TN/OH VLYS EARLY THIS AM. MOIST LOW LEVEL
RETURN FLOW (SFC DEWPTS IN 40S) ON WESTERN AND SOUTHERN PERIPHERY OF
HIGH WITH 11-3.9 MICRON SATL IMAGERY SHOWING LARGE AREA OF LOW
CLOUDS WITHIN THIS MOIST AXIS. SOME FOG ALSO FOUND OVER REGION BUT
MAINLY LIGHT (2-6SM) DUE TO BLANKET OF LOW CLOUDS AND ALSO S/SW WINDS
OF 5-10 KTS KEEPING BL MIXED JUST ENOUGH.
&&
.SHORT TERM...TODAY AND TONIGHT...
ANOTHER DIFFICULT FCST REVOLVING AROUND SKY COVER TRENDS WITH HUGE IMPACT
ON TEMPS. COMPOUNDING DIFFICULTY IS THAT IT/S HARD TO FIND MODEL DOING
WELL IN CAPTURING COVERAGE/EXTENT OF LOW CLOUDS. OBSERVED SOUNDINGS
SHOW MOISTURE TO BE VERY SHALLOW ON THE ORDER OF 20 MB OR SO IN DEPTH
BUT BELOW VERY STRONG LOW LEVEL INVERSION. IT IS EXPECTED THOUGH THAT
MIXING TO INCREASE TDY AIDED BY STRENGTHENING SFC PRESSURE GRADIENT
WITH DEVELOPING GUSTY S/SW WINDS. THIS SHOULD BE SUFFICIENT TO TAP LARGE
AMOUNTS OF DRY AIR NEAR BASE OF INVERSION TO BEGIN EROSION PROCESS/
CLEARING TREND LATER THIS AM THROUGH AFTN. HIGHEST CONFIDENCE OF SEEING
CLEARING TDY IS ACROSS W/SW SECTIONS BEING IN CLOSER PROXIMITY TO
BACK EDGE OF STRATUS. LOWEST CONFIDENCE OF ANY CLEARING OF IS ACROSS NW IL
COUNTIES WHERE MOIST LOW LEVEL PARCEL TRAJECTORIES ARE AIMED. THE
HRRR LOW CLOUD PRODUCT... WHICH DID REALLY WELL YSTDY WITH STRATUS...
SUPPORTS THIS IDEA OF BEST CLEARING POTENTIAL W/SW OF MISSISSIPPI RVR TDY
AND HAVE TAILORED FCST CLOSELY TOWARD THIS SCENARIO. OBVIOUSLY AS CLOUDS
GO TDY... SO GO TEMPS. LOOKING BACK YSTDY TO OUR WEST NOTICED THAT AREAS
KEPT STRATUS THROUGH 18Z BEFORE DECREASING SAW HIGHS GENERALLY IN RANGE
OF 47-55 DEGS WITH U50S NEAR KC METRO. WENT WITH THIS GENERAL RANGE FOR MOST
OF CWA BEING COOLEST NW IL... AND WARMEST SE IA INTO NORTHEAST MO WHERE HAVE
SOME U50S/NR 60 DEGS. OF COURSE IF STRATUS HOLDS AND WHERE THAT DOES
OCCUR WILL SEE TEMPS ONLY GO UP 3-5 DEGS FOR HIGHS GENERALLY MID 40S.
IF CLEARING BUSTS OPEN EARLIER THEN WITH GUSTY S/SW WINDS WOULD SEE MORE
AREAS NR 60 OR IN THE 60S FOR HIGHS AND POSSIBLY NEARING RECORDS. SHOULD THIS
OCCUR MOST LIKELY WRN/SRN CWA.
TNGT... WENT WITH GENERAL IDEA THAT ANY CLEARING TO FILL BACK IN WITH
STRATUS WITH MOIST LOW LEVEL SFC PARCEL TRAJECTORIES STILL AIMED AT REGION.
THIS ALSO SUPPORTED BY BACKUP RUC MODEL AVIATION FLIGHT CATEGORIES PRODUCT
WHICH SHOWS IFR CONDITIONS BLOSSOMING THROUGHOUT REGION. GIVEN THIS AND
SLY WINDS AROUND 10 KTS WITH SOME GUSTS STAYED AT OR ABOVE WARMEST GUIDANCE
FOR LOWS... WITH WIDESPREAD L/M 40S. SOME FOG POSSIBLE BUT MAINLY LIGHT
(2-6SM) DUE TO CLOUDS AND SOUTH WINDS AROUND 10 KTS WITH SOME GUSTS.
..05..
.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
FORECAST FOCUS ON RAIN FRIDAY NIGHT AND SATURDAY OTHERWISE MAINLY A
CHILLY BUT DRY PERIOD.
FRIDAY...EXPECTING A WARM DAY IN THE BRISK SOUTHERLY FLOW AS TROUGH
DIVES INTO THE NORTHERN ROCKIES AND ANOTHER LIFTS INTO THE SOUTHERN
ROCKIES. MAX TEMPS IN THE 60 TO 65 RANGE ROUGHLY SOUTH OF HIGHWAY 30
WITH 55 TO 60 TO THE NORTH. THESE TEMPS BASED ON INCREASING CLOUD
COVER AS THE DAY PROGRESSES. BUT IF THERE IS MORE SUNSHINE THEN
TEMPS MAY BE SOMEWHAT HIGHER. HOWEVER A BIG PROBLEM COULD BE STRATUS
FORMING UNDER THE STRENGTHENING INVERSION EARLY FRIDAY THAT IF
LINGERS TOO LONG WOULD PUT A BIG DENT INTO THE WARM TEMPS. BASED ON
THIS CURRENT FORECAST RECORD HIGHS ARE NOT IN JEOPARDY. SEE CLIMATE
SECTION BELOW. PREVIOUS SHIFT HAD REMOVED MENTION OF RAIN FOR FRIDAY
AND BASED ON LATEST DATA THIS STILL LOOKS GOOD. SHOULD HAVE SOUTH
WINDS GUSTING TO AROUND 30 MPH.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE 00Z ECM HAS SLOWED THE
PHASING OF THE TWO STREAMS AND KEEPS MUCH OF THE CWA DRY FRIDAY
EVENING...AND IN FACT KEEPS OUR FAR EASTERN CWA TOTALLY DRY FRIDAY
NIGHT. OTHERWISE WILL GRADUALLY WORK THE LIKELY POPS EASTWARD AS
MOST OF THE OPERATIONAL MODELS PAINT A WET NIGHT. RAINY DAY ON
SATURDAY MOST OF THE CWA EXCEPT OUR WESTERN CWA WHERE WE WILL HAVE A
CHANCE. TIMING THE ENDING OF THE RAIN VARIES UPON THE MODELS AND
LATER SHIFTS MAY NEED TO ADJUST. WIDESPREAD 0.20 TO 0.40 INCH RAIN
AMOUNTS STILL APPEAR LIKELY. ANY RAIN THAT CHANGES TO SNOW SHOWERS
AT THE TAIL END OF THIS EVENT BY SATURDAY NIGHT LOOKS SHORT-LIVED
AND UNEVENTFUL AS OF NOW. BACK TO REALITY AS MUCH COLDER AIR RETURNS
ON SATURDAY WITH STRONG COLD ADVECTION. MAX TEMPS ONLY IN THE MID
40S TO LOWER 50S...ALONG WITH NORTHWEST WINDS GUSTING OVER 30 MPH
ADDING TO THE CHILL. A RATHER WET AND RAW DAY ON SATURDAY.
SUNDAY THROUGH WEDNESDAY...INTERESTING THAT THE PAST COUPLE OF RUNS
OF THE ECM SHOWED EITHER A PROGRESSIVE TROUGH MOVING ACROSS THE
EASTERN UNITED STATES EARLY NEXT WEEK...OR A CLOSED LOW FORMING WELL
TO OUR EAST. AMAZINGLY THE 00Z RUN NOW IS DEPICTING THE CLOSED LOW
FARTHER TO THE WEST FORMING IN THE GULF STATES AND MOVING INTO THE
OHIO VALLEY. THE PRECIPITATION JUST GRAZES OUR FAR SE CWA. THE
GFS/GEM INDICATE A DIGGING TROUGH IN THE EASTERN STATES KEEPING THE
PRECIPITATION WELL EAST OF THE DVN CWA. BASICALLY FOR THE PAST 7
DAYS THE GFS/ECM HAVE BEEN ERRATIC AND SHOWING A LOT OF FLIP-
FLOPPING. THEREFORE THE EXTENDED REMAINS LOW CONFIDENCE. OTHER THAN
A SLIGHT CHANCE OF SNOW SHOWERS EAST OF THE MS RIVER ON SUNDAY THE
EXTENDED INDICATES DRY AND CHILLY WEATHER FOR NOW.
IF THE ECM IS CORRECT THE RECORD COLD ARCTIC AIR THAT HAS BEEN
BUILDING IN ALASKA THE PAST SEVERAL WEEKS WILL BE GETTING CLOSER AND
CLOSER THE FIRST WEEK OF DECEMBER. FAIRBANKS HAS NOT BEEN ABOVE ZERO
FOR THE PAST 10 DAYS. THE ARCTIC OSCILLATION IS ALSO FORECAST TO
START GOING NEGATIVE DURING THAT TIME. THIS MAY ALSO INCREASE THE
POTENTIAL FOR A SNOWSTORM.
..HAASE..
&&
.AVIATION... /ISSUED 1135 PM CST WED NOV 23 2011/
THE STRATUS REMAINS IN PLACE OVER THE EASTERN THIRD OF IOWA AND
HAD EXPANDED ACROSS NORTHERN IL LATE THIS EVENING. WITH VERY
LITTLE CHANGE IN THE LOCATION OF THE BACK EDGE OF THE STRATUS THIS
EVENING...IT APPEARS THAT THE CLOUDS WILL REMAIN OVER THE AREA
MUCH OF THE NIGHT WITH MAINLY IFR CIGS. AS LONG AS THE CLOUDS ARE
IN PLACE...VISIBILITIES SHOULD REMAIN IN THE 3 TO 5SM RANGE DUE TO
FOG. AS THE SOUTHWEST LOW LEVEL FLOW INCREASES LATE TONIGHT AND
THURSDAY MORNING...THE CLOUDS SHOULD START ERRODING FROM WEST TO
EAST. HAVE CLEARED TAF SITES OUT BETWEEN 12Z AND 15Z. EXPECT VFR
CONDITIONS THE REST OF THE PERIOD WITH SOUTHWEST WINDS GUSTING TO
AROUND 20 KTS BY THURSDAY AFTERNOON. ..DLF..
&&
.CLIMATE...
RECORD HIGHS FOR NOVEMBER 24...
MOLINE.........66 IN 1966
CEDAR RAPIDS...63 IN 1931
DUBUQUE........63 IN 1931
BURLINGTON.....68 IN 1915
RECORD HIGHS FOR NOVEMBER 25...
MOLINE.........67 IN 1896
CEDAR RAPIDS...68 IN 1896
DUBUQUE........65 IN 1896
BURLINGTON.....68 IN 1915
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1140 PM EST WED NOV 23 2011
.SYNOPSIS...
AFTER SOME CLOUDS OVERNIGHT TONIGHT INTO THE MORNING HOURS...HIGH
PRESSURE WILL BRING CLEARING SKIES AND SEASONABLY MILD TEMPERATURES
FOR THANKSGIVING DAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
CLOUDS ARE FORMING ALONG THE RIDGES...WITH A LARGE AREA OF LOW
CLOUDS MARCHING ACROSS WESTERN OHIO. HI RES MODELS SHOW THE AREA
TO THE WEST ENVELOPING EASTERN OHIO IN HE NEXT 2-4 HOURS...MOVING
INTO WESTERN PA AROUND SUNRISE. FURTHER EAST...THE CLOUD DECK
THERE LOOKS TO BE EXPANDING TO THE WEST AND EAST. GIVEN THESE
CONDITIONS...WILL INCREASE SKY COVER GRADUALLY OVERNIGHT TO
MOSTLY CLOUDY TO OVERCAST AREA WIDE BY MORNING. THINK THIS
DECK WILL DISSIPATE BY LATE MORNING...WITH HIGH PRESSURE GIVING
A MOSTLY SUNNY THANKSGIVING AFTN. LOWER TO MID 30S WILL PREVAIL
FOR LOWS TNGT...WITH LOWER/MID 50S FOR HIGHS THANKSGIVING DAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
LARGE DOME OF HIGH PRESSURE WILL COVER THE EASTERN THIRD OF THE
NATION THROUGH PERIOD WITH TEMPERATURES AVERAGING ABOVE NORMAL AND
GENERALLY CLEAR SKIES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LATEST MEDIUM RANGE MODELS CONTINUE TO SHOW A SHARP UPPER TROUGH
PUSHING INTO THE EASTERN STATES EARLY NEXT WEEK...BUT GFS AND ECMWF
STILL DIFFER ON WHERE AND WHEN SOUTHERN BRANCH TROUGH WILL CLOSE
OFF. WENT CLOSE TO HPC GUIDANCE WHICH PUSHES A COLD FRONT THROUGH
THE UPPER OHIO VALLEY SUNDAY AND THEN DEVELOPS A SURFACE LOW OVER
THE MID ATLANTIC REGION MONDAY INTO EARLY TUESDAY. LIKELY POPS FOR
SHOWERS ARE FORECAST FOR SUNDAY INTO SUNDAY NIGHT WITH COVERAGE
BECOMING MORE SCATTERED MONDAY INTO TUESDAY.
ANOTHER UPPER TROUGH WILL SWING INTO THE GREAT LAKES REGION AND WILL
BRING A REINFORCING SHOT OF COLDER AIR AND SCATTERED PRECIPITATION
EARLY WEDNESDAY.
ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL GRADUALLY COOL DOWN
TO A FEW DEGREES BELOW NORMAL BY WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
FORECAST PROBLEM FOR THE SHORT TERM IS THE AREA OF IFR/LIFR STRATUS
DEVELOPING IN THE STRONG WAA. MAIN AREA IS TO THE WEST, WITH A
SMALLER AREA FILLING IN OVER THE RIDGES. CURRENT HI RES MODELS
INDICATE THAT THE AREA TO THE WEST WILL EXPAND EASTWARD DURING THE
OVERNIGHT HOURS, WHILE THE AREA EAST WILL ALSO FILL INTO THE WEST.
THIS WILL NEED TO BE MONITORED CLOSELY, BUT WITH HI RES MODELS AND
TO AN EXTENT, LATEST NAM RUN, SHOWING THIS EXPANSION, WILL NEED TO
BRING IN IFR/LIFR CIGS TO ALL PORTS AS DAWN APPROACHES. WILL USE
TIMING FROM HRRR MODEL, IN THE WEST, RESTRICTIONS WILL BEGIN AT ZZV
AROUND 08Z AND THEN REACH PIT AROUND 12Z. IN THE EAST, WILL BEGIN
FORECAST WITH MVFR CIGS AT LBE AND MGW, THEN MAY NEED TO LOWER
FURTHER AS DAWN APPROACHES. OBVIOUSLY, IF EXPANSION OF LOW CIGS DOES
NOT TAKE PLACE, WILL NEED TO MAKE MAJOR CHANGES TO FORECAST.
MODEL DATA IS SHOWING THAT THE LOWER CLOUDS SHOULD DISPERSE RAPIDLY
BY MID-MORNING ONCE THE ATMOSPHERE BEGINS THE MIXING PROCESS.
EXPECT A RETURN TO VFR CONDITION FOLLOWING THE ELIMINATION OF THE
STRATUS.
OUTLOOK... THURSDAY NIGHT THROUGH MONDAY...
VFR INTO SATURDAY EVENING. PREFRONTAL SHOWERS WITH RESTRICTIONS
POSSIBLE STARTING LATE SATURDAY NIGHT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST THU NOV 24 2011
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(1246 PM EST THU NOV 24 2011)
A TEMPERATURE INVERSION WAS HOLDING IN THE LOW CLOUDS THIS
AFTERNOON. CEILINGS WERE MAINLY IFR ALONG AND SOUTH OF I-96...WITH
MVFR TO THE NORTH. DRYING IN THE LOW LEVELS SLOWLY OCCURS FROM THE
SW AND THIS IS EVIDENT WITH THE CLEARING THAT WAS OCCURRING ACROSS
CENTRAL IL AS OF 17Z. FEEL WE WILL SEE SOME IMPROVEMENT INTO THE
EVENING AND OVERNIGHT AS THIS DRIER LOW LEVEL AIR ARRIVES. THE I-94
TAF SITES SHOULD IMPROVE DURING THE 00-04Z TIME FRAME. WHILE THE
I-96 AREA SHOULD IMPROVE 03-07Z. SOME LOW CLOUDS COULD LINGER EVEN
LONGER ALONG THE LAKE MICHIGAN SHORE. ONCE THE CLOUDS BREAK OUT VFR
CONDITIONS SHOULD PREVAIL THROUGH MID DAY FRI. HOWEVER...SW WINDS
SHOULD GUST TO AROUND 25 KTS AFTER 14Z FRI.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: JK
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 PM EST THU NOV 24 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
LOW CLOUDS/VSBY EARLY THIS AFTN AT KSAW...OTHERWISE SHOULD BE QUIET INTO
EARLY EVENING AT ALL TAF SITES WITH JUST SOME GUSTY SW WINDS. AS
SOUTHWEST WINDS PUSH MOISTURE BACK INTO THE REGION TONIGHT AND AS
INVERSION STRENGTHENS...EXPECT LOW CLOUDS TO REDEVELOP AND PUSH
INTO THE TAF SITES. GREATEST CHANCE OF LOW CLOUDS FORMING TONIGHT
WILL BE AT KSAW...BUT THERE SHOULD BE IFR/LOWER MVFR CLOUDS AT ALL
SITES BY MID MORNING ON FRIDAY. LLWS IS EXPECTED AGAIN TONIGHT AHEAD
OF AN APPROACHING SURFACE TROUGH THAT MOVES THROUGH ON FRIDAY.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
639 AM EST THU NOV 24 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
LOW CLOUDS CONTINUE TO MAKE FOR A DIFFICULT FORECAST FOR SOME OF THE
TAF SITES. AREA OF LOW CLOUDS OVER NORTHERN WI SPREAD INTO KSAW
OVERNIGHT. EXPECT THE LIFR CONDITIONS TO CONTINUE THROUGH MUCH OF
THE MORNING BEFORE MIXING BREAKS UP THE CLOUDS. WITH SOUTHWEST FLOW
CONTINUING TONIGHT...EXPECT LOW CLOUDS TO ONCE AGAIN REDEVELOP AND
PUSH INTO THE TAF SITES. UNCERTAIN ON COVERAGE AND NORTHWARD
EXTENT...SO HAVE ONLY WENT MVFR/IFR CIGS AT KSAW/KIWD. LLWS IS
EXPECTED AGAIN TONIGHT AHEAD OF AN APPROACHING SURFACE TROUGH ON
FRIDAY.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
611 AM EST THU NOV 24 2011
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(611 AM EST THU NOV 24 2011)
IFR AND LIFR CONDITIONS EXPECTED TO CONTINUE PAST 18Z AS STRATUS
DECK HAS MOVED IN AND WILL BE SLOW TO LEAVE. THE LAYER OF CLOUDS
WILL HAVE BASES FROM 200 TO 800 FEET AGL AND TOPS LOWER THAN 200
FEET AGL. WILL HAVE SOME CLEARING AFTER 18Z...BUT THIS IS
QUESTIONABLE GIVEN THE PERSISTENCE OF THESE CLOUDS YESTERDAY ACROSS
AREAS WEST OF LOWER MICHIGAN.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: OSTUNO
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
547 AM EST THU NOV 24 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
ACROSS THE CNTRL CONUS. A SHORTWAVE TROUGH OFFSHORE FROM THE PAC NW
WILL HELP AMPLIFY A PROGRESSIVE MID LEVEL TROUGH THAT WILL MOVE INTO
THE PLAINS TONIGHT AND TO THE WRN GREAT LAKES BY LATE SAT. AT THE
SFC...SSW FLOW PREVAILED OVER THE REGION BTWN LOW PRES INTO SRN
MANITOBA AND A RIDGE OVER THE OH AND LOWER MS VALLEY. 11-3.9 IR LOOP
INDICATED LOW CLOUDS ALONG THE WI BORDER FROM IWD TO IMT AND OVER
MUCH OF THE EAST HALF OF THE CWA. OTHERWISE...WAA HIGH CLOUDS WERE
SPREADING FROM NRN MN INTO WRN UPPER MI.
&&
.DISCUSSION...
TODAY AND TONIGHT...VERY MILD AIR HAS SPREAD OVER THE COLDER AIR NEAR THE
SURFACE CREATING A STRONG INVERSION AS 00Z KGRB SOUNDING SHOWED 925
MB TEMP AT 9C. MAX TEMPS WILL DEPEND ON HOW QUICKLY ANY MORNING
FOG/STRATUS BURNS OFF AND THE MIXING DEPTH. EVEN WITH LATE NOV SUN
ANGLE AND A VERY STABLE SFC-900 MB LAYER...EXPECT ENOUGH MIXING FOR
TEMPS ABOVE CONS GUIDANCE VALUES...CLIMBING INTO THE UPPER 40S TO
AROUND 50. AREAS WITH DOWNSLOPE SW WINDS COULD SEE READINGS INTO AT
LEAST THE MID 50S. SOUTHWEST WINDS WILL HELP KEEP MIN TEMPS WELL
ABOVE NORMAL TONIGHT WITH READINGS ONLY DROPPING INT0 THE UPPER 30S
TO AROUND 40.
FRIDAY...INCREASING CLOUDS WILL LIMIT POTENTIAL FOR HIGHER TEMPS BUT
WITH THE MILD AIRMASS IN PLACE TEMPS SHOULD STILL CLIMB INTO THE MID
AND UPPER 40S.
LATE FRIDAY NIGHT INTO SATURDAY...THE GFS/ECMWF WERE IN REASONABLE
AGREEMENT WITH THE PROGRESSIVE MID LEVEL TROUGH AND THE SFC LOW
DEVELOPING OVER THE PLAINS AND MOVING INTO TO NEAR IMT BY 18Z SAT.
STRONG MOISTURE INFLOW WITH PWAT VALUES TO 0.75 INCH AND 295K-300K
ISENTROPIC LIFT AHEAD OF THE LOW SUPPORT LIKELY RAIN CHANCES OVER THE
AREA...WITH THE HEAVIEST PCPN MAINLY IN THE MORNING. CAA IN THE WAKE
OF THE LOW ALONG WILL BRING A CHANGEOVER TO SNOW AND LAKE ENHANCED
SNOW LATE SAT NIGHT INTO SUN MORNING AS 850 MB TEMPS DROP TO AROUND
-8C.
MODEL DIFFERENCES EMERGE THAT IMPACT THE SNOWFALL POTENTIAL OVER WRN
UPPER MI. THE GFS CLOSES OFF A MID LEVEL LOW WHICH KEEPS THE DEEPER
MOISTURE AND LIFT ALONG WITH STRONGER CYCLONIC CIRCULATION INTO THE
WRN CWA. THE ECMWF AND CANADIAN GLOBAL GEM WITH A MORE PROGRESSIVE
MID LEVEL TROUGH WOULD BRING THE DRIER AIR IN FASTER WITH REDUCED
CHANCES FOR ACCUMULATING SNOW. UNTIL THE MODELS COME INTO BETTER
AGREEMENT A COMPROMISE WAS USED WHICH SUGGEST THE POTENTIAL FOR
SEVERAL INCHES OF SNOW OVER THE WEST. WITH ONLY MARGINALLY COLD AIR
INTO THE REGION...ANY ACCUMULATING SNOW WILL DIMINISH RAPIDLY AS THE
DEEPER MOISTURE AND WEAK LIFT MOVE OFF TO THE EAST SUNDAY.
MONDAY THROUGH WED...THE GFS...ECMWF AND MAJORITY OF ENSEMBLE
MEMBERS NOW SUGGEST THAT THE NRN STREAM WILL PREVAIL ACROSS THE NRN
LAKES AND THAT EITHER NO CUTOFF WILL DEVELOP TO THE SOUTH OR IT WILL
REMAIN FAR ENOUGH AWAY TO HAVE LITTLE IMPACT ON THE WEATHER OVER THE
REGION. SFC AND MID LEVEL RIDGING INTO THE AREA MON ALONG WITH
SIGNIFICANT WAA WILL KEEP THE AREA DRY WITH SW WINDS AND TEMPS
CLIMBING TO NEAR 40F. LOW CONFIDENCE BY TUE/WED BUT MODELS SUGGEST
POTENTIAL FOR A A COLD FROPA BEHIND A NRN STREAM SHRTWV COULD BRING
ENOUGH COLD AIR INTO THE AREA FOR SOME LAKE EFFECT SNOW.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOOKING AT IR SATELLITE IMAGERY...THE COMBINATION OF DOWNSLOPE SW
WINDS AOA 20 KTS WITHIN BOUNDARY LYR AND HIGHER DEWPOINT DEPRESSIONS
MAKES STRATUS/FOG DEVELOPMENT LESS LIKELY AT KIWD AND KCMX
OVERNIGHT. THUS HAVE DECIDED TO GO WITH CLEAR SKIES AND VFR
CONDITIONS AT KIWD AND KCMX. SLOW ADVANCE OF STRATUS/FOG FROM NRN WI
WILL LIKELY REACH INTO KSAW BY 08Z BUT MIXING FROM SW WINDS SHOULD
SCOUR OUT STRATUS/FOG WITHIN A FEW HRS AFTER SUNRISE. MAINTAINED
LLWS IN ALL SITES OVERNIGHT WITH STRONG WRLY WINDS JUST OFF THE
SFC.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
SOUTHWESTERLY WINDS WILL CONTINUE TODAY INTO TONIGHT...ALTHOUGH A
STRENGTHENING INVERSION WILL LIKELY KEEP WINDS FROM GUSTING OVER
30KTS. ON FRIDAY...A WEAK SFC TROUGH WILL STALL OVER LK SUPERIOR AND
DIMINISH THE WINDS BELOW 20KTS. A LOW IS THEN EXPECTED TO MOVE OUT
OF THE CENTRAL PLAINS AND FOLLOW THE TROUGH OVER EASTERN LAKE
SUPERIOR ON SATURDAY. AS THE LOW SHIFTS NORTHEAST ON SATURDAY
NIGHT...NORTH TO NORTHWEST GALE FORCE GUSTS TO 35KTS ARE POSSIBLE
OVER CENTRAL/EASTERN LAKE SUPERIOR. HIGH PRESSURE RIDGE WILL BUILD
OVER LAKE SUPERIOR ON SUNDAY NIGHT AND LEAD TO DECREASING
WINDS...BEFORE THEY PICK UP AGAIN OUT OF THE SOUTHWEST ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
400 AM EST THU NOV 24 2011
LATEST UPDATE...SYNOPSIS/SHORT AND LONG TERM/MARINE...
.SYNOPSIS...(400 AM EST THU NOV 24 2011)
THANKSGIVING DAY WILL SEE SOME CLOUDS MOVE IN WITH HIGHS IN THE
UPPER 40S. NO RAIN IS EXPECTED UNTIL THE WEEKEND WHEN A COLD FRONT
MOVES THROUGH. RAIN SHOWERS COULD MIX WITH WET SNOW BY SUNDAY NIGHT
AS COLDER AIR MOVES IN BEHIND THE COLD FRONT.
&&
.SHORT TERM...(400 AM EST THU NOV 24 2011)
(TODAY THROUGH SATURDAY)
FORECAST PROBLEMS IN THE NEAR TERM INCLUDE LOW CLOUDS AND POTENTIAL
IMPACT ON MAX TEMPS TODAY AND TIMING IN THE RAIN ON SATURDAY.
LOWERED MAXES FROM THE LOWER 50S TO UPPER 40S FOR TODAY AS SATELLITE
AND OBS SHOW AREA OF LOW STRATUS MOVING INTO THE WESTERN FORECAST
AREA ATTM. MAX TEMPS WERE HELD TO THE LOWER 40S ACROSS IOWA ON
WEDNESDAY AFTERNOON UNDER THESE CLOUDS.
00Z NAM RH PROFILES SHOW INVERSION SLOWLY LOWERING AND SUGGESTS
CLOUDS COULD BREAK UP THIS AFTERNOON...BUT LATEST RUC IS MORE
PESSIMISTIC AND WOULD MEAN A CLOUDY DAY AND MAXES PROBABLY HELD IN
THE MID 40S. STRATUS MAY HANG ON EVEN INTO TONIGHT AND POSSIBLE
FRIDAY MORNING BEFORE INCREASING WINDS AND MIXING SCOUR THEM OUT.
KEPT CHANCE POPS UP NORTH FOR FRIDAY NIGHT AS SOME ISENTROPIC ASCENT
AND MID LEVEL MOISTURE IS AVAILABLE. THE STEADIER RAIN SHOULD
HOLD OFF UNTIL AFTER 12Z SATURDAY AND POSSIBLY UNTIL 00Z SUNDAY IF
THE SLOWER EURO SOLUTION PANS OUT...AS DIGGING SHORTWAVE TROUGH
APPROACHES AND COUPLED JET ALONG WITH DEEP MOISTURE MOVES IN.
&&
.LONG TERM...(400 AM EST THU NOV 24 2011)
(SATURDAY NIGHT THROUGH WEDNESDAY)
THE MID RANGE MODELS CONTINUE TO SHOW DIFFERENCES IN THE LONG TERM.
THERE IS GOOD AGREEMENT ON THE SYSTEM SATURDAY NIGHT THROUGH SUNDAY
NIGHT. HOWEVER... CONFIDENCE IS LOWER FOR THE POTENTIAL
PRECIPITATION WITH A SYSTEM MONDAY NIGHT INTO WEDNESDAY. IN FACT...
THE ECMWF SHOWS THE WEATHER ASSOCIATED WITH A CUT OFF LOW SWEEPING
BY TO THE SOUTHEAST OF THE AREA. MEANWHILE... THE GFS HAS NO CUTOFF
LOW AND MOVES A WEAK CANADIAN WAVE BY TO THE NORTH. THEREFORE...
CONFIDENCE AND THE POPS ARE LOWER AFTER MONDAY AND SOME PERIODS HAVE
BEEN DRIED OUT. THE PRECIPITATION... IF IT OCCURS... COULD BE
RAIN... SNOW OR A RAIN/SNOW MIX.
TEMPERATURES WILL BE A LITTLE ABOVE NORMAL THROUGH THE WEEKEND. THEY
WILL BE AROUND NORMAL NEXT WEEK. NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 40 DEGREES AND NORMAL LOWS ARE IN THE UPPER 20S.
&&
.AVIATION...(1146 PM EST WED NOV 23 2011)
CERTAINLY A RISK FOR IFR OR LOWER CONDITIONS TONIGHT INTO THURSDAY.
LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE INVERSION LOCATED
ROUGHLY 2K FT OFF THE GROUND. ANY POCKETS OF CLEAR SKIES HAVE BEEN
FILLING IN WITH FOG AND STRATUS. IN ADDITION A LARGE AREA OF SUB
MVFR CLOUDS WILL ADVECT IN FROM THE SOUTHWEST BEGINNING AROUND 08Z.
IT IS BECOMING MORE LIKELY THAT THE LOW CLOUDS WILL PERSIST THROUGH
THE MORNING AND PERHAPS INTO THE AFTERNOON. EXTRA CAUTION IS
ADVISED FOR AVIATORS TONIGHT INTO THURSDAY GIVEN THIS SETUP.
ANOTHER RISK FOR LOW CLOUDS AND FOG EXISTS FOR THURSDAY NIGHT AS
WELL.
&&
.MARINE...(400 AM EST THU NOV 24 2011)
ISSUED A SMALL CRAFT ADVISORY FOR TODAY THROUGH FRIDAY NIGHT AS A
TIGHTENING PRESSURE GRADIENT WILL BRING WEST TO SOUTHWEST WINDS
GUSTING TO 25 KNOTS AND WAVES BUILDING ABOVE FOUR FEET.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY TODAY THROUGH FRIDAY NIGHT.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO
LONG TERM: 63
AVIATION: MJS
MARINE: OSTUNO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
119 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW
MOVING ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH
COUNTRY INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA
FOR MIDWEEK NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1241 PM EST THURSDAY...STRATUS DECK WILL HOLD TODAY GIVEN
STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING AND
AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO KEEP AFTN
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN THRU REMAINDER OF TODAY OR
TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE OVERCAST REMAIN
MUCH OF THE NIGHT. STRENGTHENING S-SW FLOW TOWARD DAYBREAK SHOULD
HELP TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE...BUT COULD
HOLD OFF UNTIL AFTER 12Z. WINDS OVERNIGHT REMAIN 5-10 MPH RANGE
WITH PREVAILING GRADIENT FLOW...ESPECIALLY IN THE WIDER VALLEY
LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE CHAMPLAIN AFTER
MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW TEMPERATURES MAINLY
IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR THE FAR NERN PORTIONS
OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA
EXPECTED TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS
OVER THE TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH
DAYS HIGHS NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW
DEGREES ABV NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING
OVERNGT THAT THE NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE
WSW. MDLS DO HINT AT THE POSSIBILITY OF INCR CLDS DURING THE DAY
SATURDAY FOR N ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY
ULTIMATELY INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF
CONCERN WILL BE GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET
NEAR CANADIAN BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF
MIXING OCCURS SO WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE
FAIRLY NICE 2-DAY STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR
RAIN SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE
LIFTING NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING
FROM THE GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO
OFFER SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE
PERIOD. GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD
FRONT MOVING SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD
RESULT IN SOME SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT
INTO MONDAY WITH GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS
SYSTEM THEN GETS PUSHED TO THE EAST BY SERIES OF POTENT NORTHERN
STREAM SHORTWAVES WHICH WOULD TRAVERSE THE REGION TUESDAY THROUGH
THURSDAY...ACCOMPANIED BY SCATTERED RAIN/SNOW SHOWERS. ECMWF
BRINGS INITIAL SHORTWAVE AND COLD FRONT ACROSS THE AREA BY
MONDAY. SOUTHERN STREAM SHORTWAVE THEN LIFTS NORTHEAST FROM THE
MISSISSIPPI VALLEY BRINGING POSSIBILITY OF MORE WIDESPREAD
RAINFALL FOR TUESDAY INTO WEDNESDAY. WITH SUCH A WIDE DISPARITY
BETWEEN THE MODELS...FORECASTER CONFIDENCE FOR MUCH OF THE
EXTENDED PERIOD IS RATHER LOW. BEST CHANCE FOR RAINFALL ON ALL OF
THE MODELS APPEARS TO BE SUNDAY NIGHT. FOR THE REST OF THE
PERIOD...HAVE GONE WITH FORECAST OF MAINLY CLOUDY WITH A CHANCE
OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH MONDAY...BUT SOME
SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER TERRAIN AS TEMPS
RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE CONTINUES TO
REMAIN OVER THE REGION THIS AFTERNOON WITH WIDESPREAD MVFR AND
LOCAL IFR CEILINGS. HIGH PRESSURE WILL CONTINUE TO BUILD
EAST...THOUGH DO NOT FORESEE MUCH CLEARING TILL AFTER SUNRISE
FRIDAY MORNING. WINDS WILL PICK UP AT THAT TIME AND SKIES WILL
FINALLY MIX OUT. SOUTH TO SOUTHWEST AT 5 TO 15 KTS WILL CONTINUE
THROUGH THE PERIOD.
OUTLOOK 12Z FRIDAY THROUGH TUESDAY...VFR CONDITIONS EXPECTED
THROUGH SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE
REGION. SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT
AND MONDAY AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA. VFR
CONDITIONS WILL RETURN FOR TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1245 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW MOVING
ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH COUNTRY
INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA FOR MIDWEEK
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1241 PM EST THURSDAY...STRATUS DECK WILL HOLD TODAY GIVEN
STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING AND
AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO KEEP AFTN
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN THRU REMAINDER OF TODAY OR
TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE OVERCAST REMAIN
MUCH OF THE NIGHT. STRENGTHENING S-SW FLOW TOWARD DAYBREAK SHOULD HELP
TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE...BUT COULD HOLD
OFF UNTIL AFTER 12Z. WINDS OVERNIGHT REMAIN 5-10 MPH RANGE WITH
PREVAILING GRADIENT FLOW...ESPECIALLY IN THE WIDER VALLEY
LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE CHAMPLAIN AFTER
MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW TEMPERATURES MAINLY
IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR THE FAR NERN PORTIONS
OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA EXPECTED
TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS OVER THE
TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH DAYS HIGHS
NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW DEGREES ABV
NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING OVERNGT THAT THE
NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE WSW. MDLS DO HINT AT
THE POSSIBILITY OF INCR CLDS DURING THE DAY SATURDAY FOR N
ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY ULTIMATELY
INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF CONCERN WILL BE
GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET NEAR CANADIAN
BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF MIXING OCCURS SO
WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE FAIRLY NICE 2-DAY
STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR RAIN
SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE LIFTING
NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING FROM THE
GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO OFFER
SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE PERIOD.
GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD FRONT MOVING
SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD RESULT IN SOME
SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT INTO MONDAY WITH
GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS SYSTEM THEN GETS PUSHED
TO THE EAST BY SERIES OF POTENT NORTHERN STREAM SHORTWAVES WHICH
WOULD TRAVERSE THE REGION TUESDAY THROUGH THURSDAY...ACCOMPANIED BY
SCATTERED RAIN/SNOW SHOWERS. ECMWF BRINGS INITIAL SHORTWAVE AND
COLD FRONT ACROSS THE AREA BY MONDAY. SOUTHERN STREAM SHORTWAVE
THEN LIFTS NORTHEAST FROM THE MISSISSIPPI VALLEY BRINGING
POSSIBILITY OF MORE WIDESPREAD RAINFALL FOR TUESDAY INTO WEDNESDAY.
WITH SUCH A WIDE DISPARITY BETWEEN THE MODELS...FORECASTER
CONFIDENCE FOR MUCH OF THE EXTENDED PERIOD IS RATHER LOW. BEST
CHANCE FOR RAINFALL ON ALL OF THE MODELS APPEARS TO BE SUNDAY
NIGHT. FOR THE REST OF THE PERIOD...HAVE GONE WITH FORECAST OF MAINLY
CLOUDY WITH A CHANCE OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH
MONDAY...BUT SOME SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER
TERRAIN AS TEMPS RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 12Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION THIS MORNING WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. SLOW IMPROVEMENT AS HIGH PRESSURE BUILDS EAST FROM THE
OHIO VALLEY. BY 16Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A
TREND TO VFR BY 19Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS
MAY PERSIST THROUGH THE PERIOD. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5 TO 15 KTS TODAY.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED THROUGH
SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE REGION.
SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT AND MONDAY
AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1243 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY STRETCH OF WEATHER THROUGH
SATURDAY ALONG WITH MODERATING TEMPERATURES. BY SUNDAY, A COLD
FRONT WILL BRING SCATTERED SHOWERS TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE. TOUCHY CLOUD FORECAST TODAY...WITH LOW LEVEL CLOUDS
IN WESTERN NY AND ALSO MOHAWK VALLEY AND PARTS OF THE
CATSKILLS...VERY POORLY RESOLVED BY THE MODELS. HIGH RES MODELS
HAVE STARTED TO CATCH UP...THOUGH RIC MODEL OVERCOMPENSATING.
BASED ON HR RR DEPICTION OF CLOUD COVER...I BRING MORE CLOUDS BACK
GENERALLY ALONG AND NORTH OF I-90 CORRIDOR THIS AFTERNOON AND
PARTS OF WESTERN FINGER LAKES REGION...WHERE INVERSION IS MORE
RETAINED. DRY POCKET WITH SUNSHINE IN BETWEEN...KEEPS THINGS MIXED
ENOUGH WITH DISSIPATION OF INVERSION...TO PREVENT CLOUDS FROM CREEPING
EASTWARD. TEMPERATURES ALSO ADJUSTED SLIGHTLY LOWER WHERE MORE
CLOUDS ARE NOW EXPECTED.
LOOKING INTO TONIGHT...EXPECTING CLOUDS TO CONTINUE TO BE STUCK
OVER PARTS OF WESTERN MOHAWK VALLEY. MODELS CURRENTLY NOT
SUGGESTING ENOUGH LOW LEVEL MOISTURE FOR CLOUDS OVER REMAINDER OF
AREA...THOUGH THIS WILL HAVE TO MONITORED SINCE THEY PERFORMED
POORLY UPSTREAM FOR LAST NIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRIDAY THROUGH SATURDAY...A BROAD UPPER LEVEL RIDGE WILL BUILD
OVER THE NORTHEAST AS AFC HIGH PRES IN THE MID ATLANTIC PROVIDES A
MODERATING SOUTHWEST FLOW. LATE FRIDAY NIGHT INTO SATURDAY, LOW
PRES OVER THE UPPER GREAT LAKES WITH WARM FRONT STRETCHING ACROSS
NEARBY SOUTHERN ONTARIO WILL PRODUCE MORE CLOUD COVER. ANY THREAT
OF PRECIP WILL REMAIN WELL NORTH OF REGION JUST SOME MID CLOUDS
DUE TO MID LEVEL WARMING BUT STILL PARTLY CLOUDY.
MAX TEMPS FRIDAY/SATURDAY WILL GENERALLY RANGE IN THE MID TO UPPER
50S WITH THE NORMALLY WARMER AREAS NEAR 60.
SATURDAY NIGHT...AN APPROACHING COLD FRONT FROM THE WESTERN LAKES
WILL BE IN THE VICINITY OF EXTREME WESTERN NEW YORK BY 12Z
SUNDAY. WILL CONTINUE WITH SLIGHT CHC POPS FOR RAIN SHOWERS LATE
SATURDAY NIGHT OVER THE FINGER LAKES REGION AND CENTRAL SOUTHERN
TIER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS PERSIST AT SYR AND RME AT 1230 PM WITH SKC ELSEWHERE.
XPCT THE SRN PERIPHERY OF THE MVFR CIGS TO FLIRT WITH SYR INTO THE
EARLY EVNG HRS...WITH MAINLY SKC AFTERWARDS. AT RME...MVFR CIGS
ARE XPCTD TO PERSIST INTO THE OVRNGT HRS...WITH PSBLTY OF IFR CIGS
LATER TNGT IN MOIST WRLY FLOW. OTRW XPCT SKC AT OTHER SITES. AT
ELM...POTNL FOR DENSE VLY FOG DOES NOT LOOK AS FVRBL DUE TO INCRSD
LOW LVL WINDS...BUT TD`S THERE ARE IN THE M30S AND WITH MIN TEMPS
FCST TO BE BLO THE CROSSOVER TEMP...WE COULD SEE SOME RESTRICTIONS
THERE. FOR NOW JUST INDICATED PTNL FOR MVFR VSBY`S LATE. MAINLY
SKC ON FRI...XCPT FOR SOME LINGERING MVFR AT RME INTO MID MRNG.
WINDS THIS AFTN BECMG MORE W TO SW 10-15 KTS WITH G20...SWLY 5-10
KTS TNGT AND SW 10-20 KTS ON FRI.
OUTLOOK...
FRI THROUGH SUN...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
MON NGT/TUE...PATCHY MVFR IN SCT -SHRA/-SHSN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...MDP
SHORT TERM...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1035 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY STRETCH OF WEATHER THROUGH
SATURDAY ALONG WITH MODERATING TEMPERATURES. BY SUNDAY, A COLD
FRONT WILL BRING SCATTERED SHOWERS TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE. TOUCHY CLOUD FORECAST TODAY...WITH LOW LEVEL CLOUDS
IN WESTERN NY AND ALSO MOHAWK VALLEY AND PARTS OF THE
CATSKILLS...VERY POORLY RESOLVED BY THE MODELS. HIGH RES MODELS
HAVE STARTED TO CATCH UP...THOUGH RIC MODEL OVERCOMPENSATING.
BASED ON HR RR DEPICTION OF CLOUD COVER...I BRING MORE CLOUDS BACK
GENERALLY ALONG AND NORTH OF I-90 CORRIDOR THIS AFTERNOON AND
PARTS OF WESTERN FINGER LAKES REGION...WHERE INVERSION IS MORE
RETAINED. DRY POCKET WITH SUNSHINE IN BETWEEN...KEEPS THINGS MIXED
ENOUGH WITH DISSIPATION OF INVERSION...TO PREVENT CLOUDS FROM CREEPING
EASTWARD. TEMPERATURES ALSO ADJUSTED SLIGHTLY LOWER WHERE MORE
CLOUDS ARE NOW EXPECTED.
LOOKING INTO TONIGHT...EXPECTING CLOUDS TO CONTINUE TO BE STUCK
OVER PARTS OF WESTERN MOHAWK VALLEY. MODELS CURRENTLY NOT
SUGGESTING ENOUGH LOW LEVEL MOISTURE FOR CLOUDS OVER REMAINDER OF
AREA...THOUGH THIS WILL HAVE TO MONITORED SINCE THEY PERFORMED
POORLY UPSTREAM FOR LAST NIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRIDAY THROUGH SATURDAY...A BROAD UPPER LEVEL RIDGE WILL BUILD
OVER THE NORTHEAST AS AFC HIGH PRES IN THE MID ATLANTIC PROVIDES A
MODERATING SOUTHWEST FLOW. LATE FRIDAY NIGHT INTO SATURDAY, LOW
PRES OVER THE UPPER GREAT LAKES WITH WARM FRONT STRETCHING ACROSS
NEARBY SOUTHERN ONTARIO WILL PRODUCE MORE CLOUD COVER. ANY THREAT
OF PRECIP WILL REMAIN WELL NORTH OF REGION JUST SOME MID CLOUDS
DUE TO MID LEVEL WARMING BUT STILL PARTLY CLOUDY.
MAX TEMPS FRIDAY/SATURDAY WILL GENERALLY RANGE IN THE MID TO UPPER
50S WITH THE NORMALLY WARMER AREAS NEAR 60.
SATURDAY NIGHT...AN APPROACHING COLD FRONT FROM THE WESTERN LAKES
WILL BE IN THE VICINITY OF EXTREME WESTERN NEW YORK BY 12Z
SUNDAY. WILL CONTINUE WITH SLIGHT CHC POPS FOR RAIN SHOWERS LATE
SATURDAY NIGHT OVER THE FINGER LAKES REGION AND CENTRAL SOUTHERN
TIER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
DENSE FOG AT ELM...AND PTCHY IFR/MVFR CIGS ELSEWHERE THIS MRNG.
DRY AIR UNDER HIPRES WILL HELP MIX OUT THE LL MOISTURE AND BRING
ALL CIGS AND VSBY TO VFR. MAINLY CLR CONDS TODAY IN TNGT UNDER THE
HI. SOME MVFR FOG PSBL AGAIN TNGT AT ELM...BUT STRONGER LL WINDS
SHD KEEP IFR CIGS AND VSBY FROM OCCURRING.
OUTLOOK...
THU THROUGH SAT...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MDP
SHORT TERM...RRM
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1020 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION TODAY...AND
REMAIN OVER THE NORTHEAST THROUGH THE UPCOMING WEEKEND. A FRONTAL
BOUNDARY APPROACHES THE AREA LATE SUNDAY INTO MONDAY. A LOW MOVING
ALONG THIS FRONT WILL KEEP PRECIPITATION OVER THE NORTH COUNTRY
INTO TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE AREA FOR MIDWEEK
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1009 AM EST THURSDAY...STRATUS DECK WILL LIKELY HOLD FIRM
TODAY GIVEN STRONG INVERSION 950-850MB LAYER PER 12Z ALB SOUNDING
AND AVAILABLE RUC FCST SOUNDINGS. THIS WILL LIKELY ALSO HOLD
TEMPERATURES SLIGHTLY BELOW MOS VALUES. WINDS WILL GRADUALLY
BECOME S-SW 5-10 MPH...MAINLY WEST OF THE GREEN MTNS...WITH WINDS
MORE LIGHT/VARIABLE EAST OF THE GREENS. COULD BE A BRIEF FLURRY OR
TWO...BUT SHALLOW NATURE OF CLOUD DECK AND BUILDING HEIGHTS ALOFT
WILL GENERALLY PRECLUDE ANY PCPN TODAY OR TONIGHT.
FOR TONIGHT...CLOUDS REMAIN TRICKY. LIKELY TO SEE A SLOWER
CLEARING TREND...BUT STRENGTHENING S-SW FLOW OVERNIGHT SHOULD HELP
TO EVENTUALLY ADVECT THE STRATUS AWAY FROM SW-NE. WINDS OVERNIGHT
REMAIN 5-10 MPH RANGE WITH PREVAILING GRADIENT FLOW...ESPECIALLY
IN THE WIDER VALLEY LOCATIONS. WINDS WILL APPROACH 20 KTS ON LAKE
CHAMPLAIN AFTER MIDNIGHT. CLOUDS AND WIND WILL HELP HOLD LOW
TEMPERATURES MAINLY IN THE 30S...EXCEPT LOCALLY LOW-MID 20S FOR
THE FAR NERN PORTIONS OF VERMONT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
AS OF 227 AM EST THURSDAY...HIGH PRESSURE SOUTH OF THE CWA ON
FRIDAY...PUSHING OFFSHORE DURING THE DAY SATURDAY. W/ CWA EXPECTED
TO BE UNDER WSW FLOW...WAA WILL BRING IN INCR HIGH TEMPS OVER THE
TWO-DAY PERIOD. W/ 850/925 TEMPS NEAR +4C TO +8C BOTH DAYS HIGHS
NEAR 50F ARE NOT OUT OF THE QUESTION. HAVE GONE A FEW DEGREES ABV
NORMALS/MDL GUIDANCE AS DO NOT SEE ENOUGH COOLING OVERNGT THAT THE
NUMBERS SHOW WITH CWA STILL UNDER WAA FROM THE WSW. MDLS DO HINT AT
THE POSSIBILITY OF INCR CLDS DURING THE DAY SATURDAY FOR N
ZONES/ST LAW VALLEY DUE TO WK WARM FRNT THAT MAY ULTIMATELY
INHIBIT SUNSHINE THERE. OTHER WX ISSUE TO BE OF CONCERN WILL BE
GUST POTENTIAL OVER N NY DUE TO MID LEVEL JET NEAR CANADIAN
BORDER. BUFKIT SUGGEST GUSTS TO NEAR 30 MPH IF MIXING OCCURS SO
WILL PUT IN MENTION...OTHERWISE...CWA WILL SEE FAIRLY NICE 2-DAY
STRETCH OF WX FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 405 AM EST THURSDAY...DRY CONDITIONS WILL CONTINUE SATURDAY
NIGHT INTO EARLY SUNDAY AS WE REMAIN UNDER INFLUENCE OF HIGH
PRESSURE...WHICH WILL BE MOVING FURTHER OFFSHORE. CHANCES FOR RAIN
SHOWERS INCREASE DURING THE DAY ON SUNDAY WITH LOW PRESSURE LIFTING
NORTH OF THE REGION AND ASSOCIATED COLD FRONT APPROACHING FROM THE
GREAT LAKES/OHIO VALLEY. BUT ECMWF AND GFS CONTINUE TO OFFER
SIGNIFICANTLY DIFFERENT SOLUTIONS FOR THE REMAINDER OF THE PERIOD.
GFS DEPICTING FULL LATITUDE TROUGH...WITH SURFACE COLD FRONT MOVING
SLOWLY ACROSS THE NORTHEAST. THIS SCENARIO WOULD RESULT IN SOME
SIGNIFICANT RAINFALL ACROSS THE AREA SUNDAY NIGHT INTO MONDAY WITH
GOOD FEED OF MOISTURE OFF THE ATLANTIC. THIS SYSTEM THEN GETS PUSHED
TO THE EAST BY SERIES OF POTENT NORTHERN STREAM SHORTWAVES WHICH
WOULD TRAVERSE THE REGION TUESDAY THROUGH THURSDAY...ACCOMPANIED BY
SCATTERED RAIN/SNOW SHOWERS. ECMWF BRINGS INITIAL SHORTWAVE AND
COLD FRONT ACROSS THE AREA BY MONDAY. SOUTHERN STREAM SHORTWAVE
THEN LIFTS NORTHEAST FROM THE MISSISSIPPI VALLEY BRINGING
POSSIBILITY OF MORE WIDESPREAD RAINFALL FOR TUESDAY INTO WEDNESDAY.
WITH SUCH A WIDE DISPARITY BETWEEN THE MODELS...FORECASTER
CONFIDENCE FOR MUCH OF THE EXTENDED PERIOD IS RATHER LOW. BEST
CHANCE FOR RAINFALL ON ALL OF THE MODELS APPEARS TO BE SUNDAY
NIGHT. FOR THE REST OF THE PERIOD...HAVE GONE WITH FORECAST OF MAINLY
CLOUDY WITH A CHANCE OF SHOWERS. PRECIPITATION TYPE RAIN THROUGH
MONDAY...BUT SOME SNOW SHOWERS POSSIBLE THEREAFTER OVER THE HIGHER
TERRAIN AS TEMPS RETURN TO MORE SEASONABLE LEVELS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION THIS MORNING WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. SLOW IMPROVEMENT AS HIGH PRESSURE BUILDS EAST FROM THE
OHIO VALLEY. BY 16Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A
TREND TO VFR BY 19Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS
MAY PERSIST THROUGH THE PERIOD. LIGHT AND VARIABLE WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5 TO 15 KTS TODAY.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED THROUGH
SUNDAY AS A RIDGE OF HIGH PRESSURE PASSES SOUTH OF THE REGION.
SHOWERS WITH MVFR/IFR CONDITIONS EXPECTED SUNDAY NIGHT AND MONDAY
AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE AREA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...BANACOS
SHORT TERM...JN
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1244 AM EST THU NOV 24 2011
.SYNOPSIS...
LOW LEVEL MOISTURE BEHIND DEPARTED FRONT...CAUSES ONLY GRADUAL
BREAKUP OF CLOUDS TONIGHT...AND AREAS OF FOG WHERE IT DOES CLEAR.
DRY HIGH PRESSURE AND WARMING TEMPERATURES THANKSGIVING DAY RIGHT
INTO THE WEEKEND. WET SYSTEM BY EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
930 PM UPDATE...BACK EDGE OF THE CLEARING SKIES IS MAKING GOOD
PROGRESS EAST...NOW INTO STEUBEN AND YATES COUNTIES. THIS LINE
WILL CONTINUE TO MAKE PROGRESS EAST THROUGH THE NEXT FEW
HOURS...REACHING THE SYRACUSE AREA BY MIDNIGHT. FARTHER SOUTH AND
EAST WHILE THE SKY IS STILL EXPECTED TO CLEAR...MOISTURE FROM THE
FINGER LAKES AND THE UPSLOPE FLOW (NORTHWEST WIND) MAY KEEP SKIES
CLOUDY A BIT LONGER. STILL EXPECT EVERYONE TO CLEAR OUT...AT LEAST
CLOUD WISE...BY 10Z. BASED ON THE OBS ACROSS STEUBEN COUNTY WITH
HORNELL DOWN TO 1/4SM IN FOG...EXPECT AREAS OF FOG TO FORM
OVERNIGHT AND IT COULD BE QUITE DENSE GIVEN OUR RECENT RAINFALL.
WILL CONTINUE TO HIGHLIGHT AREAS OF FOG IN THE GRIDS.
ONE MORE THING TO ADD....WITH THE RUC SHOWING THE CORE OF COLD AIR
OVER THE FINGER LAKES NOW (-3C) AND A WIND OUT OF THE
NORTHWEST...KBGM IN CLEAR AIR MODE IS SHOWING SOME LIGHT ECHOES
DOWNWIND OF CAYUGA AND OWASCO LAKES (LAKE EFFECT FLURRIES). THROUGH
MIDNIGHT SOME SCT. FLURRIES ARE POSSIBLE...MAINLY ACROSS THE
HIGHER TERRAIN...ACROSS
TOMPKINS...CORTLAND...TIOGA...BROOME...BRADFORD...SUSQUEHANNA...AND
WAYNE COUNTIES.
AT 3 PM...FRONT IS WELL EAST OF THE AREA...BUT UPPER TROUGH
AXIS IS STILL FINISHING ITS TREK THROUGH THE AREA...AS CLEARLY
MARKED VIA MOISTURE SPOKE ON THE WATER VAPOR IMAGERY LOOP. UPPER
TROUGH AXIS AND WEAKENING MID LEVEL DEFORMATION ARE PAIRED UP OVER
THE EASTERN HALF OF THE AREA...YET DEEPER MOISTURE IS ALREADY WELL
TO OUR EAST. SO WITH SHALLOW SATURATED LAYER...ONLY DIMINISHING
LIGHT SHOWERS AND PATCHY DRIZZLE EARLY THIS EVENING. OUR HIGH
TEMPS OCCURRED EARLY TODAY...YET BECAUSE TEMPERATURE WITHIN THE
SHALLOW SATURATED LAYER STAYS ABOVE MINUS-5 DEGREES CELSIUS...NOT
SEEING ANY OPPORTUNITY FOR CRYSTAL FORMATION. THUS WITH ANY
SHOWERS THAT ARE LEFT...VERY LITTLE IF ANY MIX WITH SNOW EVEN AT
HIGHER ELEVATIONS...AND CERTAINLY NO ACCUMULATION.
TONIGHT...925MB RH FIELDS SUGGEST THAT DESPITE DRY OVERALL
AIR MASS...LOW LEVEL MOISTURE FROM LAKE ONTARIO...AND IN
GENERAL...GETS TRAPPED UNDER DEVELOPING INVERSION AS WARM AIR
ADVECTION ALREADY BEGINS ALOFT OVERNIGHT. THE WET GROUND FROM 1-2
INCHES OF PRIOR RAINFALL ALSO WILL AID IN MOIST LOW LEVELS.
THUS...LOW CLOUDS WILL BE VERY STUBBORN TO BREAK...AND SKY GRIDS
HAVE BEEN ADJUSTED ACCORDINGLY. THOSE AREAS THAT DO CLEAR COULD
HAVE AREAS OF FOG FORM BECAUSE OF THE WET GROUND...WITH WET GROUND
AND WEAKENING/DECOUPLING WINDS. AREAS WEST OF I-81 HAVE THE BEST
CHANCE FOR FOG FORMATION. WE WILL HAVE TO MONITOR FOR PROSPECTS OF
FREEZING FOG EARLY IN THE MORNING IF IT MANAGES TO GET LOCALLY
DENSE. WITH AMOUNT OF LOW LEVEL MOISTURE...I EXPECT LOW
TEMPERATURES TONIGHT TO BE SLIGHTLY ABOVE MODEL GUIDANCE NUMBERS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
HIGH PRESSURE RIDGE AT SURFACE AND ALOFT TAKES OVER FOR
THANKSGIVING AND FRIDAY. IN ADDITION TO ABUNDANT SUNSHINE...THE
SOUTHWEST SURFACE FLOW AROUND THE HIGH CENTERED TO OUR SOUTH...AND
RISING THICKNESSES...ALL HELP YIELD WARMING
TEMPERATURES...ESPECIALLY FRIDAY AND SATURDAY WITH HIGHS ABOUT 15
TO 20 DEGREES ABOVE NORMAL. ONLY FLY IN THE OINTMENT IS THAT
MOISTURE WILL STILL BE COMING OFF OF LAKE ONTARIO INITIALLY
THURSDAY...WHICH MAY MEAN SOME CLOUD COVER IN ONEIDA COUNTY...YET
STILL TEMPERATURES WILL BE IN A WARMING TREND THERE.
A NORTHERN STREAM FRONTAL BOUNDARY WILL ATTEMPT TO SAG SOUTH
FRIDAY NIGHT TO SATURDAY MORNING...BUT AT THIS TIME I AGREE WITH
NAM/GFS IN NOT BRINGING IT CLOSE ENOUGH TO IMPACT OUR WEATHER
OTHER THAN PERHAPS A FEW EXTRA CLOUDS IN THE NORTHERN ZONES.
HOWEVER CLOSE THAT FRONT APPROACHES...IT WILL SURGE BACK NORTHWARD
SATURDAY WITH INCREASING SOUTHWESTERLY FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS IN THE MEDIUM RNG IS THE AMPLIFYING TROF WHICH IS
FORECAST TO MOV INTO THE CNTRL AND THE ERN U.S. EARLY NXT WEEK.
THERE ARE SIG DIFFS IN THE MDLS W/RESPECT TO TIMING...PCPN
AMTS...AND NRN/SRN STREAM INTERACTION. GFS PAINTS A POTNL FLOOD
SCENARIO WITH SRN PORTION OF THE TROF CUTTING OFF THEN LIFTING
NEWD...WITH +RA ACRS THE FSCT AREA SUN NGT INTO MONDAY ALONG AN
INVERTED TROF. THE EURO SHOWS LESS INTERACTION BETWEEN NRN AND SRN
STREAMS...BUT STILL SHOWS RAIN WORKING NWD INTO THE RGN LATE MON
NGT INTO TUE...BUT THE HEAVIEST PCPN IS SHUNTED OFF TO OUR
SOUTHEAST. GIVEN THESE DIFFS...WE LEANED HEAVILY ON HPC GUIDANCE
FOR THE MEDIUM RNG..WHICH PAINTS AN UNSETTLED PICTURE INTO
MIDWEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SOME GRADUAL CLRG ATTM BUT WITH PLENTY OF LL MOISTURE STILL
ARND...PTCHY IFR CIGS AND VSBYS PSBL THRU THE NGT. ON THU...DRIER
AIR ALOFT WILL HELP MIX OUT THE MOISTURE AND RETURN ALL STATIONS
TO VFR. VFR CONDS SHD REMAIN THRU THE END OF THE PD WITH THE DRY
AIR.
OUTLOOK...
THU THROUGH SAT...VFR.
SUN NGT/MON...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MDP
LONG TERM...
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1230 AM EST THU NOV 24 2011
.SYNOPSIS...
LOW PRESSURE IS EXITING EASTWARD THROUGH THE GULF OF MAINE. IN
THE WAKE OF THE LOW PRESSURE SYSTEM...A RIDGE OF HIGH PRESSURE
WILL BUILD EASTWARD ACROSS THE NORTH COUNTRY BRINGING DRY WEATHER
FOR THANKSGIVING AND RIGHT THROUGH THE UPCOMING WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL FOR THANKSGIVING WITH HIGHS IN
THE UPPER 30S...THEN MODERATING TO ABOVE AVERAGE READINGS FOR
FRIDAY THROUGH NEXT MONDAY. THE NEXT CHANCE FOR PRECIPITATION
WILL BE LATE SUNDAY INTO MONDAY AS A FRONTAL BOUNDARY APPROACHES
THE AREA FROM THE WEST.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
AS OF 1212 AM EST THURSDAY...NO CHANGES PLANNED TO GOING FORECAST
ATTM. LL CLD COVER REMAINS INTACT OVER THE NORTH COUNTRY...WITH NO
REAL SIGNS OF ANY SCOURING OUT TAKING PLACE. SO WILL KEEP CWA
CLOUDY. TEMPS SLOWLY DROPPING DESPITE CLDY SKIES...AIDED THOUGH BY
WK NORTHERLY FLOW. TRENDS LOOK GD.
PREVIOUS DISCUSSION...MADE SOME MINOR ADDITIONAL ADJUSTMENTS
TO SKY COVER THROUGH TOMORROW AFTERNOON BASED OFF CURRENT
OBSERVATIONS AND LATEST NEAR-TERM MODEL DATA. RUC13 275K
ISENTROPIC PROGS SEEM TO CAPTURE CURRENT SITUATION NICELY INTO THE
OVERNIGHT HOURS...WITH CLOUDS ESSENTIALLY HANGING TOUGH...ESP THE
NORTHWESTERN HALF OF THE FORECAST AREA DESPITE LOW PRESSURE
PULLING WELL EAST INTO THE MARITIMES. AS FLOW ALOFT TRENDS
WESTERLY LATER TONIGHT...SOME CLEARING LIKELY IN THE CT RIVER
VALLEY...AND POSSIBLY INTO THE SLV. ELSEWHERE GENERALLY MOSTLY
CLOUDY TO CLOUDY. THIS WILL TEMPER OVERNIGHT LOWS ABOVE 12/18Z MOS
GUIDANCE...WITH VALUES GENERALLY BOTTOMING OUT IN THE 20S...THOUGH
LOCALLY TEENS IN THE NRN CT RVR VALLEY FROM ORANGE COUNTY
NORTHWARD. OUTSIDE A STRAY FLURRY...NO ADDITIONAL PCPN EXPECTED
OVERNIGHT AS NORTHERLY WINDS TREND LIGHT.
FOR THANKSGIVING DAY...A DRY FORECAST WITH RISING HEIGHTS ALOFT.
AS MENTIONED ABOVE I`VE MADE SOME ADDITIONAL CHANGES TO SKY
COVER...KEEPING MAINLY CLOUDY SKIES ACROSS OUR CENTRAL/NRN
COUNTIES...AND OFFERING PTLY SUNNY CONDS SOUTH. AIR MASS IS
SLOWLY MODERATING...BUT GENERALLY EXPECTING HIGHS FROM THE MID 30S
ACROSS ERN VT TO THE UPR 30S IN THE CHAMPLAIN VALLEY. WARMEST
TEMPS EXPECTED IN THE ST. LAWRENCE VALLEY /LOW TO MID 40S/. SNOW
COVER WILL HELP HOLD DOWN TEMPS SOMEWHAT FROM THE ADIRONDACKS EWD
ACROSS VT. WINDS WILL START LIGHT...THEN BECOMING S-SW AT 5-10 MPH
IN THE AFTN.
&&
.SHORT TERM /11 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 247 PM EST WEDNESDAY...A QUIET PERIOD OF WEATHER EXPECTED
FOR THE SHORT-TERM PERIOD WITH NIL POPS. SFC RIDGE AXIS SHIFTS
SOUTH OF NEW ENGLAND ALLOWING FOR A STRONGER WSWLY GRADIENT FLOW
TO DEVELOP OVER THE NORTH COUNTRY. WINDS ON FRIDAY COULD BECOME
LOCALLY BREEZY...GENERALLY SOUTHWEST 15-25 MPH. THERE WILL ALSO
BE MODERATING TEMPERATURES DURING THE PERIOD. LOWS THURSDAY NIGHT
WILL GENERALLY BE 25-30F...THOUGH LOCALLY COLDER READINGS ARE
POSSIBLE IN FAR NERN VT. WITH 850MB THERMAL RIDGE AXIS IN
PLACE...HIGHS BOUNCE BACK TO THE UPR 40S ON FRIDAY AND A FEW LOW
50S ACROSS NRN NY. THIS WILL ALLOW FOR SOME MELTING OF RECENT
SNOWFALL. THERE MAY BE A TENDENCY FOR A FRONTAL BOUNDARY TO
DEVELOP ALONG THE INTL BORDER FRIDAY INTO FRIDAY NIGHT. CLOUD
FORECAST IS GENERALLY PARTLY TO MOSTLY CLOUDY...WITH THE GREATER
CLOUD AMTS ACROSS NRN AREAS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 330 PM EST WEDNESDAY...HIGH PRESSURE IS EXPECTED TO
CONTINUE FROM SATURDAY THROUGH EARLY SUNDAY...WITH DRY WEATHER
AND ABOVE-NORMAL TEMPERATURES. EUROPEAN AND GFS CONTINUE TO
DISAGREE WITH RESPECTS TO THE SUNDAY THROUGH WEDNESDAY TIME
PERIOD. BOTH MODELS SHOW A LOW PRESSURE SYSTEM LIFTING NORTH OF
THE REGION ON SUNDAY...WITH BULK OF PRECIPITATION SUNDAY
NIGHT....MAINLY RAIN SHOWERS IN THE VALLEYS WITH SOME SNOW MIXING
IN THE HIGHER ELEVATIONS. MODELS DIVERGE GREATLY AFTER SUNDAY
NIGHT...WITH THE GFS KEEPING AFOREMENTIONED FRONT AROUND THROUGH
TUESDAY AND LIFTING A CUT OFF LOW ACROSS THE REGION. ECMWF DOES
NOT HAVE THIS FEATURE AT ALL. THEREFORE...CAN NOT PUT MUCH WEIGHT
BEHIND EITHER OF THESE MODELS. WOULD LIKE TO SEE MODELS COME INTO
BETTER AGREEMENT WITH RESPECT TO THE EXTENDED. AT THIS TIME BEST
CHANCE FOR PRECIP IN THE EXTENDED LOOKS TO BE SUNDAY INTO SUNDAY
NIGHT.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THROUGH 06Z FRIDAY...ABUNDANT LOW-LEVEL MOISTURE WILL REMAIN OVER
THE REGION INTO THURSDAY WITH WIDESPREAD MVFR AND LOCAL IFR
CEILINGS. BY 13Z ALL TAF SITES EXPECTED TO BE MVFR...WITH A TREND
TO VFR BY 18Z. EXCEPTIONS WILL BE KSLK/KMSS WHERE MVFR CIGS MAY
PERSIST THROUGH THE PERIOD. LIGHT NORTH WINDS OVERNIGHT WILL
BECOME SOUTH TO SOUTHWEST ON THURSDAY AS HIGH PRESSURE PASSES
WELL SOUTH OF THE AREA.
OUTLOOK 06Z FRIDAY THROUGH MONDAY...VFR CONDITIONS EXPECTED
THROUGH SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE
REGION. SHOWERS WITH MVFR CONDITIONS EXPECTED SUNDAY NIGHT AND
MONDAY AS A FRONTAL SYSTEM MOVES SLOWLY ACROSS THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...JMG/JN
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1226 PM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE RIDGE WILL KEEP LOW CLOUDS AND COOL AIR LOCKED IN
PLACE OVER MUCH OF THE REGION TODAY AND TONIGHT. THE RIDGE WILL
SLIDE EASTWARD AND BRING SOUTHERLY FLOW AND A WARMING TREND FOR
FRIDAY AND SATURDAY. BY SATURDAY NIGHT...AN APPROACHING COLD FRONT
WILL INCREASE CLOUD COVER AND CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A DIFFICULT CLOUD AND TEMPERATURE FORECAST FOR THIS
AFTERNOON.
VISIBLE SATELLITE IMAGERY CONTINUED TO SHOW AN EXPANSIVE AREA OF
STRATUS ACRS THE FORECAST AREA. THE EXCEPTION WAS OVER NE OHIO AND
TO OUR SOUTHEAST OVER EASTERN KENTUCKY AND WESTERN WEST VIRGINIA
WHERE STRATUS WAS ERODING AWAY AT THE STRATUS/CLEAR SKY INTERFACE.
THE RUC MODEL HAS BEEN HANDLING THE LOW LEVEL MOISTURE THE BEST.
HOWEVER...NO MODEL IS GOING TO CAPTURE THE AMOUNT OF ERODING THAT
MAY OCCUR TO OUR EAST/SOUTHEAST THIS AFTERNOON. BASED ON EROSION
TRENDS...HAVE ALLOWED SKIES TO BECOME PARTLY CLOUDY/MOSTLY SUNNY
IN OUR SOUTHEASTERN/SOUTHERN AREAS. WE SHOULD KNOW BY 3 TO 4 PM
HOW FAR EROSION TAKES PLACE AND HOW THIS WILL AFFECT TONIGHTS SKY
CONDITION AND OVERNIGHT LOWS. HAVE RAISED TEMPS SLIGHTLY SE/S TO
AROUND 50 WITH MORE INSOLATION POSSIBLE. OTHERWISE...THE MAJORITY
OF THE REGION WILL HAVE HIGHS IN THE MID 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD TOWARD THE MID
ATLANTIC TONIGHT. BIGGEST DILEMMA OVERNIGHT WILL BE SKY CONDITION
AND OVERNIGHT LOWS. NAM-WRF AND GFS HAVE NOT HANDLED THE CURRENT
LOW LEVEL STRATUS AND THUS DO NOT HAVE FULL CONFIDENCE IN ITS
RH/MODEL SOUNDING SOLUTIONS WHERE INDICATE A CLEARING TREND FROM
SOUTH TO NORTH OVERNIGHT. THAT BEING SAID...CURRENT THINKING IS
THAT WHERE CLOUDS STAY SOCKED IN THROUGH THE DAY...THEY WILL
LIKELY REMAIN SO OVERNIGHT. HOWEVER...IT IS STILL POSSIBLE THAT
SOME DRIER AIR MAY PUSH NORTHWARD IN THE BOUNDARY LAYER. THUS...IT
IS A VERY DIFFICULT FORECAST TO PINPOINT CLOUDY TO CLEAR AND
WHETHER AREAS THAT CLEAR MAY SEE VERY LOW STRATUS FORM AGAIN.
ATTM...HAVE KEPT WEST CENTRAL OHIO...THE WHITEWATER/MIAMI VALLEYS
AND MUCH OF CENTRAL OHIO CLOUDY WHILE LEAVING SRN/SERN LOCATIONS
IN THE PARTLY CLOUDY/MOSTLY CLEAR REGIME. OVERNIGHT LOWS WILL BE
CLOUD DEPENDENT...THUS THEY SHOULD BE WARMEST ACRS THE NW WHERE
CLOUDS/WINDS WILL KEEP TEMPS FROM FALLING TOO MUCH.
FRIDAY THROUGH FRIDAY NIGHT...SOUTHERLY FLOW WILL BRING WARMER
TEMPERATURES ACROSS OUR AREA. CLOUDS ON FRIDAY SHOULD ERODE
AWAY..LEAVING MOSTLY SUNNY SKIES BY FRIDAY AFTERNOON. SUNSHINE AND
SOUTHERLY FLOW THIS WILL BRING MAXIMUM TEMPERATURES ON FRIDAY AND
FRIDAY NIGHT TO ABOVE NORMAL VALUES.
THE SOUTHERLY FLOW WILL SHIFT SOUTHWESTERLY AND INCREASE AS A LOW
PRESSURE SYSTEM DEVELOPS AND MOVES EASTWARD ACROSS THE NORTHERN
PLAINS...AND A COLD FRONT APPROACHES OUR AREA. CLOUD COVER WILL
INCREASE AHEAD OF THIS SYSTEM BY SATURDAY AFTERNOON. SINCE THE
FORECAST AREA WILL STILL BE IN THE WARM SECTOR OF THE SYSTEM
DURING THE DAY SATURDAY...TEMPERATURES WILL BE WELL ABOVE NORMAL.
THE COLD FRONT WILL BRING WITH IT AMPLE MOISTURE AND GOOD
CHANCES FOR PRECIPITATION BY SATURDAY EVENING TO THE OHIO VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND SUNDAY AS THE
FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST AS IT
APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
A RIDGE OF HIGH PRESSURE STRETCHED FROM CENTRAL PENNSYLVANIA
SOUTHWEST INTO THE DEEP SOUTH THIS AFTERNOON. THE HIGH WILL MOVE
SLOWLY SOUTHEAST THROUGH THE TAF PERIOD.
CIGS AND VSBYS CONTINUE TO BE A CONCERN. VISIBLE SATELLITE IMAGERY
DEPICTED AN EXPANSIVE AREA OF LOW CLOUDS FROM EASTERN TEXAS
NORTHEAST INTO THE GREAT LAKES. EROSION OF THE LOW CLOUDS...DUE TO
DAYTIME HEATING AT THE STRATUS/CLEAR SKY INTERFACE...WAS
OCCURRING OVER NE OHIO AND ACROSS SE OHIO...EASTERN KENTUCKY AND
WESTERN WEST VIRGINIA. MODELS ARE NOT CAPTURING THIS MOISTURE VERY
WELL AND HENCE FORECASTS OF SKIES GOING CLEAR OR GOING BACK TO
CLOUDY ARE NOT OF THE HIGHEST CONFIDENCE. EROSION OF THE LOW
CLOUDS WILL LIKELY CREEP TOWARD THE KCVG/KLUK TAFS AND THE
KCMH/KLCK TAFS...BUT WHETHER THEY MAKE IT BEFORE THE SUN SETS
REMAINS TO BE SEEN. ATTM...HAVE DECIDED TO KEEP CIGS IN FOR ALL
TAF SITES AND TO BRIEFLY ALLOW THEM TO RISE TO MVFR CIGS AND VFR
VSBYS. FOR TONIGHT...RUC MODEL INDICATES THAT WHERE CLOUDS HAVE
ERODED...LOW LEVEL STRATUS MAY FORM AGAIN. HAVE ALLOWED CIGS TO
DROP INTO THE LIFR CATEGORY WITH VSBYS IN THE MVFR CATEGORY. SOME
MODELS INDICATE THAT RELATIVELY DRIER AIR MAY TRY TO CREEP NORTH
OVERNIGHT. WHETHER THIS MATERIALIZES INTO CLEAR SKIES IS VERY
UNCERTAIN AT THIS POINT. CURRENT THINKING IS THAT ON FRIDAY WITH
AN INCREASING LOW LEVEL FLOW AND DAYTIME HEATING...ANY RESIDUAL LOW
CLOUDS WILL FINALLY ERODE AWAY COMPLETELY...ALLOWING TAF SITES TO
RETURN TO VFR CONDITIONS.
OUTLOOK...MVFR/IFR CIGS/VSBYS POSSIBLE SATURDAY NIGHT INTO MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN/LATTO
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1146 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE RIDGE WILL KEEP LOW CLOUDS AND COOL AIR LOCKED IN
PLACE OVER MUCH OF THE REGION TODAY AND TONIGHT. THE RIDGE WILL
SLIDE EASTWARD AND BRING SOUTHERLY FLOW AND A WARMING TREND FOR
FRIDAY AND SATURDAY. BY SATURDAY NIGHT...AN APPROACHING COLD FRONT
WILL INCREASE CLOUD COVER AND CHANCES FOR PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A DIFFICULT CLOUD AND TEMPERATURE FORECAST FOR THIS
AFTERNOON.
VISIBLE SATELLITE IMAGERY CONTINUED TO SHOW AN EXPANSIVE AREA OF
STRATUS ACRS THE FORECAST AREA. THE EXCEPTION WAS OVER NE OHIO AND
TO OUR SOUTHEAST OVER EASTERN KENTUCKY AND WESTERN WEST VIRGINIA
WHERE STRATUS WAS ERODING AWAY AT THE STRATUS/CLEAR SKY INTERFACE.
THE RUC MODEL HAS BEEN HANDLING THE LOW LEVEL MOISTURE THE BEST.
HOWEVER...NO MODEL IS GOING TO CAPTURE THE AMOUNT OF ERODING THAT
MAY OCCUR TO OUR EAST/SOUTHEAST THIS AFTERNOON. BASED ON EROSION
TRENDS...HAVE ALLOWED SKIES TO BECOME PARTLY CLOUDY/MOSTLY SUNNY
IN OUR SOUTHEASTERN/SOUTHERN AREAS. WE SHOULD KNOW BY 3 TO 4 PM
HOW FAR EROSION TAKES PLACE AND HOW THIS WILL AFFECT TONIGHTS SKY
CONDITION AND OVERNIGHT LOWS. HAVE RAISED TEMPS SLIGHTLY SE/S TO
AROUND 50 WITH MORE INSOLATION POSSIBLE. OTHERWISE...THE MAJORITY
OF THE REGION WILL HAVE HIGHS IN THE MID 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD TOWARD THE MID
ATLANTIC TONIGHT. BIGGEST DILEMMA OVERNIGHT WILL BE SKY CONDITION
AND OVERNIGHT LOWS. NAM-WRF AND GFS HAVE NOT HANDLED THE CURRENT
LOW LEVEL STRATUS AND THUS DO NOT HAVE FULL CONFIDENCE IN ITS
RH/MODEL SOUNDING SOLUTIONS WHERE INDICATE A CLEARING TREND FROM
SOUTH TO NORTH OVERNIGHT. THAT BEING SAID...CURRENT THINKING IS
THAT WHERE CLOUDS STAY SOCKED IN THROUGH THE DAY...THEY WILL
LIKELY REMAIN SO OVERNIGHT. HOWEVER...IT IS STILL POSSIBLE THAT
SOME DRIER AIR MAY PUSH NORTHWARD IN THE BOUNDARY LAYER. THUS...IT
IS A VERY DIFFICULT FORECAST TO PINPOINT CLOUDY TO CLEAR AND
WHETHER AREAS THAT CLEAR MAY SEE VERY LOW STRATUS FORM AGAIN.
ATTM...HAVE KEPT WEST CENTRAL OHIO...THE WHITEWATER/MIAMI VALLEYS
AND MUCH OF CENTRAL OHIO CLOUDY WHILE LEAVING SRN/SERN LOCATIONS
IN THE PARTLY CLOUDY/MOSTLY CLEAR REGIME. OVERNIGHT LOWS WILL BE
CLOUD DEPENDENT...THUS THEY SHOULD BE WARMEST ACRS THE NW WHERE
CLOUDS/WINDS WILL KEEP TEMPS FROM FALLING TOO MUCH.
FRIDAY THROUGH FRIDAY NIGHT...SOUTHERLY FLOW WILL BRING WARMER
TEMPERATURES ACROSS OUR AREA. CLOUDS ON FRIDAY SHOULD ERODE
AWAY..LEAVING MOSTLY SUNNY SKIES BY FRIDAY AFTERNOON. SUNSHINE AND
SOUTHERLY FLOW THIS WILL BRING MAXIMUM TEMPERATURES ON FRIDAY AND
FRIDAY NIGHT TO ABOVE NORMAL VALUES.
THE SOUTHERLY FLOW WILL SHIFT SOUTHWESTERLY AND INCREASE AS A LOW
PRESSURE SYSTEM DEVELOPS AND MOVES EASTWARD ACROSS THE NORTHERN
PLAINS...AND A COLD FRONT APPROACHES OUR AREA. CLOUD COVER WILL
INCREASE AHEAD OF THIS SYSTEM BY SATURDAY AFTERNOON. SINCE THE
FORECAST AREA WILL STILL BE IN THE WARM SECTOR OF THE SYSTEM
DURING THE DAY SATURDAY...TEMPERATURES WILL BE WELL ABOVE NORMAL.
THE COLD FRONT WILL BRING WITH IT AMPLE MOISTURE AND GOOD
CHANCES FOR PRECIPITATION BY SATURDAY EVENING TO THE OHIO VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND SUNDAY AS THE
FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST AS IT
APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE IS CENTERED OVER THE MID OHIO VALLEY THIS MORNING
WITH A SOLID IFR STRATUS DECK IN PLACE BELOW IT. THIS STRATUS HUNG
IN THROUGH THE DAY BACK TO OUR WEST ON WEDNESDAY...SO WOULD NOT
BE SURPRISED IF IT HOLDS ON THROUGH MUCH OF THE DAY TODAY. CIGS
MAY BRIEFLY GO TO LOW MVFR. HOWEVER...WITH MOISTURE IN PLACE
OVERNIGHT...THEY MAY VERY WELL DROP TO LIFR OR LOWER. HAVE SLOWED
DOWN ANY ONSET OF CLEARING FOR TODAY AND TONIGHT.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN/LATTO
LONG TERM...CONIGLIO
AVIATION...HICKMAN/JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
640 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO THE FORECAST. LATEST IR SAT SHOWING
STRATUS CLOUDS ACROSS MUCH OF THE FORECAST AREA THIS MORNING. SOME
PEAKS OF SUN MAY BE POSSIBLE ACROSS A FEW LOCATIONS...BUT ANY
CLEAR SPOTS ARE FILLING IN SO WILL CONTINUE WITH A MOSTLY CLOUDY
TO CLOUDY FORECAST. PREVIOUS DISCUSSION BELOW.
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
STRATUS DECK HAS MOVED OVER THE ENTIRE AREA OVERNIGHT. STILL A FEW
BREAKS FLOATING AROUND BUT THINK THE LOW CLOUDS WILL PERSIST MOST
OF THE DAY. BETTER MIXING IS LIKELY LATER THIS MORNING AND
AFTERNOON. THIS MAY CAUSE THE CIGS TO LIFT SLIGHTLY AND MAY ALSO
ALLOW FOR A FEW PEAKS OF THE SUN. FOR THE MOST PART THOUGH...CIGS
WILL REMAIN IFR TODAY. NOT REALLY SURE HOW FAST THE STRATUS DECK
WILL DISSIPATE AS THE MODELS HAVE NO FEEL FOR THE CURRENT
SITUATION. WILL TRY TO CLEAR THINGS FROM WEST TO EAST THIS EVENING
BUT WOULD NOT BE SURPRISED TO SEE THE CLOUDS PERSIST OVERNIGHT. SW
TO S FLOW EXPECTED THE ENTIRE PERIOD.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
629 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO THE FORECAST. LATEST IR SAT SHOWING
STRATUS CLOUDS ACROSS MUCH OF THE FORECAST AREA THIS MORNING. SOME
PEAKS OF SUN MAY BE POSSIBLE ACROSS A FEW LOCATIONS...BUT ANY
CLEAR SPOTS ARE FILLING IN SO WILL CONTINUE WITH A MOSTLY CLOUDY
TO CLOUDY FORECAST. PREVIOUS DISCUSSION BELOW.
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
BAND OF STRATUS OVER WESTERN OHIO CONTINUING TO MOVE EAST AND
EXPAND. ANOTHER AREA OF STATUS MOVING RAPIDLY NORTHEAST FROM
CENTRAL INDIANA. THE MODELS DO NOT HAVE A HANDLE ON THIS WHICH IS
TYPICAL FOR THIS TIME OF YEAR WHEN LOW LEVEL MOISTURE GETS TRAPPED
BELOW THE INVERSION. MY FORECAST IS FOR THE STRATUS TO EVENTUALLY
COVER THE ENTIRE FORECAST AREA BY DAYBREAK THURSDAY. THE VISIBILITY
SHOULD BE MAINLY MVFR BUT COULD FLUCTUATE TO IFR AT TIMES. THE
CEILING SHOULD BE MAINLY IFR BUT COULD IMPROVE TO MVFR AT TIMES.
CONDITIONS SHOULD BE WORSE AT DAYBREAK. WITH THE TIME OF THE YEAR
THE CEILINGS MAY JUST GO BROKEN DURING THE AFTERNOON. NOT EXPECTING CLEAR
SKIES AS THE SURFACE RIDGE WILL BE EAST OF THE AREA...SO NO REAL
SUBSIDENCE. THURSDAY AFTERNOON CEILINGS MAY BE NEAR 1000 FEET WITH
THE VISIBILITY 6SM OR BETTER. CONDITIONS WILL BEGIN TO DETERIORATE AGAIN
THURSDAY NIGHT.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
406 AM EST THU NOV 24 2011
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE LOWER OHIO VALLEY WILL
SLOWLY MOVE EAST THROUGH THE END OF THE WEEK. LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE PLAINS FRIDAY AND APPROACH THE GREAT
LAKES REGION SATURDAY. THE COLD FRONT FROM THE LOW PRESSURE IS
EXPECTED TO CROSS THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO THE SOUTH WILL KEEP THE AREA DRY TODAY...BUT THE
SIGNIFICANT WEATHER FEATURE OF TODAY WILL BE THE LOW CLOUDS THAT
HAVE BEEN ADVANCING EASTWARD ACROSS THE FORECAST AREA OVERNIGHT.
IR SAT SHOWING A LARGE AREA OF LOW STRATUS CLOUDS EXTENDING BACK
INTO IN AND IL THIS MORNING. THERE ARE SOME BREAKS IN THE CLOUDS
ACROSS THE WESTERN HALF OF THE AREA...BUT THINKING EVEN THIS AREA
WILL FILL IN BY AROUND OR JUST SUNRISE THIS MORNING.
MAV AND MET GUIDANCE WAY OFF THIS MORNING HANDLING THESE LOW
CLOUDS...SO ACTUALLY LEANED TOWARD THE HRRR MODEL FOR THIS
SITUATION. RECENT RUNS SINCE AROUND 04Z HAVE HANDLING THE LOW
CLOUDS FAIRLY WELL BRINGING THEM INTO THE AREA...AND THE HRRR
ACTUALLY PERSISTS THEM THROUGH MUCH OF THE DAY. LEANED TOWARD THIS
SOLUTION WITH A MAINLY CLOUDY FORECAST FOR TODAY ACROSS THE AREA
WITH SOME BREAKS POSSIBLE LATE AFTN/AROUND SUNSET THIS EVENING.
WITH THE ADDED CLOUDS IN THE FORECAST ALSO HAD TO ADJUST TEMPS
ACCORDINGLY. LOWERED TEMPS TO MAINLY UPPER 40S TO AROUND 50 FOR
TODAY WITH LITTLE RISE THROUGH THIS MORNING. MY CONCERN IS THAT IF
THE LOW STRATUS CLOUDS DO DOMINATE THROUGH THE ENTIRE AFTERNOON
THAT TEMPS TODAY MAY END UP EVEN COOLER THAN FORECAST. THEN RATHER
THAN A NORMAL DIURNAL CURVE TEMPS SIMPLY JUST CONTINUE TO SLOWLY
RISE THIS EVENING AND TONIGHT WITH WAA. FOR NOW WILL PROTECT
EITHER SOLUTION AND ALLOW THE FORECAST TEMPS TO BE A COMPROMISE
BETWEEN POSSIBLE SOLUTIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE TO THE SOUTH WILL REMAIN IN CONTROL TONIGHT THROUGH
FRIDAY NIGHT. GUIDANCE SUGGESTING THAT THE CLOUDS SHOULD DISSIPATE
TONIGHT ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES. WILL
LEAN TOWARD THAT TREND FOR NOW...BUT WILL BE SOMETHING WORTH
WATCHING THROUGH TODAY. TEMPS WILL BE TRICKY REGARDING THE
OVERNIGHT TRENDS...BUT OVERALL LOOKING FOR A MILDER NIGHT TONIGHT.
WITH INCREASING SOUTHERLY FLOW TEMPS WILL BE MILD ON FRIDAY AND
THEN EVEN A FEW BETTER ON SAT AHEAD OF AN APPROACHING COLD FRONT.
MADE LITTLE CHANGES TO TEMPS FRIDAY NIGHT THRU SAT NIGHT AS LIKED
LEANING ON THE WARMER SIDE OF CURRENT GUIDANCE. ALSO MADE LITTLE
CHANGES TO POPS THROUGH SAT NIGHT WITH LIKELY ALREADY MENTIONED IN
SOME AREAS. KEPT POPS RATHER HIGH IN THE LIKELY CATEGORY ON SUNDAY
WITH THE ECMWF A BIT SLOWER...BUT DID TREND TO LOWERING POPS
ACROSS THE WEST SUNDAY NIGHT. FOR SUNDAY AND SUNDAY NIGHT MADE
LITTLE CHANGES DUE TO TIMING ISSUES WITH THE FRONT...AS WELL AS
AIRMASS DIFFERENCES BETWEEN THE COOLER GFS AND WARMER ECMWF.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LIKE YESTERDAY...MODELS CONTINUE TO HAVE SIGNIFICANT DIFFERENCES
DURING THE LONG TERM PERIOD. THE GFS CONTINUES TO BE COLDER AND
FASTER WITH THE MAIN FEATURES. HAVE NOT MADE MANY CHANGES TO THE
LONG TERM DURING THE PERIOD GIVEN THIS UNCERTAINTY. APPEARS THAT
NEARLY EVERY PERIOD WILL SEE AT LEAST A CHANCE FOR PRECIPITATION.
IT COULD BE COLD ENOUGH FOR MIXED SNOW AND RAIN BOTH TUESDAY AND
WEDNESDAY NIGHTS WITH LIQUID PRECIPITATION DURING THE DAY.
TEMPERATURES DURING THE PERIOD WILL AVERAGE WITHIN A DEGREE OR TWO
OF NORMAL.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
BAND OF STRATUS OVER WESTERN OHIO CONTINUING TO MOVE EAST AND
EXPAND. ANOTHER AREA OF STATUS MOVING RAPIDLY NORTHEAST FROM
CENTRAL INDIANA. THE MODELS DO NOT HAVE A HANDLE ON THIS WHICH IS
TYPICAL FOR THIS TIME OF YEAR WHEN LOW LEVEL MOISTURE GETS TRAPPED
BELOW THE INVERSION. MY FORECAST IS FOR THE STRATUS TO EVENTUALLY
COVER THE ENTIRE FORECAST AREA BY DAYBREAK THURSDAY. THE VISIBILITY
SHOULD BE MAINLY MVFR BUT COULD FLUCTUATE TO IFR AT TIMES. THE
CEILING SHOULD BE MAINLY IFR BUT COULD IMPROVE TO MVFR AT TIMES.
CONDITIONS SHOULD BE WORSE AT DAYBREAK. WITH THE TIME OF THE YEAR
THE CEILINGS MAY JUST GO BROKEN DURING THE AFTERNOON. NOT EXPECTING CLEAR
SKIES AS THE SURFACE RIDGE WILL BE EAST OF THE AREA...SO NO REAL
SUBSIDENCE. THURSDAY AFTERNOON CEILINGS MAY BE NEAR 1000 FEET WITH
THE VISIBILITY 6SM OR BETTER. CONDITIONS WILL BEGIN TO DETERIORATE AGAIN
THURSDAY NIGHT.
OUTLOOK...NON VFR SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
PERSIST WSW TO SW FLOW IS EXPECTED ON LAKE ERIE TILL A COLD FRONT
CROSSES THE LAKE SOMETIME SATURDAY NIGHT. WILL HOIST A SMALL CRAFT
FOR ABOUT THE EAST HALF OF THE AREA AS LOCAL SCHEMES AND MODELS ARE
GIVING 4 FOOT OR GREATER WAVES. THE FLOW WILL BECOME WESTERLY
BEHIND THE FRONT AND THEN REMAIN THAT WAY THROUGH THE END OF THE
PERIOD. LOT`S OF MODEL UNCERTAINTY DURING THE PERIOD SO THIS
FORECAST COULD BE IN FLUX...ESPECIALLY EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 3 AM EST
SATURDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1208 AM EST THU NOV 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN TONIGHT. HIGH PRESSURE
WILL THEN REMAIN IN PLACE THROUGH THE END OF THE WEEK...GIVING US
DRY CONDITIONS AND A WARMING TREND INTO SATURDAY. A COLD FRONT
WILL APPROACH BY LATE SATURDAY WITH SHOWERS FOR SATURDAY NIGHT
INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A LARGE AREA OF STRATUS EXTENDS FROM THE CENTRAL AND WESTERN PARTS
OF OUR FORECAST AREA...SOUTHWESTWARD ACROSS SOUTHERN
INDIANA...WESTERN KENTUCKY...AND MUCH OF THE UPPER MISSISSIPPI
VALLEY. THIS MOISTURE IS TRAPPED UNDERNEATH THE RIDGE OF HIGH
PRESSURE CURRENTLY CENTERED JUST SOUTH OF OUR FORECAST AREA. THIS
CLOUD DECK WILL SLOWLY MOVE EASTWARD WITH THE RIDGE...WHICH MEANS
OUR EASTERN ZONES WILL JOIN THE REST OF THE FORECAST AREA BY
BECOMING MOSTLY CLOUDY AS WELL BY LATE TONIGHT. THIS SHOULD
PREVENT FOG FROM DEVELOPING ACROSS ANY OF OUR ZONES
OVERNIGHT. HOWEVER...THERE WILL STILL BE AREAS OF LIGHT MIST
CAUSING MINOR REDUCTIONS IN VISIBILITIES. HAVE UPDATED THE
FORECAST TO KEEP CLOUD COVER IN PLACE THROUGH SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL BE CENTERED ACROSS THE OHIO VALLEY AS IT SLOWLY
WORKS OFF TO THE EAST. ANY MORNING LOW LEVEL MOISTURE CLOUDS THAT
MIGHT HAPPEN TO DRIFT INTO THE AREA SHOULD DIMINISH. TEMPS NEAR
GUIDANCE THROUGH PERIOD EXCEPT A BIT LOWER THURSDAY NIGHT AND
LITTLE WARMER FRIDAY NIGHT WITH SOUTHERLY FLOW WITH DRY
CONDITIONS THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A STRONG COLD FRONT WITH COPIOUS MOISTURE WILL APPROACH THE AREA ON
SATURDAY. WITH GFS TRENDING FASTER WITH RESPECT TO THIS
SYSTEM...SPED UP ONSET OF CHANCE OF SHOWERS TO SATURDAY AFTERNOON IN
WESTERN COUNTIES. ENTIRE AREA SHOULD SEE SHOWERS SATURDAY NIGHT AND
SUNDAY AS THE FRONT PUSHES THROUGH. KEPT THUNDER OUT OF THE FORECAST
AS IT APPEARS THAT INSTABILITY WILL BE LACKING.
AFTER THE FRONT MOVES EAST ON SUNDAY...AN UPPER TROUGH WILL KEEP A
LOW CHANCE OF SHOWERS INTO MONDAY...MAINLY IN EASTERN COUNTIES.
ANOTHER UPPER DISTURBANCE PASSING THROUGH THE GREAT LAKES MAY BRING
A FEW SHOWERS TO NORTHERN LOCATIONS ON TUESDAY. EXPECT MAINLY DRY
WEATHER ON WEDNESDAY WITH HIGH PRESSURE PUSHING IN FROM THE
SOUTHWEST.
TEMPERATURES WILL START OUT ABOVE NORMAL ON SATURDAY AHEAD OF THE
COLD FRONT...WITH HIGHS FORECAST TO BE AROUND 60. HIGHS WILL BE NEAR
NORMAL IN THE 40S SUNDAY THROUGH TUESDAY. COLDER READINGS AROUND 40
MAY BE IN STORE FOR WEDNESDAY.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE CURRENTLY CENTERED OVER THE LOWER OHIO
VALLEY WILL SLOWLY DRIFT EASTWARD OVERNIGHT INTO THURSDAY WITH LOW
LEVEL FLOW BACKING TO THE SOUTHWEST. MAIN FORECAST CONCERN FOR
THE TAF PERIOD IS THE POTENTIAL FOR LOW CEILINGS TONIGHT. A
PERSISTENT LOW STRATUS DECK OVER INDIANA... SOUTHERN
ILLINOIS...AND WESTERN KENTUCKY WAS SLOWLY ERODING EARLIER THIS
AFTERNOON. HOWEVER...NOW THAT THE SUN IS DOWN THOSE CLOUDS SHOULD
STICK AROUND FOR TONIGHT AND PERHAPS EVEN INCREASE IN AERIAL
COVERAGE AS THE LATEST RUC GUIDANCE SUGGESTS. THESE CLOUDS ARE
THE RESULT OF TRAPPED LOW LEVEL MOISTURE DUE TO A SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH. LATEST SATELLITE IMAGERY SHOWS
A SLOW EASTWARD PROGRESSION WITH THIS CLOUD DECK...ALREADY
ENCROACHING ON KCVG. WENT WITH IFR CEILINGS TONIGHT FOR THE
WESTERN TAF SITES BASED ON WHAT HAPPENED FURTHER UPSTREAM LAST
NIGHT. MAY ALSO SEE SOME VFR TO MVFR VSBY REDUCTION AT KCVG/KLUK
DUE TO MIST...BUT EXPECT THE CLOUD DECK TO GENERALLY LIMIT MIST
DEVELOPMENT TONIGHT. CONFIDENCE IN CEILINGS IS LOWER FOR THE
EASTERN TAF SITES SO ONLY WENT WITH A SCATTERED LOW CLOUD DECK
THERE. ANY STRATUS THAT LINGERS INTO THURSDAY MORNING WILL TAKE
TIME TO ERODE...BUT WENT WITH SKC BY 17Z.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE SUNDAY AND MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...PADGETT
NEAR TERM...LATTO
SHORT TERM...PADGETT
LONG TERM...CONIGLIO
AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
1118 AM CST THU NOV 24 2011
.AVIATION...
18Z TAFS... VFR CONDITIONS THROUGHOUT THE TAF PERIOD. SOME
LIMITED VISIBILITIES OF MVFR MAY OCCUR EARLY FRIDAY MORNING AT A
FEW SITES BUT TOO UNCERTAIN FOR MENTION IN TAF AT THIS TIME.
OTHERWISE... GUSTY WINDS WILL AFFECT THE AREA.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST THU NOV 24 2011/
AVIATION...
RECENT SATELLITE TREND SHOWS LOW CLOUDS AND DENSE FOG EXPANDING
MORE NORTHWARD WITH A SLOWER PROGRESSION TO THE WEST. THEREFORE...
WILL NOT MENTION IFR CEILINGS AT TAF SITES. COULD SEE SOME LIGHT
FOG ACROSS NORTH CENTRAL OKLAHOMA DURING THE NEXT FEW HOURS SO
WILL MENTION FOG IN PNC TAF. OTHERWISE VFR CONDITIONS EXPECTED AT
TAF SITES THROUGH AT LEAST 6Z FRIDAY.
PREV DISCUSSION... /ISSUED 219 AM CST THU NOV 24 2011/
DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
22/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
545 AM CST THU NOV 24 2011
.AVIATION...
RECENT SATELLITE TREND SHOWS LOW CLOUDS AND DENSE FOG EXPANDING
MORE NORTHWARD WITH A SLOWER PROGRESSION TO THE WEST. THEREFORE...
WILL NOT MENTION IFR CEILINGS AT TAF SITES. COULD SEE SOME LIGHT
FOG ACROSS NORTH CENTRAL OKLAHOMA DURING THE NEXT FEW HOURS SO
WILL MENTION FOG IN PNC TAF. OTHERWISE VFR CONDITIONS EXPECTED AT
TAF SITES THROUGH AT LEAST 6Z FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 219 AM CST THU NOV 24 2011/
DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR OKZ026-
030>032-040>043-046>048-050>052.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
219 AM CST THU NOV 24 2011
.DISCUSSION...
CLOUD COVER...WITH CEILINGS AROUND 200 FT AND DENSE FOG...CONTINUES
TO SPREAD NORTH AND WEST THIS MORNING AROUND 15-20KT. THIS BRINGS
AREA OF LOW CLOUDS TO I-35 AROUND 11Z. HRRR WHICH IS USUALLY TOO
AGGRESSIVE...HAS LOW CEILINGS TO HWY 81 AND SOUTH OF I-40 BY 13Z.
WILL ADJUST SKY GRIDS TO REFLECT CLOUDS NEAR HWY 81 AND NORTH INTO
LINCOLN/PAYNE COUNTIES. HEATING AND INCREASING WINDS SHOULD ERODE
CLOUDS BY MID MORNING...ESPECIALLY WESTERN EDGE.
WINDS TONIGHT AND A MILD THANKSGIVING SHOULD KEEP THE FOG PONTENTIAL
LOW BUT SOME LOW CLOUDS MAY DEVELOP/MOVE INTO SOUTHERN PARTS OF
THE FA BY EARLY FRIDAY. ONLY MINOR ADJUSTMENTS WERE MADE TO
TIMING OF WX/POPS WITH FRIDAY/EARLY SATURDAY TROUGH. OVERNIGHT
LOWS FRIDAY NIGHT WILL BE A LITTLE TRICKY WITH PLACEMENT OF COLD
FRONT/CAA.
MOST OF THE RAIN SHOULD END BY MID MORNING SATURDAY. STRONG...GUSTY
NORTH WINDS SATURDAY SHOULD BE THE MAIN WEATHER STORY. RATHER DRY
AIRMASS BEHIND EARLY SATURDAY COLD FRONT WILL RESULT IN COLD
OVERNIGHT LOWS SUNDAY AND MONDAY. WITH SURFACE HIGH BUILDING SOUTH
INTO TEXAS...PER GFS...AFTERNOON TEMPERATURES USUALLY REBOUND QUICKER
THAN EXPECTED. ANOTHER COLD FRONT WILL PUSH ACROSS THE SOUTHERN
PLAINS LATE MONDAY INTO TUESDAY..BUT NO PRECIPITATION IS EXPECTED
WITH THE FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 47 64 45 / 0 0 20 70
HOBART OK 67 48 64 40 / 0 0 40 50
WICHITA FALLS TX 68 48 65 46 / 0 0 40 70
GAGE OK 71 47 65 36 / 0 0 40 40
PONCA CITY OK 68 47 65 43 / 0 0 20 70
DURANT OK 68 48 65 51 / 0 0 30 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUNSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENESIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...THROUGH 18Z FRIDAY
1146 AM CST THU NOV 24 2011
STRATUS THAT WAS OVER THE TAF SITES HAS MIXED OUT THIS MORNING ON
SCHEDULE...THOUGH SOME MVFR BR STILL PERSISTS. THIS MVFR BR SHOULD
GO VFR BY 19Z WITH CONTINUED MIXING. QUESTION THEN BECOMES IF
STRATUS CAN REDEVELOP TONIGHT AS MOISTURE SURGES UP FROM THE
CENTRAL PLAINS ON BREEZY SOUTHWEST WINDS. THERE IS A LOT OF
UNCERTAINTY ON THIS...SINCE IT DEPENDS ON HOW WARM IT ENDS UP
THIS AFTERNOON AND HOW MUCH COOLING CAN TAKE PLACE TONIGHT GIVEN
THE AMOUNT OF WIND. RIGHT NOW HAVE KEPT THE IDEA OF A SCATTERED
IFR/MVFR DECK AFTER 09Z IN CASE CLOUDS DEVELOP. MORE CONFIDENCE
EXISTS THAT THE MOISTURE MAY END UP RESULTING IN MVFR BR AND HAVE
THIS IN THE FORECAST FROM 09-15Z.
ANOTHER ISSUE WITH THE AVIATION FORECAST IS WINDS. MIXING TODAY IS
ALLOWING FROM SOUTHERLY GUSTS OF 20-30KT...HIGHEST IN KRST. THIS
SHOULD CONTINUE AT KRST THROUGH THE EARLY MORNING HOURS WITH A
TIGHT PRESSURE GRADIENT IN PLACE AHEAD OF TROUGHING OVER THE
DAKOTAS. HOWEVER...AT KLSE...LOW LEVEL WIND SHEAR IS LIKELY TO
DEVELOP AFTER 23Z WITH COOLING AND BEING IN THE VALLEY. SHOULD
GUSTS STOP AT KRST...LOW LEVEL WIND SHEAR WILL BE NEEDED THERE AS
WELL. KEPT THE LOW LEVEL WIND SHEAR GOING AT KLSE UNTIL 15Z WHEN
AT THAT POINT MIXING CAN START PRODUCING GUSTS AGAIN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
536 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUNSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENESIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...TODAY AND TONIGHT
536 AM CST THU NOV 24 2011
ANOTHER MORNING WITH A LOW STRATUS DECK OVER THE AREA AND THE MAIN
PROBLEM IS AGAIN WHEN WILL THE CLOUDS CLEAR OUT. CEILINGS ARE
EITHER IFR TO LOW MVFR IN THE DECK AND ARE EXPECTED TO REMAIN THAT
WAY UNTIL THE CLOUDS SCATTER OUT. THE 24.07Z HRRR LOW CLOUD
PRODUCT HAS A GOOD HANDLE ON WHERE THE CLOUDS ARE AND INDICATES A
SLOW EASTWARD DRIFT THROUGH THE MORNING AND THEN A PRETTY RAPID
EASTWARD PROGRESSION DURING THE LATE MORNING AND AFTERNOON AS THE
WINDS INCREASE AND THE SUN BEATS ON THE CLOUDS. THIS IS ALSO IN
VERY GOOD AGREEMENT WITH THE 24.06Z NAM BUFKIT SOUNDINGS. WILL
INDICATE THE CLOUDS SCATTERING OUT AT BOTH TAF SITES BY 18Z. THERE
IS SOME SIGNAL IN THE NAM...24.00Z GFS AND 24.03Z SREFS THAT THE
CLOUDS COULD ONCE AGAIN COME BACK LATE TONIGHT. EACH NIGHT THE
BACK EDGE OF THE CLOUDS HAS GOTTEN A LITTLE FARTHER TO THE EAST SO
THINKING THE BACK EDGE TONIGHT MAY BE JUST TO THE EAST OF KLSE.
ALSO...THE TIMING MAY NOT BE UNTIL VERY LATE IN THE FORECAST
PERIOD...SO A LOT OF UNCERTAINTY AND WILL NOT REINTRODUCE THE LOW
DECK AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION...CORRECTED TYPO
NWS LA CROSSE WI
354 AM CST THU NOV 24 2011
.SHORT TERM...TODAY THROUGH SATURDAY
352 AM CST THU NOV 24 2011
AT 3 AM...VLIFR/IFR CEILINGS WERE SEEN ACROSS ACROSS THE FORECAST
AREA. THESE CLOUDS HAVE BEEN SPREADING IN ALL DIRECTIONS
UNDERNEATH THE STRONG INVERSION LOCATED JUST ABOVE THE SURFACE.
OVERALL...THE HRRR HAS BEEN HANDLING THESE CLOUDS THE BEST...AND
IT SUGGESTS THAT THERE WILL BE GRADUAL DISSIPATION OF THESE CLOUDS
ON THE OUTER EDGES BETWEEN 16Z AND 18Z...AND THEN THIS PROGRESS A
BIT FASTER ACROSS THE REMAINING AREAS AS SOME DRIER AIR FROM ALOFT
MIXES DOWN.
DESPITE THE PERSISTENT CLOUDS THIS MORNING...THE COMBINATION OF
SOUTHERLY WINDS AND AFTERNOON SUSHINE WILL HELP THE TEMPERATURES
CLIMB INTO THE 50S ACROSS THE FORECAST AREA. DUE TO THE SUNSHINE
ARRIVE EARLIER...THE WARMEST TEMPERATURES /UPPER 50S/ WILL LIKELY
FOUND IN SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. WITH
NORTH CENTRAL WISCONSIN BEING ONE OF LAST TO LOSE THE CLOUDS...SO
THEY WILL LIKELY ONLY SEE TEMPERATURES CLIMBING TO AROUND 50 DEGREES.
FOR TONIGHT...BOTH THE 24.00Z NAM AND GFS SOUNDINGS SUGGEST THAT
THE CLOUDS ACROSS NORTHERN AND EASTERN WISCONSIN WILL ONCE AGAIN
SPREAD WESTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF THESE
CLOUDS AND UNUSUALLY MOIST DEW POINTS WILL RESULT IN MINIMUM
TEMPERATURES ONLY FALLING INTO THE LOWER AND MID 40S. THIS IS
ABOUT 5 DEGREES WARMER THAN OUR NORMAL HIGH TEMPERATURE FOR THIS
DATE.
ON FRIDAY...THE LOW CLOUDS WILL GRADUALLY LIFT AND DISSIPATE
DURING THE DAY. HOWEVER AT THE SAME TIME...MID AND HIGH CLOUDS
WILL BE STREAMING INTO THE REGION AHEAD OF AN APPROACHING LONG
WAVE TROUGH. AS RESULT...NOT EXPECTING TOO MUCH SUNSHINE. DESPITE
THE LACK OF ABUNDANT SUNSHINE...SOUTHERLY WINDS WILL HELP WARM
TEMPERATURES INTO THE LOWER AND MID 50S.
ON FRIDAY NIGHT...THE MODELS CONTINUE TO INDICATE THAT MODERATE TO
STRONG MOISTURE TRANSPORT WILL MOVE INTO THE FORECAST AREA. THIS
WILL BE THE BEST ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA
DURING THE EVENING. DURING THE OVERNIGHT...MODERATE TO STRONG
ISENTROPIC LIFT AND FRONTOGENESIS WILL MOVE EAST INTO THE AREA.
AT THIS TIME...IT LOOKS LIKE THE BEST RAIN CHANCES WILL BE FROM
ALONG THE MISSISSIPPI RIVER EAST. DESPITE THE RAIN...THE SOUTHERLY
WINDS SHOULD HELP KEEP THE MINIMUM TEMPERATURES UNUSUALLY WARM FOR
THIS TIME OF YEAR. THEY WILL BE IN THE LOWER AND MID 40S ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AND IN THE MID TO UPPER
40S FOR WESTERN WISCONSIN.
ON SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF SHOW THAT
THERE WILL BE RAPID CYCLOGENSIS OCCURRING ACROSS MINNESOTA. THIS
IS IN RESPONSE TO SOME INTERACTION BETWEEN THE NORTHERN AND
SOUTHERN SHORT WAVE TROUGH EMBEDDED IN THE LONG WAVE TROUGH. THIS
RESULT IN THE TROPOPAUSE DESCENDING TO AROUND 500 MB...AND A RAPID
TIGHTENING OF THE SURFACE PRESSURE GRADIENT. SUSTAINED WINDS WILL
CLIMB INTO THE 15 TO 30 MPH RANGE...AND THE WIND GUSTS WILL RANGE
FROM 30 TO 40 MPH.
WITH STRONG COLD AIR ADVECTION BEING FOUND IN THE WAKE OF THE
COLD FRONT ON SATURDAY...TEMPERATURES SHOULD FALL STEADILY THROUGH
THE EARLY AFTERNOON AND THEN STABILIZE. THIS TREND WAS INTRODUCED
TO THE HOURLY TEMPERATURE GRIDS. IN ADDITION...GFS SOUNDINGS ARE
COLD ENOUGH FOR A SOME SNOW TO MIX IN. THIS WAS ALREADY IN THE
SOUTHEAST MINNESOTA AND NORTHEAST FORECAST GRIDS...BUT IT NOW
LOOKS LIKE WESTERN WISCONSIN MAY ALSO SEE SOME OF THIS SNOW
TOO...SO IT WAS ADDED TO THE GRIDS DURING THE MID AND LATE
AFTERNOON.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
352 AM CST THU NOV 24 2011
ON SATURDAY NIGHT...IT CONTINUE TO LOOK LIKE THERE WILL BE SOME
LINGERING LIGHT PRECIPITATION. AS RESULT...KEPT A CHANCE OF LIGHT
RAIN AND SNOW DURING THE EVENING...AND LIGHT SNOW OVERNIGHT. LIKE
THE PAST COUPLE OF DAYS...NOT EXPECTING TOO MUCH SNOW AT ALL FROM
THIS SYSTEM. IN ADDITION TO THE MIXED PRECIPITATION...THE STRONG
WINDS WILL LIKELY CONTINUE THROUGH THE NIGHT. SUSTAINED WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE...AND THE WINDS WILL GUST UP TO
40 MPH.
BEYOND THIS TIME PERIOD...THERE CONTINUES TO BE VERY LITTLE
CONSISTENCY. HOWEVER WITH THIS SAID...I DO LIKE THAT THE MODELS
ARE STARTING TO BECOME MORE TRANSITORY WITH THEIR SYSTEM. THIS
MAKES SENSE WHEN LOOKING AT THE RATHER ACTIVE WAVE PATTERN FROM
AFRICA INTO THE WESTERN PACIFIC. THE GFS PATTERN ACTUALLY
RESEMBLES ONE OF THE PATTERNS THAT YOU WOULD TYPICALLY SEE DURING
A LA NINA. ANOTHER FEATURE THAT WE WILL HAVE TO PAY ATTENTION TO
AS WE HEAD INTO DECEMBER IS THE INTENSIFYING MADDEN JULIAN
OSCILLATION /WHICH HAS BEEN CONSISTENTLY FORECAST BY THE
BRAZILLIAN...ECMWF...JAPANESE...AND U.S. MODEL ENSEMBLES FOR THE
PAST WEEK/ THAT IS LOCATED OVER THE WESTERN INDIAN OCEAN. THIS WILL
LIKELY CAUSE SOME ISSUES WITH THE MODEL RUN TO RUN CONSISTENCY AT
LEAST INITIALLY. IN ADDITION...IT MAY BE ONE OF THE REASONS WHY THE
CLIMATE FORECAST SYSTEM VERSION 2 MODEL IS SUGGESTING THAT AT
LEAST THE FIRST HALF OF DECEMBER MAY END UP BEING WARMER THAN
NORMAL.
&&
.AVIATION...THROUGH 06Z FRIDAY
1135 PM CST WED NOV 23 2011
STRATUS HAD DEVELOPED WESTWARD THIS EVENING AND HAS SPREAD VLIFR
CEILINGS INTO KRST WITH A LOWER MVFR CEILING AT KLSE. MODEL SOUNDINGS
SHOW THIS LOW LEVEL MOISTURE TO REMAIN TRAPPED UNDER THE INVERSION
INTO THURSDAY MORNING. THUS HAVE KEPT THE STRATUS AT BOTH TAF
SITES THROUGH AT LEAST 15Z THURSDAY AND THEN WINDS SHOULD MIX THE
MOISTURE OUT BY LATE MORNING WITH VFR CONDITIONS. WITH A RATHER
TIGHT PRESSURE GRADIENT...EXPECT SOUTHWEST WINDS TO GUST TO
BETWEEN 20 AND 25 KNOTS AT BOTH SITES...WITH THE WINDS REMAINING
AROUND 10 TO 12 KNOTS AFTER SUNSET THROUGH 06Z FRIDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 AM CST THU NOV 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
329 AM CST THU NOV 24 2011
.SHORT TERM...THANKSGIVING DAY THROUGH FRIDAY...SKY COVER AND
IT`S EFFECT ON TEMPERATURES WILL BE THE MAIN FCST CONCERNS.
WIDESPREAD LOW STRATUS HAS ONCE AGAIN OVERSPREAD THE ENTIRE CWA
THIS MORNING...DUE TO LLVL MOISTURE TRAPPED BENEATH A STRONG
INVERSION. PATCHY FOG WAS ALSO OCCURRING...ESPECIALLY OVER
NORTHERN WI...WHERE SOME SNOW PACK REMAINED.
HAVE DECIDED TO STOP FIGHTING WITH THE CLOUDS. WITH LITTLE
CHANGE IN THE PATTERN ANTICIPATED THROUGH FRIDAY...BELIEVE
THAT LOW CLOUDS WILL PERSIST. BUFKIT SOUNDINGS AND 950 MB
RH PROGS SUPPORT THIS. SOME PARTIAL CLEARING MAY OCCUR DURING
THE EARLY TO MID AFTERNOON TODAY...ESPECIALLY IN FAR NE WI...
BUT EXPECT CLOUDS TO FILL BACK IN DURING THE EVENING. WILL
ALSO CONTINUE TO MENTION PATCHY FOG TONIGHT INTO FRIDAY
MORNING...WITH AREAS OF FOG OVER THE NORTHERN WI SNOW PACK.
ANY CLEARING ON FRIDAY IS DOUBTFUL...AS LLVL MOISTURE DEEPENS
A LITTLE IN ADVANCE OF THE APPROACHING COLD FRONT.
HAVE LOWERED MAX TEMPS BY 3 TO 5 DEGREES TODAY AND FRIDAY...
WHICH SHOULD ACCOUNT FOR THE EFFECTS OF THE CLOUD COVER.
USED A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR
MIN TEMPS TONIGHT...BUT AREAS WITH PARTIAL CLEARING COULD
QUICKLY DROP BLO THE FCST VALUES THIS EVENING...SO TEMPS WILL
NEED TO BE MONITORED.
.LONG TERM...FRIDAY NIGHT TO NEXT THURSDAY.
THE GFS ENSEMBLE MEAN INDICATES THAT AN AMPLIFYING TROUGH OVER THE
EASTERN CONUS THIS WEEKEND WILL GET REINFORCED THROUGH EARLY TO
MIDDLE OF NEXT WEEK AS FLATTENED RIDGING BUILDS OVER THE WESTERN
CONUS. OPERATIONAL MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION
OF THIS EASTERN CONUS TROUGH...AND THE POTENTIAL FOR A CUTOFF LOW TO
MEANDER OVER THE OHIO VALLEY. WILL BLEND THE ECMWF AND GFS...BUT
TRIED TO KEEP SIGNIFICANT CHANGES TO A MINIMUM.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...AS A SHORTWAVE TROUGH DIGS
ACROSS THE CENTRAL GREAT PLAINS...LOW PRESSURE WILL MOVE ACROSS THE
NORTHERN MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN BY 12Z
SATURDAY. WITH UPPER DIVERGENCE INCREASING THROUGH THE NIGHT...AND
LOW LEVEL FORCING VIA A WARM FRONT DRAPED OVER NORTHERN
WISCONSIN...SHOULD SEE RAIN SHOWERS PUSH NE ACROSS THE
STATE...MAINLY AFTER MIDNIGHT AS A BEEFY DRY WEDGE IN THE MID-LEVELS
WILL HAVE TO BE OVERCOME. LOW PRESSURE THEN TRACKS ACROSS THE STATE
OF WISCONSIN ON SATURDAY...WITH SHOWERS CONTINUING. COLDER AIR WILL
EVENTUALLY WRAP AROUND THE LOW INTO THE STATE LATE SATURDAY
AFTERNOON INTO SATURDAY EVENING...WITH RAIN SHOWERS TURNING OVER TO
SNOW SHOWERS. SOME ACCUMULATIONS APPEAR POSSIBLE SATURDAY NIGHT
OVER N-C WISCONSIN...WITH AN ADDED BONUS FROM LAKE EFFECT WHICH
SHOULD BE CRANKING UP LATE SATURDAY NIGHT. WILL INCREASE POPS
SATURDAY NIGHT.
REST OF THE FORECAST...NW FLOW BEHIND THE SURFACE LOW WILL CONTINUE
INTO SUNDAY...WITH LAKE EFFECT SNOW SHOWERS PROBABLE OVER N-C
WISCONSIN AND A FEW SNOW SHOWERS LINGERING OVER THE EASTERN HALF OF
THE STATE. DRIER AIR WILL ARRIVE FOR THE AFTERNOON...BUT CYCLONIC
FLOW WILL LIKELY KEEP THE CLOUDS AROUND. NW WINDS WILL ALSO BE
GUSTY WITH SOME GUSTS TO 30 OR 35 MPH POSSIBLE. A SURFACE RIDGE
AXIS WILL QUICKLY PUSH INTO THE STATE SUNDAY NIGHT AND SO WILL
WARMER AIR...WHICH WILL ERODE ANY LINGERING LOW STRATUS. THE
REINFORCING SHORTWAVE AND COLD FRONT WILL PLOW ACROSS THE WESTERN
GREAT LAKES MONDAY INTO MONDAY NIGHT WITH ANOTHER SURGE OF COLD AIR
IN ITS WAKE. CURRENTLY CARRYING POPS MONDAY NIGHT FOR THIS
FEATURE...AND THIS LOOKS GOOD. THE COLD AIR LOOKS COLD ENOUGH FOR
LAKE EFFECT OVER NORTH-CENTRAL WISCONSIN HEADING INTO TUESDAY.
UNDER NW FLOW ALOFT...SIGNS OF ANOTHER WAVE ARRIVING WEDNESDAY NIGHT
INTO THURSDAY. OTHER THAN A BRIEF WARM UP ON MONDAY...TEMPERATURES
LOOK NEAR OR BELOW NORMAL FOR THE REST OF THE WEEK.
&&
.AVIATION...(FOR 06Z TAF ISSUANCE) EVENING SOUNDING AT GRB
SHOWING STRONG INVERSION...THIS LEADING TO STRATUS ONCE AGAIN
EXPANDING ACROSS STATE. RUC SEEMS TO HAVE BEST HANDLE ON THINGS SO
HAVE CONTINUED TO FOLLOW IT. IFR CIGS ARE EXPECTED...WITH LOCAL
LIFR OVER THE NORTH...INCLUDING RHI. MVFR VSBYS WITH WINDS
REMAINING UP OVERNIGHT...ALTHOUGH PATCHY IFR VSBYS WILL OCCUR OVER
THE REMAINING SNOW PACK IN NORTHERN WI. LOW LEVEL WIND SHEAR
POSSIBLE OVERNIGHT WITH SOUTHWEST WINDS AROUND 30 KNOTS AT 1000 FT
AGL AND SURFACE WINDS FROM THE SOUTH AT 5 TO 10 KNOTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
KIECKBUSCH/MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
309 AM CST THU NOV 24 2011
.TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
CURRENT LOW STRATUS DECK AND PATCHY FOG IS LOCATED ALONG AND EAST OF
A SUBTLE RIDGE AT SURFACE FROM TWIN CITIES DOWN INTO EASTERN
MISSOURI. WEST OF THIS RIDGE THE WINDS ARE MORE SOUTH...EAST OF THE
RIDGE THEY ARE SOUTHWEST. THEREFORE...A ZONE OF SUBSIDENCE EXITS IN
THIS WIND SEPARATION BAND...AND THIS IS WHERE THE STRATUS EDGE
IS...ROUGHLY. MODELS MOVE THIS RIDGE EAST TODAY. THE USUAL EROSION
WILL TAKE PLACE AS WELL. BASED ON 1000-950 MB RELATIVE HUMIDITY
VALUES SHOWN BY MODELS OVER MY COUNTY WARNING AREA...AREAS WEST OF
MADISON WILL BREAK UP BETWEEN 15Z AND 17Z. AREAS TOWARD MILWAUKEE
WILL NOT BREAK UP UNTIL 18-19Z. THEREAFTER...HAZY SUNSHINE WITH
SOUTHWEST WINDS IN THE 10 TO 15 MPH RANGE WITH GUSTS TO 20 MPH. MAX
TEMPS THIS AFTERNOON SHOULD MAKE IT INTO THE LOWER 50S...WHICH IS A
FEW POINTS HIGHER THAN YESTERDAY. BUT..I DON/T SEE THOSE MID-UPPER
50S DUE TO SLOW EROSION/MIXING OF STRATUS DECK AND LOW SUN ANGLE.
IF EVERYTHING I SAID IS WRONG...AND STRATUS BREAKS UP EARLIER THAN
EXPECTED...THEN WE/LL SEE UPPER 50S TO 60.
BUFKIT SOUNDINGS SHOW LOW-LEVEL INVERSION HANGING IN THIS AFTERNOON
INTO TONIGHT. THE 1000-950 RELATIVE HUMIDITY VALUES TONIGHT INCREASE
ONCE AGAIN TO 90 TO 95 PCT RANGE...SO EXPECT STRATUS DECK AND AREAS
OF FOG TO DEVELOP ONCE AGAIN TONIGHT. HOWEVER...SURFACE SOUTH TO
SOUTHWEST WINDS WILL REMAIN IN THE 8 TO 15 MPH RANGE TONIGHT PER
MODEL FORECASTS DUE TO DECENT SURFACE PRESSURE GRADIENT. JUST ABOVE
THE INVERSION...THE RUC AND NAM MODELS HAVE SOUTHWEST WINDS OF 47 TO
54 KNOTS AT AROUND 2000 FT AGL. GOOD THING INVERSION HANGS IN
THERE..OTHERWISE WE/D HAVE A WIND ADVISORY OR LOW-END HIGH WIND
EVENT ON OUR HANDS.
FRIDAY - CONFIDENCE...MEDIUM
1000-950 MILLIBAR RH PROG AND BUFKIT SOUNDINGS SUGGEST STRATUS
POTENTIAL BEST BETWEEN 12-15Z. SOUNDINGS ERODE THIS LOW LEVEL
MOISTURE AND THEN MID LEVEL MOISTURE INCREASES...AOA 15K FEET DURING
THE AFTERNOON. THE 850 THERMAL RIDGE IS REINFORCED BY THE CONTINUED
SOUTHWEST FLOW. STRONG SOUTHWEST UPPER FLOW HAS WEAKLY ANTICYCLONIC
LOOK TO IT. HOWEVER MODELS DO SHOW INCREASING VORTICITY...MOSTLY
SHEARED...INTO NORTHERN WI. THOUGH NAM/ECMWF DO SHOW SOME WEAK DCVA
INTO THE CWA IN THE AFTERNOON.
FRIDAY NIGHT THROUGH SATURDAY NIGHT - CONFIDENCE...MEDIUM
UPPER TROUGH APPROACHES AND DEEPENS WITH CLOSED LOW EVOLVING ACROSS
THE WESTERN GREAT LAKES SATURDAY NIGHT. 700 MILLIBAR OMEGA INCREASES
FRIDAY NIGHT...ESPECIALLY IN THE 6-12Z TIME FRAME. DIFFERENTIAL
CYCLONIC VORTICITY ADVECTION INCREASES FRIDAY NIGHT. BOTH THE ECMWF
AND GEMNH SUGGEST A DRY WEDGE IN THE FAR SOUTHEAST SO WILL HAVE
LOWER POPS THERE. SEVERAL SPOKES MAY ROTATE THROUGH AHEAD OF THE
LOW/UPPER TROUGH RIGHT THROUGH SATURDAY NIGHT. RIGHT REAR QUADRANT
UPPER JET DIVERGENCE IS ALSO NOTED FRIDAY NIGHT INTO SATURDAY
MORNING WITH JET CORE ON EASTERN SIDE OF ADVANCING TROUGH. PROGS
SUGGEST LATER FRIDAY NIGHT INTO SATURDAY MORNING AS THE BEST WINDOW
FOR WIDESPREAD RAIN POTENTIAL...SO WILL CONCENTRATE HIGHEST POPS IN
THAT TIME FRAME. COLD ADVECTION IS MUCH SLOWER TO ARRIVE ON THE ECMWF
WITH GFS AND NAM VERY QUICK TO ADVECT COLDER 850 TEMPS. WITH
LINGERING UPPER CYCLONIC FLOW SATURDAY NIGHT...ANY LIGHT PRECIP
COULD BECOME MIXY ESPECIALLY IN THE WESTERN CWA...THOUGH ECMWF
SUPPORTS LIQUID.
SUNDAY - CONFIDENCE...LOW
TIMING OF TROUGH AND ASSOCIATED LINGERING PRECIP A QUESTION. GFS/NAM
SUGGEST LINGERING LIGHT QPF WITH MUCH COLDER THERMAL
PROFILES...WHILE THE ECMWF IS MORE PROGRESSIVE...DRIER AND WARMER.
WILL LEAVE ALLBLEND POPS ALONE FOR NOW.
MONDAY - CONFIDENCE...LOW TO MEDIUM
WHILE THE ECMWF/GEM VARY ON POSITION OF UPPER LOW IN THE SE US...ALL
MODELS POINT TO A QUIET REGIME HERE IN SRN WI WITH MID LEVEL
RIDGING. WEAK WAVE IN MONDAY NIGHT TIME FRAME...WILL LEAN TOWARDS
DRY ALLBLEND POPS.
TUESDAY - CONFIDENCE...MEDIUM
THE STRONGER LOOKING GFS WAVE PASSES BY TO THE NORTH EARLY WHILE THE
ECMWF AND GEMNH HAVE MUCH WEAKER WAVE. IN ALL CASES PRECIP POTENTIAL
LOOKS LOW ENOUGH TO GO WITH THE DRY LOOK OF THE ALLBLEND.
WEDNESDAY - CONFIDENCE...LOW TO MEDIUM
GFS THE OUTLIER AT THIS POINT WITH A MORE VIGOROUS WAVE DRIVING
INTO THE AREA...WHILE THE ECMWF AND TRENDS IN GEMNH SUGGEST DRY
WITH VORT ACTION WELL NORTH AND BROAD WESTERLY ANTICYCLONIC FLOW.
&&
.AVIATION/12Z TAFS/...LOW STRATUS DECK AND FOG TRENDS PER FORECAST MODEL
OUTPUT SUGGESTS EROSION BY 15Z WEST OF MADISON...PROGRESSING TO
THE MILWAUKEE TO KENOSHA AREA BY 18 TO 19Z TODAY. SOUTHWEST WINDS
TO STAY UP IN THE 8 TO 15 KNOT RANGE WITH GUSTS TO 20 KNOTS...SO
DON/T EXPECT VSBYS TO GET BELOW 1 MILE..AND LOWEST CEILINGS WILL
BE 3 TO 4 HUNDRED FT. STRATUS DECK WILL SCATTER OUT FOR THE
AFTERNOON...WITH HAZY SUNSHINE AND VSBYS OF 5 TO 6 MILES UNDER
INVERSION. ABOVE THE INVERSION THE SOUTHWEST WINDS WILL BE
INCREASING TO 30 TO 40 KTS.
FOR TONIGHT...EXPECT THE LOW-LEVEL STRATUS DECK TO REFORM...IFR
CONDS WITH CIGS 5 TO 9 HUNDRED FT AGL. VSBYS SHOULD BE IN THE 2 TO 5
MILE RANGE UNDER INVERSION. FORECAST MODELS INCREASE SOUTHWEST WINDS
JUST ABOVE THE INVERSION TO 48 TO 54 KNOTS..ABOUT 2 THSD FT AGL.
WILL KEEP LOW-LEVEL WIND SHEAR TERM IN THE TAFS FOR TONIGHT. SURFACE
WINDS WILL REMAIN IN THE 10 TO 15 KNOT RANGE WITH SOME HIGHER GUSTS
TO AROUND 20 KNOTS.
&&
.MARINE...THE PRESSURE GRADIENT WILL TIGHTEN TODAY...AND REMAIN TIGHT
THROUGH FRIDAY. GUSTS TO 20 TO 25 KNOTS ON ORDER...SO HAVE ISSUED
A SMALL CRAFT ADVISORY THROUGH FRIDAY...ENDING FRIDAY EVENING AS
LOW PRESSURE MOVES ACROSS NORTHERN WISCONSIN. SOME PATCHY FOG
TODAY AND TONIGHT WITH MOIST LOW-LEVEL AIR UNDER INVERSION WHICH
NEVER REALLY BREAKS UP OVER THE WATERS.
MORE GUSTY WINDS AFTER THE COLD FRONTAL PASSAGE SATURDAY INTO
SUNDAY. GUSTY WEST TO NORTHWEST WINDS OF 30 TO 35 KNOTS ARE
POSSIBLE. THE HIGHEST WAVES AGAIN WOULD BE TOWARD THE OPEN WATERS
WITH THE OFFSHORE FLOW. A SMALL CRAFT ADVISORY OR GALE WATCH/WARNING
MAY BE NEEDED FOR THIS PERIOD.
BRISK WINDS AND HIGH WAVES ARE POSSIBLE AGAIN NEXT MONDAY AND
TUESDAY...AHEAD OF AND BEHIND A PASSING COLD FRONT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CST FRIDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...KAPELA
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1052 PM CST WED NOV 23 2011
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...FORECASTING CLOUD COVER IS THE BIGGEST CHALLENGE OF
TONIGHT AND TOMORROWS FORECAST...AS IT HAS BEEN FOR THE LAST FEW
DAYS. IT IS USUALLY WISE TO KEEP CLOUDS AROUND IN NOVEMBER AND
DECEMBER AND WILL KEEP MORE CLOUDS IN THE FORECAST THAN THE
GUIDANCE WOULD INDICATE. THE RUC HAD THE BEST FORECAST OF THE
CLOUD COVER THIS AFTERNOON WITH CLEARING OCCURRING IN THE DOWNSLOPE
AREA OF NORTHEAST WISCONSIN. IT WOULD KEEP THE CURRENT CLOUDS IN
THE WESTERN PART OF THE FORECAST AREA FOR MOST OF THE NIGHT WITH
CLOUDS REFORMING GENERALLY NORTH OF GREEN BAY IN THE EAST.
DIFFICULT TO SAY FOR SURE. WE HAVE TRIED JUST ABOUT EVERY MODEL
FIELD (1000MB TO 925MB, 925MB, 925 TO 950MB RELATIVE HUMIDITY,
MOISTURE TRANSPORT VECTORS, AND HRR CEILING HEIGHTS) BUT NONE
DEPICT THE CURRENT CLOUDS THAT WELL. LOWS TONIGHT SHOULD BE ABOVE
NORMAL ONCE AGAIN DUE TO MILD BOUNDARY LAYER TEMPERATURES, A
STEADY BREEZE AND CLOUDS. THE COOLEST TEMPERATURES SHOULD BE IN
VALLEYS WITH CLEAR SKIES AND IN AREAS WITH SNOW ON THE GROUND.
THANKSGIVING MAY NOT BE QUITE AS MILD AS IT LOOKED LIKE A FEW
DAYS AGO AS THERE IS A POSSIBILITY THAT THE DAY COULD START OUT
WITH CLOUDS LIKE MOST OF THE LAST FEW DAYS. 925MB TEMPERATURES ARE
VERY MILD THOUGH, AND EVEN WITH CLOUDS IT WILL BE 10 TO 15 DEGREES
ABOVE NORMAL AND THERE SHOULD AT LEAST BE SOME SUNSHINE BY
AFTERNOON IN MOST PLACES.
.LONG TERM...THURSDAY NIGHT TO WEDNESDAY.
SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT EXPECTED THURSDAY
EVENING. GRADIENT EXPECTED TO SLACKEN DURING THE NIGHT...ESPECIALLY
ACROSS THE NORTH. DEPENDING ON HOW MUCH SNOW PACK IS LEFT...ENOUGH
EVIDENCE TO ADD FOG AFTER MIDNIGHT OVER THE FAR NORTH. MODELS TODAY
ARE SHOWING LOW LEVEL MOISTURE TRAPPED BELOW AN INVERSION LATER
THURSDAY NIGHT INTO FRIDAY. QUESTION IS HOW QUICK THIS LAYER WILL
SATURATE. DO THINK BEST SATURATION WILL OCCUR ACROSS THE NORTH. CONFIDENCE
IS NOT THAT GREAT ACROSS THE SOUTH DUE TO DIFFERING NUMERICAL
GUIDANCE VALUES FOR CLOUD HEIGHT. WITH EXPECTED LOW CLOUDS TO
DEVELOP ACROSS THE NORTH AND WEAK UPWARD VERTICAL MOTIONS...THOUGHTS
TURNED TO THE POTENTIAL FOR DRIZZLE LATE THURSDAY NIGHT INTO FRIDAY.
DO THINK MOISTURE WILL BE TOO SHALLOW THURSDAY NIGHT INTO FRIDAY MORNING...
BUT CLOUD LAYER MAY BE DEEP ENOUGH TO SUPPORT DRIZZLE FRIDAY AFTERNOON.
DID NOT ADD DRIZZLE TO THE FORECAST ACROSS THE NORTH ON FRIDAY AND
WILL PASS ON MY CONCERNS TO MIDNIGHT SHIFT.
FOR FRIDAY NIGHT...MOIST SOUTHERLY FLOW EXPECTED ACROSS THE AREA. THINK
PRECIPITATION WILL START OUT AS DRIZZLE WITH A MORE STEADIER RAIN LATE
FRIDAY NIGHT INTO SATURDAY AS FRONT APPROACHES. PRECIPITATION WILL
CONTINUE INTO SATURDAY. MORE QUESTIONS APPEAR ON SATURDAY AS SEVERAL
MODELS SHOW A DRY SLOT MOVING ACROSS THE REGION SATURDAY AFTERNOON
INTO SATURDAY NIGHT. DESPITE A FEW MODELS DRYING US OUT FOR AWHILE...
WILL CONTINUE A CHANCE OF RAIN SATURDAY AFTERNOON AND RAIN OR SNOW
SATURDAY NIGHT. MANY QUESTIONS LINGER SATURDAY NIGHT ON HOW FAST THE
COLD AIR WILL ARRIVE. LATER SHIFTS WILL PROBABLY NEED TO ALTER TIMING
THE CHANGEOVER TO ALL SNOW ACROSS SOME PORTION OF THE FORECAST AREA.
OTHERWISE...ANOTHER SYSTEM WILL MOVE ACROSS THE AREA MONDAY NIGHT
AND TUESDAY AND WILL BRING ANOTHER SMALL CHANCE FOR RAIN OR SNOW
TO THE AREA.
&&
.AVIATION...
EVENING SOUNDING AT GRB SHOWING STRONG INVERSION...THIS
LEADING TO STRATUS ONCE AGAIN EXPANDING ACROSS STATE. RUC SEEMS
TO HAVE BEST HANDLE ON THINGS SO HAVE CONTINUED TO FOLLOWED...CLEARING
EAST WILL BE TAKEN OVER BY STRATUS BETWEEN 6Z AND 9Z. CIG MVFR
CIGS WILL DROP TO IFR...LOCAL LIFR OVER NORTH...RHI. MVFR VISBYS
WITH WINDS REMAINING UP OVERNIGHT. LOW LEVEL WIND SHEAR POSSIBLE
THROUGH 9Z WITH SOUTHWEST WINDS AROUND 30 KNOTS AT 1000 FT AGL AND
SURFACE WINDS FROM THE SOUTH AT 5 TO 10 KNOTS.
TE
&&
.MARINE...HAZARDOUS CONDITIONS WITH GALE FORCE ARE POSSIBLE OVER
THE UPCOMING WEEKEND. MODEL DIFFERENCES IN STRENGTH AND TIMING OF
THIS SYSTEM THIS WEEKEND ARE MITIGATING FACTORS IN INTRODUCING
GALES IN THE HAZARDOUS WEATHER OUTLOOK. IT APPEARS THAT THE
STRONGEST WINDS WILL BE SATURDAY NIGHT INTO SUNDAY...BUT COULD
START SATURDAY AFTERNOON IF THE QUICKER MODEL SOLUTION IS CORRECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
240 AM MST SAT NOV 26 2011
.SHORT TERM (TODAY-MONDAY)...
240 AM MST SAT NOV 26 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW AMPLIFIED
RIDGE-TROUGH-RIDGE PATTERN OVER THE CONUS...WITH MEAN TROUGH AXIS
CENTERED ALONG CO/KS STATE LINE. AT THE SURFACE COLD FRONT CURRENTLY
SOUTHEAST OF CWA...WITH SURFACE HIGH PRESSURE QUICKLY BUILDING IN
BEHIND FRONT OVER CWA. UPSTREAM 3HR PRESSURE RISES AROUND 7MB HAVE
BEEN OBSERVED OVER PARTS OF EASTERN WYOMING/WESTERN NEBRASKA...WITH
3-5MB PRESSURE RISES OVER WESTERN PARTS OF CWA. VAD WIND PROFILER
DATA SHOWS 45-55KT LOW LEVEL JET OVERHEAD...WITH LOCAL OBSERVATIONS
REPORTING SURFACE WINDS GUSTING 45-48KT.
IMMEDIATE FORECAST CONCERNS IN THE SHORT RANGE ARE ON PRECIP CHANCES
EARLY THIS MORNING AND HIGH WINDS THROUGH THIS AFTERNOON.
RIGHT ENTRANCE REGION OF H25-H3 JET COMBINED WITH STEEP MID LEVEL
LAPSE RATES HAVE LED TO DEVELOPMENT ON SCT-ISO SHOWERS OVER NE
COLORADO...WHICH HAS PROGRESSED EAST INTO SW NEBRASKA AND EXTREME NW
KANSAS EARLY THIS MORNING. AS CAA CONTINUES EXPECT MOST LOCATION TO
SEE SNOW BECOME PREDOMINANT PRECIP TYPE. WEAK MOISTURE ADVECTION
COMBINED WITH BUILDING SUBSIDENCE ALOFT SHOULD LIMIT PRECIP
AMOUNTS...SO ONLY EXPECTING LOCALIZED SNOW TOTALS OF LESS THAN ONE
HALF INCH...WHILE MOST LOCATIONS WILL STRUGGLE TO SEE EVEN A FEW
TENTHS OF AN INCH DUE TO MELTING. GUIDANCE SNOWS STRONG SUBSIDENCE
OVERTAKING AREA BY 12Z ALONG WITH VERY DRY AIR ADVECTING IN OVER THE
AREA...WHICH SHOULD END PRECIP CHANCES. WILL KEEP FORECAST DRY AFTER
12Z FOR NOW AND ADJUST BASED ON TRENDS.
WIND FORECAST IS CURRENTLY ON TRACK...WITH WIND GUSTS EARLY THIS
MORNING ALREADY ON HIGH END OF WIND ADVISORY OVER MOST THE AREA. RUC
CURRENTLY HAS BEST HANDLE ON H85-H7 WINDS BASED ON PROFILER
DATA...AND SHOWS 50KT H85 JET SPREADING EAST OVER REMAINING CWA.
WHILE PEAK PRESSURE RISES OCCUR BEFORE 12Z THIS MORNING...PERSISTENT
50KT H85 JET AND INCREASED MIXING AFTER SUNRISE SHOULD SUPPORT WINDS
INCREASING TO WARNING CRITERIA. THE STRONGEST SURFACE WINDS SHOULD
THEN DECREASE TOWARDS 00Z AS MIXING DECREASES AND WINDS ALOFT BEGIN
TO SLACKEN.
TONIGHT-MONDAY NIGHT...H5 RIDGE BUILDS EAST AND STRENGTHENS OVER SW
CONUS...WITH SHORTWAVE RIDGE AXIS EXTENDING NORTH ACROSS CWA BY MON
NIGHT. LARGE SCALE SUBSIDENCE AND DEEP DRY AIR MASS OVER CWA WILL
HELP KEEP CONDITIONS DRY THROUGH THESE PERIODS WITH TEMPS WARMING TO
ABOUT 10-15F ABOVE NORMAL SUN/MON. TEMPS A LITTLE TRICKY ON MON AS
SHORTWAVE AND ASSOCIATED COLD FRONT MOVES ACROSS REGION. GUIDANCE
CONTINUING TO DIFFER ON POSITION/TIMING OF FRONT...WHICH WILL IMPACT
HIGH TEMPS MON ALONG WITH GUSTY WINDS MON AFTERNOON. FOR NOW HAVE
KEPT IN LINE WITH PREVIOUS FORECAST OF UPPER 50S NORTH/LOW 60S
SOUTH...HOWEVER TEMPS MAY END UP NEEDING TO BE LOWERED IF FASTER
FRONTAL TIMING OF SREF/GEM WERE TO BE REALIZED.
DR
.LONG TERM (TUESDAY-FRIDAY)...
240 AM MST SAT NOV 26 2011
AN UPPER LEVEL RIDGE WILL BUILD INTO THE TRI-STATE AREA THROUGH
THURSDAY. MODELS THEN BEGIN TO DISAGREE AS TO HOW QUICKLY THE
UPPER LEVEL RIDGE MOVES EAST AS THE UPPER LEVEL TROUGH BUILDS IN AND
WHEN THE COLD FRONT WILL MOVE THROUGH THURSDAY. AS A RESULT
HIGH TEMPERATURES FOR THURSDAY VARY SIGNIFICANTLY BETWEEN THE
MODELS. FRONTAL TIMING WILL ALSO AFFECT THE ARRIVAL AND TYPE OF
PRECIPITATION. CURRENT CONSENSUS HAS THE PRECIP. OCCURRING DURING
THE DAY FOR MOST OF THE CWA. DIFFICULT TO NAIL DOWN PRECIP. TYPE
THURSDAY DUE TO THE DIFFERENCE IN FRONTAL TIMING. GENERALLY HAVE
SNOW IN THE NORTHWEST AND FAR NORTH CWA WHICH TRANSITIONS TO A
NARROW BAND OF RAIN-SNOW MIX FOLLOWED BY RAIN FURTHER SOUTH. BEHIND
THE FRONT THE 850MB WINDS WILL BE GUSTY. HOWEVER MODELS DISAGREE
WITH THE TIMING AND PLACEMENT OF THE WINDS BEHIND THE FRONT...BUT
CONSENSUS HAS BREEZY CONDITIONS THURSDAY AFTERNOON. AFTER THURSDAY
THE UPPER LEVEL FLOW TURNS TO THE SOUTHWEST AND THE ENVIRONMENT
DRIES OUT. HOWEVER TEMPERATURES WILL REMAIN COOL AFTER THURSDAY AS
THE UPPER LEVEL TROUGH MOVES TOWARD THE AREA.
JTL
&&
.AVIATION...
949 PM MST FRI NOV 25 2011
FOR THE 06Z TAFS...STRONG WINDS THROUGH MUCH OF THE PERIOD AND THE
POSSIBILITY FOR MVFR CEILINGS EARLY IN THE PERIOD WILL BE THE MAIN
CONCERNS. WHILE WINDS WILL BE STRONG TONIGHT BEHIND THE
FRONT...WINDS WILL BE STRONGER STILL DURING THE DAYTIME ON
SATURDAY AS WINDS MIX DOWNWARD. HAVE INCLUDED 45 KNOT DAYTIME WINDS
IN THE TAFS...BUT THERE IS THE POTENTIAL FOR GUSTS TO BE EVEN
HIGHER CONSIDERING THE 850 MB WINDS FROM THE MOST RECENT MODEL
RUNS. THERE IS A CHANCE FOR MVFR CEILINGS IN THE 08Z TO 10Z TIME
FRAME. MODEL SOUNDINGS ARE INDICATING BETTER CHANCES FOR MVFR
CEILINGS AT KGLD AND WORSE AT KMCK COMPARED TO EARLIER TODAY...SO
HAVE ONLY INCLUDED MVFR CONDITIONS AT KGLD.
CJS
&&
.FIRE WEATHER...
240 AM MST SAT NOV 26 2011
RED FLAG WARNING CURRENTLY IN EFFECT FOR THIS AFTERNOON ACROSS
CWA. TD VALUES HAVE BEEN SLOWER TO DECREASE THAN PREVIOUS GUIDANCE
INDICATED...HOWEVER FINALLY BEGINNING TO SEE 10-15F TD VALUES
ADVECTING INTO EASTERN COLORADO. SINGLE DIGIT TD VALUES OVER
WYOMING SHOULD EVENTUALLY ADVECT OVER CWA...AND DESPITE AFTERNOON
TEMPS IN THE UPPER 30S/LOW 40S...CURRENTLY THINK RH VALUES 18-25%
SEEM REASONABLE. COMBINED WITH VERY STRONG WINDS THIS
AFTERNOON...CRITICAL FIRE CONDITIONS WILL CONTINUE TO BE A
CONCERN...SO NO CHANGES PLANNED FOR CURRENT HIGHLIGHT.
CRITICAL FIRE CONDITIONS WILL BE POSSIBLE AGAIN MONDAY AFTERNOON.
TIMING OF STRONGEST WINDS AND LOCATION OF LOWEST TD VALUES WILL
LIKELY BE DEPENDENT ON TIMING OF COLD FRONT...WHICH GUIDANCE IS
CURRENTLY DOING A POOR JOB OF TIMING OUT...SO WILL NEED TO MONITOR
THIS.
DR
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
KSZ001>004-013>016-027>029-041-042.
RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM
MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-
027>029-041-042.
WIND ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS MORNING FOR
KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
NEZ079>081.
RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM
MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081.
WIND ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS MORNING FOR
NEZ079>081.
CO...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092.
RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS
AFTERNOON FOR COZ252>254.
WIND ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
309 AM CST SAT NOV 26 2011
.SYNOPSIS...
UPPER AIR ANALYSIS SHOWS THAT A LARGE TROF IS MOVING ACROSS THE
PLAINS THIS MORNING. THIS FEATURE CAUSED THE PRECIPITATION EVENT
THAT OCCURRED LAST NIGHT AND BROUGHT THE WELCOMED RAINS. A COLD
FRONT WAS PUSHING INTO WESTERN KANSAS EARLY THIS MORNING AND WILL
BE THE MAIN IMPACT TODAY IN TERMS OF WEATHER.
&&
.DISCUSSION...
DAYS 1-2...
IMMEDIATE CONCERN IS THE PRECIPITATION MOVING OUT OF THE AREA. KDDC
WSR-88D SHOWS THAT THE PRECIPITATION SHIELD IS SLOWLY MOVING OUT
OF THE CWFA AND HAVE TAPERED POPS DOWN AS A RESULT. I HAVE 15 PERCENT
POPS NORTH WHERE THE GFS AND THE RUC ARE INDICATING THE POTENTIAL FOR
A FEW SPRINKLES OR FLURRIES.
THE OTHER FOCUS TODAY IS WIND. 1 KM WINDS ARE AROUND 50 KT WITH 850
HPA WINDS IN THE 45 TO 55 KT RANGE. A FRONT IS MOVING ACROSS WESTERN
KANSAS EARLY THIS MORNING WITH STRONG WINDS ALREADY BEING REPORTED ACROSS
THE HIGH PLAINS OF EASTERN COLORADO. THE MOST RECENT HRRR SHOWS 10M
WINDS AROUND 35 KT THROUGH THIS AFTERNOON. AS A RESULT, HAVE ISSUED
A HIGH WIND WARNING FOR POINTS WEST OF A LINE FROM TREGO TO CLARK
COUNTIES. FURTHER EAST TOWARDS HAYS, THE MOS GUIDANCE IS MORE
MARGINAL SO HAVE DECIDED TO KEEP THE AREA EAST OF A LINE FROM ELLIS
TO COMANCHE COUNTIES IN A WIND ADVISORY. FURTHER WEST, MOS GUIDANCE
WAS SUPPORTING WIND WARNING CRITERIA WITH FORECAST OF 40G50KT AT
GARDEN CITY AND LIBERAL. SINCE WE WILL HAVE A NORTHWESTERLY
DOWNSLOPE COMPONENT, I INCREASED TEMPERATURES A DEGREE OR TWO ABOVE
GUIDANCE. TEMPERATURES SHOULD WARM TO THE UPPER 40S TO LOWER 50S.
THE FIRE WEATHER WATCH WAS ALSO CANCELLED AS RH`S NOW LOOK LIKE TO NOT
MEET THE 15 PERCENT CRITERIA. FOR MORE INFORMATION, SEE THE FIRE WEATHER
AFD SECTION BELOW.
BY TONIGHT, WE WILL HAVE NORTHERLY FLOW ALOFT IN THE WAKE OF THE UPPER
LEVEL TROF. SKIES SHOULD CLEAR AS DRY AIR ADVECTION STARTS THROUGH THE
ATMOSPHERIC COLUMN SO AM EXPECTING COOLER OVERNIGHT LOWS...GENERALLY IN
THE 20S.
THE WEATHER WILL STILL BE QUIET SUNDAY AS 500 HPA HEIGHTS INCREASE IN
RESPONSE TO RIDGING ACROSS THE DESERT SOUTHWEST. POPS WILL REMAIN
AT ZERO. MAX TEMPERATURES ARE EXPECTED IN THE 50S WHICH IS SLIGHTLY
ABOVE NORMAL.
DAYS 3-7...
THE 00Z RUNS OF THE MEDIUM RANGE MODELS HAVE COME INTO BETTER
AGREEMENT IN HANDLING THE UPPER TROUGH THAT IS CURRENTLY MOVING OUT
INTO THE CENTRAL CONUS. THE GFS HAS TRENDED TOWARD THE OTHER MODELS
IN THAT IT IS NOW CLOSING OFF AN UPPER LOW OVER THE LOWER
MISSISSIPPI VALLEY SIMILAR TO...BUT NOT AS FAR SOUTH...AS THE ECMWF.
ANY SENSIBLE WEATHER IMPACTS FROM THIS WILL BE WELL TO THE EAST OF
WESTERN KANSAS. THE MODELS CONTINUE TO SHOW THE NEXT STRONG
SHORTWAVE TROUGH MOVING EAST THROUGH THE NORTHERN CONUS WITH SOME
SHORTWAVE ENERGY MOVING SOUTHEAST OVER THE CENTRAL HIGH PLAINS.
ANOTHER STRONG COLD FRONT WILL PUSH SOUTH THROUGH WESTERN KANSAS LATE
MONDAY AFTERNOON AND EVENING. THE MODELS ARE NOT INDICATING MUCH IN
THE WAY OF PRECIPITATION WITH THIS FRONT. THIS LOOKS REASONABLE
GIVEN THAT LOW LEVEL MOISTURE WILL NOT HAVE AN OPPORTUNITY TO RETURN
NORTHWARD IN THE WAKE OF TODAYS UPPER TROUGH. THERE COULD BE A
PERIOD OF STRONG WINDS BEHIND THE FRONT AS AT LEAST THE GFS IS
SHOWING 850 MB WINDS TO 50 KNOTS.
THE MIDDLE PART OF NEXT WEEK SHOULD BE FAIRLY QUIET AS UPPER LEVEL
RIDGING MOVES OVER THE CENTRAL PLAINS. HOWEVER...ANOTHER UPPER
TROUGH WILL BE DIGGING SOUTH INTO THE WESTERN STATES. THE MODELS ARE
DIFFERING IN SOMEWHAT IN HOW THIS SYSTEM DEVELOPS BUT THEY ALL
DEVELOP IT INTO A CLOSED LOW OVER SOUTHERN CALIFORNIA/ARIZONA BY
NEXT FRIDAY. THE MODELS BRING ANOTHER COLD FRONT WITH MUCH COOLER
AIR SOUTH ACROSS WESTERN KANSAS AROUND THURSDAY OR FRIDAY AND THEN
MOVE THE UPPER LOW EAST TOWARD THE CENTRAL AND SOUTHERN PLAINS NEXT
WEEKEND. THIS COULD HAVE SOME SIGNIFICANT WEATHER IMPACTS WITH THE
POSSIBILITY FOR A SNOWSTORM ACROSS SOUTHWEST KANSAS NEXT WEEKEND
DEPENDING ON THE TRACK OF THE UPPER LOW.
&&
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
VERY STRONG NORTHERLY WINDS WILL PERSIST AT THE TAF SITES THROUGH
TODAY. LOOK FOR SUSTAINED WINDS AROUND 30 TO 40 KNOTS WITH GUSTS TO
AROUND 50 KNOTS AT GARDEN CITY AND DODGE CITY WITH WINDS NEARLY THAT
STRONG AT HAYS. THERE COULD ALSO BE A PERIOD OF LIGHT RAIN CHANGING
TO LIGHT SNOW ALONG WITH MVFR CIGS FROM AROUND 12Z TO 16Z WITH VFR
CONDITIONS PREVAILING THROUGH THE REST OF THE DAY. NORTH WINDS WILL
DECREASE INTO THE 15 TO 25 KNOT RANGE AFTER 00Z
&&
.FIRE WEATHER...
HAVE CANCELLED THE FIRE WEATHER WATCH AS UPSTREAM DEWPOINT OBSERVATIONS
ARE SHOWING THAT THE MODEL DEWPOINTS ARE RUNNING A LITTLE LOW. EVEN
WARMING UP TEMPERATURES AND ARTIFICIALLY LOWERING DEWPOINTS ONLY PRODUCES
RH`S IN THE 20 TO 30 PERCENT RANGE. WINDS WILL BE STRONG TODAY THOUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 25 54 31 / 40 0 0 0
GCK 46 23 55 31 / 20 0 0 0
EHA 45 23 58 35 / 10 0 0 0
LBL 47 23 56 32 / 20 0 0 0
HYS 48 24 52 30 / 20 0 0 0
P28 50 27 53 30 / 40 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ031-046-065-066-
079>081-089-090.
&&
$$
FN36/02/02
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST SAT NOV 26 2011
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROFFING OVER
THE PLAINS BTWN PERSISTENT RDG OVER THE ERN CONUS AND ANOTHER RDG
OVER THE W COAST. THERE ARE 3 SHRTWVS OF SIGNIFICANCE EMBEDDED
WITHIN THE TROF OVER THE PLAINS...ONE OVER SASKTATCHEWAN...ANOTHER
IN WYOMING...AND ANOTHER CENTERED NEAR THE TX PANHANDLE. THE COMPLEX
INTERACTION BTWN THESE SEPARATE DISTURBANCES HAS MADE THE EVOLUTION
OF THE UPCOMING WX PATTERN A BIT TRICKY FOR RECENT SHIFTS. THE
DISTURBANCE OVER WYOMING IS SUPPORTING A SFC LO OVER WCNTRL MN. A
FAIRLY WELL DEFINED COMMA CLD IS PRESENT WITH COMMA HEAD PCPN NOTED
UNDER COLDER CLD TOPS OVER THE DAKOTAS ON THE COLD SIDE OF THE
ACCOMPANYING H85 LO. THE WARM CONVEYOR BELT CLD EXTENDS THRU THE UPR
MIDWEST/UPR MS RIVER VALLEY INTO THE GRT LKS...BUT DRY AIR NOTED AT
H7 BY THE BULK OF THE RAOBS...VERY WELL SHOWN BY THE 00Z GRB/MPX
RAOBS...E OF THE UPR TROF AXIS HAS PREVENTED WDSPRD RA FM DVLPG
DESPITE INCRSG UPR DVGC UNDER COUPLED UPR JET STRUCTURE BTWN H3
SPEED MAX IN ONTARIO AND ANOTHER IN SDAKOTA/NEBRASKA. HOWEVER...THE
INTERACTION BTWN THIS DYNAMIC AND THE STRONG SW FLOW E OF THE MN LO
THAT IS ADVECTING UNSEASONABLY HI H85 DWPTS UP TO 6C FROM OMAHA TO
THRU IOWA TOWARD THE UPR MIDWEST HAS CAUSED A RECENT EXPANSION OF
THE RADAR ECHOES TO THE SW. ALTHOUGH A SFC COLD FNT...ASSOCIATED
WITH THE JET MAX IN ONTARIO...HAS SLID OVER UPR MI...TEMPS OVER UPR
MI ARE WELL ABV NORMAL IN THE UPR 30S/40S. THIS FNT HAS PRETTY MUCH
STALLED BUT COULD SERVE AS A FOCAL POINT FOR INCRSG LLVL MSTR CNVGC/
FGEN/ISENTROPIC ASCENT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THRU THIS WEEKEND ARE PCPN CHCS/TYPES/POTENTIAL
SN ACCUMS AND TIMING OF DRYING TREND FOLLOWING THE PASSAGE OF UPR
TROF/SFC LO.
TDAY...RECENT MODEL RUNS HAVE COME INTO BETTER AGREEMENT ON EXPECTED
STRENGTH/TRACK OF SFC LO THAT WL IMPACT THE CWA AHEAD OF DISTURBANCE
NOW IN WYOMING. THIS LO IS PROGGED TO MOVE TO BTWN MQT AND MUNISING
BY 00Z SUN. AS THE SFC LO NOW IN MN MOVES TOWARD UPR MI...GUIDANCE
SHOWS INCRSG ISENTROPIC ASCENT FOCUSED ON THE 290K SFC/UPR DVGC
UNDER FVRBL ORIENTATION OF UPR JET CORES/PWAT SURGING TO ALMOST 250
PCT OF NORMAL WITH THE ARRIVAL OF H85 DWPTS OF 5C. BOTH THE 00Z
NAM/GFS SHOW THE SHARPEST H85-7 FGEN ACCOMPANYING THE FVRBL
INTERACTION BTWN THESE DYNAMICS/MOISTENING AND THE FNTL BNDRY
IMPACTING MAINLY THE NW CWA WITH THE HIEST QPF THEN SHIFTING OUT
OVER LK SUP AND TO THE E IN THE AFTN. ALTHOUGH THE FCST LLVL CYC NNW
FLOW IN THE WAKE OF THE SFC LO PASSING TO THE E WL PROBABLY KEEP
SOME PCPN GOING OVER THE W...FCST DEEP LYR QVECTOR DVGC ARRIVING FM
THE SW IN THE AFTN WL LIKELY LIMIT THE INTENSITY OF THE PCPN THERE
MORE THAN EARLIER ANTICIPATED AND WEAKEN THE COMMA HEAD PCPN NOTED
OVER THE DAKOTAS EARLY THIS MRNG. THE ARRIVAL OF SOMEWHAT COLDER
LLVL AIR INTO THE W LATE...WITH THE MORE AGGRESSIVE GFS SHOWING H85
TEMPS FALLING AS LO AS -3C AT IWD BY 00Z SUN...MAY CAUSE ANY PCPN TO
AT LEAST MIX WITH SN...BUT THE WEAKER DYNAMIC COOLING AND SFC TEMPS
HOLDING ABV 32 WL PREVENT ANY ACCUMULATION.
TNGT...AS THE SFC LO SHIFTS NE INTO ERN ONTARIO BY 12Z SUN...A
COLDER CYC NNW FLOW WL ENVELOP THE ENTIRE CWA IN ITS WAKE. WITH DEEP
LYR QVECTOR DVGC DOMINATING IN THE CAD/DRYING IN THE WAKE OF THE
SHRTWV...LINGERING PCPN WL SHIFT TO AN LES MODE WITH H85 TEMPS
WITHIN THE TRAILING THERMAL TROF FALLING TO -8C TO -10C /LK WATER
TEMPS ARE 5-6C/ OVER THE W BY 12Z SUN UNDER CYC FLOW/SLOWLY DECAYING
DEEPER MSTR WITHIN THE COMMA HEAD. SINCE THE DGZ IS FCST TO BE
WITHIN THE LARGER SCALE SUBSIDENCE AT THE TOP OF THE MOIST LYR AND
ABV THE SHARPER LLVL CNVGC/FORCING...SUSPECT THIS EVENT WL BE A HI
POP/FAIRLY LO QPF WITH NO NEED FOR HEADLINES ATTM. STILL...A FEW
INCHES OF WET SN ARE LIKELY OVER MAINLY THE HIER TERRAIN IN THE NNW
WIND SN BELTS OF THE W WHERE THE UPSLOPE COOLING/LLVL CNVGC WL BE
MAXIMIZED. ALTHOUGH THE FLOW WL TURN TO THE NW AFT 06Z OVER THE E...
THE AIR WL NOT BE SUFFICIENTLY COLD FOR SGNFT LES THERE THRU 12Z.
CUT POPS SGNFTLY OVER THE SCNTRL WITH EXPECTED DOWNSLOPE NW FLOW IN
THE ABSENCE OF ANY DYNAMIC SUPPORT.
SUN...AS THE H85 THERMAL TROF SHIFTS E FOLLOWING THE DEPARTING SFC
LO...EXPECT LES TO ENVELOP MAINLY THE NNW WIND SN BELTS OVER THE E.
BUT THRU THE DAY...RISING HGTS/MORE ACYC FLOW WL TEND TO DIMINISH
THIS ACTIVITY W-E AS WELL. ANY SN ACCUMULATIONS SHOULD REMAIN ON THE
LGT SIDE WITH POOR SN GROWTH PARAMETERS/DGZ ABV THE RELATIVELY
SHALLOW MSTR/LLVL FORCING IN THE ABSENCE OF DYNAMIC SUPPORT. OTRW...
THE DAY SHOULD FEATURE MORE SEASONABLY CHILLY TEMPS. THE SC WL
SLOWLY BREAK UP...ESPECIALLY OVER THE SCNTRL IN THE PRESENCE OF
DOWNSLOPE FLOW.
SUN NGT...UNDER BLDG UPR RDG...SFC HI PRES RDG AXIS WL SHIFT OVER
THE CWA. LGT WINDS UNDER THIS HI/FCST PWAT 60 PCT OF NORMAL WARRANTS
LOWERING PREVIOUS FCST MIN TEMPS TOWARD THE LO END OF GUIDANCE...
ESPECIALLY OVER THE INTERIOR W AND CNTRL.
MON...WARMER AIR IS FCST TO RETURN WITH STRENGTHENING SW FLOW BTWN
HI PRES SINKING INTO THE LOWER GRT LKS AND NEXT SHRTW/SFC LO
TRACKING INTO NW ONTARIO. H85 TEMPS ARE FCST TO REACH ARND 5C DURING
THE AFTN. THE COLD FNT ATTENDANT TO THE LO WL APRCH THE WRN ZNS LATE
IN THE DAY...BUT RELATIVE DRYNESS OF AIRMASS IN PLACE WITH MSTR
INFLOW DISRUPTED BY DVLPG LO IN THE OH RIVER VALLEY AND PASSAGE OF
STRONGER DYNAMICS FARTHER TO THE N WL MAINTAIN DRY WX.
MON NGT...EXPECT COLD FROPA ATTENDANT TO SHRTWV/SFC LO PASSAGE IN
NRN ONTARIO. HIER RH IS FCST TO STAY TO THE N CLOSER TO SHRTWV
TRACK...SO EXPECT A DRY FROPA. FCST SCHC POPS OVER THE NRN TIER
WHERE VEERING FLOW FM SW TO NW WL RESULT IN SOME UPSLOPE WIND
COMPONENT.
EXTENDED...CWA WL BE DOMINATED BY RELATIVELY DRY NRN BRANCH UPR
FLOW. SO EXPECT NO SGNFT PCPN EVENTS DURING THIS TIME THAT WL LIKELY
FEATURE FAIRLY CHANGEABLE TEMPS. TIMING DIFFERENCES ON SHRTWVS
EMBEDDED WITHIN THE FLOW WARRANTS HOLDING CLOSE TO ALL BLEND FCST.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
TAF FCSTS WILL CONTINUE TO BE A CHALLENGE. IT APPEARS UPSLOPE LIFR
TO VLIFR STRATUS IS BEGINNING TO TAKE SHAPE AT KCMX AND KSAW SO
EXPECT THESE CONDITIONS TO CONTINUE INTO SAT MORNING PERHAPS EVEN
ENHANCED BY INCOMING RAIN FM SYSTEM MOVING UP FM THE CENTRAL PLAINS.
KIWD WILL STAY AT MVFR/IFR UNTIL RAIN MOVES IN LATE TONIGHT AND THEN
I WOULD EXPECT A TREND TOWARD LIFR THERE INTO SAT MORNING.
CONDITIONS WILL MODESTLY IMPROVE TO IFR AT ALL SITES TOWARD EVENING
FROM WEST TO EAST WITH ADVECTION OF DRIER DEWPOINTS BEHIND SYSTEM/S
ASSOC COLD FRONT. SCT SHRA WILL CHANGE TO SCT SHSN AT KIWD AROUND
00Z AND THEN AT KCMX AND KSAW LATER IN THE EVENING.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM IN MN WILL SLIDE NE TODAY AND ACROSS UPPER
MICHIGAN. THIS WILL PRODUCE EASTERLY WINDS UP TO 30KTS OVER THE NRN
HALF OF LAKE SUPERIOR...WITH A FEW GALE FORCE GUSTS TOP 35KTS NEAR
ISLE ROYALE. AS THE LOW SHIFTS EAST TONIGHT...EXPECT WINDS TO TURN
TO THE NNW. MODELS HAVE TRENDED MUCH WEAKER WITH THE LOW AND THUS
HAVE LIMITED CONFIDENCE IN SEEING WINDS WARRENTING A GALE
WATCH/WARNING. THUS...HAVE DECIDED TO CANCEL THE WATCH SINCE THE
MAIN WINDS WILL BE IN THE 30KT RANGE. BEST CHANCE FOR SOME GALE
FORCE GUSTS WILL COME FROM 09-15Z TONIGHT OVER CENTRAL LAKE SUPERIOR
AND WILL MENTION SOME GUSTS FOR THAT TIME FRAME. WINDS WILL DIMINISH
BELOW 20KTS ON SUN NIGHT DUE TO A WEAK SFC TROUGH. EXPECT ANOTHER
SFC TROUGH TO SLIDE ACROSS LK SUPERIOR ON MONDAY EVENING...WITH ONCE
AGAIN COULD PRODUCE WINDS UP TO 30KTS. CENTRAL LK SUPERIOR COULD
ALSO SEE A FEW GALE FORCE GUSTS TO 35KTS. EXPECT WINDS TO FALL BELOW
25KTS TUES AFTN AND CONTINUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 AM CST SAT NOV 26 2011
.DISCUSSION...
MAIN FORECAST CONCERN IS WIND TODAY. WATER VAPOR IMAGERY EARLY THIS
MORNING SHOWED A FAIRLY IMPRESSIVE TROUGH EXTENDING FROM SASKATCHEWAN
DOWN INTO MEXICO. 500 MB HEIGHT FALLS WERE AROUND OR IN EXCESS OF
100 METERS FROM SOUTHWEST NEBRASKA TO WEST TEXAS LAST EVENING. A FEW
THUNDERSTORMS WERE NOTED NEAR THE KANSAS/OKLAHOMA BORDER. A COLD
FRONT STRETCHED FROM LOW PRESSURE OVER SOUTHERN MINNESOTA DOWN INTO
WESTERN OKLAHOMA.
THE TROUGH AND FRONT WILL BOTH CONTINUE TO MOVE EAST TODAY...WITH A
TIGHT PRESSURE GRADIENT AND STRONG WINDS SPREADING EAST ACROSS THE
AREA. DELAYED WIND ADVISORY A FEW HOURS FOR PARTS OF THE AREA THIS
MORNING...BUT OTHERWISE WIND FORECAST IS SIMILAR TO PREVIOUS GRIDS.
THE 06Z RUC MODEL DID SHOW SOME LIGHT PRECIPITATION MOVING INTO PARTS
OF NORTHEAST NEBRASKA THROUGH 18Z. OTHERWISE...THE SHOWERS IN FAR
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA SHOULD MOVE OUT VERY EARLY
THIS MORNING. MUCH COLDER AIR WILL MOVE INTO THE AREA TODAY. LOWS
TONIGHT SHOULD BOTTOM OUT IN THE UPPER TEENS TO MID 20S. WINDS WILL
REMAIN BRISK AT LEAST EARLY TONIGHT BUT MOST LIKELY BELOW ADVISORY
LEVELS. AS HIGH PRESSURE AT THE SURFACE BUILDS INTO THE AREA ON
SUNDAY...WINDS WILL DECREASE. EXPECT WEAK RETURN FLOW TO SETUP LATE
SUNDAY NIGHT...BUT IS NOT EXPECTED TO BE STRONG ENOUGH TO KEEP LOWS
UP MUCH ABOVE MOS GUIDANCE.
MILDER AIR SHOULD BE OVER THE AREA MONDAY...WITH HIGHS IN THE UPPER
40S AND LOWER 50S. NEXT COLD FRONT PUSHES THROUGH MONDAY NIGHT...BUT
SHOULD NOT PRODUCE ANY PRECIPITATION. KEPT TUESDAY AND WEDNESDAY DRY
BUT ADDED A SLIGHT CHANCE OF LIGHT SNOW FOR ABOUT THE NORTHERN HALF
OF THE FORECAST AREA THURSDAY. 00Z GFS WAS THE BEST MODEL DEPICTING
THAT SCENARIO.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK AND KOFK.
VFR CONDITIONS ARE FORECAST AT KOFK THROUGH THE FORECAST PERIOD. SOME
MVFR CEILINGS MAY OCCUR AT KOMA AND KLNK AFTER 18Z. STRONG SURFACE
COLD FRONT WILL MOVE ACROSS THE AREA WITH STRONG NORTHWEST WINDS
SHOULD MOVE ACROSS KOFK BY 08Z...KLNK BY 11Z AND KOMA BY 15Z. WINDS
DURING THE DAY ON SATURDAY ARE EXPECTED TO GUST OUT OF THE NORTHWEST
BETWEEN 35 TO 40 KT. LOW LEVEL WIND SHEAR IS LIKELY FROM 08Z TO 15Z
AT KOFK BEFORE TURBULENT MIXING ALLOWS WINDS TO INCREASE AT THE
SURFACE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NEZ015-033-034-043>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR IAZ043-055-056-069-079-080-090-091.
&&
$$
DISCUSSION...MILLER
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
307 AM CST SAT NOV 26 2011
.SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE MAIN CONCERN IN THE
SHORT TERM FORECAST PERIOD WILL BE WINDS TODAY ALONG WITH THE
POSSIBILITY OF RED FLAG CONDITIONS. THE RED FLAG CONCERNS WILL BE
ADDRESSED IN THE FIRE WEATHER PORTION OF THE DISCUSSION LOCATED
BELOW.
A LARGE MID LEVEL TROUGH MOVING ACROSS THE CENTRAL UNITED STATES
THIS MORNING IS PUSHING A STRONG COLD FRONT ACROSS THE REGION. MSAS
3 HOUR PRESSURE CHANGE ANALYSIS SHOWS PRESSURE RISES NEAR 7
MILLIBARS BEHIND THE FRONT WHICH IS HELPING BRING A NICE SURGE OF
WINDS AS THE BOUNDARY PASSES. WINDS WILL LIKELY SETTLE DOWN TO SOME
DEGREE THIS MORNING BEHIND THE FRONT...HOWEVER IT WILL NOT TAKE LONG
FOR THE WINDS TO INCREASE AGAIN AS MIXING COMMENCES THIS MORNING.
ALL SIGNS STILL POINT TO A DECENT WIND EVENT FOR TODAY WITH A STRONG
SURFACE PRESSURE GRADIENT DEVELOPING DUE TO LOW PRESSURE TO THE
EAST...AND HIGH PRESSURE TO THE WEST.
THE PRIMARY CONCERN SURROUNDS THE GOING HIGH WIND WARNING AND
WIND ADVISORY...AND POTENTIAL CHANGES/ADJUSTMENTS TO THE HEADLINES
FOR TODAY. NAM PROXIMITY SOUNDINGS SUGGEST MIXING TO NEAR H8 IS
LIKELY ACROSS A MAJORITY OF THE FORECAST AREA TODAY...WITH 50 TO
60 KTS OF WIND EXPECTED AT THAT LEVEL. THE FLOW WILL BE FAIRLY
UNIDIRECTIONAL IN THE MIXED LAYER...SO SOME OF THE THE STRONG
WINDS COULD POTENTIALLY TRANSFER TO THE SURFACE. THE HEART OF THE
STRONGER WINDS ARE SHOWN TO RESIDE ACROSS WESTERN PORTIONS OF THE
FORECAST AREA...AND THE CURRENT HIGH WIND WARNING COVERS THAT
WELL. WILL GO AHEAD AND LEAVE THE HEADLINES IN THEIR PRESENT
CONFIGURATION...THOUGH THE NEXT SHIFT WILL OBVIOUSLY HAVE TO WATCH
TRENDS AS THE STRONGER H8 WINDS SHIFT SOUTHEAST THIS AFTERNOON.
A SMALLER CONCERN FOR TODAY WILL BE THE POSSIBILITY OF ANY LINGERING
FLURRIES OR SPRINKLES AS THE LEFT EXIT REGION OF A 100KT UPPER
JET SEGMENT SHIFTS THROUGH THE AREA. THE LATEST SREF AND NCEP 4KM
WRF KEEP IT DRY AFTER 12Z TODAY...WHILE THE GFS AND NOW 26.06Z
NAM SUGGESTS THERE COULD BE LINGERING LIGHT PRECIPITATION IN PARTS
OF NORTH CENTRAL KANSAS THIS MORNING...WHILE THE RUC DEVELOPS
LIGHT QPF IN EASTERN PARTS OF THE FORECAST AREA. CROSS SECTIONS
OF RELATIVE HUMIDITY/OMEGA FROM THE NAM REVEAL DRY LOW LEVELS
WHICH WILL BE TOUGH TO OVERCOME...ESPECIALLY AS THE FORCING
WEAKENS...SO WOULD RATHER CARRY A NON MEASURABLE EVENT SUCH AS
SPRINKLES OR FLURRIES. H85 TEMPERATURES QUICKLY FALL BELOW
FREEZING THIS MORNING...HOWEVER ABOVE FREEZING H925 TEMPERATURES
WILL PERSIST...SO WILL GO WITH SPRINKLES/FLURRIES IN THE GRIDS.
THE STRONGEST OF THE WINDS SHOULD SUBSIDE BY EARLY EVENING AS MIXING
BEGINS TO DIMINISH. H5 HEIGHTS BEGIN TO RISE TONIGHT...WITH WARMER
AIR GRADUALLY RETURNING FOR SUNDAY AND MONDAY. IN FACT...H85
TEMPERATURES RISE FROM -5 DEGREES CELSIUS TONIGHT...TO NEARLY +10
DEGREES CELSIUS ON MONDAY IN PORTIONS OF THE FORECAST AREA. WILL
AIM FOR HIGHS IN THE MID 40S TO LOWER 50S ON SUNDAY...WITH 50S ON
MONDAY.
ANOTHER MID LEVEL WAVE HELPS KNOCK DOWN THE RIDGE MONDAY AFTERNOON
INTO MONDAY NIGHT...WITH ANOTHER COLD FRONT PLOWING THROUGH THE
AREA. MOISTURE APPEARS LIMITED WITH THE PASSAGE OF THE WAVE/FRONT
AND WILL MAINTAIN A DRY FORECAST AS IT PASSES. WINDS WILL AGAIN
BECOME GUSTY AS THE FRONT PASSES...BUT CURRENTLY IT APPEARS SPEEDS
SHOULD STAY BELOW ADVISORY LEVELS.
.LONG TERM...TUESDAY THROUGH FRIDAY.
MODELS NOT IN TOO BAD OF AGREEMENT AT THE START OF THE LONG TERM
PERIOD...WITH NORTHWESTERLY FLOW SET UP IN THE UPPER LEVELS AS A LOW
PRESSURE SYSTEM SPINS OVER THE SOUTHEASTERN CONUS AND A RIDGE AXIS
SETS UP OVER THE WEST COAST. WITH NO DISTURBANCES EXPECTED TO PUSH
THROUGH THE REGION...FORECAST FOR TUESDAY REMAINS DRY. GETTING INTO
TUESDAY NIGHT THROUGH THURSDAY...EXPECTING TO SEE SHORTWAVE UPPER
LEVEL RIDGING BUILD INTO THE CENTRAL PLAINS EXTENDING FROM THE AREA
OF HIGH PRESSURE CENTERED JUST OFF THE SRN COAST OF CA...BETWEEN THE
LOW PRESSURE CONTINUES TO PUSH NORTHEAST TOWARD THE EAST COAST AND
ANOTHER DISTURBANCE MOVING FROM THE PAC NW INTO THE ROCKIES.
A LITTLE MORE UNCERTAINTY ARISES INTO THURSDAY AND FRIDAY WITH THE
LATEST MODEL RUNS HAVING A FEW DIFFERENCES. THE GENERAL STORY IS
THE DISTURBANCE WHICH HAS SHIFTED INTO THE ROCKIES BECOMES
SPLIT...WITH A CLOSED LOW DEVELOPING OVER THE WRN/SWRN CONUS...BUT
MODELS VARY ON THE TIMING AND LOCATION OF THE LOW AND WHAT HAPPENS
WITH THE NORTHERN ENERGY. THE GFS PUSHES THE NORTHERN ENERGY
FURTHER SOUTH INTO THE REGION...WHILE THE ECMWF SHOWS MORE RIDGING
HELPING TO PUSH IT FURTHER EAST. INTRODUCED SMALL PRECIPITATION
CHANCES ACROSS THE NORTHERN PORTIONS OF THE CWA TO ACCOUNT FOR THIS
DISTURBANCE IN THE REGION...BUT KEPT IT CONFINED TO THE DAYTIME
HOURS ON THURSDAY. TEMPERATURES SUGGEST THE PTYPE WOULD BE SNOW.
ANY PRECIPITATION WOULD NOT STICK AROUND LONG...AND KEPT THURSDAY
NIGHT AND FRIDAY DRY.
WHILE A BUMP UP IN TEMPERATURES IS EXPECTED ON WEDNESDAY WITH THE
RIDGING SET UP AND HIGHS IN THE UPPER 40S TO LOWER/MID
50S...COMPARED TO THE LOWER/MID 40S ON TUESDAY...A COLD FRONT IS
EXPECTED TO PUSH THROUGH THE CWA EARLY THURSDAY. THE COOLER AIR
ACCOMPANYING THE FRONT LOOKS TO DROP HIGHS FOR THURSDAY INTO THE MID
30S TO LOWER 40S...WITH MID 30S EXPECTED FOR FRIDAY.
&&
.AVIATION...06Z TAF. PRIMARY FORECAST CONCERN FOR THIS TAF PERIOD
CONTINUES TO LIE WITH STRONG WINDS EXPECTED. SURFACE COLD FRONT
CURRENTLY PUSHING ITS WAY ACROSS THE CWA...WITH WINDS AT THE
TERMINAL ALREADY HAVING SHIFTED TO THE WEST...AND WILL SOON BE OUT
OF THE NORTHWEST. BETWEEN A TIGHTENING PRESSURE GRADIENT/PRESSURE
RISES AND A CORRIDOR OF STRONGER WINDS ALOFT...EXPECTING WINDS TO
BE ON THE INCREASE...TOPPING OUT IN THE MID MORNING THROUGH MID
AFTERNOON HOURS. SUSTAINED SPEEDS OF 30 TO 40 MPH AND GUSTS NEAR
50 MPH ARE EXPECTED. VFR CONDITIONS ARE EXPECTED WITH CLOUD COVER
REMAINING IN THE MID/UPPER LEVELS...BUT CANT COMPLETELY RULE OUT A
BRIEF PERIOD OF MVFR CEILINGS WITH THE STRATUS ACCOMPANYING THE
SURFACE FRONT. OTHERWISE CLEARING SKIES ARE EXPECTED BY
MIDDAY...CONTINUING THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.FIRE WEATHER...AS STATED ABOVE WINDS TODAY WILL EASILY EXCEED
THE 25 KT GUST CRITERIA NEEDED FOR A RED FLAG WARNING. THE BIGGEST
CONCERN WILL BE RELATIVE HUMIDITY VALUES DROPPING TO 20 PERCENT OR
LESS. THE NAM AND GFS HAVE BOTH COME IN WITH HIGHER SURFACE
DEWPOINTS ON THE 00Z RUNS...AND THIS TREND IS ALSO EVIDENT EVEN
WHEN MIXING DEWPOINTS ALOFT TO THE SURFACE. THAT BEING SAID...AM
STILL CONCERNED ABOUT FIRE WEATHER ISSUES TODAY...ESPECIALLY WITH
THE LATEST ECMWF STILL SUPPORTING LOWER DEWPOINTS THIS AFTERNOON.
WILL HOLD ONTO THE LOWER DEWPOINTS SHOWN BY THE CURRENT FORECAST
AND LATEST ECMWF AND KEEP THE RED FLAG WARNING IN PLACE FOR THIS
AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ041-048-049-063-
064-076-077-086-087.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ039-040-046-
047-060>062-072>075-082>085.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ039-040-046-047-060>062-072>075-082>085.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ007-019.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005-006-017-
018.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
KSZ005>007-017>019.
&&
$$
SHORT TERM/FIRE WEATHER...KING
LONG TERM/AVIATION...ADO
AREA FORECAST DISCUSSION
NWS NORMAN OK
1047 PM CST FRI NOV 25 2011
.AVIATION...
/06Z TAFS/
SCATTERED SHOWERS WILL CONTINUE TO AFFECT MUCH OF THE AREA
OVERNIGHT AS AN UPPER LEVEL STORM SYSTEM MOVES EAST ACROSS THE
PLAINS. CEILINGS WILL LOWER AT TIMES BELOW MVFR THRESHOLDS.
MEANWHILE... A COLD FRONT WILL MOVE INTO NW OK LATE TONIGHT AND
ACROSS REMAINING TERMINAL LOCATIONS BY SATURDAY MORNING. ALTHOUGH
THE RAIN WILL BE SHIFTING EAST OUT OF THE AREA AND CEILINGS
GRADUALLY IMPROVING DURING THE DAY... STRONG SURFACE WINDS...
WITH GUSTS IN EXCESS OF 35 KTS... WILL CONTINUE BEHIND THE FRONT
THROUGH MUCH OF THE FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1012 PM CST FRI NOV 25 2011/
UPDATE...
FIRST BAND OF PRECIPITATION CONTINUES TO SHIFT EAST AS THE AREAS
OF RAIN THEMSELVES MOVE NORTHEAST. ADDITIONAL SHOWER AND
THUNDERSTORM DEVELOPMENT CONTINUES IN WESTERN KANSAS AND THE
OKLAHOMA AND NORTHERN TEXAS PANHANDLES NEAR THE SURFACE FRONT.
LOCAL WRF.. HRRR AND RUC SUGGEST THAT THERE WILL BE THE CHANCE OF
DEVELOPMENT DOWN THE FRONT AS IT MOVES SOUTHEAST. HAVE UPDATED THE
POPS TO ACCOUNT FOR THE CURRENT POSITION AND MOVEMENTS OF THE
FIRST BAND... AND THE POTENTIAL FOR REDEVELOPMENT SOUTHWEST ALONG
THE FRONT OVERNIGHT. HAVE ALSO MADE SOME ADJUSTMENTS TO THE HOURLY
TEMPERATURE GRIDS AS TEMPERATURES WILL BE SLOW TO COOL AHEAD OF
THE FRONT WITH THE WIDESPREAD CLOUD COVER. DID NOT ADJUST THE MINS
AT THIS TIME... ALTHOUGH THERE WILL BE THE POTENTIAL FOR SOME
ADJUSTMENTS LATER DEPENDING ON THE TIMING OF THE FRONT OVERNIGHT.
WE UPDATED THE WIND ADVISORY EARLIER THIS EVENING TO INCLUDE THE
SOUTHERN THREE OF OUR TEXAS COUNTIES TO BRIDGE THE GAP WITH
NEIGHBORS AND AS WINDS TOMORROW LOOK TO BE AROUND THE SAME AS
ADJACENT AREAS THAT WERE IN THE ADVISORY.
PREV DISCUSSION... /ISSUED 558 PM CST FRI NOV 25 2011/
AVIATION...
/00Z TAFS/
WIDESPREAD AREAS OF RAIN WILL SPREAD FROM WEST TO EAST ACROSS THE
AREA OVERNIGHT AS AN UPPER LEVEL STORM SYSTEM MOVES THROUGH THE
PLAINS. FREQUENT MVFR CEILINGS ARE EXPECTED THROUGH MUCH OF THE
NIGHT. A COLD FRONT WILL MOVE INTO NW OK LATE TONIGHT AND ACROSS
REMAINING TERMINAL LOCATIONS BY SATURDAY MORNING. ALTHOUGH THE
RAIN WILL BE SHIFTING EAST OUT OF THE AREA AND CEILINGS GRADUALLY
IMPROVING IN THE MORNING... STRONG SURFACE WINDS... WITH GUSTS IN
EXCESS OF 30 KTS... WILL PREVAIL BEHIND THE FRONT THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 253 PM CST FRI NOV 25 2011/
DISCUSSION...RAIN TONIGHT...WINDY AND COLDER SATURDAY...AND LOOKING
AT MODEL DIFFERENCES WITH RELATIVELY LOW IMPACT BEYOND SATURDAY.
LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH AN INVERSION...GIVING US
DULL OVERCAST THROUGH THIS EVENING. MEANWHILE...RAIN WILL DEVELOP
FROM A MID LEVEL CLOUD DECK AS BROAD AND NEARLY UNIFORM HEIGHT FALLS
OVERSPREAD OUR REGION IN ADVANCE OF AN UPPER LEVEL TROUGH. THIS WAVE
OF HEIGHT FALLS WILL BRING A WIDE BAND OF LIGHT RAIN EASTWARD DURING
THE EVENING. THE LOWER LEVELS START TO PARTICIPATE IN THE LIFTING
LATER TONIGHT WHEN A RELATIVELY STRONG FRONT OFF THE NORTHERN
PACIFIC DIVES IN FROM THE NORTHWEST. FORECAST SOUNDINGS BECOME
DEEPLY SATURATED BEHIND THE FRONT...AND WE SHOULD SEE A SWATH OF
SOMEWHAT HEAVIER RAINFALL TRANSLATE FROM NORTHWEST TO SOUTHEAST
DURING THE EARLY MORNING HOURS SATURDAY. SOME EMBEDDED THUNDER IS
POSSIBLE.
WINDS WILL BECOME STRONG AND GUSTY BEHIND THE FRONT...BUT WILL BE
ESPECIALLY STRONG AFTER SUNRISE TO THE WEST OF THE CLEARING LINE.
SINCE CLOUDS ARE FORECAST TO LINGER IN SOUTHEAST OKLAHOMA...WE DID
NOT ADD THE REMAINING COUNTIES TO OUR WIND ADVISORY...BUT COLD
ADVECTION WILL BE MAXIMIZED IN THOSE COUNTIES DURING THE DAY...SO
ANY ANTICIPATION OF CLEARING SKIES AND DEEPER MIXING WOULD SIGNAL
THE NEED TO EXPAND THE ADVISORY. LOOKS LIKE A SOLID ADVISORY
ELSEWHERE WITH SPEEDS SUSTAINED OVER 30 AT TIMES...GUSTING 45-50 MPH.
THE WIND WILL MAKE IT FEEL VERY COOL COMPARED TO RECENT DAYS. WITH A
MODEL CONSENSUS OF 850 MB TEMPS BELOW ZERO...WE LOWERED SURFACE
TEMPS TO THE 40S AND LOW 50S SATURDAY. WIND CHILL DIP TO THE TEENS
SUNDAY MORNING.
THE REMAINDER OF THE FORECAST LOOKS DRY...BUT NOT EASY BY ANY MEANS.
IN WATCHING THE RUN TO RUN VOLATILITY OF THE MODELS...IT APPEARS THE
SYNOPTIC PATTERN IS IN A LESS PREDICTABLE STATE RIGHT NOW. THE ECMWF
SOLUTION MAKES SOME SENSE...IN STRETCHING AND DEEPENING THE CURRENT
UPPER TROUGH WHILE IT GETS SQUEEZED BETWEEN TWO AMPLIFYING RIDGES.
THE DEGREE TO WHICH THE ECMWF CLOSES OFF AND DEEPENS MAY BE
OVERDONE...BUT IT APPEARS MORE REASONABLE THAN THE EXTREMELY
PROGRESSIVE GFS/NAM. WE DID NOTE THAT FINALLY THIS MORNING SEVERAL
OF THE GFS ENSEMBLE MEMBERS MOVED OVER TO SUPPORT THE ECMWF
SOLUTION...LEAVING THE OPERATIONAL GFS AT THE VERY FAR PROGRESSIVE
END OF THE ENVELOPE.
AFTER ALL THAT FUN DISCUSSION...THE DIFFERENCES DO NOT REALLY MEAN
MUCH FOR US...OTHER THAN A FEW DEGREES COOLER TEMPERATURE ON SUNDAY
AND MONDAY...AND SOME POTENTIAL FOR WRAPAROUND MID CLOUDS IN EASTERN
OKLAHOMA. THE MODELS MOVE BACK INTO BETTER AGREEMENT BY MID
WEEK...AND PREDICT A SPLIT FLOW PATTERN THAT IS BECOMING MORE
PRONOUNCED. THE NORTHERN STREAM IS SET TO DUMP A DECENTLY COLD AIR
MASS HERE BY LATE NEXT WEEK...WHILE ANOTHER CLOSED LOW FORMS IN THE
SOUTHERN STREAM OVER CALIFORNIA. INTERPOLATING FORWARD...WE COULD
HAVE OUR FIRST RUN-IN WITH WINTER PRECIPITATION TYPES BY NEXT
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 43 49 27 49 / 80 30 0 0
HOBART OK 41 50 25 54 / 50 10 0 0
WICHITA FALLS TX 48 54 29 55 / 70 20 0 0
GAGE OK 37 48 21 54 / 50 0 0 0
PONCA CITY OK 42 49 28 47 / 100 20 0 0
DURANT OK 55 59 32 51 / 80 60 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 7 AM TO 8 PM CST SATURDAY FOR OKZ004>042-
044>046-050.
TX...WIND ADVISORY FROM 7 AM TO 8 PM CST SATURDAY FOR TXZ083>090.
&&
$$
26/25/32
AREA FORECAST DISCUSSION
NWS NORMAN OK
1012 PM CST FRI NOV 25 2011
.UPDATE...
FIRST BAND OF PRECIPITATION CONTINUES TO SHIFT EAST AS THE AREAS
OF RAIN THEMSELVES MOVE NORTHEAST. ADDITIONAL SHOWER AND
THUNDERSTORM DEVELOPMENT CONTINUES IN WESTERN KANSAS AND THE
OKLAHOMA AND NORTHERN TEXAS PANHANDLES NEAR THE SURFACE FRONT.
LOCAL WRF.. HRRR AND RUC SUGGEST THAT THERE WILL BE THE CHANCE OF
DEVELOPMENT DOWN THE FRONT AS IT MOVES SOUTHEAST. HAVE UPDATED THE
POPS TO ACCOUNT FOR THE CURRENT POSITION AND MOVEMENTS OF THE
FIRST BAND... AND THE POTENTIAL FOR REDEVELOPMENT SOUTHWEST ALONG
THE FRONT OVERNIGHT. HAVE ALSO MADE SOME ADJUSTMENTS TO THE HOURLY
TEMPERATURE GRIDS AS TEMPERATURES WILL BE SLOW TO COOL AHEAD OF
THE FRONT WITH THE WIDESPREAD CLOUD COVER. DID NOT ADJUST THE MINS
AT THIS TIME... ALTHOUGH THERE WILL BE THE POTENTIAL FOR SOME
ADJUSTMENTS LATER DEPENDING ON THE TIMING OF THE FRONT OVERNIGHT.
WE UPDATED THE WIND ADVISORY EARLIER THIS EVENING TO INCLUDE THE
SOUTHERN THREE OF OUR TEXAS COUNTIES TO BRIDGE THE GAP WITH
NEIGHBORS AND AS WINDS TOMORROW LOOK TO BE AROUND THE SAME AS
ADJACENT AREAS THAT WERE IN THE ADVISORY.
&&
.PREV DISCUSSION... /ISSUED 558 PM CST FRI NOV 25 2011/
AVIATION...
/00Z TAFS/
WIDESPREAD AREAS OF RAIN WILL SPREAD FROM WEST TO EAST ACROSS THE
AREA OVERNIGHT AS AN UPPER LEVEL STORM SYSTEM MOVES THROUGH THE
PLAINS. FREQUENT MVFR CEILINGS ARE EXPECTED THROUGH MUCH OF THE
NIGHT. A COLD FRONT WILL MOVE INTO NW OK LATE TONIGHT AND ACROSS
REMAINING TERMINAL LOCATIONS BY SATURDAY MORNING. ALTHOUGH THE
RAIN WILL BE SHIFTING EAST OUT OF THE AREA AND CEILINGS GRADUALLY
IMPROVING IN THE MORNING... STRONG SURFACE WINDS... WITH GUSTS IN
EXCESS OF 30 KTS... WILL PREVAIL BEHIND THE FRONT THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 253 PM CST FRI NOV 25 2011/
DISCUSSION...RAIN TONIGHT...WINDY AND COLDER SATURDAY...AND LOOKING
AT MODEL DIFFERENCES WITH RELATIVELY LOW IMPACT BEYOND SATURDAY.
LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH AN INVERSION...GIVING US
DULL OVERCAST THROUGH THIS EVENING. MEANWHILE...RAIN WILL DEVELOP
FROM A MID LEVEL CLOUD DECK AS BROAD AND NEARLY UNIFORM HEIGHT FALLS
OVERSPREAD OUR REGION IN ADVANCE OF AN UPPER LEVEL TROUGH. THIS WAVE
OF HEIGHT FALLS WILL BRING A WIDE BAND OF LIGHT RAIN EASTWARD DURING
THE EVENING. THE LOWER LEVELS START TO PARTICIPATE IN THE LIFTING
LATER TONIGHT WHEN A RELATIVELY STRONG FRONT OFF THE NORTHERN
PACIFIC DIVES IN FROM THE NORTHWEST. FORECAST SOUNDINGS BECOME
DEEPLY SATURATED BEHIND THE FRONT...AND WE SHOULD SEE A SWATH OF
SOMEWHAT HEAVIER RAINFALL TRANSLATE FROM NORTHWEST TO SOUTHEAST
DURING THE EARLY MORNING HOURS SATURDAY. SOME EMBEDDED THUNDER IS
POSSIBLE.
WINDS WILL BECOME STRONG AND GUSTY BEHIND THE FRONT...BUT WILL BE
ESPECIALLY STRONG AFTER SUNRISE TO THE WEST OF THE CLEARING LINE.
SINCE CLOUDS ARE FORECAST TO LINGER IN SOUTHEAST OKLAHOMA...WE DID
NOT ADD THE REMAINING COUNTIES TO OUR WIND ADVISORY...BUT COLD
ADVECTION WILL BE MAXIMIZED IN THOSE COUNTIES DURING THE DAY...SO
ANY ANTICIPATION OF CLEARING SKIES AND DEEPER MIXING WOULD SIGNAL
THE NEED TO EXPAND THE ADVISORY. LOOKS LIKE A SOLID ADVISORY
ELSEWHERE WITH SPEEDS SUSTAINED OVER 30 AT TIMES...GUSTING 45-50 MPH.
THE WIND WILL MAKE IT FEEL VERY COOL COMPARED TO RECENT DAYS. WITH A
MODEL CONSENSUS OF 850 MB TEMPS BELOW ZERO...WE LOWERED SURFACE
TEMPS TO THE 40S AND LOW 50S SATURDAY. WIND CHILL DIP TO THE TEENS
SUNDAY MORNING.
THE REMAINDER OF THE FORECAST LOOKS DRY...BUT NOT EASY BY ANY MEANS.
IN WATCHING THE RUN TO RUN VOLATILITY OF THE MODELS...IT APPEARS THE
SYNOPTIC PATTERN IS IN A LESS PREDICTABLE STATE RIGHT NOW. THE ECMWF
SOLUTION MAKES SOME SENSE...IN STRETCHING AND DEEPENING THE CURRENT
UPPER TROUGH WHILE IT GETS SQUEEZED BETWEEN TWO AMPLIFYING RIDGES.
THE DEGREE TO WHICH THE ECMWF CLOSES OFF AND DEEPENS MAY BE
OVERDONE...BUT IT APPEARS MORE REASONABLE THAN THE EXTREMELY
PROGRESSIVE GFS/NAM. WE DID NOTE THAT FINALLY THIS MORNING SEVERAL
OF THE GFS ENSEMBLE MEMBERS MOVED OVER TO SUPPORT THE ECMWF
SOLUTION...LEAVING THE OPERATIONAL GFS AT THE VERY FAR PROGRESSIVE
END OF THE ENVELOPE.
AFTER ALL THAT FUN DISCUSSION...THE DIFFERENCES DO NOT REALLY MEAN
MUCH FOR US...OTHER THAN A FEW DEGREES COOLER TEMPERATURE ON SUNDAY
AND MONDAY...AND SOME POTENTIAL FOR WRAPAROUND MID CLOUDS IN EASTERN
OKLAHOMA. THE MODELS MOVE BACK INTO BETTER AGREEMENT BY MID
WEEK...AND PREDICT A SPLIT FLOW PATTERN THAT IS BECOMING MORE
PRONOUNCED. THE NORTHERN STREAM IS SET TO DUMP A DECENTLY COLD AIR
MASS HERE BY LATE NEXT WEEK...WHILE ANOTHER CLOSED LOW FORMS IN THE
SOUTHERN STREAM OVER CALIFORNIA. INTERPOLATING FORWARD...WE COULD
HAVE OUR FIRST RUN-IN WITH WINTER PRECIPITATION TYPES BY NEXT
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 43 49 27 49 / 80 30 0 0
HOBART OK 41 50 25 54 / 50 10 0 0
WICHITA FALLS TX 48 54 29 55 / 70 20 0 0
GAGE OK 37 48 21 54 / 50 0 0 0
PONCA CITY OK 42 49 28 47 / 100 20 0 0
DURANT OK 55 59 32 51 / 80 60 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY FROM 7 AM TO 8 PM CST SATURDAY FOR OKZ004>042-
044>046-050.
TX...WIND ADVISORY FROM 7 AM TO 8 PM CST SATURDAY FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER CO
320 AM MST SAT NOV 26 2011
.SHORT TERM...AN UPPER LEVEL TROUGH WILL QUICKLY MOVE EAST OF THE
AREA THIS MORNING WITH SNOW ENDING IN THE MTNS AND OVER THE FAR NERN
PLAINS BY SUNRISE. WINDS WILL REMAIN GUSTY OVER THE NERN PLAINS
THRU EARLY AFTN BEFORE GRADUALLY DECREASING BY LATE AFTN. BASED ON
CURRENT DATA MOST GUSTS WILL BE AROUND 50 MPH HOWEVER STILL COULD
SEE A FEW HIGHER GUSTS THRU EARLY AFTN SO WILL KEEP HIGH WIND
WARNING IN PLACE ALTHOUGH IT PROBABLY COULD BE CANCELED BY 21Z. AS
FAR AS FIRE WEATHER WATCH LATEST HRR SHOWS HUMIDITY LEVELS ONLY
DROPPING TO 35-40 PERCENT OVER THE NERN PLAINS THIS AFTN WITH TEMPS
AROUND 40 DEGREES. IN ADDITION THERE WAS SOME SNOW OVERNIGHT WITH
ACCUMULATIONS UP TO AN INCH IN SPOTS. ALTHOUGH WINDS WILL BE GUSTY
BELIEVE THREAT IS LOW ENOUGH TO NOT ISSUE A RED FLAG WARNING. AS
FOR HIGHS THIS AFTN WILL KEEP READINGS MAILY IN THE UPPER 30S TO
LOWER 40S OVER THE NERN PLAINS WITH MID 40S CLOSER TO THE FOOTHILLS.
FOR TONIGHT WINDS WILL QUICKLY DIMINISH OVER THE PLAINS SHORTLY
AFTER SUNSET WITH DRY CONDITIONS OVER THE ENTIRE CWA.
.LONG TERM...STRONG NORTH-NORTHWESTERLY FLOW ALOFT IS PROGGED TO
DECREASE ACROSS THE CWA ON SUNDAY AS AN UPPER RIDGE MOVES IN. THE
RIDGE AXIS MOVES ACROSS THE FORECAST AREA LATE SUNDAY NIGHT INTO MID
DAY MONDAY...WITH WEAKER ZONAL FLOW ALOFT. LATE MONDAY AND MONDAY
NIGHT...A WEAK UPPER TROUGH IS PROGGED TO MOVE IN WITH WESTERLY FLOW
ALOFT ON THE INCREASE MONDAY EVENING. THE SYNOPTIC SCALE ENERGY IS
NEGLIGIBLE SUNDAY AND SUNDAY NIGHT...THEN WEAK UPWARD QG VERTICAL
VELOCITY IS PROGGED MONDAY AFTERNOON INTO THE EARLY EVENING HOURS.
AFTER THAT...WEAK DOWNWARD MOTION MOVES IN FOR THE REST OF MONDAY
NIGHT. THE LOW LEVEL PRESSURE AND WIND FIELDS KEEP A DECENT
GRADIENT IN PLACE...WITH LOW PRESSURE EAST OF THE MOUNTAINS.
DOWNSLOPING BOUNDARY LAYER WINDS ARE A GOOD BET SUNDAY THROUGH MUCH
OF MONDAY. A WEAK COLD FRONT IS PROGGED TO MOVE INTO THE PLAINS
MONDAY AFTERNOON WITH BOUNDARY LAYER UPSLOPE CONTINUING PAST
MIDNIGHT MONDAY NIGHT. FOR MOISTURE...SUNDAY LOOKS PRETTY DRY...
WITH JUST OF A BIT OF UPPER LEVEL MOISTURE PROGGED SUNDAY NIGHT INTO
MONDAY. BY 00Z TUESDAY...MOISTURE INCREASES A BIT BEHIND THE FRONT
...WITH THE GFS SHOWING IT TO GET FAIRLY DEEP OVER THE FOOTHILLS AND
WESTERN CWA PLAINS. THE NAM HAS LESS. THE MOUNTAINS STAY FAIRLY
DRY. BOTH MODELS SHOW IT PRETTY DRY BY 12Z TUESDAY MORNING...JUST A
BIT OF MID LEVEL MOISTURE ON THE NAM. THE ONLY MEASURABLE
PRECIPITATION NOTED ON THE QPF FIELDS FROM SUNDAY THROUGH TUESDAY
MORNING...IS A TAD OVER THE FOOTHILLS AND ADJACENT PLAINS ON THE GFS
MONDAY EVENING. WILL GO WITH NO POPS FOR CWA THROUGH THE PERIODS.
WILL WATCH FOR THE MONDAY AFTERNOON/EVENING UPSLOPE ON FURTHER MODEL
RUNS. FOR TEMPERATURES...SUNDAY`S HIGHS ARE 8-11 C WARMER THAN
TODAY`S EXPECTED READINGS. MONDAY`S HIGHS ARE A TAD COOLER THAN
SUNDAY`S...AT LEAST FOR THE PLAINS. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...MODELS HAVE MORE UPPER RIDGING TUESDAY INTO
WEDNESDAY FOR THE CWA. BY WEDNESDAY NIGHT AND THURSDAY...MODELS
SHOW A DECENT CLOSED LOW OVER THE WEST CENTRAL U.S. COAST. IT MOVES
LITTLE THROUGH FRIDAY...DEPENDING ON THE MODEL. THE GFS BRINGS A
FAIRLY COLD AIRMASS AND UPSLOPE TO THE PLAINS WEDNESDAY EVENING.
THE ECMWF DOESN`T SHOW THIS UNTIL THURSDAY AFTERNOON. BOTH HAVE A
FAIRLY COLD AIRMASS IN PLACE ON FRIDAY. THE MODELS HAVE BEEN ALL
OVER THE HE PLACE WITH THIS FEATURE THE LAST FEW RUNS. CONFIDENCE
IS LOW. WILL LEAVE THE EXTENDED-BLENDED-GFE STUFF PRETTY MUCH
ALONE.
&&
.AVIATION...WINDS HAVE REMAINED GUSTY OUT OF THE NORTH AT 20-30 MPH
EARLY THIS MORNING HOWEVER LATEST HRRR SHOWS THEM DECREASING BY
SUNRISE TO THE 10-20 MPH RANGE. BY MID MORNING THE HRRR SHOWS A
WELL DEFINED LONGMONT ANTICYCLONE WITH THE CENTER STAYING TO THE NW
OF THE AIRPORT THRU THE AFTN. THIS KEEPS WINDS AT THE AIRPORT NNW
THRU EARLY AFTN WITH SPEEDS IN THE 15-25 MPH WITH SOME GUSTS TO
30-35 MPH AT TIMES THRU 20Z. AFTER 20Z THE HRRR SHOWS WINDS
DECREASING TO 10-20 MPH AND BECOMING MORE NELY AS THE ANTICYCLONE
SHIFTS A BIT FURTHER EAST. BY SUNSET THE WINDS SHOULD BECOME LIGHT
ESE AND THEN MORE SLY BY 03Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 5 PM THIS
AFTERNOON FOR NERN CO ZONES 42..48..49..50 AND 51.
&&
$$
RPK/RJK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 AM MST SAT NOV 26 2011
.SHORT TERM (TODAY-MONDAY)...
240 AM MST SAT NOV 26 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW AMPLIFIED
RIDGE-TROUGH-RIDGE PATTERN OVER THE CONUS...WITH MEAN TROUGH AXIS
CENTERED ALONG CO/KS STATE LINE. AT THE SURFACE COLD FRONT CURRENTLY
SOUTHEAST OF CWA...WITH SURFACE HIGH PRESSURE QUICKLY BUILDING IN
BEHIND FRONT OVER CWA. UPSTREAM 3HR PRESSURE RISES AROUND 7MB HAVE
BEEN OBSERVED OVER PARTS OF EASTERN WYOMING/WESTERN NEBRASKA...WITH
3-5MB PRESSURE RISES OVER WESTERN PARTS OF CWA. VAD WIND PROFILER
DATA SHOWS 45-55KT LOW LEVEL JET OVERHEAD...WITH LOCAL OBSERVATIONS
REPORTING SURFACE WINDS GUSTING 45-48KT.
IMMEDIATE FORECAST CONCERNS IN THE SHORT RANGE ARE ON PRECIP CHANCES
EARLY THIS MORNING AND HIGH WINDS THROUGH THIS AFTERNOON.
RIGHT ENTRANCE REGION OF H25-H3 JET COMBINED WITH STEEP MID LEVEL
LAPSE RATES HAVE LED TO DEVELOPMENT ON SCT-ISO SHOWERS OVER NE
COLORADO...WHICH HAS PROGRESSED EAST INTO SW NEBRASKA AND EXTREME NW
KANSAS EARLY THIS MORNING. AS CAA CONTINUES EXPECT MOST LOCATION TO
SEE SNOW BECOME PREDOMINANT PRECIP TYPE. WEAK MOISTURE ADVECTION
COMBINED WITH BUILDING SUBSIDENCE ALOFT SHOULD LIMIT PRECIP
AMOUNTS...SO ONLY EXPECTING LOCALIZED SNOW TOTALS OF LESS THAN ONE
HALF INCH...WHILE MOST LOCATIONS WILL STRUGGLE TO SEE EVEN A FEW
TENTHS OF AN INCH DUE TO MELTING. GUIDANCE SNOWS STRONG SUBSIDENCE
OVERTAKING AREA BY 12Z ALONG WITH VERY DRY AIR ADVECTING IN OVER THE
AREA...WHICH SHOULD END PRECIP CHANCES. WILL KEEP FORECAST DRY AFTER
12Z FOR NOW AND ADJUST BASED ON TRENDS.
WIND FORECAST IS CURRENTLY ON TRACK...WITH WIND GUSTS EARLY THIS
MORNING ALREADY ON HIGH END OF WIND ADVISORY OVER MOST THE AREA. RUC
CURRENTLY HAS BEST HANDLE ON H85-H7 WINDS BASED ON PROFILER
DATA...AND SHOWS 50KT H85 JET SPREADING EAST OVER REMAINING CWA.
WHILE PEAK PRESSURE RISES OCCUR BEFORE 12Z THIS MORNING...PERSISTENT
50KT H85 JET AND INCREASED MIXING AFTER SUNRISE SHOULD SUPPORT WINDS
INCREASING TO WARNING CRITERIA. THE STRONGEST SURFACE WINDS SHOULD
THEN DECREASE TOWARDS 00Z AS MIXING DECREASES AND WINDS ALOFT BEGIN
TO SLACKEN.
TONIGHT-MONDAY NIGHT...H5 RIDGE BUILDS EAST AND STRENGTHENS OVER SW
CONUS...WITH SHORTWAVE RIDGE AXIS EXTENDING NORTH ACROSS CWA BY MON
NIGHT. LARGE SCALE SUBSIDENCE AND DEEP DRY AIR MASS OVER CWA WILL
HELP KEEP CONDITIONS DRY THROUGH THESE PERIODS WITH TEMPS WARMING TO
ABOUT 10-15F ABOVE NORMAL SUN/MON. TEMPS A LITTLE TRICKY ON MON AS
SHORTWAVE AND ASSOCIATED COLD FRONT MOVES ACROSS REGION. GUIDANCE
CONTINUING TO DIFFER ON POSITION/TIMING OF FRONT...WHICH WILL IMPACT
HIGH TEMPS MON ALONG WITH GUSTY WINDS MON AFTERNOON. FOR NOW HAVE
KEPT IN LINE WITH PREVIOUS FORECAST OF UPPER 50S NORTH/LOW 60S
SOUTH...HOWEVER TEMPS MAY END UP NEEDING TO BE LOWERED IF FASTER
FRONTAL TIMING OF SREF/GEM WERE TO BE REALIZED.
DR
.LONG TERM (TUESDAY-FRIDAY)...
240 AM MST SAT NOV 26 2011
AN UPPER LEVEL RIDGE WILL BUILD INTO THE TRI-STATE AREA THROUGH
THURSDAY. MODELS THEN BEGIN TO DISAGREE AS TO HOW QUICKLY THE
UPPER LEVEL RIDGE MOVES EAST AS THE UPPER LEVEL TROUGH BUILDS IN AND
WHEN THE COLD FRONT WILL MOVE THROUGH THURSDAY. AS A RESULT
HIGH TEMPERATURES FOR THURSDAY VARY SIGNIFICANTLY BETWEEN THE
MODELS. FRONTAL TIMING WILL ALSO AFFECT THE ARRIVAL AND TYPE OF
PRECIPITATION. CURRENT CONSENSUS HAS THE PRECIP. OCCURRING DURING
THE DAY FOR MOST OF THE CWA. DIFFICULT TO NAIL DOWN PRECIP. TYPE
THURSDAY DUE TO THE DIFFERENCE IN FRONTAL TIMING. GENERALLY HAVE
SNOW IN THE NORTHWEST AND FAR NORTH CWA WHICH TRANSITIONS TO A
NARROW BAND OF RAIN-SNOW MIX FOLLOWED BY RAIN FURTHER SOUTH. BEHIND
THE FRONT THE 850MB WINDS WILL BE GUSTY. HOWEVER MODELS DISAGREE
WITH THE TIMING AND PLACEMENT OF THE WINDS BEHIND THE FRONT...BUT
CONSENSUS HAS BREEZY CONDITIONS THURSDAY AFTERNOON. AFTER THURSDAY
THE UPPER LEVEL FLOW TURNS TO THE SOUTHWEST AND THE ENVIRONMENT
DRIES OUT. HOWEVER TEMPERATURES WILL REMAIN COOL AFTER THURSDAY AS
THE UPPER LEVEL TROUGH MOVES TOWARD THE AREA.
JTL
&&
.AVIATION...
418 AM MST SAT NOV 26 2011
VFR CONDITIONS FOR THE 12Z TAFS. CURRENT RADAR AND UPPER AIR
ANALYSIS SHOW THE PRECIPITATION MOVING EAST AHEAD OF THE UPPER
LEVEL TROUGH. AS THE UPPER LEVEL TROUGH MOVES THROUGH THE
PRECIPITATION WILL COME TO AN END AND CEILINGS WILL INCREASE.
DURING THE DAY STRONG UPPER LEVEL WINDS WILL LIE OVER THE TAF
SITES. THE WARMER TEMPERATURES WILL ALLOW THE STRONG WINDS TO MIX
DOWN TO THE SURFACE. WINDS WILL REACH THEIR PEAK DURING THE MID
MORNING BEFORE DISSIPATING DURING THE LATE AFTERNOON.
JTL
&&
.FIRE WEATHER...
240 AM MST SAT NOV 26 2011
RED FLAG WARNING CURRENTLY IN EFFECT FOR THIS AFTERNOON ACROSS
CWA. TD VALUES HAVE BEEN SLOWER TO DECREASE THAN PREVIOUS GUIDANCE
INDICATED...HOWEVER FINALLY BEGINNING TO SEE 10-15F TD VALUES
ADVECTING INTO EASTERN COLORADO. SINGLE DIGIT TD VALUES OVER
WYOMING SHOULD EVENTUALLY ADVECT OVER CWA...AND DESPITE AFTERNOON
TEMPS IN THE UPPER 30S/LOW 40S...CURRENTLY THINK RH VALUES 18-25%
SEEM REASONABLE. COMBINED WITH VERY STRONG WINDS THIS
AFTERNOON...CRITICAL FIRE CONDITIONS WILL CONTINUE TO BE A
CONCERN...SO NO CHANGES PLANNED FOR CURRENT HIGHLIGHT.
CRITICAL FIRE CONDITIONS WILL BE POSSIBLE AGAIN MONDAY AFTERNOON.
TIMING OF STRONGEST WINDS AND LOCATION OF LOWEST TD VALUES WILL
LIKELY BE DEPENDENT ON TIMING OF COLD FRONT...WHICH GUIDANCE IS
CURRENTLY DOING A POOR JOB OF TIMING OUT...SO WILL NEED TO MONITOR
THIS.
DR
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
KSZ001>004-013>016-027>029-041-042.
RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM
MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-
027>029-041-042.
WIND ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS MORNING FOR
KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
NEZ079>081.
RED FLAG WARNING FROM 11 AM MST /NOON CST/ THIS MORNING TO 5 PM
MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081.
WIND ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS MORNING FOR
NEZ079>081.
CO...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092.
RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS
AFTERNOON FOR COZ252>254.
WIND ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR COZ090>092.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
529 AM CST SAT NOV 26 2011
.AVIATION...
FOR THE 12Z TAF ISSUANCE...VERY STRONG NORTHERLY WINDS WILL
PERSIST AT THE TAF SITES THROUGH TODAY. LOOK FOR SUSTAINED WINDS
AROUND 30 TO 40 KNOTS WITH GUSTS TO AROUND 50 KNOTS AT GARDEN CITY
AND DODGE CITY WITH WINDS NEARLY THAT STRONG AT HAYS. THERE COULD
ALSO BE A PERIOD OF LIGHT RAIN CHANGING TO LIGHT SNOW ALONG WITH
MVFR CIGS FROM AROUND 12Z TO 16Z. A PERIOD OF MVFR VSBYS IN LIGHT
SNOW WILL BE POSSIBLE AT HAYS FOR A WHILE THIS MORNING. VFR
CONDITIONS WILL BE PREVAILING AT ALL THE TAF SITES BY 16Z-18Z.
NORTH WINDS WILL DECREASE INTO THE 15 TO 25 KNOT RANGE AFTER 00Z.
&&
.PREV DISCUSSION... /ISSUED 309 AM CST SAT NOV 26 2011/
SYNOPSIS...
UPPER AIR ANALYSIS SHOWS THAT A LARGE TROF IS MOVING ACROSS THE
PLAINS THIS MORNING. THIS FEATURE CAUSED THE PRECIPITATION EVENT
THAT OCCURRED LAST NIGHT AND BROUGHT THE WELCOMED RAINS. A COLD
FRONT WAS PUSHING INTO WESTERN KANSAS EARLY THIS MORNING AND WILL
BE THE MAIN IMPACT TODAY IN TERMS OF WEATHER.
DISCUSSION...
DAYS 1-2...
IMMEDIATE CONCERN IS THE PRECIPITATION MOVING OUT OF THE AREA. KDDC
WSR-88D SHOWS THAT THE PRECIPITATION SHIELD IS SLOWLY MOVING OUT
OF THE CWFA AND HAVE TAPERED POPS DOWN AS A RESULT. I HAVE 15 PERCENT
POPS NORTH WHERE THE GFS AND THE RUC ARE INDICATING THE POTENTIAL FOR
A FEW SPRINKLES OR FLURRIES.
THE OTHER FOCUS TODAY IS WIND. 1 KM WINDS ARE AROUND 50 KT WITH 850
HPA WINDS IN THE 45 TO 55 KT RANGE. A FRONT IS MOVING ACROSS WESTERN
KANSAS EARLY THIS MORNING WITH STRONG WINDS ALREADY BEING REPORTED ACROSS
THE HIGH PLAINS OF EASTERN COLORADO. THE MOST RECENT HRRR SHOWS 10M
WINDS AROUND 35 KT THROUGH THIS AFTERNOON. AS A RESULT, HAVE ISSUED
A HIGH WIND WARNING FOR POINTS WEST OF A LINE FROM TREGO TO CLARK
COUNTIES. FURTHER EAST TOWARDS HAYS, THE MOS GUIDANCE IS MORE
MARGINAL SO HAVE DECIDED TO KEEP THE AREA EAST OF A LINE FROM ELLIS
TO COMANCHE COUNTIES IN A WIND ADVISORY. FURTHER WEST, MOS GUIDANCE
WAS SUPPORTING WIND WARNING CRITERIA WITH FORECAST OF 40G50KT AT
GARDEN CITY AND LIBERAL. SINCE WE WILL HAVE A NORTHWESTERLY
DOWNSLOPE COMPONENT, I INCREASED TEMPERATURES A DEGREE OR TWO ABOVE
GUIDANCE. TEMPERATURES SHOULD WARM TO THE UPPER 40S TO LOWER 50S.
THE FIRE WEATHER WATCH WAS ALSO CANCELLED AS RH`S NOW LOOK LIKE TO NOT
MEET THE 15 PERCENT CRITERIA. FOR MORE INFORMATION, SEE THE FIRE WEATHER
AFD SECTION BELOW.
BY TONIGHT, WE WILL HAVE NORTHERLY FLOW ALOFT IN THE WAKE OF THE UPPER
LEVEL TROF. SKIES SHOULD CLEAR AS DRY AIR ADVECTION STARTS THROUGH THE
ATMOSPHERIC COLUMN SO AM EXPECTING COOLER OVERNIGHT LOWS...GENERALLY IN
THE 20S.
THE WEATHER WILL STILL BE QUIET SUNDAY AS 500 HPA HEIGHTS INCREASE IN
RESPONSE TO RIDGING ACROSS THE DESERT SOUTHWEST. POPS WILL REMAIN
AT ZERO. MAX TEMPERATURES ARE EXPECTED IN THE 50S WHICH IS SLIGHTLY
ABOVE NORMAL.
DAYS 3-7...
THE 00Z RUNS OF THE MEDIUM RANGE MODELS HAVE COME INTO BETTER
AGREEMENT IN HANDLING THE UPPER TROUGH THAT IS CURRENTLY MOVING OUT
INTO THE CENTRAL CONUS. THE GFS HAS TRENDED TOWARD THE OTHER MODELS
IN THAT IT IS NOW CLOSING OFF AN UPPER LOW OVER THE LOWER
MISSISSIPPI VALLEY SIMILAR TO...BUT NOT AS FAR SOUTH...AS THE ECMWF.
ANY SENSIBLE WEATHER IMPACTS FROM THIS WILL BE WELL TO THE EAST OF
WESTERN KANSAS. THE MODELS CONTINUE TO SHOW THE NEXT STRONG
SHORTWAVE TROUGH MOVING EAST THROUGH THE NORTHERN CONUS WITH SOME
SHORTWAVE ENERGY MOVING SOUTHEAST OVER THE CENTRAL HIGH PLAINS.
ANOTHER STRONG COLD FRONT WILL PUSH SOUTH THROUGH WESTERN KANSAS LATE
MONDAY AFTERNOON AND EVENING. THE MODELS ARE NOT INDICATING MUCH IN
THE WAY OF PRECIPITATION WITH THIS FRONT. THIS LOOKS REASONABLE
GIVEN THAT LOW LEVEL MOISTURE WILL NOT HAVE AN OPPORTUNITY TO RETURN
NORTHWARD IN THE WAKE OF TODAYS UPPER TROUGH. THERE COULD BE A
PERIOD OF STRONG WINDS BEHIND THE FRONT AS AT LEAST THE GFS IS
SHOWING 850 MB WINDS TO 50 KNOTS.
THE MIDDLE PART OF NEXT WEEK SHOULD BE FAIRLY QUIET AS UPPER LEVEL
RIDGING MOVES OVER THE CENTRAL PLAINS. HOWEVER...ANOTHER UPPER
TROUGH WILL BE DIGGING SOUTH INTO THE WESTERN STATES. THE MODELS ARE
DIFFERING IN SOMEWHAT IN HOW THIS SYSTEM DEVELOPS BUT THEY ALL
DEVELOP IT INTO A CLOSED LOW OVER SOUTHERN CALIFORNIA/ARIZONA BY
NEXT FRIDAY. THE MODELS BRING ANOTHER COLD FRONT WITH MUCH COOLER
AIR SOUTH ACROSS WESTERN KANSAS AROUND THURSDAY OR FRIDAY AND THEN
MOVE THE UPPER LOW EAST TOWARD THE CENTRAL AND SOUTHERN PLAINS NEXT
WEEKEND. THIS COULD HAVE SOME SIGNIFICANT WEATHER IMPACTS WITH THE
POSSIBILITY FOR A SNOWSTORM ACROSS SOUTHWEST KANSAS NEXT WEEKEND
DEPENDING ON THE TRACK OF THE UPPER LOW.
FIRE WEATHER...
HAVE CANCELLED THE FIRE WEATHER WATCH AS UPSTREAM DEWPOINT OBSERVATIONS
ARE SHOWING THAT THE MODEL DEWPOINTS ARE RUNNING A LITTLE LOW. EVEN
WARMING UP TEMPERATURES AND ARTIFICIALLY LOWERING DEWPOINTS ONLY PRODUCES
RH`S IN THE 20 TO 30 PERCENT RANGE. WINDS WILL BE STRONG TODAY THOUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 25 54 31 / 40 0 0 0
GCK 46 23 55 31 / 20 0 0 0
EHA 45 23 58 35 / 10 0 0 0
LBL 47 23 56 32 / 20 0 0 0
HYS 48 24 52 30 / 20 0 0 0
P28 50 27 53 30 / 40 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ031-046-065-066-
079>081-089-090.
&&
$$
FN36/02/02
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1056 AM EST SAT NOV 26 2011
...Forecast Update...
A few changes to the forecast this morning. First of all, light
radar echoes moving NE from southeast MO/western KY/southern IL seem
to be producing light brief rain showers. The 12Z HRRR has picked
up on this activity bringing it into our southwest Indiana counties
by early afternoon. This seems reasonable given the current radar
trends and light isentropic lift increasing throughout the day ahead
of the approaching front. Therefore expanded 20% POPs in the far
western CWA from 18Z to 0Z.
As of 10am EST, winds were already gusting out of the south between
20-25 mph with a few higher gusts noted. Based on these already
gusty conditions with BKN upper level clouds, think that we`ll see
gusts between 30-35 mph this afternoon with BKN mid and upper level
clouds continuing throughout the day.
Last, on such strong southerly flow, temps are running 2-3 degrees
warmer than previously forecast. The 12Z NAM has caught on to this
temp trend. Based on this new model data and this morning`s trends,
think that high temps should reach the upper 60s with a few lower
70s possible near the BWG area.
&&
.Short Term (Today - Sunday)...
Surface low currently over south central Minnesota will lift
northeasward across the Great Lakes through the forecast period,
with a trailing cold front moving near the western CWA border by
dawn on Sunday. Meanwhile, a full CONUS amplified trough axis will
slide from the central United States to the Middle Mississipi River
Valley by Sunday afternoon. Anomalous closed low is expected to
develop over the Ark/La/Tex region sometime on Sunday with
associated surface low situated over the Tennessee Valley.
Today...
Another dry day is in store for the CWA as model trends have
continued to be slower with precipitation ahead of aforementioned
frontal boundary. The main focus for today will be on gusty
southerly winds and how warm temperatures will get under variably
cloudy skies. Pressure gradient between southeast CONUS high and low
moving across the Great Lakes will be quite strong with southerly
winds between 15 and 20 mph, gusting up around the 30 mph mark at
times. Cannot rule out a few gusts up to the 35 mph range, depending
on how much mixing will occur. Kept wind gusts tempered compared to
potential just a bit based on expected increasing clouds throughout
the day and the impact on mixing.
High temperatures are expected to jump nicely on steady southerly
flow, into the solid mid 60s in most spots. The mercury will range
in the upper 60s near the Bowling Green region. The northwest CWA
will be the coolest in the lower 60s as mostly cloudy skies by
midday hamper heating.
Tonight and Sunday...
Precipitation chances are expected to increase west of I-65 between
7 PM and 1 AM EST as moisture convergence/ascent with 40-50 knot low
level jet ramps up across the region, coincident with the right
entrance region of the upper level jet. Best moisture/lift will
continue to spread eastward by dawn with categorical POPS along and
west of the I 65 corridor and likely POPS west of I 75. Categorical
wording will continue through the entire day on Sunday with frontal
boundary slowly working through the CWA. It should be noted that an
even slower solution could hamper the forecast with categorical rain
showers holding west of I 65 until 12Z Sunday morning as suggested
by 26/00Z SPC WRF. This is the most extreme/slow solution, so
preferred a slightly faster forecast although attention should be
paid to subsequent forecasts if slower trend continues.
Have gone with a limited diurnal trend during this time with mild
lows in the 50 to 55 degree range and highs on Sunday only in the 50
to 60 degree range, dependent on frontal passage. Areas east of I-65
will likely see the 60 degree mark early before temperatures remain
steady or gradually fall off through the day. West of this line,
expect 50 to 55 degree highs, remaining steady or gradually falling
into the upper 40s through the afternoon.
Overall precipitation amounts through Sunday afternoon should range
in the 0.75 to 1.5 inch range. At this point, the Blue Grass region
appears to be the most likely area to see just under an inch.
.Long term (Sunday Night - Friday)...
Models in pretty good agreement for the start of the period, placing
the cold front over our eastern border with JKL Sunday night and a
broad north-south trough stretching from the Gulf of Mexico over
Louisiana up to St. James Bay. Given that the upper trough lags well
behind the front, have an extensive area of post-frontal
precipitation. Thermal profiles look too warm for any frozen precip
Sunday night. Only exception may be over the NW forecast area, so
have kept in slight chances for snow there after midnight.
During the day Monday, the models now are in better agreement,
closing off a low on the southern end of the above-mentioned trough.
The GEFS/SREF/12Z and new 00Z ECMWF/NAM all place this low over MS
Monday evening, whereas the GFS has it in central TN. Will leave the
GFS as an outlier and go with the rest of the guidance for this
system. The 18Z GEFS indicates heights for the 500mb low are 4-5
standard deviations below normal. Thus expect a good feed of
moisture to come up the east side of the system from the Gulf. This
feed will mean continued precip chances until after both the axis of
the upper low and its associated deformation zone passes east of the
area, which looks like it may not occur until Wednesday morning over
the Bluegrass. The next chance for snow during this period will come
Tuesday night. Thicknesses will be at there lowest at that point,
with the cold upper low pulling east of the region and merging with
a broader trough over the area. Surface temperatures should remain
too warm for accumulations, but if the snow dominates over the rain
and falls faster than expected here, some light accumulations are
possible. Will be optimistic for now and just mention the chance for
rain or snow with no accumulations.
From that point on, assuming the closed low behaves as these models
predict, difficult to do in the long range, our area looks to dry
out some. The entire week looks chilly, with generally staying in
the 40s. Lows Monday and Tuesday morning also should be in the 40s,
with extensive cloud cover. Clearing skies for the second half of
the week will allow colder nighttime lows, to around 30.
&&
.Aviation (12Z TAF Issuance)...
Expecting VFR to prevail through the majority of the forecast period
with deteriorating conditions right at the end and beyond the
forecast period. Strong pressure gradient between a surface low over
the upper Midwest and surface high off the Carolina coast will keep
steady winds out of the south through the forecast period. Although
surface winds are expected to stay up slightly through mid morning,
a low level jet between 35-40 knots will allow for LLWS below 2 K
feet up to 40 knots. LLWS has been confirmed by AMDAR soundings in
the Louisville region overnight.
Expect SCT to, at times, BKN cumulus clouds between 3 and 4 K feet
on Saturday afternoon with south winds between 15 and 20 mph gusting
to around 30 mph at times. Low level clouds will be on the increase
this evening with rain chances at BWG and SDF increasing after
midnight as frontal boundary approaches. LEX will likely hold off on
rain until around dawn on Sunday. Once the rain arrives, expect
prevailing MVFR conditions with occasional IFR conditions possible.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......BJS
Long Term........RJS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
656 AM EST SAT NOV 26 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROFFING OVER
THE PLAINS BTWN PERSISTENT RDG OVER THE ERN CONUS AND ANOTHER RDG
OVER THE W COAST. THERE ARE 3 SHRTWVS OF SIGNIFICANCE EMBEDDED
WITHIN THE TROF OVER THE PLAINS...ONE OVER SASKTATCHEWAN...ANOTHER
IN WYOMING...AND ANOTHER CENTERED NEAR THE TX PANHANDLE. THE COMPLEX
INTERACTION BTWN THESE SEPARATE DISTURBANCES HAS MADE THE EVOLUTION
OF THE UPCOMING WX PATTERN A BIT TRICKY FOR RECENT SHIFTS. THE
DISTURBANCE OVER WYOMING IS SUPPORTING A SFC LO OVER WCNTRL MN. A
FAIRLY WELL DEFINED COMMA CLD IS PRESENT WITH COMMA HEAD PCPN NOTED
UNDER COLDER CLD TOPS OVER THE DAKOTAS ON THE COLD SIDE OF THE
ACCOMPANYING H85 LO. THE WARM CONVEYOR BELT CLD EXTENDS THRU THE UPR
MIDWEST/UPR MS RIVER VALLEY INTO THE GRT LKS...BUT DRY AIR NOTED AT
H7 BY THE BULK OF THE RAOBS...VERY WELL SHOWN BY THE 00Z GRB/MPX
RAOBS...E OF THE UPR TROF AXIS HAS PREVENTED WDSPRD RA FM DVLPG
DESPITE INCRSG UPR DVGC UNDER COUPLED UPR JET STRUCTURE BTWN H3
SPEED MAX IN ONTARIO AND ANOTHER IN SDAKOTA/NEBRASKA. HOWEVER...THE
INTERACTION BTWN THIS DYNAMIC AND THE STRONG SW FLOW E OF THE MN LO
THAT IS ADVECTING UNSEASONABLY HI H85 DWPTS UP TO 6C FROM OMAHA TO
THRU IOWA TOWARD THE UPR MIDWEST HAS CAUSED A RECENT EXPANSION OF
THE RADAR ECHOES TO THE SW. ALTHOUGH A SFC COLD FNT...ASSOCIATED
WITH THE JET MAX IN ONTARIO...HAS SLID OVER UPR MI...TEMPS OVER UPR
MI ARE WELL ABV NORMAL IN THE UPR 30S/40S. THIS FNT HAS PRETTY MUCH
STALLED BUT COULD SERVE AS A FOCAL POINT FOR INCRSG LLVL MSTR CNVGC/
FGEN/ISENTROPIC ASCENT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THRU THIS WEEKEND ARE PCPN CHCS/TYPES/POTENTIAL
SN ACCUMS AND TIMING OF DRYING TREND FOLLOWING THE PASSAGE OF UPR
TROF/SFC LO.
TDAY...RECENT MODEL RUNS HAVE COME INTO BETTER AGREEMENT ON EXPECTED
STRENGTH/TRACK OF SFC LO THAT WL IMPACT THE CWA AHEAD OF DISTURBANCE
NOW IN WYOMING. THIS LO IS PROGGED TO MOVE TO BTWN MQT AND MUNISING
BY 00Z SUN. AS THE SFC LO NOW IN MN MOVES TOWARD UPR MI...GUIDANCE
SHOWS INCRSG ISENTROPIC ASCENT FOCUSED ON THE 290K SFC/UPR DVGC
UNDER FVRBL ORIENTATION OF UPR JET CORES/PWAT SURGING TO ALMOST 250
PCT OF NORMAL WITH THE ARRIVAL OF H85 DWPTS OF 5C. BOTH THE 00Z
NAM/GFS SHOW THE SHARPEST H85-7 FGEN ACCOMPANYING THE FVRBL
INTERACTION BTWN THESE DYNAMICS/MOISTENING AND THE FNTL BNDRY
IMPACTING MAINLY THE NW CWA WITH THE HIEST QPF THEN SHIFTING OUT
OVER LK SUP AND TO THE E IN THE AFTN. ALTHOUGH THE FCST LLVL CYC NNW
FLOW IN THE WAKE OF THE SFC LO PASSING TO THE E WL PROBABLY KEEP
SOME PCPN GOING OVER THE W...FCST DEEP LYR QVECTOR DVGC ARRIVING FM
THE SW IN THE AFTN WL LIKELY LIMIT THE INTENSITY OF THE PCPN THERE
MORE THAN EARLIER ANTICIPATED AND WEAKEN THE COMMA HEAD PCPN NOTED
OVER THE DAKOTAS EARLY THIS MRNG. THE ARRIVAL OF SOMEWHAT COLDER
LLVL AIR INTO THE W LATE...WITH THE MORE AGGRESSIVE GFS SHOWING H85
TEMPS FALLING AS LO AS -3C AT IWD BY 00Z SUN...MAY CAUSE ANY PCPN TO
AT LEAST MIX WITH SN...BUT THE WEAKER DYNAMIC COOLING AND SFC TEMPS
HOLDING ABV 32 WL PREVENT ANY ACCUMULATION.
TNGT...AS THE SFC LO SHIFTS NE INTO ERN ONTARIO BY 12Z SUN...A
COLDER CYC NNW FLOW WL ENVELOP THE ENTIRE CWA IN ITS WAKE. WITH DEEP
LYR QVECTOR DVGC DOMINATING IN THE CAD/DRYING IN THE WAKE OF THE
SHRTWV...LINGERING PCPN WL SHIFT TO AN LES MODE WITH H85 TEMPS
WITHIN THE TRAILING THERMAL TROF FALLING TO -8C TO -10C /LK WATER
TEMPS ARE 5-6C/ OVER THE W BY 12Z SUN UNDER CYC FLOW/SLOWLY DECAYING
DEEPER MSTR WITHIN THE COMMA HEAD. SINCE THE DGZ IS FCST TO BE
WITHIN THE LARGER SCALE SUBSIDENCE AT THE TOP OF THE MOIST LYR AND
ABV THE SHARPER LLVL CNVGC/FORCING...SUSPECT THIS EVENT WL BE A HI
POP/FAIRLY LO QPF WITH NO NEED FOR HEADLINES ATTM. STILL...A FEW
INCHES OF WET SN ARE LIKELY OVER MAINLY THE HIER TERRAIN IN THE NNW
WIND SN BELTS OF THE W WHERE THE UPSLOPE COOLING/LLVL CNVGC WL BE
MAXIMIZED. ALTHOUGH THE FLOW WL TURN TO THE NW AFT 06Z OVER THE E...
THE AIR WL NOT BE SUFFICIENTLY COLD FOR SGNFT LES THERE THRU 12Z.
CUT POPS SGNFTLY OVER THE SCNTRL WITH EXPECTED DOWNSLOPE NW FLOW IN
THE ABSENCE OF ANY DYNAMIC SUPPORT.
SUN...AS THE H85 THERMAL TROF SHIFTS E FOLLOWING THE DEPARTING SFC
LO...EXPECT LES TO ENVELOP MAINLY THE NNW WIND SN BELTS OVER THE E.
BUT THRU THE DAY...RISING HGTS/MORE ACYC FLOW WL TEND TO DIMINISH
THIS ACTIVITY W-E AS WELL. ANY SN ACCUMULATIONS SHOULD REMAIN ON THE
LGT SIDE WITH POOR SN GROWTH PARAMETERS/DGZ ABV THE RELATIVELY
SHALLOW MSTR/LLVL FORCING IN THE ABSENCE OF DYNAMIC SUPPORT. OTRW...
THE DAY SHOULD FEATURE MORE SEASONABLY CHILLY TEMPS. THE SC WL
SLOWLY BREAK UP...ESPECIALLY OVER THE SCNTRL IN THE PRESENCE OF
DOWNSLOPE FLOW.
SUN NGT...UNDER BLDG UPR RDG...SFC HI PRES RDG AXIS WL SHIFT OVER
THE CWA. LGT WINDS UNDER THIS HI/FCST PWAT 60 PCT OF NORMAL WARRANTS
LOWERING PREVIOUS FCST MIN TEMPS TOWARD THE LO END OF GUIDANCE...
ESPECIALLY OVER THE INTERIOR W AND CNTRL.
MON...WARMER AIR IS FCST TO RETURN WITH STRENGTHENING SW FLOW BTWN
HI PRES SINKING INTO THE LOWER GRT LKS AND NEXT SHRTW/SFC LO
TRACKING INTO NW ONTARIO. H85 TEMPS ARE FCST TO REACH ARND 5C DURING
THE AFTN. THE COLD FNT ATTENDANT TO THE LO WL APRCH THE WRN ZNS LATE
IN THE DAY...BUT RELATIVE DRYNESS OF AIRMASS IN PLACE WITH MSTR
INFLOW DISRUPTED BY DVLPG LO IN THE OH RIVER VALLEY AND PASSAGE OF
STRONGER DYNAMICS FARTHER TO THE N WL MAINTAIN DRY WX.
MON NGT...EXPECT COLD FROPA ATTENDANT TO SHRTWV/SFC LO PASSAGE IN
NRN ONTARIO. HIER RH IS FCST TO STAY TO THE N CLOSER TO SHRTWV
TRACK...SO EXPECT A DRY FROPA. FCST SCHC POPS OVER THE NRN TIER
WHERE VEERING FLOW FM SW TO NW WL RESULT IN SOME UPSLOPE WIND
COMPONENT.
EXTENDED...CWA WL BE DOMINATED BY RELATIVELY DRY NRN BRANCH UPR
FLOW. SO EXPECT NO SGNFT PCPN EVENTS DURING THIS TIME THAT WL LIKELY
FEATURE FAIRLY CHANGEABLE TEMPS. TIMING DIFFERENCES ON SHRTWVS
EMBEDDED WITHIN THE FLOW WARRANTS HOLDING CLOSE TO ALL BLEND FCST.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A LOW PRESSURE SYSTEM MOVING ACROSS UPPER MICHIGAN TODAY WILL BRING
RAIN TO ALL THREE TAF SITES. AS HAS BEEN THE CASE OVER THE LAST
SEVERAL DAYS...LOW CLOUDS EXPECTED TO INFLUENCE THE AREA. KIWD HAS
BEEN BUCKING THE TREND WITH VFR CIGS UNDER LIGHT ERLY FLOW...BUT
ADDITIONAL RAIN AND LLVL MOISTURE MOVING INTO THE SITE SHOULD PULL
CIGS/VSBY TO IFR. FAVORABLE ESE FLOW AT BOTH KCMX/KSAW WILL LEAD TO
VLIFR CONDITIONS THROUGH MUCH OF THE DAY...ALTHOUGH MIXING FROM
STRONGER RAIN SHOWERS COULD PROVIDE A BRIEF REPRIEVE. AS THE LOW
SHIFTS E TONIGHT...EXPECT WINDS TO INCREASE OUT OF THE NW AND TRY TO
PULL IN DRIER LLVL AIR. THUS...HAVE SHOWED A IMPROVING TREND WITH
CIGS/VSBYS.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM IN MN WILL SLIDE NE TODAY AND ACROSS UPPER
MICHIGAN. THIS WILL PRODUCE EASTERLY WINDS UP TO 30KTS OVER THE NRN
HALF OF LAKE SUPERIOR...WITH A FEW GALE FORCE GUSTS TOP 35KTS NEAR
ISLE ROYALE. AS THE LOW SHIFTS EAST TONIGHT...EXPECT WINDS TO TURN
TO THE NNW. MODELS HAVE TRENDED MUCH WEAKER WITH THE LOW AND THUS
HAVE LIMITED CONFIDENCE IN SEEING WINDS WARRENTING A GALE
WATCH/WARNING. THUS...HAVE DECIDED TO CANCEL THE WATCH SINCE THE
MAIN WINDS WILL BE IN THE 30KT RANGE. BEST CHANCE FOR SOME GALE
FORCE GUSTS WILL COME FROM 09-15Z TONIGHT OVER CENTRAL LAKE SUPERIOR
AND WILL MENTION SOME GUSTS FOR THAT TIME FRAME. WINDS WILL DIMINISH
BELOW 20KTS ON SUN NIGHT DUE TO A WEAK SFC TROUGH. EXPECT ANOTHER
SFC TROUGH TO SLIDE ACROSS LK SUPERIOR ON MONDAY EVENING...WITH ONCE
AGAIN COULD PRODUCE WINDS UP TO 30KTS. CENTRAL LK SUPERIOR COULD
ALSO SEE A FEW GALE FORCE GUSTS TO 35KTS. EXPECT WINDS TO FALL BELOW
25KTS TUES AFTN AND CONTINUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
548 AM CST SAT NOV 26 2011
.AVIATION...12Z TAF. NO SIGNIFICANT CHANGES FOR THIS TAF
PERIOD...WITH THE MAIN CONCERN CONTINUING TO LIE WITH WINDS. THE
SURFACE COLD FRONT HAS CLEARED THE TERMINAL AREA...AND
NORTHWESTERLY WINDS HAVE BUILT IN BEHIND...WHICH WILL STICK AROUND
FOR THE ENTIRE TAF PERIOD. SPEEDS ARE ALREADY SUSTAINED NEAR 25 TO
30 MPH WITH GUSTS NEAR 45 MPH...AND INCREASED SPEEDS OF 30 TO 40
MPH WITH HIGHER GUSTS WILL BE POSSIBLE. THIS EVENING WINDS WILL
BEGIN TO TAPER OFF. VFR CONDITIONS WILL REMAIN AS CURRENT CLOUD
COVER SITS IN THE MID/UPPER LEVELS...AND BY MIDDAY SKIES ARE
EXPECTED TO CLEAR.
&&
.PREV DISCUSSION... /ISSUED 307 AM CST SAT NOV 26 2011/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE MAIN CONCERN IN THE
SHORT TERM FORECAST PERIOD WILL BE WINDS TODAY ALONG WITH THE
POSSIBILITY OF RED FLAG CONDITIONS. THE RED FLAG CONCERNS WILL BE
ADDRESSED IN THE FIRE WEATHER PORTION OF THE DISCUSSION LOCATED
BELOW.
A LARGE MID LEVEL TROUGH MOVING ACROSS THE CENTRAL UNITED STATES
THIS MORNING IS PUSHING A STRONG COLD FRONT ACROSS THE REGION.
MSAS 3 HOUR PRESSURE CHANGE ANALYSIS SHOWS PRESSURE RISES NEAR 7
MILLIBARS BEHIND THE FRONT WHICH IS HELPING BRING A NICE SURGE OF
WINDS AS THE BOUNDARY PASSES. WINDS WILL LIKELY SETTLE DOWN TO
SOME DEGREE THIS MORNING BEHIND THE FRONT...HOWEVER IT WILL NOT
TAKE LONG FOR THE WINDS TO INCREASE AGAIN AS MIXING COMMENCES THIS
MORNING. ALL SIGNS STILL POINT TO A DECENT WIND EVENT FOR TODAY
WITH A STRONG SURFACE PRESSURE GRADIENT DEVELOPING DUE TO LOW
PRESSURE TO THE EAST...AND HIGH PRESSURE TO THE WEST.
THE PRIMARY CONCERN SURROUNDS THE GOING HIGH WIND WARNING AND
WIND ADVISORY...AND POTENTIAL CHANGES/ADJUSTMENTS TO THE HEADLINES
FOR TODAY. NAM PROXIMITY SOUNDINGS SUGGEST MIXING TO NEAR H8 IS
LIKELY ACROSS A MAJORITY OF THE FORECAST AREA TODAY...WITH 50 TO
60 KTS OF WIND EXPECTED AT THAT LEVEL. THE FLOW WILL BE FAIRLY
UNIDIRECTIONAL IN THE MIXED LAYER...SO SOME OF THE THE STRONG
WINDS COULD POTENTIALLY TRANSFER TO THE SURFACE. THE HEART OF THE
STRONGER WINDS ARE SHOWN TO RESIDE ACROSS WESTERN PORTIONS OF THE
FORECAST AREA...AND THE CURRENT HIGH WIND WARNING COVERS THAT
WELL. WILL GO AHEAD AND LEAVE THE HEADLINES IN THEIR PRESENT
CONFIGURATION...THOUGH THE NEXT SHIFT WILL OBVIOUSLY HAVE TO WATCH
TRENDS AS THE STRONGER H8 WINDS SHIFT SOUTHEAST THIS AFTERNOON.
A SMALLER CONCERN FOR TODAY WILL BE THE POSSIBILITY OF ANY
LINGERING FLURRIES OR SPRINKLES AS THE LEFT EXIT REGION OF A
100KT UPPER JET SEGMENT SHIFTS THROUGH THE AREA. THE LATEST SREF
AND NCEP 4KM WRF KEEP IT DRY AFTER 12Z TODAY...WHILE THE GFS AND
NOW 26.06Z NAM SUGGESTS THERE COULD BE LINGERING LIGHT
PRECIPITATION IN PARTS OF NORTH CENTRAL KANSAS THIS
MORNING...WHILE THE RUC DEVELOPS LIGHT QPF IN EASTERN PARTS OF THE
FORECAST AREA. CROSS SECTIONS OF RELATIVE HUMIDITY/OMEGA FROM THE
NAM REVEAL DRY LOW LEVELS WHICH WILL BE TOUGH TO
OVERCOME...ESPECIALLY AS THE FORCING WEAKENS...SO WOULD RATHER
CARRY A NON MEASURABLE EVENT SUCH AS SPRINKLES OR FLURRIES. H85
TEMPERATURES QUICKLY FALL BELOW FREEZING THIS MORNING...HOWEVER
ABOVE FREEZING H925 TEMPERATURES WILL PERSIST...SO WILL GO WITH
SPRINKLES/FLURRIES IN THE GRIDS.
THE STRONGEST OF THE WINDS SHOULD SUBSIDE BY EARLY EVENING AS
MIXING BEGINS TO DIMINISH. H5 HEIGHTS BEGIN TO RISE
TONIGHT...WITH WARMER AIR GRADUALLY RETURNING FOR SUNDAY AND
MONDAY. IN FACT...H85 TEMPERATURES RISE FROM -5 DEGREES CELSIUS
TONIGHT...TO NEARLY +10 DEGREES CELSIUS ON MONDAY IN PORTIONS OF
THE FORECAST AREA. WILL AIM FOR HIGHS IN THE MID 40S TO LOWER 50S
ON SUNDAY...WITH 50S ON MONDAY.
ANOTHER MID LEVEL WAVE HELPS KNOCK DOWN THE RIDGE MONDAY AFTERNOON
INTO MONDAY NIGHT...WITH ANOTHER COLD FRONT PLOWING THROUGH THE
AREA. MOISTURE APPEARS LIMITED WITH THE PASSAGE OF THE WAVE/FRONT
AND WILL MAINTAIN A DRY FORECAST AS IT PASSES. WINDS WILL AGAIN
BECOME GUSTY AS THE FRONT PASSES...BUT CURRENTLY IT APPEARS SPEEDS
SHOULD STAY BELOW ADVISORY LEVELS.
LONG TERM...TUESDAY THROUGH FRIDAY.
MODELS NOT IN TOO BAD OF AGREEMENT AT THE START OF THE LONG TERM
PERIOD...WITH NORTHWESTERLY FLOW SET UP IN THE UPPER LEVELS AS A
LOW PRESSURE SYSTEM SPINS OVER THE SOUTHEASTERN CONUS AND A
RIDGE AXIS SETS UP OVER THE WEST COAST. WITH NO DISTURBANCES
EXPECTED TO PUSH THROUGH THE REGION...FORECAST FOR TUESDAY REMAINS
DRY. GETTING INTO TUESDAY NIGHT THROUGH THURSDAY...EXPECTING TO
SEE SHORTWAVE UPPER LEVEL RIDGING BUILD INTO THE CENTRAL PLAINS
EXTENDING FROM THE AREA OF HIGH PRESSURE CENTERED JUST OFF THE SRN
COAST OF CA...BETWEEN THE LOW PRESSURE CONTINUES TO PUSH NORTHEAST
TOWARD THE EAST COAST AND ANOTHER DISTURBANCE MOVING FROM THE PAC
NW INTO THE ROCKIES.
A LITTLE MORE UNCERTAINTY ARISES INTO THURSDAY AND FRIDAY WITH THE
LATEST MODEL RUNS HAVING A FEW DIFFERENCES. THE GENERAL STORY IS
THE DISTURBANCE WHICH HAS SHIFTED INTO THE ROCKIES BECOMES
SPLIT...WITH A CLOSED LOW DEVELOPING OVER THE WRN/SWRN CONUS...BUT
MODELS VARY ON THE TIMING AND LOCATION OF THE LOW AND WHAT HAPPENS
WITH THE NORTHERN ENERGY. THE GFS PUSHES THE NORTHERN ENERGY
FURTHER SOUTH INTO THE REGION...WHILE THE ECMWF SHOWS MORE RIDGING
HELPING TO PUSH IT FURTHER EAST. INTRODUCED SMALL PRECIPITATION
CHANCES ACROSS THE NORTHERN PORTIONS OF THE CWA TO ACCOUNT FOR
THIS DISTURBANCE IN THE REGION...BUT KEPT IT CONFINED TO THE
DAYTIME HOURS ON THURSDAY. TEMPERATURES SUGGEST THE PTYPE WOULD BE
SNOW. ANY PRECIPITATION WOULD NOT STICK AROUND LONG...AND KEPT
THURSDAY NIGHT AND FRIDAY DRY.
WHILE A BUMP UP IN TEMPERATURES IS EXPECTED ON WEDNESDAY WITH THE
RIDGING SET UP AND HIGHS IN THE UPPER 40S TO LOWER/MID
50S...COMPARED TO THE LOWER/MID 40S ON TUESDAY...A COLD FRONT IS
EXPECTED TO PUSH THROUGH THE CWA EARLY THURSDAY. THE COOLER AIR
ACCOMPANYING THE FRONT LOOKS TO DROP HIGHS FOR THURSDAY INTO THE
MID 30S TO LOWER 40S...WITH MID 30S EXPECTED FOR FRIDAY.
FIRE WEATHER...AS STATED ABOVE WINDS TODAY WILL EASILY EXCEED
THE 25 KT GUST CRITERIA NEEDED FOR A RED FLAG WARNING. THE BIGGEST
CONCERN WILL BE RELATIVE HUMIDITY VALUES DROPPING TO 20 PERCENT
OR LESS. THE NAM AND GFS HAVE BOTH COME IN WITH HIGHER SURFACE
DEWPOINTS ON THE 00Z RUNS...AND THIS TREND IS ALSO EVIDENT EVEN
WHEN MIXING DEWPOINTS ALOFT TO THE SURFACE. THAT BEING SAID...AM
STILL CONCERNED ABOUT FIRE WEATHER ISSUES TODAY...ESPECIALLY WITH
THE LATEST ECMWF STILL SUPPORTING LOWER DEWPOINTS THIS AFTERNOON.
WILL HOLD ONTO THE LOWER DEWPOINTS SHOWN BY THE CURRENT FORECAST
AND LATEST ECMWF AND KEEP THE RED FLAG WARNING IN PLACE FOR THIS
AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ041-048-049-063-
064-076-077-086-087.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ039-040-046-
047-060>062-072>075-082>085.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ039-040-046-047-060>062-072>075-082>085.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ007-019.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005-006-017-
018.
RED FLAG WARNING FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
KSZ005>007-017>019.
&&
$$
SHORT/FIRE...KING
LONG/AVIATION...ADO
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTH PLATTE NE
537 AM CST SAT NOV 26 2011
.AVIATION...
EXPECT VFR CONDITIONS AND VERY GUSTY NORTHWEST WINDS TODAY. COLD
FRONT HAS PUSHED WELL TO THE EAST WITH HIGH PRESSURE BUILDING
OVER THE ROCKIES WHICH IS RESULTING IN WIDESPREAD NORTHWEST WINDS
ON THE INCREASE. LOCALLY GUSTS ABOVE 40 KTS WILL CONTINUE INTO
THE MID MORNING HOURS...THEN WIDESPREAD GUSTS ABOVE 40 KTS AND
APPROACHING 50 KTS ARE EXPECTED. SUNSET WILL ALLOW FOR WINDS TO
DIMINISH QUICKLY AS THE BOUNDARY LAYER DECOUPLES. BKN/OVC CIGS
AROUND 10K FT AGL WILL PUSH EAST BY MID MORNING OR EARLY
AFTERNOON. ONCE SKIES CLEAR...EXPECT THEM TO REMAIN CLR INTO
SATURDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 312 AM CST SAT NOV 26 2011/
DISCUSSION...
SHORT TERM...
BUFKIT IS ON TRIAL TODAY AS IT CONTINUES TO ADVERTISE VERY STRONG
WINDS...40 TO 45 KTS AT 1000 TO 1500 FT AGL. THIS SHOULD TRANSLATE
TO SFC WINDS OF 40 MPH OR STRONGER AND ALL MODELS IN BUFKIT SHOW
THIS.
THE MODEL GUIDANCE AND DIRECT OUTPUT HAVE BEEN WOBBLING SHOWING
WIND SPEEDS RUNNING ABOVE AND BELOW HIGH WIND CRITERIA. BUFKIT HAS
BEEN VERY RELIABLE THOUGH SUGGESTING HIGH WINDS WILL DEVELOP.
THE LATEST MAV MET GUIDANCE WIND SPEEDS HAVE SLOWED
SOME...SUGGESTING A HIGH END WIND ADVISORY ACROSS MOST AREAS. THE
EXCEPTION AT KBBW. THE 06Z NAM HOWEVER INDICATES 65 KT WINDS AT
800MB...THE APPROXIMATE MIXING DEPTH EXPECTED ACROSS NCNTL NEB
THIS AFTN. A CORRIDOR OF HIGH WINDS IS EXPECTED TO DEVELOP FROM
KVTN SSE THROUGH KBBW TODAY. DEEPER VERTICAL MIXING IS EXPECTED TO
PRODUCE HIGH WIND GUSTS ACROSS SWRN NEB THIS AFTERNOON ALSO. A
BLEND OF HRRR AND NAMDNG WIND GUST DATA PRODUCED GUSTS TO 55 MPH.
A FEW KNOTS WERE ADDED TO THE FCST TO BRING GUSTS SPEEDS TO 60 MPH
WHICH IS CERTAINLY REACHABLE GIVEN THE 65 KT WINDS AT 800MB SHOWN
IN THE NAM. ALSO KTIF AND KLBF GUSTED TO 47 MPH BETWEEN 8 AND 9Z
BUT HRRR SUGGESTED GUSTS TO 58 MPH WOULD DEVELOP. THE 06Z NAM
FRH68 DATA SUGGESTED 35 KTS IN LOWEST 35 MB THIS AFTERNOON AT
KLBF...ROUGHLY 35 MPH AT THE SFC. 35 MPH IN THE VALLEY SHOULD
EQUATE TO 40 MPH IN THE SANDHILLS NORTH AND SOUTH OF TOWN.
THE HIGH WIND WARNING APPEARS TO BE ON TRACK ACROSS A GOOD
PORTION OF THE FORECAST AREA. WEAKNESSES IN THE WIND FIELDS WERE
NOTED AT BOYD AND WHEELER COUNTIES AND ACROSS SHERIDAN COUNTY.
WIND SPEEDS SHOULD DROP OFF RAPIDLY BETWEEN 4 AND 6 PM CST AS
VERY DRY AIR WILL MOVE IN THIS AFTN. BY SUNDAY MORNING 1035MB HIGH
PRESSURE SHOULD BE ACROSS THE FCST AREA AND WINDS IN THE VALLEYS
SHOULD FALL OFF TO LESS THAN 10 MPH. LOWS IN THE TEENS SHOULD BE
COMMON.
LONG TERM...
ANOTHER STRONG PACIFIC COLD FRONT WILL MOVE THROUGH THE FCST AREA
MONDAY WITH WINDS INCREASING...PERHAPS TO WIND ADVISORY
CRITERIA...30 MPH. MIX DOWN WIND TOOLS PRODUCED WINDS NEAR 30 MPH
AND GFS AND ECMWF SHOW SOME 50 KT WINDS AT 850MB MONDAY AFTERNOON.
FOR NOW A LIMITER WAS USED FOR 20 TO 30 MPH WIND SPEEDS AND LATER
FCSTS CAN ADJUST UP IF NECESSARY. BY TUESDAY MORNING 1035 MPH HIGH
PRESSURE IS CENTERED SOMEWHERE BETWEEN SD AND NERN COLO WITH LOWS
IN THE TEENS. THIS HIGH WILL THEN MOVE OFF TO THE SOUTHEAST TO BE
FOLLOWED BY A STRONGER MORE ARCTIC TYPE HIGH PRESSURE SYSTEM
WEDNESDAY NIGHT AND THURSDAY. THE FRONT APPEARS TO BE CARRYING
SOME MOISTURE WITH IT FROM THE HIGH LATITUDES. SO WE CONTINUE THE
FORECAST FOR SCATTERED SNOW SHOWERS. TEMPS AHEAD OF THE FRONT
APPEAR TO BE COLD ENOUGH FOR SNOW VS FREEZING DRIZZLE CHANGING TO
SNOW. EITHER WAY VERY LIGHT PCPN AMOUNTS ARE EXPECTED WITH THE
FRONT AND MAINLY ACROSS THE NORTHWEST ZONES.
MAX TEMPS TODAY THROUGH WEDNESDAY WILL BE MOSTLY IN THE 40S TO
LOWER 50S. BEHIND THE ARCTIC FRONT THURSDAY AND FRIDAY HIGHS
REACH ONLY INTO THE 30S.
SO THE GEM...GFS...ECMWF AND GEF ARE IN VERY GOOD AGREEMENT
THROUGH WEDNESDAY. THEREAFTER...TIMING PROBLEMS DEVELOP WITH THE
ARCTIC FRONT WHICH APPEAR TO BE RELATED TO DISTURBANCES UPSTREAM
AND DOWNSTREAM ACROSS THE WRN AND ERN U.S. THE GFS APPEARED TO BE
THE MOST RATIONAL SOLN. TIMING-WISE IT WAS SLOWER THAN THE GEM
AND FASTER THAN THE ECMWF.
AVIATION...
EXPECT VFR CONDITIONS AND VERY GUSTY NORTHWEST TODAY. COLD FRONT HAS
PUSHED WELL TO THE EAST WITH WIDESPREAD NORTHWEST WINDS ON THE
INCREASE. LOCALLY GUSTS ABOVE 40 KTS WILL CONTINUE INTO THE MID
MORNING HOURS...THEN WIDESPREAD GUSTS ABOVE 40 KTS ARE EXPECTED.
SUNSET WILL ALLOW FOR WINDS TO DIMINISH QUICKLY AS THE BOUNDARY
LAYER DECOUPLES. BKN/OVC CIGS AROUND 10K FT AGL WILL PUSH EAST BY
MID MORNING OR EARLY AFTERNOON. THERE IS A POSSIBILITY FOR A SCT/BKN
VFR CU FIELD THIS AFTERNOON...HOWEVER LOW CONFIDENCE IN ITS
DEVELOPMENT AS DRY AIR ADVECTS INTO THE REGION. SKIES SHOULD BE
CLEAR BY THIS EVENING INTO SATURDAY NIGHT.
FIRE WEATHER...
VERY GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH THE DAY. DRY AIR
IS EXPECTED TO ADVECT INTO THE REGION...DROPPING DEW POINT TEMPS
INTO THE TEENS AND SINGLE DIGITS. THIS WILL COMBINE WITH HIGHS IN
THE 40S TO PRODUCE MINIMUM RELATIVE HUMIDITY VALUES AROUND 20
PERCENT...LOWEST IN SW NEB. WILL CONTINUE THE RED FLAG WARNING FOR
ALL BUT ZONE 208...WHERE RH VALUES CLOSER TO 30 PERCENT ARE
EXPECTED. ALTHOUGH THE AREA MAY NOT REACH THE TYPICAL WIDESPREAD
RH MINIMUM PERCENTAGES OF 15 PERCENT NEEDED FOR A RED FLAG...THE
COMBINATION OF WIND GUSTS ABOVE 50 MPH...THE VERY DRY FUELS AND
STILL LOW RH VALUES AROUND 20 PERCENT WARRANT THE HEADLINE. THERE
IS A SMALL CHANCE THE DRIER AIR IS DELAYED...WHICH WOULD RESULT IN
WIDESPREAD MINIMUM RH PERCENTAGES IN THE 30S. LOW CONFIDENCE ON
THIS SCENARIO AND WANT TO ERROR ON THE SIDE OF CAUTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 6 PM
CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
RED FLAG WARNING FROM NOON CST /11 AM MST/ TODAY TO 6 PM CST /5
PM MST/ THIS EVENING FOR NEZ204-206-209-210-219.
&&
$$
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
536 AM CST SAT NOV 26 2011
.AVIATION...
EXPECT VFR CONDITIONS AND VERY GUSTY NORTHWEST TODAY. COLD FRONT
HAS PUSHED WELL TO THE EAST WITH HIGH BUILDING OVER THE ROCKIES
WHICH IS RESULTING IN WIDESPREAD NORTHWEST WINDS ON THE INCREASE.
LOCALLY GUSTS ABOVE 40 KTS WILL CONTINUE INTO THE MID MORNING
HOURS...THEN WIDESPREAD GUSTS ABOVE 40 KTS AND APPROACHING 50 KTS
ARE EXPECTED. SUNSET WILL ALLOW FOR WINDS TO DIMINISH QUICKLY AS
THE BOUNDARY LAYER DECOUPLES. BKN/OVC CIGS AROUND 10K FT AGL WILL
PUSH EAST BY MID MORNING OR EARLY AFTERNOON. ONCE SKIES
CLEAR...EXPECT THEM TO REMAIN CLR INTO SATURDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 312 AM CST SAT NOV 26 2011/
DISCUSSION...
SHORT TERM...
BUFKIT IS ON TRIAL TODAY AS IT CONTINUES TO ADVERTISE VERY STRONG
WINDS...40 TO 45 KTS AT 1000 TO 1500 FT AGL. THIS SHOULD TRANSLATE
TO SFC WINDS OF 40 MPH OR STRONGER AND ALL MODELS IN BUFKIT SHOW
THIS.
THE MODEL GUIDANCE AND DIRECT OUTPUT HAVE BEEN WOBBLING SHOWING
WIND SPEEDS RUNNING ABOVE AND BELOW HIGH WIND CRITERIA. BUFKIT HAS
BEEN VERY RELIABLE THOUGH SUGGESTING HIGH WINDS WILL DEVELOP.
THE LATEST MAV MET GUIDANCE WIND SPEEDS HAVE SLOWED
SOME...SUGGESTING A HIGH END WIND ADVISORY ACROSS MOST AREAS. THE
EXCEPTION AT KBBW. THE 06Z NAM HOWEVER INDICATES 65 KT WINDS AT
800MB...THE APPROXIMATE MIXING DEPTH EXPECTED ACROSS NCNTL NEB
THIS AFTN. A CORRIDOR OF HIGH WINDS IS EXPECTED TO DEVELOP FROM
KVTN SSE THROUGH KBBW TODAY. DEEPER VERTICAL MIXING IS EXPECTED TO
PRODUCE HIGH WIND GUSTS ACROSS SWRN NEB THIS AFTERNOON ALSO. A
BLEND OF HRRR AND NAMDNG WIND GUST DATA PRODUCED GUSTS TO 55 MPH.
A FEW KNOTS WERE ADDED TO THE FCST TO BRING GUSTS SPEEDS TO 60 MPH
WHICH IS CERTAINLY REACHABLE GIVEN THE 65 KT WINDS AT 800MB SHOWN
IN THE NAM. ALSO KTIF AND KLBF GUSTED TO 47 MPH BETWEEN 8 AND 9Z
BUT HRRR SUGGESTED GUSTS TO 58 MPH WOULD DEVELOP. THE 06Z NAM
FRH68 DATA SUGGESTED 35 KTS IN LOWEST 35 MB THIS AFTERNOON AT
KLBF...ROUGHLY 35 MPH AT THE SFC. 35 MPH IN THE VALLEY SHOULD
EQUATE TO 40 MPH IN THE SANDHILLS NORTH AND SOUTH OF TOWN.
THE HIGH WIND WARNING APPEARS TO BE ON TRACK ACROSS A GOOD
PORTION OF THE FORECAST AREA. WEAKNESSES IN THE WIND FIELDS WERE
NOTED A BOYD AND WHEELER COUNTIES AND ACROSS SHERIDAN COUNTY.
WIND SPEEDS SHOULD DROP OFF RAPIDLY BETWEEN 4 AND 6 PM CST AS
VERY DRY AIR WILL MOVE IN THIS AFTN. BY SUNDAY MORNING 1035MB HIGH
PRESSURE SHOULD BE ACROSS THE FCST AREA AND WINDS IN THE VALLEYS
SHOULD FALL OFF TO LESS THAN 10 MPH. LOWS IN THE TEENS SHOULD BE
COMMON.
LONG TERM...
ANOTHER STRONG PACIFIC COLD FRONT WILL MOVE THROUGH THE FCST AREA
MONDAY WITH WINDS INCREASING...PERHAPS TO WIND ADVISORY
CRITERIA...30 MPH. MIX DOWN WIND TOOLS PRODUCED WINDS NEAR 30 MPH
AND GFS AND ECMWF SHOW SOME 50 KT WINDS AT 850MB MONDAY AFTERNOON.
FOR NOW A LIMITER WAS USED FOR 20 TO 30 MPH WIND SPEEDS AND LATER
FCSTS CAN ADJUST UP IF NECESSARY. BY TUESDAY MORNING 1035 MPH HIGH
PRESSURE IS CENTERED SOMEWHERE BETWEEN SD AND NERN COLO WITH LOWS
IN THE TEENS. THIS HIGH WILL THEN MOVE OFF TO THE SOUTHEAST TO BE
FOLLOWED BY A STRONGER MORE ARCTIC TYPE HIGH PRESSURE SYSTEM
WEDNESDAY NIGHT AND THURSDAY. THE FRONT APPEARS TO BE CARRYING
SOME MOISTURE WITH IT FROM THE HIGH LATITUDES. SO WE CONTINUE THE
FORECAST FOR SCATTERED SNOW SHOWERS. TEMPS AHEAD OF THE FRONT
APPEAR TO BE COLD ENOUGH FOR SNOW VS FREEZING DRIZZLE CHANGING TO
SNOW. EITHER WAY VERY LIGHT PCPN AMOUNTS ARE EXPECTED WITH THE
FRONT AND MAINLY ACROSS THE NORTHWEST ZONES.
MAX TEMPS TODAY THROUGH WEDNESDAY WILL BE MOSTLY IN THE 40S TO
LOWER 50S. BEHIND THE ARCTIC FRONT THURSDAY AND FRIDAY HIGHS
REACH ONLY INTO THE 30S.
SO THE GEM...GFS...ECMWF AND GEF ARE IN VERY GOOD AGREEMENT
THROUGH WEDNESDAY. THEREAFTER...TIMING PROBLEMS DEVELOP WITH THE
ARCTIC FRONT WHICH APPEAR TO BE RELATED TO DISTURBANCES UPSTREAM
AND DOWNSTREAM ACROSS THE WRN AND ERN U.S. THE GFS APPEARED TO BE
THE MOST RATIONAL SOLN. TIMING-WISE IT WAS SLOWER THAN THE GEM
AND FASTER THAN THE ECMWF.
AVIATION...
EXPECT VFR CONDITIONS AND VERY GUSTY NORTHWEST TODAY. COLD FRONT HAS
PUSHED WELL TO THE EAST WITH WIDESPREAD NORTHWEST WINDS ON THE
INCREASE. LOCALLY GUSTS ABOVE 40 KTS WILL CONTINUE INTO THE MID
MORNING HOURS...THEN WIDESPREAD GUSTS ABOVE 40 KTS ARE EXPECTED.
SUNSET WILL ALLOW FOR WINDS TO DIMINISH QUICKLY AS THE BOUNDARY
LAYER DECOUPLES. BKN/OVC CIGS AROUND 10K FT AGL WILL PUSH EAST BY
MID MORNING OR EARLY AFTERNOON. THERE IS A POSSIBILITY FOR A SCT/BKN
VFR CU FIELD THIS AFTERNOON...HOWEVER LOW CONFIDENCE IN ITS
DEVELOPMENT AS DRY AIR ADVECTS INTO THE REGION. SKIES SHOULD BE
CLEAR BY THIS EVENING INTO SATURDAY NIGHT.
FIRE WEATHER...
VERY GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH THE DAY. DRY AIR
IS EXPECTED TO ADVECT INTO THE REGION...DROPPING DEW POINT TEMPS
INTO THE TEENS AND SINGLE DIGITS. THIS WILL COMBINE WITH HIGHS IN
THE 40S TO PRODUCE MINIMUM RELATIVE HUMIDITY VALUES AROUND 20
PERCENT...LOWEST IN SW NEB. WILL CONTINUE THE RED FLAG WARNING FOR
ALL BUT ZONE 208...WHERE RH VALUES CLOSER TO 30 PERCENT ARE
EXPECTED. ALTHOUGH THE AREA MAY NOT REACH THE TYPICAL WIDESPREAD
RH MINIMUM PERCENTAGES OF 15 PERCENT NEEDED FOR A RED FLAG...THE
COMBINATION OF WIND GUSTS ABOVE 50 MPH...THE VERY DRY FUELS AND
STILL LOW RH VALUES AROUND 20 PERCENT WARRANT THE HEADLINE. THERE
IS A SMALL CHANCE THE DRIER AIR IS DELAYED...WHICH WOULD RESULT IN
WIDESPREAD MINIMUM RH PERCENTAGES IN THE 30S. LOW CONFIDENCE ON
THIS SCENARIO AND WANT TO ERROR ON THE SIDE OF CAUTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 6 PM
CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
RED FLAG WARNING FROM NOON CST /11 AM MST/ TODAY TO 6 PM CST /5
PM MST/ THIS EVENING FOR NEZ204-206-209-210-219.
&&
$$
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
523 AM CST SAT NOV 26 2011
.AVIATION...12Z TAFS FOR KOFK...KOMA...KLNK.
MAIN CONCERN WILL BE VERY GUSTY NORTHWEST SFC WINDS THRU THE DAY.
GUSTS ARE EXPECTED TO INCREASE TO NEAR 40 KTS BY LATE MORNING AND
EARLY AFTERNOON. MVFR CONDITIONS ARE EXPECTED THIS MORNING FOR
KOFK AND KOMA HOWEVER SHOULD IMPROVE TO VFR BY EARLY AFTERNOON.
WINDS WILL BEGIN TO DIMINISH LATER THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 325 AM CST SAT NOV 26 2011/
DISCUSSION...
MAIN FORECAST CONCERN IS WIND TODAY. WATER VAPOR IMAGERY EARLY THIS
MORNING SHOWED A FAIRLY IMPRESSIVE TROUGH EXTENDING FROM SASKATCHEWAN
DOWN INTO MEXICO. 500 MB HEIGHT FALLS WERE AROUND OR IN EXCESS OF
100 METERS FROM SOUTHWEST NEBRASKA TO WEST TEXAS LAST EVENING. A FEW
THUNDERSTORMS WERE NOTED NEAR THE KANSAS/OKLAHOMA BORDER. A COLD
FRONT STRETCHED FROM LOW PRESSURE OVER SOUTHERN MINNESOTA DOWN INTO
WESTERN OKLAHOMA.
THE TROUGH AND FRONT WILL BOTH CONTINUE TO MOVE EAST TODAY...WITH A
TIGHT PRESSURE GRADIENT AND STRONG WINDS SPREADING EAST ACROSS THE
AREA. DELAYED WIND ADVISORY A FEW HOURS FOR PARTS OF THE AREA THIS
MORNING...BUT OTHERWISE WIND FORECAST IS SIMILAR TO PREVIOUS GRIDS.
THE 06Z RUC MODEL DID SHOW SOME LIGHT PRECIPITATION MOVING INTO PARTS
OF NORTHEAST NEBRASKA THROUGH 18Z. OTHERWISE...THE SHOWERS IN FAR
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA SHOULD MOVE OUT VERY EARLY
THIS MORNING. MUCH COLDER AIR WILL MOVE INTO THE AREA TODAY. LOWS
TONIGHT SHOULD BOTTOM OUT IN THE UPPER TEENS TO MID 20S. WINDS WILL
REMAIN BRISK AT LEAST EARLY TONIGHT BUT MOST LIKELY BELOW ADVISORY
LEVELS. AS HIGH PRESSURE AT THE SURFACE BUILDS INTO THE AREA ON
SUNDAY...WINDS WILL DECREASE. EXPECT WEAK RETURN FLOW TO SETUP LATE
SUNDAY NIGHT...BUT IS NOT EXPECTED TO BE STRONG ENOUGH TO KEEP LOWS
UP MUCH ABOVE MOS GUIDANCE.
MILDER AIR SHOULD BE OVER THE AREA MONDAY...WITH HIGHS IN THE UPPER
40S AND LOWER 50S. NEXT COLD FRONT PUSHES THROUGH MONDAY NIGHT...BUT
SHOULD NOT PRODUCE ANY PRECIPITATION. KEPT TUESDAY AND WEDNESDAY DRY
BUT ADDED A SLIGHT CHANCE OF LIGHT SNOW FOR ABOUT THE NORTHERN HALF
OF THE FORECAST AREA THURSDAY. 00Z GFS WAS THE BEST MODEL DEPICTING
THAT SCENARIO.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ015-033-034-
043>045-050>053-065>068-078-088>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
545 AM CST SAT NOV 26 2011
...VERY STRONG WINDS DEVELOPING TODAY...
.AVIATION...
TWO CHALLENGES OF CONCERN TODAY...THE FIRST IS THE DEVELOPMENT OF
SOME POST-FRONTAL MVFR LAYERS FROM CLOVIS EAST TO NEAR CHILDRESS
AND THE SECOND AND MORE PROLONGED THREAT IS THAT OF STRONG
NORTHERLY WINDS FOR MUCH OF THE DAY. BEHAVIOR OF MVFR CIGS IS SUCH
THAT THEY QUICKLY TREND VFR AS COLDER AND DRIER AIR PUSHES
SOUTH...SO WILL ONLY CARRY A TEMPO GROUP AT LBB THIS MORNING. CDS
HAS ALREADY RISEN TO VFR LAYERS IN THIS DRIER AIR.
GREATEST AVIATION HAZARD IS STRONG NORTHERLY WINDS INCREASING TO
BETWEEN 30 AND 40 KNOTS LATER THIS MORNING. THUS FAR WE HAVE LITTLE
REASON TO DOUBT THE FEW MODELS INDICATING SUCH HIGH WINDS AS 50
KNOTS WAS RECENTLY SAMPLED BY THE LBB WSR-88D VAD WIND PROFILE A
MERE 1K FEET AGL. ONCE MIXING LAYERS DEEPEN AROUND 15Z...EXPECT
OCCASIONAL GUSTS TO APPROACH 50 KNOTS WITH SUSTAINED SPEEDS
RESIDING BETWEEN 30 AND 35 KNOTS. AN AIRPORT WX WARNING FOR HIGH
WINDS WILL BE ISSUED SHORTLY FOR LBB STARTING ~15Z. BLOWING DUST
SHOULD NOT BE AS SEVERE AS WITH A WESTERLY WIND EVENT...BUT TEMPO
5SM APPEARS REASONABLE AT LBB. EXPECT WINDS AND STRONG GUSTS TO
QUICKLY SUBSIDE AROUND SUNSET.
&&
.PREV DISCUSSION... /ISSUED 407 AM CST SAT NOV 26 2011/
SHORT TERM...
SHARP UPPER TROUGH CURRENTLY BISECTING THE CONUS WILL INTENSIFY
TODAY AS A VORTICITY MAXIMUM SLIDES SOUTHWARD FROM NERN COLORADO
AND INTO THE BASE OF THE TROUGH. THIS PROCESS IS ALREADY SENDING
A POLAR FRONT SOUTH FROM THE PANHANDLE WHICH SHOULD CLEAR THE CWA
BY MID-MORNING. OF GREATER INTEREST IS A STRONG HEIGHT GRADIENT
TAKING AIM ON MUCH OF THE HIGH PLAINS BY MIDDAY RESULTING IN
NEARLY 100 KNOTS AND 50-60 KNOTS AT 500MB AND 700MB RESPECTIVELY.
DEEP SUBSIDENCE ON THE BACKSIDE OF THE UPPER TROUGH WILL FOSTER
STRONG LOW-LEVEL DRYING TO THE TUNE OF SINGLE-DIGIT DEWPOINTS ON
THE CAPROCK BY EARLY AFTERNOON. EVEN THOUGH MAX TEMPS WILL BE
STUNTED 10 DEG BELOW NORMAL...DEWPOINT DEPRESSIONS RISING TO 40
DEG SHOULD ONLY AID IN DEEPER DRY ADIABATIC LAPSE RATES AND HIGHER
MOMENTUM TRANSFER OVER TIME. CONSIDERING THE MID-LEVEL JET CORE
WILL RESIDE NEAR/JUST WEST OF I-27 AND MAX PRESSURE RISES WILL BE
FAVORABLY TIMED...WE FEEL A HIGH WIND WARNING IS IN ORDER FOR MUCH
OF THE CAPROCK WITH A WIND ADVISORY ELSEWHERE. ALTHOUGH OUR LOCAL
HIGH WIND CHECKLIST FALLS A BIT SHORT OF SOLID HIGH WIND
CRITERIA...THIS PATTERN OF CAA AND DEEP NORTHERLY FLOW COMBINED
WITH SHARP LOW-LEVEL DRYING IS ENOUGH TO TIP THE SCALE IN FAVOR OF
A LOW-END HIGH WIND WARNING SCENARIO. IF THE RUC AND GFS ARE
CORRECT...THE HIGH WIND WARNING MAY NEED TO BE EXPANDED AREA WIDE
THIS MORNING. THE MEMPHIS WTM SITE IS ALREADY ATTEMPTING TO CRASH
THIS PARTY WITH A RECENT GUST TO 55 MPH...HOWEVER CONFIDENCE IN
SUCH A WIDESPREAD AND PROLONGED HIGH WIND THREAT AREA IS NOT
SUFFICIENTLY HIGH AT THIS TIME...BUT LATER FORECASTS WILL REVISIT
THIS POTENTIAL.
A BROAD SURFACE RIDGE WILL THEN OVERSPREAD THE CAPROCK TONIGHT
RESULTING IN LIGHTER WINDS THAN IN THE ROLLING PLAINS. EXPECT
STRONG RADIATIONAL COOLING ON THE CAPROCK TO GARNER SOME OF
COLDEST OVERNIGHT LOWS IN SEVERAL DAYS.
LONG TERM...
REMAINDER OF THE FORECAST PACKAGE IS RELATIVELY QUIET COMPARED
WITH ISSUES FOR TODAY. DEEP NORTHERLY FLOW ALOFT WILL REMAIN IN
PLACE BUT SURFACE WINDS WILL GRADUALLY TRANSITION TO THE WEST LATE
SUNDAY INTO MONDAY. HIGHS TOMORROW WILL AT OR A TICK UNDER NORMAL
FOR THIS TIME OF YEAR BUT WILL REBOUND TO AROUND 10 DEGREES ABOVE
NORMAL ON MONDAY AS DECENT DOWNSLOPE FLOW AND AMPLE SUNSHINE HELP
TO BOOST HIGH TEMPS.
A SECOND COLD FRONT WILL ARRIVE LATE MONDAY INTO TUESDAY ONCE
AGAIN DROPPING HIGH TEMPERATURES BELOW NORMAL FOR TUESDAY FOR
TUESDAY AND POSSIBLY BUMPING WIND SPEEDS UP INTO THE BREEZY
RANGE. RIGHT NOW IT APPEARS THAT WIND SPEEDS WILL NOT BE AS HIGH
AS WE ARE EXPECTING FOR TODAY. SIMILAR CYCLE WILL THEN ENSUE WITH
WEST TO SOUTHWEST WINDS ON WEDNESDAY HELPING TO BRING TEMPERATURES
BACK ABOVE NORMAL FOR A DAY.
STILL ARE SOME CONSIDERABLE DIFFERENCES FOR THE END OF NEXT WEEK
AND THE END OF THIS FORECAST. ALL MODELS ARE NOW DEVELOPING A
CLOSED LOW SOMEWHERE IN THE WESTERN PART OF THE COUNTRY WITH A
STRONG COLD FRONT EXPECTED TO ARRIVE SOMETIME LATE THURSDAY INTO
FRIDAY. GFS IS A FULL DAY FASTER WITH THE COLD FRONT ARRIVAL AND
BRINGS A PRETTY COLD ARCTIC AIRMASS INTO THE REGION. THE ECMWF IS
NOT AS COLD AS THE GFS AND RAPIDLY MIXES OUT THE COLD AIR IN
ADVANCE OF THE APPROACHING CLOSED LOW AND RAPIDLY PULLS IN GULF
MOISTURE. GFS KEEPS THE COLD AIRMASS OVER THE REGION EVEN WITH THE
ADVANCING LOW HEADING TOWARDS THE REGION. WILL HOLD OFF MAKING
CHANGES TO THE LAST TWO DAYS OF THE FORECAST UNTIL THE MODELS
SETTLE DOWN A BIT AND COME INTO BETTER AGREEMENT...BUT THE
POTENTIAL IS THERE FOR SOME PRETTY CHILLY DAYS BY THE END OF NEXT
WEEK INTO NEXT WEEKEND.
JORDAN
FIRE WEATHER...
STRONG LOW-LEVEL DRYING BEHIND A COLD FRONT TODAY COMBINED WITH
NORTHERLY WINDS OF 25-35 MPH AT THE 20-FOOT LEVEL WILL CREATE
PERIODS OF CRITICAL FIRE WEATHER CONDITIONS PRIMARILY OVER THE
SOUTHERN SOUTH PLAINS. ALTHOUGH WIND SPEEDS ARE MORE THAN
SUFFICIENT...BELOW NORMAL TEMPERATURES AND MARGINAL RELATIVE
HUMIDITY VALUES ARE NOT FULLY SUPPORTIVE OF A RED FLAG WARNING. WE
HAVE INSTEAD ISSUED A FIRE DANGER STATEMENT TO HIGHLIGHT PERIODS
THIS AFTERNOON WHEN RELATIVE HUMIDITIES SHOULD BRIEFLY DIP TO
AROUND 15-20 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 22 57 32 66 / 0 0 0 0 0
TULIA 46 24 58 31 70 / 0 0 0 0 0
PLAINVIEW 47 24 58 32 70 / 0 0 0 0 0
LEVELLAND 49 24 59 32 69 / 0 0 0 0 0
LUBBOCK 49 26 59 32 69 / 0 0 0 0 0
DENVER CITY 51 26 59 35 69 / 0 0 0 0 0
BROWNFIELD 49 26 60 32 70 / 0 0 0 0 0
CHILDRESS 52 30 57 30 66 / 0 0 0 0 0
SPUR 52 27 59 34 70 / 0 0 0 0 0
ASPERMONT 54 30 58 32 69 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ025-026-031-032-037>044.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>024-027>030-033>036.
&&
$$
93/14/93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
407 AM CST SAT NOV 26 2011
.SHORT TERM...
SHARP UPPER TROUGH CURRENTLY BISECTING THE CONUS WILL INTENSIFY
TODAY AS A VORTICITY MAXIMUM SLIDES SOUTHWARD FROM NERN COLORADO
AND INTO THE BASE OF THE TROUGH. THIS PROCESS IS ALREADY SENDING
A POLAR FRONT SOUTH FROM THE PANHANDLE WHICH SHOULD CLEAR THE CWA
BY MID-MORNING. OF GREATER INTEREST IS A STRONG HEIGHT GRADIENT
TAKING AIM ON MUCH OF THE HIGH PLAINS BY MIDDAY RESULTING IN
NEARLY 100 KNOTS AND 50-60 KNOTS AT 500MB AND 700MB RESPECTIVELY.
DEEP SUBSIDENCE ON THE BACKSIDE OF THE UPPER TROUGH WILL FOSTER
STRONG LOW-LEVEL DRYING TO THE TUNE OF SINGLE-DIGIT DEWPOINTS ON
THE CAPROCK BY EARLY AFTERNOON. EVEN THOUGH MAX TEMPS WILL BE
STUNTED 10 DEG BELOW NORMAL...DEWPOINT DEPRESSIONS RISING TO 40
DEG SHOULD ONLY AID IN DEEPER DRY ADIABATIC LAPSE RATES AND HIGHER
MOMENTUM TRANSFER OVER TIME. CONSIDERING THE MID-LEVEL JET CORE
WILL RESIDE NEAR/JUST WEST OF I-27 AND MAX PRESSURE RISES WILL BE
FAVORABLY TIMED...WE FEEL A HIGH WIND WARNING IS IN ORDER FOR MUCH
OF THE CAPROCK WITH A WIND ADVISORY ELSEWHERE. ALTHOUGH OUR LOCAL
HIGH WIND CHECKLIST FALLS A BIT SHORT OF SOLID HIGH WIND
CRITERIA...THIS PATTERN OF CAA AND DEEP NORTHERLY FLOW COMBINED
WITH SHARP LOW-LEVEL DRYING IS ENOUGH TO TIP THE SCALE IN FAVOR OF
A LOW-END HIGH WIND WARNING SCENARIO. IF THE RUC AND GFS ARE
CORRECT...THE HIGH WIND WARNING MAY NEED TO BE EXPANDED AREA WIDE
THIS MORNING. THE MEMPHIS WTM SITE IS ALREADY ATTEMPTING TO CRASH
THIS PARTY WITH A RECENT GUST TO 55 MPH...HOWEVER CONFIDENCE IN
SUCH A WIDESPREAD AND PROLONGED HIGH WIND THREAT AREA IS NOT
SUFFICIENTLY HIGH AT THIS TIME...BUT LATER FORECASTS WILL REVISIT
THIS POTENTIAL.
A BROAD SURFACE RIDGE WILL THEN OVERSPREAD THE CAPROCK TONIGHT
RESULTING IN LIGHTER WINDS THAN IN THE ROLLING PLAINS. EXPECT
STRONG RADIATIONAL COOLING ON THE CAPROCK TO GARNER SOME OF
COLDEST OVERNIGHT LOWS IN SEVERAL DAYS.
&&
.LONG TERM...
REMAINDER OF THE FORECAST PACKAGE IS RELATIVELY QUIET COMPARED
WITH ISSUES FOR TODAY. DEEP NORTHERLY FLOW ALOFT WILL REMAIN IN
PLACE BUT SURFACE WINDS WILL GRADUALLY TRANSITION TO THE WEST LATE
SUNDAY INTO MONDAY. HIGHS TOMORROW WILL AT OR A TICK UNDER NORMAL
FOR THIS TIME OF YEAR BUT WILL REBOUND TO AROUND 10 DEGREES ABOVE
NORMAL ON MONDAY AS DECENT DOWNSLOPE FLOW AND AMPLE SUNSHINE HELP
TO BOOST HIGH TEMPS.
A SECOND COLD FRONT WILL ARRIVE LATE MONDAY INTO TUESDAY ONCE
AGAIN DROPPING HIGH TEMPERATURES BELOW NORMAL FOR TUESDAY FOR
TUESDAY AND POSSIBLY BUMPING WIND SPEEDS UP INTO THE BREEZY
RANGE. RIGHT NOW IT APPEARS THAT WIND SPEEDS WILL NOT BE AS HIGH
AS WE ARE EXPECTING FOR TODAY. SIMILAR CYCLE WILL THEN ENSUE WITH
WEST TO SOUTHWEST WINDS ON WEDNESDAY HELPING TO BRING TEMPERATURES
BACK ABOVE NORMAL FOR A DAY.
STILL ARE SOME CONSIDERABLE DIFFERENCES FOR THE END OF NEXT WEEK
AND THE END OF THIS FORECAST. ALL MODELS ARE NOW DEVELOPING A
CLOSED LOW SOMEWHERE IN THE WESTERN PART OF THE COUNTRY WITH A
STRONG COLD FRONT EXPECTED TO ARRIVE SOMETIME LATE THURSDAY INTO
FRIDAY. GFS IS A FULL DAY FASTER WITH THE COLD FRONT ARRIVAL AND
BRINGS A PRETTY COLD ARCTIC AIRMASS INTO THE REGION. THE ECMWF IS
NOT AS COLD AS THE GFS AND RAPIDLY MIXES OUT THE COLD AIR IN
ADVANCE OF THE APPROACHING CLOSED LOW AND RAPIDLY PULLS IN GULF
MOISTURE. GFS KEEPS THE COLD AIRMASS OVER THE REGION EVEN WITH THE
ADVANCING LOW HEADING TOWARDS THE REGION. WILL HOLD OFF MAKING
CHANGES TO THE LAST TWO DAYS OF THE FORECAST UNTIL THE MODELS
SETTLE DOWN A BIT AND COME INTO BETTER AGREEMENT...BUT THE
POTENTIAL IS THERE FOR SOME PRETTY CHILLY DAYS BY THE END OF NEXT
WEEK INTO NEXT WEEKEND.
JORDAN
&&
.FIRE WEATHER...
STRONG LOW-LEVEL DRYING BEHIND A COLD FRONT TODAY COMBINED WITH
NORTHERLY WINDS OF 25-35 MPH AT THE 20-FOOT LEVEL WILL CREATE
PERIODS OF CRITICAL FIRE WEATHER CONDITIONS PRIMARILY OVER THE
SOUTHERN SOUTH PLAINS. ALTHOUGH WIND SPEEDS ARE MORE THAN
SUFFICIENT...BELOW NORMAL TEMPERATURES AND MARGINAL RELATIVE
HUMIDITY VALUES ARE NOT FULLY SUPPORTIVE OF A RED FLAG WARNING. WE
HAVE INSTEAD ISSUED A FIRE DANGER STATEMENT TO HIGHLIGHT PERIODS
THIS AFTERNOON WHEN RELATIVE HUMIDITIES SHOULD BRIEFLY DIP TO
AROUND 15-20 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 22 57 32 66 / 0 0 0 0 0
TULIA 46 24 58 31 70 / 0 0 0 0 0
PLAINVIEW 47 24 58 32 70 / 0 0 0 0 0
LEVELLAND 49 24 59 32 69 / 0 0 0 0 0
LUBBOCK 49 26 59 32 69 / 0 0 0 0 0
DENVER CITY 51 26 59 35 69 / 0 0 0 0 0
BROWNFIELD 49 26 60 32 70 / 0 0 0 0 0
CHILDRESS 52 30 57 30 66 / 0 0 0 0 0
SPUR 52 27 59 34 70 / 0 0 0 0 0
ASPERMONT 54 30 58 32 69 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ025-026-031-032-037>044.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>024-027>030-033>036.
&&
$$
93/14
AREA FORECAST DISCUSSION
NWS DENVER CO
1210 PM MST SAT NOV 26 2011
.UPDATE...HAVE OPTED TO CANCEL THE HIGH WIND WARNING FOR THE
NORTHEAST PLAINS. LESS THAN CRITERIA CONDITIONS AT THIS TIME AND
DO NOT ANTICIPATE IT WORSENING.
&&
.PREV DISCUSSION... /ISSUED 914 AM MST SAT NOV 26 2011/
UPDATE...ONLY MINOR ADJUSTMENTS TO THE GRIDS AT THIS TIME.
ALTHOUGH IT WILL BE WINDY ACROSS THE PLAINS...THERE IS STILL SOME
QUESTION AS TO WHETHER A WARNING IS WARRANTED. WL HOLD ON TO THE
HIGHLIGHT FOR NOW AND SEE HOW THINGS DEVELOP BEFORE THE NEXT
UPDATE TO THE NPW WHICH WILL BE AROUND 1830Z.
&&
.AVIATION...NO MAJOR ADJUSTMENTS AT THIS TIME. THE MAIN CONCERN
WILL REVOLVE AROUND THE DEVELOPMENT OF THE LONGMONT ANTICYCLONE
THIS AFTERNOON. THIS HAS ALREADY BEEN ADDRESSED IN THE PRVS
DISCUSSION AND SEE NO REASON TO TAMPER MUCH WITH THE TERMINAL FCSTS
I INHERITED.
.PREV DISCUSSION... /ISSUED 320 AM MST SAT NOV 26 2011/
SHORT TERM...AN UPPER LEVEL TROUGH WILL QUICKLY MOVE EAST OF THE
AREA THIS MORNING WITH SNOW ENDING IN THE MTNS AND OVER THE FAR NERN
PLAINS BY SUNRISE. WINDS WILL REMAIN GUSTY OVER THE NERN PLAINS
THRU EARLY AFTN BEFORE GRADUALLY DECREASING BY LATE AFTN. BASED ON
CURRENT DATA MOST GUSTS WILL BE AROUND 50 MPH HOWEVER STILL COULD
SEE A FEW HIGHER GUSTS THRU EARLY AFTN SO WILL KEEP HIGH WIND
WARNING IN PLACE ALTHOUGH IT PROBABLY COULD BE CANCELED BY 21Z. AS
FAR AS FIRE WEATHER WATCH LATEST HRR SHOWS HUMIDITY LEVELS ONLY
DROPPING TO 35-40 PERCENT OVER THE NERN PLAINS THIS AFTN WITH TEMPS
AROUND 40 DEGREES. IN ADDITION THERE WAS SOME SNOW OVERNIGHT WITH
ACCUMULATIONS UP TO AN INCH IN SPOTS. ALTHOUGH WINDS WILL BE GUSTY
BELIEVE THREAT IS LOW ENOUGH TO NOT ISSUE A RED FLAG WARNING. AS
FOR HIGHS THIS AFTN WILL KEEP READINGS MAILY IN THE UPPER 30S TO
LOWER 40S OVER THE NERN PLAINS WITH MID 40S CLOSER TO THE FOOTHILLS.
FOR TONIGHT WINDS WILL QUICKLY DIMINISH OVER THE PLAINS SHORTLY
AFTER SUNSET WITH DRY CONDITIONS OVER THE ENTIRE CWA.
LONG TERM...STRONG NORTH-NORTHWESTERLY FLOW ALOFT IS PROGGED TO
DECREASE ACROSS THE CWA ON SUNDAY AS AN UPPER RIDGE MOVES IN. THE
RIDGE AXIS MOVES ACROSS THE FORECAST AREA LATE SUNDAY NIGHT INTO MID
DAY MONDAY...WITH WEAKER ZONAL FLOW ALOFT. LATE MONDAY AND MONDAY
NIGHT...A WEAK UPPER TROUGH IS PROGGED TO MOVE IN WITH WESTERLY FLOW
ALOFT ON THE INCREASE MONDAY EVENING. THE SYNOPTIC SCALE ENERGY IS
NEGLIGIBLE SUNDAY AND SUNDAY NIGHT...THEN WEAK UPWARD QG VERTICAL
VELOCITY IS PROGGED MONDAY AFTERNOON INTO THE EARLY EVENING HOURS.
AFTER THAT...WEAK DOWNWARD MOTION MOVES IN FOR THE REST OF MONDAY
NIGHT. THE LOW LEVEL PRESSURE AND WIND FIELDS KEEP A DECENT
GRADIENT IN PLACE...WITH LOW PRESSURE EAST OF THE MOUNTAINS.
DOWNSLOPING BOUNDARY LAYER WINDS ARE A GOOD BET SUNDAY THROUGH MUCH
OF MONDAY. A WEAK COLD FRONT IS PROGGED TO MOVE INTO THE PLAINS
MONDAY AFTERNOON WITH BOUNDARY LAYER UPSLOPE CONTINUING PAST
MIDNIGHT MONDAY NIGHT. FOR MOISTURE...SUNDAY LOOKS PRETTY DRY...
WITH JUST OF A BIT OF UPPER LEVEL MOISTURE PROGGED SUNDAY NIGHT INTO
MONDAY. BY 00Z TUESDAY...MOISTURE INCREASES A BIT BEHIND THE FRONT
..WITH THE GFS SHOWING IT TO GET FAIRLY DEEP OVER THE FOOTHILLS AND
WESTERN CWA PLAINS. THE NAM HAS LESS. THE MOUNTAINS STAY FAIRLY
DRY. BOTH MODELS SHOW IT PRETTY DRY BY 12Z TUESDAY MORNING...JUST A
BIT OF MID LEVEL MOISTURE ON THE NAM. THE ONLY MEASURABLE
PRECIPITATION NOTED ON THE QPF FIELDS FROM SUNDAY THROUGH TUESDAY
MORNING...IS A TAD OVER THE FOOTHILLS AND ADJACENT PLAINS ON THE GFS
MONDAY EVENING. WILL GO WITH NO POPS FOR CWA THROUGH THE PERIODS.
WILL WATCH FOR THE MONDAY AFTERNOON/EVENING UPSLOPE ON FURTHER MODEL
RUNS. FOR TEMPERATURES...SUNDAY`S HIGHS ARE 8-11 C WARMER THAN
TODAY`S EXPECTED READINGS. MONDAY`S HIGHS ARE A TAD COOLER THAN
SUNDAY`S...AT LEAST FOR THE PLAINS. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...MODELS HAVE MORE UPPER RIDGING TUESDAY INTO
WEDNESDAY FOR THE CWA. BY WEDNESDAY NIGHT AND THURSDAY...MODELS
SHOW A DECENT CLOSED LOW OVER THE WEST CENTRAL U.S. COAST. IT MOVES
LITTLE THROUGH FRIDAY...DEPENDING ON THE MODEL. THE GFS BRINGS A
FAIRLY COLD AIRMASS AND UPSLOPE TO THE PLAINS WEDNESDAY EVENING.
THE ECMWF DOESN`T SHOW THIS UNTIL THURSDAY AFTERNOON. BOTH HAVE A
FAIRLY COLD AIRMASS IN PLACE ON FRIDAY. THE MODELS HAVE BEEN ALL
OVER THE HE PLACE WITH THIS FEATURE THE LAST FEW RUNS. CONFIDENCE
IS LOW. WILL LEAVE THE EXTENDED-BLENDED-GFE STUFF PRETTY MUCH
ALONE.
AVIATION...WINDS HAVE REMAINED GUSTY OUT OF THE NORTH AT 20-30 MPH
EARLY THIS MORNING HOWEVER LATEST HRRR SHOWS THEM DECREASING BY
SUNRISE TO THE 10-20 MPH RANGE. BY MID MORNING THE HRRR SHOWS A
WELL DEFINED LONGMONT ANTICYCLONE WITH THE CENTER STAYING TO THE NW
OF THE AIRPORT THRU THE AFTN. THIS KEEPS WINDS AT THE AIRPORT NNW
THRU EARLY AFTN WITH SPEEDS IN THE 15-25 MPH WITH SOME GUSTS TO
30-35 MPH AT TIMES THRU 20Z. AFTER 20Z THE HRRR SHOWS WINDS
DECREASING TO 10-20 MPH AND BECOMING MORE NELY AS THE ANTICYCLONE
SHIFTS A BIT FURTHER EAST. BY SUNSET THE WINDS SHOULD BECOME LIGHT
ESE AND THEN MORE SLY BY 03Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....RJK
AREA FORECAST DISCUSSION
NWS DENVER CO
914 AM MST SAT NOV 26 2011
.UPDATE...ONLY MINOR ADJUSTMENTS TO THE GRIDS AT THIS TIME.
ALTHOUGH IT WILL BE WINDY ACROSS THE PLAINS...THERE IS STILL SOME
QUESTION AS TO WHETHER A WARNING IS WARRANTED. WL HOLD ON TO THE
HIGHLIGHT FOR NOW AND SEE HOW THINGS DEVELOP BEFORE THE NEXT
UPDATE TO THE NPW WHICH WILL BE AROUND 1830Z.
&&
.AVIATION...NO MAJOR ADJUSTMENTS AT THIS TIME. THE MAIN CONCERN
WILL REVOLVE AROUND THE DEVELOPMENT OF THE LONGMONT ANTICYCLONE
THIS AFTERNOON. THIS HAS ALREADY BEEN ADDRESSED IN THE PRVS
DISCUSSION AND SEE NO REASON TO TAMPER MUCH WITH THE TERMINAL FCSTS
I INHERITED.
&&
.PREV DISCUSSION... /ISSUED 320 AM MST SAT NOV 26 2011/
SHORT TERM...AN UPPER LEVEL TROUGH WILL QUICKLY MOVE EAST OF THE
AREA THIS MORNING WITH SNOW ENDING IN THE MTNS AND OVER THE FAR NERN
PLAINS BY SUNRISE. WINDS WILL REMAIN GUSTY OVER THE NERN PLAINS
THRU EARLY AFTN BEFORE GRADUALLY DECREASING BY LATE AFTN. BASED ON
CURRENT DATA MOST GUSTS WILL BE AROUND 50 MPH HOWEVER STILL COULD
SEE A FEW HIGHER GUSTS THRU EARLY AFTN SO WILL KEEP HIGH WIND
WARNING IN PLACE ALTHOUGH IT PROBABLY COULD BE CANCELED BY 21Z. AS
FAR AS FIRE WEATHER WATCH LATEST HRR SHOWS HUMIDITY LEVELS ONLY
DROPPING TO 35-40 PERCENT OVER THE NERN PLAINS THIS AFTN WITH TEMPS
AROUND 40 DEGREES. IN ADDITION THERE WAS SOME SNOW OVERNIGHT WITH
ACCUMULATIONS UP TO AN INCH IN SPOTS. ALTHOUGH WINDS WILL BE GUSTY
BELIEVE THREAT IS LOW ENOUGH TO NOT ISSUE A RED FLAG WARNING. AS
FOR HIGHS THIS AFTN WILL KEEP READINGS MAILY IN THE UPPER 30S TO
LOWER 40S OVER THE NERN PLAINS WITH MID 40S CLOSER TO THE FOOTHILLS.
FOR TONIGHT WINDS WILL QUICKLY DIMINISH OVER THE PLAINS SHORTLY
AFTER SUNSET WITH DRY CONDITIONS OVER THE ENTIRE CWA.
LONG TERM...STRONG NORTH-NORTHWESTERLY FLOW ALOFT IS PROGGED TO
DECREASE ACROSS THE CWA ON SUNDAY AS AN UPPER RIDGE MOVES IN. THE
RIDGE AXIS MOVES ACROSS THE FORECAST AREA LATE SUNDAY NIGHT INTO MID
DAY MONDAY...WITH WEAKER ZONAL FLOW ALOFT. LATE MONDAY AND MONDAY
NIGHT...A WEAK UPPER TROUGH IS PROGGED TO MOVE IN WITH WESTERLY FLOW
ALOFT ON THE INCREASE MONDAY EVENING. THE SYNOPTIC SCALE ENERGY IS
NEGLIGIBLE SUNDAY AND SUNDAY NIGHT...THEN WEAK UPWARD QG VERTICAL
VELOCITY IS PROGGED MONDAY AFTERNOON INTO THE EARLY EVENING HOURS.
AFTER THAT...WEAK DOWNWARD MOTION MOVES IN FOR THE REST OF MONDAY
NIGHT. THE LOW LEVEL PRESSURE AND WIND FIELDS KEEP A DECENT
GRADIENT IN PLACE...WITH LOW PRESSURE EAST OF THE MOUNTAINS.
DOWNSLOPING BOUNDARY LAYER WINDS ARE A GOOD BET SUNDAY THROUGH MUCH
OF MONDAY. A WEAK COLD FRONT IS PROGGED TO MOVE INTO THE PLAINS
MONDAY AFTERNOON WITH BOUNDARY LAYER UPSLOPE CONTINUING PAST
MIDNIGHT MONDAY NIGHT. FOR MOISTURE...SUNDAY LOOKS PRETTY DRY...
WITH JUST OF A BIT OF UPPER LEVEL MOISTURE PROGGED SUNDAY NIGHT INTO
MONDAY. BY 00Z TUESDAY...MOISTURE INCREASES A BIT BEHIND THE FRONT
..WITH THE GFS SHOWING IT TO GET FAIRLY DEEP OVER THE FOOTHILLS AND
WESTERN CWA PLAINS. THE NAM HAS LESS. THE MOUNTAINS STAY FAIRLY
DRY. BOTH MODELS SHOW IT PRETTY DRY BY 12Z TUESDAY MORNING...JUST A
BIT OF MID LEVEL MOISTURE ON THE NAM. THE ONLY MEASURABLE
PRECIPITATION NOTED ON THE QPF FIELDS FROM SUNDAY THROUGH TUESDAY
MORNING...IS A TAD OVER THE FOOTHILLS AND ADJACENT PLAINS ON THE GFS
MONDAY EVENING. WILL GO WITH NO POPS FOR CWA THROUGH THE PERIODS.
WILL WATCH FOR THE MONDAY AFTERNOON/EVENING UPSLOPE ON FURTHER MODEL
RUNS. FOR TEMPERATURES...SUNDAY`S HIGHS ARE 8-11 C WARMER THAN
TODAY`S EXPECTED READINGS. MONDAY`S HIGHS ARE A TAD COOLER THAN
SUNDAY`S...AT LEAST FOR THE PLAINS. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...MODELS HAVE MORE UPPER RIDGING TUESDAY INTO
WEDNESDAY FOR THE CWA. BY WEDNESDAY NIGHT AND THURSDAY...MODELS
SHOW A DECENT CLOSED LOW OVER THE WEST CENTRAL U.S. COAST. IT MOVES
LITTLE THROUGH FRIDAY...DEPENDING ON THE MODEL. THE GFS BRINGS A
FAIRLY COLD AIRMASS AND UPSLOPE TO THE PLAINS WEDNESDAY EVENING.
THE ECMWF DOESN`T SHOW THIS UNTIL THURSDAY AFTERNOON. BOTH HAVE A
FAIRLY COLD AIRMASS IN PLACE ON FRIDAY. THE MODELS HAVE BEEN ALL
OVER THE HE PLACE WITH THIS FEATURE THE LAST FEW RUNS. CONFIDENCE
IS LOW. WILL LEAVE THE EXTENDED-BLENDED-GFE STUFF PRETTY MUCH
ALONE.
AVIATION...WINDS HAVE REMAINED GUSTY OUT OF THE NORTH AT 20-30 MPH
EARLY THIS MORNING HOWEVER LATEST HRRR SHOWS THEM DECREASING BY
SUNRISE TO THE 10-20 MPH RANGE. BY MID MORNING THE HRRR SHOWS A
WELL DEFINED LONGMONT ANTICYCLONE WITH THE CENTER STAYING TO THE NW
OF THE AIRPORT THRU THE AFTN. THIS KEEPS WINDS AT THE AIRPORT NNW
THRU EARLY AFTN WITH SPEEDS IN THE 15-25 MPH WITH SOME GUSTS TO
30-35 MPH AT TIMES THRU 20Z. AFTER 20Z THE HRRR SHOWS WINDS
DECREASING TO 10-20 MPH AND BECOMING MORE NELY AS THE ANTICYCLONE
SHIFTS A BIT FURTHER EAST. BY SUNSET THE WINDS SHOULD BECOME LIGHT
ESE AND THEN MORE SLY BY 03Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ042-
048>051.
&&
$$
SHORT TERM...COOPER
LONG TERM....RJK
AVIATION...COOPER
AREA FORECAST DISCUSSION...CORRECTED WATCH/WARNING/ADVISORY CODING
NWS DES MOINES IA
320 PM CST SAT NOV 26 2011
.SHORT TERM /TONIGHT/...
MAIN CONCERN TONIGHT WILL BE TEMP AND WIND TRENDS...AND PRECIP TO A
LESSER EXTENT. PRIMARY PRECIP SHIELD ASSOCIATED WITH CENTRAL CONUS
LONG WAVE TROUGH CURRENTLY EXTENDS FROM SRN PLAINS INTO GREAT LAKES
AND HAS ALL BUT EXITED FORECAST AREA. FORCING WITH THIS IS MAINLY
MID/UPPER LEVEL BASED IN THE FORM OF DPVA AND RIGHT ENTRANCE REGION
DIVERGENCE OF GREAT LAKES JET SEGMENT. RADAR AND SATELLITE TRENDS
DO NOT LOOK PROMISING FOR ADDITIONAL PRECIP THIS EVENING...HOWEVER
MODELS DO SUSTAIN SOME MID LEVEL KINEMATIC FORCING WITH BRIEF SURGE
OF DEEPER MOISTURE SWINGING THROUGH AROUND 00Z OR SHORTLY
THEREAFTER. THUS HAVE KEPT MENTION OF SPRINKLES OR FLURRIES NE
THIRD DURING THE EVENING.
POTENTIAL FOR ADVISORY LEVEL WINDS HAS DECREASED AS WELL...BOTH
SPATIALLY AND TEMPORALLY...WITH ONLY A SITE OR TWO WEST CURRENTLY
VERIFYING. ISALLOBARIC MAX...MAX MSLP GRADIENT...AND MAGNITUDE OF
MIXED LAYER WINDS ALL DECREASE THIS EVENING AS THEY APPROACH THE MO
RIVER SO DO NOT EXPECT ADVISORY CRITERIA WINDS TO CONTINUE AS LONG
OR AS FAR EAST AS PREVIOUSLY ANTICIPATED. THUS HEADLINE NOW ENDS AT
03Z WITH SEVERAL TIERS OF ERN COUNTIES REMOVED.
OUTSIDE OF THE RUC...RAW MODEL TEMPS ARE BEHIND THE CURVE IN TERMS
OF COOLING. HOWEVER EVEN THE COOLER NAM WHICH EVENTUALLY CATCHES UP
TO THE RUC SUGGESTS CLOUDS AND WINDS KEEPING TEMPS ABOVE GUIDANCE.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
IN THE LONG TERM...IT WILL BE FAIRLY QUIET WITH A DRY FORECAST
THROUGH DAY SEVEN. UPPER LEVEL LOW PRESSURE SYSTEM FORECAST BY ALL
MODELS OVER THE SOUTHEAST UNITED STATES HEADS NORTH INTO THE OHIO
VALLEY BY TUESDAY. MEANWHILE...A WEAK NORTHERN STREAM SHORTWAVE
SHOULD CROSS THE NORTHERN PLAINS AND UPPER MIDWEST. UPSTREAM QG
FORCING OVER THE NORTHERN PLAINS SHOULD WEAKEN AS THE WAVE
APPROACHES THE MISSISSIPPI VALLEY AND INTERACTS WITH UPPER LOW
MOVING NORTH INTO THE OHIO VALLEY. THE LACK OF SUSTAINED VERTICAL
MOTION AND LIMITED MOISTURE SHOULD KEEP THE ASSOCIATED COLD FRONT
DRY WITH SOME CLOUDS AS IT CROSSES IOWA. ON MONDAY...AHEAD OF THE
FRONT...WEAK HIGH PRESSURE OVER CENTRAL IOWA BETWEEN THE SYSTEM OVER
THE OHIO VALLEY AND THE APPROACHING COLD FRONT. ONLY MODEST MIXING
SHOULD KEEP TEMPERATURES RELATIVELY COOL CONSIDERING THE THERMAL
CHARACTERISTICS OF THE AIRMASS. GIVEN THE EXPECTED COOL TEMPERATURES
ON MONDAY...ONLY MODEST COOLING IS FORECAST BEHIND THE FRONT ON
TUESDAY. THIS IS PROBABLY DUE TO BETTER MIXING EVEN THOUGH THE
AIRMASS WILL BE COOLER.
MODELS AGREE IN DIGGING AN UPPER LOW OVER THE SOUTHWEST UNITED
STATES DURING THE EXTENDED. THE 12Z ECMWF/GFS SUGGEST NORTHWEST
FLOW OVER THE NORTH CENTRAL UNITED STATES BUT THEY HAVE TIMING
DIFFERENCES WITH SHORTWAVES AND FRONTAL PASSAGES LATE NEXT WEEK.
ALTHOUGH ALL SOLUTIONS LOOK MAINLY DRY FOR CENTRAL IOWA...DAY TO DAY
TEMPERATURE FORECASTS HAVE ONLY MODEST CONFIDENCE AT THIS POINT.
&&
.AVIATION...26/18Z
IFR STRATUS FOLLOWING COLD FRONT CROSSING MS RIVER AT 18Z WILL EXIT
KMCW/KOTM SHORTLY. WIDESPREAD MVFR CIGS FOLLOW CLOSE BEHIND AND
WILL ENCOMPASS MUCH OF STATE THIS AFTERNOON. CIGS ARE CURRENTLY SUB
2KFT BUT MAY RAISE ABOVE THAT THIS AFTERNOON BEFORE DROPPING BACK
BELOW AGAIN OVERNIGHT. PEAK WIND GUSTS WILL OCCUR THIS EVENING AS
MIXING PERSISTS AND APPROACH OF MSLP GRADIENT AND ISALLOBARIC
COMPONENT MAXES. CIGS MAY DISSIPATE OVER WRN IA LATE...VFR POSSIBLY
REACHING KFOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR
AUDUBON-CALHOUN-CARROLL-CASS-CRAWFORD-EMMET-PALO ALTO-POCAHONTAS-SAC.
&&
$$
SHORT TERM...SMALL
LONG TERM...JOHNSON
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1132 AM CST SAT NOV 26 2011
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
VERY STRONG WINDS OF 35 KNOTS ARE EXPECTED TO PERSIST THROUGH THE
MID TO LATE AFTERNOON HOURS...UNTIL DEEP ATMOSPHERIC MIXING
SUBSIDES WITH LOWER SUN ANGLE. WILL DECREASE SUSTAINED WINDS IN
THE TAFS AT 22Z TO 26 KNOTS GUSTING TO LOWER 30S KNOTS...THEN
DECREASE WINDS FURTHER TO 16 KNOTS SUSTAINED AT 02Z WHEN PRESSURE GRADIENT
RELAXES AND THERE IS NO LONGER INSOLATION TO KEEP THE LOWER
ATMOSPHERE MIXED. THE SKY WILL BE CLEAR AS THE STORM SYSTEM
CONTINUES TO MOVE AWAY FROM KANSAS. -UMSCHEID
&&
PREV DISCUSSION... /ISSUED 309 AM CST SAT NOV 26 2011/
SYNOPSIS...
UPPER AIR ANALYSIS SHOWS THAT A LARGE TROF IS MOVING ACROSS THE
PLAINS THIS MORNING. THIS FEATURE CAUSED THE PRECIPITATION EVENT
THAT OCCURRED LAST NIGHT AND BROUGHT THE WELCOMED RAINS. A COLD
FRONT WAS PUSHING INTO WESTERN KANSAS EARLY THIS MORNING AND WILL
BE THE MAIN IMPACT TODAY IN TERMS OF WEATHER.
DISCUSSION...
DAYS 1-2...
IMMEDIATE CONCERN IS THE PRECIPITATION MOVING OUT OF THE AREA. KDDC
WSR-88D SHOWS THAT THE PRECIPITATION SHIELD IS SLOWLY MOVING OUT
OF THE CWFA AND HAVE TAPERED POPS DOWN AS A RESULT. I HAVE 15 PERCENT
POPS NORTH WHERE THE GFS AND THE RUC ARE INDICATING THE POTENTIAL FOR
A FEW SPRINKLES OR FLURRIES.
THE OTHER FOCUS TODAY IS WIND. 1 KM WINDS ARE AROUND 50 KT WITH 850
HPA WINDS IN THE 45 TO 55 KT RANGE. A FRONT IS MOVING ACROSS WESTERN
KANSAS EARLY THIS MORNING WITH STRONG WINDS ALREADY BEING REPORTED ACROSS
THE HIGH PLAINS OF EASTERN COLORADO. THE MOST RECENT HRRR SHOWS 10M
WINDS AROUND 35 KT THROUGH THIS AFTERNOON. AS A RESULT, HAVE ISSUED
A HIGH WIND WARNING FOR POINTS WEST OF A LINE FROM TREGO TO CLARK
COUNTIES. FURTHER EAST TOWARDS HAYS, THE MOS GUIDANCE IS MORE
MARGINAL SO HAVE DECIDED TO KEEP THE AREA EAST OF A LINE FROM ELLIS
TO COMANCHE COUNTIES IN A WIND ADVISORY. FURTHER WEST, MOS GUIDANCE
WAS SUPPORTING WIND WARNING CRITERIA WITH FORECAST OF 40G50KT AT
GARDEN CITY AND LIBERAL. SINCE WE WILL HAVE A NORTHWESTERLY
DOWNSLOPE COMPONENT, I INCREASED TEMPERATURES A DEGREE OR TWO ABOVE
GUIDANCE. TEMPERATURES SHOULD WARM TO THE UPPER 40S TO LOWER 50S.
THE FIRE WEATHER WATCH WAS ALSO CANCELLED AS RH`S NOW LOOK LIKE TO NOT
MEET THE 15 PERCENT CRITERIA. FOR MORE INFORMATION, SEE THE FIRE WEATHER
AFD SECTION BELOW.
BY TONIGHT, WE WILL HAVE NORTHERLY FLOW ALOFT IN THE WAKE OF THE UPPER
LEVEL TROF. SKIES SHOULD CLEAR AS DRY AIR ADVECTION STARTS THROUGH THE
ATMOSPHERIC COLUMN SO AM EXPECTING COOLER OVERNIGHT LOWS...GENERALLY IN
THE 20S.
THE WEATHER WILL STILL BE QUIET SUNDAY AS 500 HPA HEIGHTS INCREASE IN
RESPONSE TO RIDGING ACROSS THE DESERT SOUTHWEST. POPS WILL REMAIN
AT ZERO. MAX TEMPERATURES ARE EXPECTED IN THE 50S WHICH IS SLIGHTLY
ABOVE NORMAL.
DAYS 3-7...
THE 00Z RUNS OF THE MEDIUM RANGE MODELS HAVE COME INTO BETTER
AGREEMENT IN HANDLING THE UPPER TROUGH THAT IS CURRENTLY MOVING OUT
INTO THE CENTRAL CONUS. THE GFS HAS TRENDED TOWARD THE OTHER MODELS
IN THAT IT IS NOW CLOSING OFF AN UPPER LOW OVER THE LOWER
MISSISSIPPI VALLEY SIMILAR TO...BUT NOT AS FAR SOUTH...AS THE ECMWF.
ANY SENSIBLE WEATHER IMPACTS FROM THIS WILL BE WELL TO THE EAST OF
WESTERN KANSAS. THE MODELS CONTINUE TO SHOW THE NEXT STRONG
SHORTWAVE TROUGH MOVING EAST THROUGH THE NORTHERN CONUS WITH SOME
SHORTWAVE ENERGY MOVING SOUTHEAST OVER THE CENTRAL HIGH PLAINS.
ANOTHER STRONG COLD FRONT WILL PUSH SOUTH THROUGH WESTERN KANSAS LATE
MONDAY AFTERNOON AND EVENING. THE MODELS ARE NOT INDICATING MUCH IN
THE WAY OF PRECIPITATION WITH THIS FRONT. THIS LOOKS REASONABLE
GIVEN THAT LOW LEVEL MOISTURE WILL NOT HAVE AN OPPORTUNITY TO RETURN
NORTHWARD IN THE WAKE OF TODAYS UPPER TROUGH. THERE COULD BE A
PERIOD OF STRONG WINDS BEHIND THE FRONT AS AT LEAST THE GFS IS
SHOWING 850 MB WINDS TO 50 KNOTS.
THE MIDDLE PART OF NEXT WEEK SHOULD BE FAIRLY QUIET AS UPPER LEVEL
RIDGING MOVES OVER THE CENTRAL PLAINS. HOWEVER...ANOTHER UPPER
TROUGH WILL BE DIGGING SOUTH INTO THE WESTERN STATES. THE MODELS ARE
DIFFERING IN SOMEWHAT IN HOW THIS SYSTEM DEVELOPS BUT THEY ALL
DEVELOP IT INTO A CLOSED LOW OVER SOUTHERN CALIFORNIA/ARIZONA BY
NEXT FRIDAY. THE MODELS BRING ANOTHER COLD FRONT WITH MUCH COOLER
AIR SOUTH ACROSS WESTERN KANSAS AROUND THURSDAY OR FRIDAY AND THEN
MOVE THE UPPER LOW EAST TOWARD THE CENTRAL AND SOUTHERN PLAINS NEXT
WEEKEND. THIS COULD HAVE SOME SIGNIFICANT WEATHER IMPACTS WITH THE
POSSIBILITY FOR A SNOWSTORM ACROSS SOUTHWEST KANSAS NEXT WEEKEND
DEPENDING ON THE TRACK OF THE UPPER LOW.
FIRE WEATHER...
HAVE CANCELLED THE FIRE WEATHER WATCH AS UPSTREAM DEWPOINT OBSERVATIONS
ARE SHOWING THAT THE MODEL DEWPOINTS ARE RUNNING A LITTLE LOW. EVEN
WARMING UP TEMPERATURES AND ARTIFICIALLY LOWERING DEWPOINTS ONLY PRODUCES
RH`S IN THE 20 TO 30 PERCENT RANGE. WINDS WILL BE STRONG TODAY THOUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 25 54 31 / 0 0 0 0
GCK 45 23 55 31 / 0 0 0 0
EHA 44 23 58 35 / 0 0 0 0
LBL 46 23 56 32 / 0 0 0 0
HYS 47 24 52 30 / 0 0 0 0
P28 49 27 53 30 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ031-046-065-066-
079>081-089-090.
&&
$$
FN99/99/25
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1004 AM MST SAT NOV 26 2011
.SHORT TERM (TODAY-MONDAY)...
240 AM MST SAT NOV 26 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW AMPLIFIED
RIDGE-TROUGH-RIDGE PATTERN OVER THE CONUS...WITH MEAN TROUGH AXIS
CENTERED ALONG CO/KS STATE LINE. AT THE SURFACE COLD FRONT CURRENTLY
SOUTHEAST OF CWA...WITH SURFACE HIGH PRESSURE QUICKLY BUILDING IN
BEHIND FRONT OVER CWA. UPSTREAM 3HR PRESSURE RISES AROUND 7MB HAVE
BEEN OBSERVED OVER PARTS OF EASTERN WYOMING/WESTERN NEBRASKA...WITH
3-5MB PRESSURE RISES OVER WESTERN PARTS OF CWA. VAD WIND PROFILER
DATA SHOWS 45-55KT LOW LEVEL JET OVERHEAD...WITH LOCAL OBSERVATIONS
REPORTING SURFACE WINDS GUSTING 45-48KT.
IMMEDIATE FORECAST CONCERNS IN THE SHORT RANGE ARE ON PRECIP CHANCES
EARLY THIS MORNING AND HIGH WINDS THROUGH THIS AFTERNOON.
RIGHT ENTRANCE REGION OF H25-H3 JET COMBINED WITH STEEP MID LEVEL
LAPSE RATES HAVE LED TO DEVELOPMENT ON SCT-ISO SHOWERS OVER NE
COLORADO...WHICH HAS PROGRESSED EAST INTO SW NEBRASKA AND EXTREME NW
KANSAS EARLY THIS MORNING. AS CAA CONTINUES EXPECT MOST LOCATION TO
SEE SNOW BECOME PREDOMINANT PRECIP TYPE. WEAK MOISTURE ADVECTION
COMBINED WITH BUILDING SUBSIDENCE ALOFT SHOULD LIMIT PRECIP
AMOUNTS...SO ONLY EXPECTING LOCALIZED SNOW TOTALS OF LESS THAN ONE
HALF INCH...WHILE MOST LOCATIONS WILL STRUGGLE TO SEE EVEN A FEW
TENTHS OF AN INCH DUE TO MELTING. GUIDANCE SNOWS STRONG SUBSIDENCE
OVERTAKING AREA BY 12Z ALONG WITH VERY DRY AIR ADVECTING IN OVER THE
AREA...WHICH SHOULD END PRECIP CHANCES. WILL KEEP FORECAST DRY AFTER
12Z FOR NOW AND ADJUST BASED ON TRENDS.
WIND FORECAST IS CURRENTLY ON TRACK...WITH WIND GUSTS EARLY THIS
MORNING ALREADY ON HIGH END OF WIND ADVISORY OVER MOST THE AREA. RUC
CURRENTLY HAS BEST HANDLE ON H85-H7 WINDS BASED ON PROFILER
DATA...AND SHOWS 50KT H85 JET SPREADING EAST OVER REMAINING CWA.
WHILE PEAK PRESSURE RISES OCCUR BEFORE 12Z THIS MORNING...PERSISTENT
50KT H85 JET AND INCREASED MIXING AFTER SUNRISE SHOULD SUPPORT WINDS
INCREASING TO WARNING CRITERIA. THE STRONGEST SURFACE WINDS SHOULD
THEN DECREASE TOWARDS 00Z AS MIXING DECREASES AND WINDS ALOFT BEGIN
TO SLACKEN.
TONIGHT-MONDAY NIGHT...H5 RIDGE BUILDS EAST AND STRENGTHENS OVER SW
CONUS...WITH SHORTWAVE RIDGE AXIS EXTENDING NORTH ACROSS CWA BY MON
NIGHT. LARGE SCALE SUBSIDENCE AND DEEP DRY AIR MASS OVER CWA WILL
HELP KEEP CONDITIONS DRY THROUGH THESE PERIODS WITH TEMPS WARMING TO
ABOUT 10-15F ABOVE NORMAL SUN/MON. TEMPS A LITTLE TRICKY ON MON AS
SHORTWAVE AND ASSOCIATED COLD FRONT MOVES ACROSS REGION. GUIDANCE
CONTINUING TO DIFFER ON POSITION/TIMING OF FRONT...WHICH WILL IMPACT
HIGH TEMPS MON ALONG WITH GUSTY WINDS MON AFTERNOON. FOR NOW HAVE
KEPT IN LINE WITH PREVIOUS FORECAST OF UPPER 50S NORTH/LOW 60S
SOUTH...HOWEVER TEMPS MAY END UP NEEDING TO BE LOWERED IF FASTER
FRONTAL TIMING OF SREF/GEM WERE TO BE REALIZED.
DR
.LONG TERM (TUESDAY-FRIDAY)...
240 AM MST SAT NOV 26 2011
AN UPPER LEVEL RIDGE WILL BUILD INTO THE TRI-STATE AREA THROUGH
THURSDAY. MODELS THEN BEGIN TO DISAGREE AS TO HOW QUICKLY THE
UPPER LEVEL RIDGE MOVES EAST AS THE UPPER LEVEL TROUGH BUILDS IN AND
WHEN THE COLD FRONT WILL MOVE THROUGH THURSDAY. AS A RESULT
HIGH TEMPERATURES FOR THURSDAY VARY SIGNIFICANTLY BETWEEN THE
MODELS. FRONTAL TIMING WILL ALSO AFFECT THE ARRIVAL AND TYPE OF
PRECIPITATION. CURRENT CONSENSUS HAS THE PRECIP. OCCURRING DURING
THE DAY FOR MOST OF THE CWA. DIFFICULT TO NAIL DOWN PRECIP. TYPE
THURSDAY DUE TO THE DIFFERENCE IN FRONTAL TIMING. GENERALLY HAVE
SNOW IN THE NORTHWEST AND FAR NORTH CWA WHICH TRANSITIONS TO A
NARROW BAND OF RAIN-SNOW MIX FOLLOWED BY RAIN FURTHER SOUTH. BEHIND
THE FRONT THE 850MB WINDS WILL BE GUSTY. HOWEVER MODELS DISAGREE
WITH THE TIMING AND PLACEMENT OF THE WINDS BEHIND THE FRONT...BUT
CONSENSUS HAS BREEZY CONDITIONS THURSDAY AFTERNOON. AFTER THURSDAY
THE UPPER LEVEL FLOW TURNS TO THE SOUTHWEST AND THE ENVIRONMENT
DRIES OUT. HOWEVER TEMPERATURES WILL REMAIN COOL AFTER THURSDAY AS
THE UPPER LEVEL TROUGH MOVES TOWARD THE AREA.
JTL
&&
.AVIATION...
1004 AM MST SAT NOV 26 2011
FOR THE 18Z TAFS...VFR CONDS WILL PREVAIL. WINDS WILL BE THE MAIN
CONCERN THROUGH THE SHORT TERM...GUSTING IN THE 40-50 KNOT RANGE AT
BOTH LOCATIONS FROM THE NORTHWEST THROUGH SUNSET. AFTER SUNSET AND
MIXING CEASES...WINDS WILL DIMINISH CONSIDERABLY. SKIES WILL BE
CLEAR THROUGH THE PERIOD AS HIGH PRESSURE BUILDS INTO THE AREA.
BAS
&&
.FIRE WEATHER...
240 AM MST SAT NOV 26 2011
RED FLAG WARNING CURRENTLY IN EFFECT FOR THIS AFTERNOON ACROSS
CWA. TD VALUES HAVE BEEN SLOWER TO DECREASE THAN PREVIOUS GUIDANCE
INDICATED...HOWEVER FINALLY BEGINNING TO SEE 10-15F TD VALUES
ADVECTING INTO EASTERN COLORADO. SINGLE DIGIT TD VALUES OVER
WYOMING SHOULD EVENTUALLY ADVECT OVER CWA...AND DESPITE AFTERNOON
TEMPS IN THE UPPER 30S/LOW 40S...CURRENTLY THINK RH VALUES 18-25%
SEEM REASONABLE. COMBINED WITH VERY STRONG WINDS THIS
AFTERNOON...CRITICAL FIRE CONDITIONS WILL CONTINUE TO BE A
CONCERN...SO NO CHANGES PLANNED FOR CURRENT HIGHLIGHT.
CRITICAL FIRE CONDITIONS WILL BE POSSIBLE AGAIN MONDAY AFTERNOON.
TIMING OF STRONGEST WINDS AND LOCATION OF LOWEST TD VALUES WILL
LIKELY BE DEPENDENT ON TIMING OF COLD FRONT...WHICH GUIDANCE IS
CURRENTLY DOING A POOR JOB OF TIMING OUT...SO WILL NEED TO MONITOR
THIS.
DR
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
KSZ001>004-013>016-027>029-041-042.
RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
KSZ001>004-013>016-027>029-041-042.
NE...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
NEZ079>081.
RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
NEZ079>081.
CO...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092.
RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ252>254.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1235 PM EST SAT NOV 26 2011
...Updated Aviation Discussion...
...Forecast Update...
A few changes to the forecast this morning. First of all, light
radar echoes moving NE from southeast MO/western KY/southern IL seem
to be producing light brief rain showers. The 12Z HRRR has picked
up on this activity bringing it into our southwest Indiana counties
by early afternoon. This seems reasonable given the current radar
trends and light isentropic lift increasing throughout the day ahead
of the approaching front. Therefore expanded 20% POPs in the far
western CWA from 18Z to 0Z.
As of 10am EST, winds were already gusting out of the south between
20-25 mph with a few higher gusts noted. Based on these already
gusty conditions with BKN upper level clouds, think that we`ll see
gusts between 30-35 mph this afternoon with BKN mid and upper level
clouds continuing throughout the day.
Last, on such strong southerly flow, temps are running 2-3 degrees
warmer than previously forecast. The 12Z NAM has caught on to this
temp trend. Based on this new model data and this morning`s trends,
think that high temps should reach the upper 60s with a few lower
70s possible near the BWG area.
&&
.Short Term (Today - Sunday)...
Surface low currently over south central Minnesota will lift
northeasward across the Great Lakes through the forecast period,
with a trailing cold front moving near the western CWA border by
dawn on Sunday. Meanwhile, a full CONUS amplified trough axis will
slide from the central United States to the Middle Mississipi River
Valley by Sunday afternoon. Anomalous closed low is expected to
develop over the Ark/La/Tex region sometime on Sunday with
associated surface low situated over the Tennessee Valley.
Today...
Another dry day is in store for the CWA as model trends have
continued to be slower with precipitation ahead of aforementioned
frontal boundary. The main focus for today will be on gusty
southerly winds and how warm temperatures will get under variably
cloudy skies. Pressure gradient between southeast CONUS high and low
moving across the Great Lakes will be quite strong with southerly
winds between 15 and 20 mph, gusting up around the 30 mph mark at
times. Cannot rule out a few gusts up to the 35 mph range, depending
on how much mixing will occur. Kept wind gusts tempered compared to
potential just a bit based on expected increasing clouds throughout
the day and the impact on mixing.
High temperatures are expected to jump nicely on steady southerly
flow, into the solid mid 60s in most spots. The mercury will range
in the upper 60s near the Bowling Green region. The northwest CWA
will be the coolest in the lower 60s as mostly cloudy skies by
midday hamper heating.
Tonight and Sunday...
Precipitation chances are expected to increase west of I-65 between
7 PM and 1 AM EST as moisture convergence/ascent with 40-50 knot low
level jet ramps up across the region, coincident with the right
entrance region of the upper level jet. Best moisture/lift will
continue to spread eastward by dawn with categorical POPS along and
west of the I 65 corridor and likely POPS west of I 75. Categorical
wording will continue through the entire day on Sunday with frontal
boundary slowly working through the CWA. It should be noted that an
even slower solution could hamper the forecast with categorical rain
showers holding west of I 65 until 12Z Sunday morning as suggested
by 26/00Z SPC WRF. This is the most extreme/slow solution, so
preferred a slightly faster forecast although attention should be
paid to subsequent forecasts if slower trend continues.
Have gone with a limited diurnal trend during this time with mild
lows in the 50 to 55 degree range and highs on Sunday only in the 50
to 60 degree range, dependent on frontal passage. Areas east of I-65
will likely see the 60 degree mark early before temperatures remain
steady or gradually fall off through the day. West of this line,
expect 50 to 55 degree highs, remaining steady or gradually falling
into the upper 40s through the afternoon.
Overall precipitation amounts through Sunday afternoon should range
in the 0.75 to 1.5 inch range. At this point, the Blue Grass region
appears to be the most likely area to see just under an inch.
.Long term (Sunday Night - Friday)...
Models in pretty good agreement for the start of the period, placing
the cold front over our eastern border with JKL Sunday night and a
broad north-south trough stretching from the Gulf of Mexico over
Louisiana up to St. James Bay. Given that the upper trough lags well
behind the front, have an extensive area of post-frontal
precipitation. Thermal profiles look too warm for any frozen precip
Sunday night. Only exception may be over the NW forecast area, so
have kept in slight chances for snow there after midnight.
During the day Monday, the models now are in better agreement,
closing off a low on the southern end of the above-mentioned trough.
The GEFS/SREF/12Z and new 00Z ECMWF/NAM all place this low over MS
Monday evening, whereas the GFS has it in central TN. Will leave the
GFS as an outlier and go with the rest of the guidance for this
system. The 18Z GEFS indicates heights for the 500mb low are 4-5
standard deviations below normal. Thus expect a good feed of
moisture to come up the east side of the system from the Gulf. This
feed will mean continued precip chances until after both the axis of
the upper low and its associated deformation zone passes east of the
area, which looks like it may not occur until Wednesday morning over
the Bluegrass. The next chance for snow during this period will come
Tuesday night. Thicknesses will be at there lowest at that point,
with the cold upper low pulling east of the region and merging with
a broader trough over the area. Surface temperatures should remain
too warm for accumulations, but if the snow dominates over the rain
and falls faster than expected here, some light accumulations are
possible. Will be optimistic for now and just mention the chance for
rain or snow with no accumulations.
From that point on, assuming the closed low behaves as these models
predict, difficult to do in the long range, our area looks to dry
out some. The entire week looks chilly, with generally staying in
the 40s. Lows Monday and Tuesday morning also should be in the 40s,
with extensive cloud cover. Clearing skies for the second half of
the week will allow colder nighttime lows, to around 30.
&&
.Aviation (18Z TAF Issuance)...
Breezy conditions are expected this afternoon ahead of an
approaching frontal boundary. Winds will be out of the south
between 15-18 kts gusting to 25-30 kts. Wind gusts will subside
after sunset this evening with flight conditions remaining VFR.
Tonight the frontal boundary will approach the region bringing rain
showers and MVFR CIGS/VSBYS between 6Z-9Z. More steady rains will
set in after 11Z and last through the morning and early afternoon
hours Sun. While VSBYS may remain in the MVFR cat, CIGS will be
questionable. Will be optimistic and drop CIGS to around 1 kft for
now, but they could drop into the IFR cat.
Gusty winds will again become an issue around the time that showers
start arriving at the TAF sites late tonight. A 45-50 kt LLJ at
H925 will develop during the early morning hours making it easy for
any showers to mix down gusty winds or the mixy atmosphere ahead of
the front outside of any showers may cause windy conditions.
Therefore will insert 25 kt gusts although the 12Z NAM bufkit
soundings indicate gusts into the 30 kt range. Will need to monitor
that.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......BJS
Long Term........RJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST SAT NOV 26 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.UPDATE...
A LITTLE DRYING HAS MOVED INTO THE WESTERN HALF OF UPPER
MICHIGAN...WHICH HELPED TO DECREASE PCPN SOMEWHAT THIS MORNING.
HOWEVER...THE PCPN HAS REDEVELOPED AS ANOTHER WAVE MOVES THROUGH THE
AREA. WITH THIS IN MIND...HAVE OPTED TO KEEP CATEGORICAL POPS ACROSS
THE ENTIRE AREA EXCEPT THE FAR WEST WHERE ADDITIONAL PCPN WILL HAVE
TO WAIT UNTIL WRAP AROUND MOISTURE MOVES IN LATER ON TODAY. AS FOR
PCPN TYPE ACROSS THE FAR WEST...LATEST MODEL SOUNDINGS FROM IWD DO
NOT SHOW THE FREEZING LEVEL LOWERING TO BELOW 1000 FT UNTIL AFTER
00Z. THAT COMBINED WITH THE FACT THAT THE BL TEMPS WILL BE AT LEAST
IN THE MID-UPPER 30S...HAVE OPTED TO REMOVE ANY MENTION OF SNOW
UNTIL THIS EVENING.
&&
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROFFING OVER
THE PLAINS BTWN PERSISTENT RDG OVER THE ERN CONUS AND ANOTHER RDG
OVER THE W COAST. THERE ARE 3 SHRTWVS OF SIGNIFICANCE EMBEDDED
WITHIN THE TROF OVER THE PLAINS...ONE OVER SASKTATCHEWAN...ANOTHER
IN WYOMING...AND ANOTHER CENTERED NEAR THE TX PANHANDLE. THE COMPLEX
INTERACTION BTWN THESE SEPARATE DISTURBANCES HAS MADE THE EVOLUTION
OF THE UPCOMING WX PATTERN A BIT TRICKY FOR RECENT SHIFTS. THE
DISTURBANCE OVER WYOMING IS SUPPORTING A SFC LO OVER WCNTRL MN. A
FAIRLY WELL DEFINED COMMA CLD IS PRESENT WITH COMMA HEAD PCPN NOTED
UNDER COLDER CLD TOPS OVER THE DAKOTAS ON THE COLD SIDE OF THE
ACCOMPANYING H85 LO. THE WARM CONVEYOR BELT CLD EXTENDS THRU THE UPR
MIDWEST/UPR MS RIVER VALLEY INTO THE GRT LKS...BUT DRY AIR NOTED AT
H7 BY THE BULK OF THE RAOBS...VERY WELL SHOWN BY THE 00Z GRB/MPX
RAOBS...E OF THE UPR TROF AXIS HAS PREVENTED WDSPRD RA FM DVLPG
DESPITE INCRSG UPR DVGC UNDER COUPLED UPR JET STRUCTURE BTWN H3
SPEED MAX IN ONTARIO AND ANOTHER IN SDAKOTA/NEBRASKA. HOWEVER...THE
INTERACTION BTWN THIS DYNAMIC AND THE STRONG SW FLOW E OF THE MN LO
THAT IS ADVECTING UNSEASONABLY HI H85 DWPTS UP TO 6C FROM OMAHA TO
THRU IOWA TOWARD THE UPR MIDWEST HAS CAUSED A RECENT EXPANSION OF
THE RADAR ECHOES TO THE SW. ALTHOUGH A SFC COLD FNT...ASSOCIATED
WITH THE JET MAX IN ONTARIO...HAS SLID OVER UPR MI...TEMPS OVER UPR
MI ARE WELL ABV NORMAL IN THE UPR 30S/40S. THIS FNT HAS PRETTY MUCH
STALLED BUT COULD SERVE AS A FOCAL POINT FOR INCRSG LLVL MSTR CNVGC/
FGEN/ISENTROPIC ASCENT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THRU THIS WEEKEND ARE PCPN CHCS/TYPES/POTENTIAL
SN ACCUMS AND TIMING OF DRYING TREND FOLLOWING THE PASSAGE OF UPR
TROF/SFC LO.
TDAY...RECENT MODEL RUNS HAVE COME INTO BETTER AGREEMENT ON EXPECTED
STRENGTH/TRACK OF SFC LO THAT WL IMPACT THE CWA AHEAD OF DISTURBANCE
NOW IN WYOMING. THIS LO IS PROGGED TO MOVE TO BTWN MQT AND MUNISING
BY 00Z SUN. AS THE SFC LO NOW IN MN MOVES TOWARD UPR MI...GUIDANCE
SHOWS INCRSG ISENTROPIC ASCENT FOCUSED ON THE 290K SFC/UPR DVGC
UNDER FVRBL ORIENTATION OF UPR JET CORES/PWAT SURGING TO ALMOST 250
PCT OF NORMAL WITH THE ARRIVAL OF H85 DWPTS OF 5C. BOTH THE 00Z
NAM/GFS SHOW THE SHARPEST H85-7 FGEN ACCOMPANYING THE FVRBL
INTERACTION BTWN THESE DYNAMICS/MOISTENING AND THE FNTL BNDRY
IMPACTING MAINLY THE NW CWA WITH THE HIEST QPF THEN SHIFTING OUT
OVER LK SUP AND TO THE E IN THE AFTN. ALTHOUGH THE FCST LLVL CYC NNW
FLOW IN THE WAKE OF THE SFC LO PASSING TO THE E WL PROBABLY KEEP
SOME PCPN GOING OVER THE W...FCST DEEP LYR QVECTOR DVGC ARRIVING FM
THE SW IN THE AFTN WL LIKELY LIMIT THE INTENSITY OF THE PCPN THERE
MORE THAN EARLIER ANTICIPATED AND WEAKEN THE COMMA HEAD PCPN NOTED
OVER THE DAKOTAS EARLY THIS MRNG. THE ARRIVAL OF SOMEWHAT COLDER
LLVL AIR INTO THE W LATE...WITH THE MORE AGGRESSIVE GFS SHOWING H85
TEMPS FALLING AS LO AS -3C AT IWD BY 00Z SUN...MAY CAUSE ANY PCPN TO
AT LEAST MIX WITH SN...BUT THE WEAKER DYNAMIC COOLING AND SFC TEMPS
HOLDING ABV 32 WL PREVENT ANY ACCUMULATION.
TNGT...AS THE SFC LO SHIFTS NE INTO ERN ONTARIO BY 12Z SUN...A
COLDER CYC NNW FLOW WL ENVELOP THE ENTIRE CWA IN ITS WAKE. WITH DEEP
LYR QVECTOR DVGC DOMINATING IN THE CAD/DRYING IN THE WAKE OF THE
SHRTWV...LINGERING PCPN WL SHIFT TO AN LES MODE WITH H85 TEMPS
WITHIN THE TRAILING THERMAL TROF FALLING TO -8C TO -10C /LK WATER
TEMPS ARE 5-6C/ OVER THE W BY 12Z SUN UNDER CYC FLOW/SLOWLY DECAYING
DEEPER MSTR WITHIN THE COMMA HEAD. SINCE THE DGZ IS FCST TO BE
WITHIN THE LARGER SCALE SUBSIDENCE AT THE TOP OF THE MOIST LYR AND
ABV THE SHARPER LLVL CNVGC/FORCING...SUSPECT THIS EVENT WL BE A HI
POP/FAIRLY LO QPF WITH NO NEED FOR HEADLINES ATTM. STILL...A FEW
INCHES OF WET SN ARE LIKELY OVER MAINLY THE HIER TERRAIN IN THE NNW
WIND SN BELTS OF THE W WHERE THE UPSLOPE COOLING/LLVL CNVGC WL BE
MAXIMIZED. ALTHOUGH THE FLOW WL TURN TO THE NW AFT 06Z OVER THE E...
THE AIR WL NOT BE SUFFICIENTLY COLD FOR SGNFT LES THERE THRU 12Z.
CUT POPS SGNFTLY OVER THE SCNTRL WITH EXPECTED DOWNSLOPE NW FLOW IN
THE ABSENCE OF ANY DYNAMIC SUPPORT.
SUN...AS THE H85 THERMAL TROF SHIFTS E FOLLOWING THE DEPARTING SFC
LO...EXPECT LES TO ENVELOP MAINLY THE NNW WIND SN BELTS OVER THE E.
BUT THRU THE DAY...RISING HGTS/MORE ACYC FLOW WL TEND TO DIMINISH
THIS ACTIVITY W-E AS WELL. ANY SN ACCUMULATIONS SHOULD REMAIN ON THE
LGT SIDE WITH POOR SN GROWTH PARAMETERS/DGZ ABV THE RELATIVELY
SHALLOW MSTR/LLVL FORCING IN THE ABSENCE OF DYNAMIC SUPPORT. OTRW...
THE DAY SHOULD FEATURE MORE SEASONABLY CHILLY TEMPS. THE SC WL
SLOWLY BREAK UP...ESPECIALLY OVER THE SCNTRL IN THE PRESENCE OF
DOWNSLOPE FLOW.
SUN NGT...UNDER BLDG UPR RDG...SFC HI PRES RDG AXIS WL SHIFT OVER
THE CWA. LGT WINDS UNDER THIS HI/FCST PWAT 60 PCT OF NORMAL WARRANTS
LOWERING PREVIOUS FCST MIN TEMPS TOWARD THE LO END OF GUIDANCE...
ESPECIALLY OVER THE INTERIOR W AND CNTRL.
MON...WARMER AIR IS FCST TO RETURN WITH STRENGTHENING SW FLOW BTWN
HI PRES SINKING INTO THE LOWER GRT LKS AND NEXT SHRTW/SFC LO
TRACKING INTO NW ONTARIO. H85 TEMPS ARE FCST TO REACH ARND 5C DURING
THE AFTN. THE COLD FNT ATTENDANT TO THE LO WL APRCH THE WRN ZNS LATE
IN THE DAY...BUT RELATIVE DRYNESS OF AIRMASS IN PLACE WITH MSTR
INFLOW DISRUPTED BY DVLPG LO IN THE OH RIVER VALLEY AND PASSAGE OF
STRONGER DYNAMICS FARTHER TO THE N WL MAINTAIN DRY WX.
MON NGT...EXPECT COLD FROPA ATTENDANT TO SHRTWV/SFC LO PASSAGE IN
NRN ONTARIO. HIER RH IS FCST TO STAY TO THE N CLOSER TO SHRTWV
TRACK...SO EXPECT A DRY FROPA. FCST SCHC POPS OVER THE NRN TIER
WHERE VEERING FLOW FM SW TO NW WL RESULT IN SOME UPSLOPE WIND
COMPONENT.
EXTENDED...CWA WL BE DOMINATED BY RELATIVELY DRY NRN BRANCH UPR
FLOW. SO EXPECT NO SGNFT PCPN EVENTS DURING THIS TIME THAT WL LIKELY
FEATURE FAIRLY CHANGEABLE TEMPS. TIMING DIFFERENCES ON SHRTWVS
EMBEDDED WITHIN THE FLOW WARRANTS HOLDING CLOSE TO ALL BLEND FCST.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
LOW PRESSURE NEAR THE WI/MI BORDER WILL DRIFT ACROSS THE AREA THIS
AFTERNOON...THEN MOVE NORTHEAST OF THE AREA TONIGHT. THIS WILL KEEP
LOW CIGS/VSBYS FOR ALL SITES AT LEAST THROUGH THE AFTERNOON BEFORE
SLOW IMPROVEMENT OCCURS TONIGHT AS COLDER/DRIER LOW LEVEL AIR AIR
MOVES IN ON NWLY WINDS. THIS WILL ALLOW FOR CIGS AND VSBYS TO RISE
TO MVFR AT ALL SITES...BUT WILL ALSO CAUSE ANY RAIN TO CHANGE TO
SNOW THIS EVENING...ESPECIALLY AT IWD. EXPECT LIGHT SNOW AT IWD AND
EVENTUALLY AT CMX TO CAUSE OCCASIONAL IFR VSBYS THROUGH SUNDAY
MORNING.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM IN MN WILL SLIDE NE TODAY AND ACROSS UPPER
MICHIGAN. THIS WILL PRODUCE EASTERLY WINDS UP TO 30KTS OVER THE NRN
HALF OF LAKE SUPERIOR...WITH A FEW GALE FORCE GUSTS TOP 35KTS NEAR
ISLE ROYALE. AS THE LOW SHIFTS EAST TONIGHT...EXPECT WINDS TO TURN
TO THE NNW. MODELS HAVE TRENDED MUCH WEAKER WITH THE LOW AND THUS
HAVE LIMITED CONFIDENCE IN SEEING WINDS WARRENTING A GALE
WATCH/WARNING. THUS...HAVE DECIDED TO CANCEL THE WATCH SINCE THE
MAIN WINDS WILL BE IN THE 30KT RANGE. BEST CHANCE FOR SOME GALE
FORCE GUSTS WILL COME FROM 09-15Z TONIGHT OVER CENTRAL LAKE SUPERIOR
AND WILL MENTION SOME GUSTS FOR THAT TIME FRAME. WINDS WILL DIMINISH
BELOW 20KTS ON SUN NIGHT DUE TO A WEAK SFC TROUGH. EXPECT ANOTHER
SFC TROUGH TO SLIDE ACROSS LK SUPERIOR ON MONDAY EVENING...WITH ONCE
AGAIN COULD PRODUCE WINDS UP TO 30KTS. CENTRAL LK SUPERIOR COULD
ALSO SEE A FEW GALE FORCE GUSTS TO 35KTS. EXPECT WINDS TO FALL BELOW
25KTS TUES AFTN AND CONTINUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SYNOPSIS...KC
DISCUSSION...KC
AVIATION...MRD
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1108 AM EST SAT NOV 26 2011
.UPDATE...
A LITTLE DRYING HAS MOVED INTO THE WESTERN HALF OF UPPER
MICHIGAN...WHICH HELPED TO DECREASE PCPN SOMEWHAT THIS MORNING.
HOWEVER...THE PCPN HAS REDEVELOPED AS ANOTHER WAVE MOVES THROUGH THE
AREA. WITH THIS IN MIND...HAVE OPTED TO KEEP CATEGORICAL POPS ACROSS
THE ENTIRE AREA EXCEPT THE FAR WEST WHERE ADDITIONAL PCPN WILL HAVE
TO WAIT UNTIL WRAP AROUND MOISTURE MOVES IN LATER ON TODAY. AS FOR
PCPN TYPE ACROSS THE FAR WEST...LATEST MODEL SOUNDINGS FROM IWD DO
NOT SHOW THE FREEZING LEVEL LOWERING TO BELOW 1000 FT UNTIL AFTER
00Z. THAT COMBINED WITH THE FACT THAT THE BL TEMPS WILL BE AT LEAST
IN THE MID-UPPER 30S...HAVE OPTED TO REMOVE ANY MENTION OF SNOW
UNTIL THIS EVENING.
&&
PREV DISCUSSION...ISSUED AT 656 AM EST SAT NOV 26 2011...
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROFFING OVER
THE PLAINS BTWN PERSISTENT RDG OVER THE ERN CONUS AND ANOTHER RDG
OVER THE W COAST. THERE ARE 3 SHRTWVS OF SIGNIFICANCE EMBEDDED
WITHIN THE TROF OVER THE PLAINS...ONE OVER SASKTATCHEWAN...ANOTHER
IN WYOMING...AND ANOTHER CENTERED NEAR THE TX PANHANDLE. THE COMPLEX
INTERACTION BTWN THESE SEPARATE DISTURBANCES HAS MADE THE EVOLUTION
OF THE UPCOMING WX PATTERN A BIT TRICKY FOR RECENT SHIFTS. THE
DISTURBANCE OVER WYOMING IS SUPPORTING A SFC LO OVER WCNTRL MN. A
FAIRLY WELL DEFINED COMMA CLD IS PRESENT WITH COMMA HEAD PCPN NOTED
UNDER COLDER CLD TOPS OVER THE DAKOTAS ON THE COLD SIDE OF THE
ACCOMPANYING H85 LO. THE WARM CONVEYOR BELT CLD EXTENDS THRU THE UPR
MIDWEST/UPR MS RIVER VALLEY INTO THE GRT LKS...BUT DRY AIR NOTED AT
H7 BY THE BULK OF THE RAOBS...VERY WELL SHOWN BY THE 00Z GRB/MPX
RAOBS...E OF THE UPR TROF AXIS HAS PREVENTED WDSPRD RA FM DVLPG
DESPITE INCRSG UPR DVGC UNDER COUPLED UPR JET STRUCTURE BTWN H3
SPEED MAX IN ONTARIO AND ANOTHER IN SDAKOTA/NEBRASKA. HOWEVER...THE
INTERACTION BTWN THIS DYNAMIC AND THE STRONG SW FLOW E OF THE MN LO
THAT IS ADVECTING UNSEASONABLY HI H85 DWPTS UP TO 6C FROM OMAHA TO
THRU IOWA TOWARD THE UPR MIDWEST HAS CAUSED A RECENT EXPANSION OF
THE RADAR ECHOES TO THE SW. ALTHOUGH A SFC COLD FNT...ASSOCIATED
WITH THE JET MAX IN ONTARIO...HAS SLID OVER UPR MI...TEMPS OVER UPR
MI ARE WELL ABV NORMAL IN THE UPR 30S/40S. THIS FNT HAS PRETTY MUCH
STALLED BUT COULD SERVE AS A FOCAL POINT FOR INCRSG LLVL MSTR CNVGC/
FGEN/ISENTROPIC ASCENT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THRU THIS WEEKEND ARE PCPN CHCS/TYPES/POTENTIAL
SN ACCUMS AND TIMING OF DRYING TREND FOLLOWING THE PASSAGE OF UPR
TROF/SFC LO.
TDAY...RECENT MODEL RUNS HAVE COME INTO BETTER AGREEMENT ON EXPECTED
STRENGTH/TRACK OF SFC LO THAT WL IMPACT THE CWA AHEAD OF DISTURBANCE
NOW IN WYOMING. THIS LO IS PROGGED TO MOVE TO BTWN MQT AND MUNISING
BY 00Z SUN. AS THE SFC LO NOW IN MN MOVES TOWARD UPR MI...GUIDANCE
SHOWS INCRSG ISENTROPIC ASCENT FOCUSED ON THE 290K SFC/UPR DVGC
UNDER FVRBL ORIENTATION OF UPR JET CORES/PWAT SURGING TO ALMOST 250
PCT OF NORMAL WITH THE ARRIVAL OF H85 DWPTS OF 5C. BOTH THE 00Z
NAM/GFS SHOW THE SHARPEST H85-7 FGEN ACCOMPANYING THE FVRBL
INTERACTION BTWN THESE DYNAMICS/MOISTENING AND THE FNTL BNDRY
IMPACTING MAINLY THE NW CWA WITH THE HIEST QPF THEN SHIFTING OUT
OVER LK SUP AND TO THE E IN THE AFTN. ALTHOUGH THE FCST LLVL CYC NNW
FLOW IN THE WAKE OF THE SFC LO PASSING TO THE E WL PROBABLY KEEP
SOME PCPN GOING OVER THE W...FCST DEEP LYR QVECTOR DVGC ARRIVING FM
THE SW IN THE AFTN WL LIKELY LIMIT THE INTENSITY OF THE PCPN THERE
MORE THAN EARLIER ANTICIPATED AND WEAKEN THE COMMA HEAD PCPN NOTED
OVER THE DAKOTAS EARLY THIS MRNG. THE ARRIVAL OF SOMEWHAT COLDER
LLVL AIR INTO THE W LATE...WITH THE MORE AGGRESSIVE GFS SHOWING H85
TEMPS FALLING AS LO AS -3C AT IWD BY 00Z SUN...MAY CAUSE ANY PCPN TO
AT LEAST MIX WITH SN...BUT THE WEAKER DYNAMIC COOLING AND SFC TEMPS
HOLDING ABV 32 WL PREVENT ANY ACCUMULATION.
TNGT...AS THE SFC LO SHIFTS NE INTO ERN ONTARIO BY 12Z SUN...A
COLDER CYC NNW FLOW WL ENVELOP THE ENTIRE CWA IN ITS WAKE. WITH DEEP
LYR QVECTOR DVGC DOMINATING IN THE CAD/DRYING IN THE WAKE OF THE
SHRTWV...LINGERING PCPN WL SHIFT TO AN LES MODE WITH H85 TEMPS
WITHIN THE TRAILING THERMAL TROF FALLING TO -8C TO -10C /LK WATER
TEMPS ARE 5-6C/ OVER THE W BY 12Z SUN UNDER CYC FLOW/SLOWLY DECAYING
DEEPER MSTR WITHIN THE COMMA HEAD. SINCE THE DGZ IS FCST TO BE
WITHIN THE LARGER SCALE SUBSIDENCE AT THE TOP OF THE MOIST LYR AND
ABV THE SHARPER LLVL CNVGC/FORCING...SUSPECT THIS EVENT WL BE A HI
POP/FAIRLY LO QPF WITH NO NEED FOR HEADLINES ATTM. STILL...A FEW
INCHES OF WET SN ARE LIKELY OVER MAINLY THE HIER TERRAIN IN THE NNW
WIND SN BELTS OF THE W WHERE THE UPSLOPE COOLING/LLVL CNVGC WL BE
MAXIMIZED. ALTHOUGH THE FLOW WL TURN TO THE NW AFT 06Z OVER THE E...
THE AIR WL NOT BE SUFFICIENTLY COLD FOR SGNFT LES THERE THRU 12Z.
CUT POPS SGNFTLY OVER THE SCNTRL WITH EXPECTED DOWNSLOPE NW FLOW IN
THE ABSENCE OF ANY DYNAMIC SUPPORT.
SUN...AS THE H85 THERMAL TROF SHIFTS E FOLLOWING THE DEPARTING SFC
LO...EXPECT LES TO ENVELOP MAINLY THE NNW WIND SN BELTS OVER THE E.
BUT THRU THE DAY...RISING HGTS/MORE ACYC FLOW WL TEND TO DIMINISH
THIS ACTIVITY W-E AS WELL. ANY SN ACCUMULATIONS SHOULD REMAIN ON THE
LGT SIDE WITH POOR SN GROWTH PARAMETERS/DGZ ABV THE RELATIVELY
SHALLOW MSTR/LLVL FORCING IN THE ABSENCE OF DYNAMIC SUPPORT. OTRW...
THE DAY SHOULD FEATURE MORE SEASONABLY CHILLY TEMPS. THE SC WL
SLOWLY BREAK UP...ESPECIALLY OVER THE SCNTRL IN THE PRESENCE OF
DOWNSLOPE FLOW.
SUN NGT...UNDER BLDG UPR RDG...SFC HI PRES RDG AXIS WL SHIFT OVER
THE CWA. LGT WINDS UNDER THIS HI/FCST PWAT 60 PCT OF NORMAL WARRANTS
LOWERING PREVIOUS FCST MIN TEMPS TOWARD THE LO END OF GUIDANCE...
ESPECIALLY OVER THE INTERIOR W AND CNTRL.
MON...WARMER AIR IS FCST TO RETURN WITH STRENGTHENING SW FLOW BTWN
HI PRES SINKING INTO THE LOWER GRT LKS AND NEXT SHRTW/SFC LO
TRACKING INTO NW ONTARIO. H85 TEMPS ARE FCST TO REACH ARND 5C DURING
THE AFTN. THE COLD FNT ATTENDANT TO THE LO WL APRCH THE WRN ZNS LATE
IN THE DAY...BUT RELATIVE DRYNESS OF AIRMASS IN PLACE WITH MSTR
INFLOW DISRUPTED BY DVLPG LO IN THE OH RIVER VALLEY AND PASSAGE OF
STRONGER DYNAMICS FARTHER TO THE N WL MAINTAIN DRY WX.
MON NGT...EXPECT COLD FROPA ATTENDANT TO SHRTWV/SFC LO PASSAGE IN
NRN ONTARIO. HIER RH IS FCST TO STAY TO THE N CLOSER TO SHRTWV
TRACK...SO EXPECT A DRY FROPA. FCST SCHC POPS OVER THE NRN TIER
WHERE VEERING FLOW FM SW TO NW WL RESULT IN SOME UPSLOPE WIND
COMPONENT.
EXTENDED...CWA WL BE DOMINATED BY RELATIVELY DRY NRN BRANCH UPR
FLOW. SO EXPECT NO SGNFT PCPN EVENTS DURING THIS TIME THAT WL LIKELY
FEATURE FAIRLY CHANGEABLE TEMPS. TIMING DIFFERENCES ON SHRTWVS
EMBEDDED WITHIN THE FLOW WARRANTS HOLDING CLOSE TO ALL BLEND FCST.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A LOW PRESSURE SYSTEM MOVING ACROSS UPPER MICHIGAN TODAY WILL BRING
RAIN TO ALL THREE TAF SITES. AS HAS BEEN THE CASE OVER THE LAST
SEVERAL DAYS...LOW CLOUDS EXPECTED TO INFLUENCE THE AREA. KIWD HAS
BEEN BUCKING THE TREND WITH VFR CIGS UNDER LIGHT ERLY FLOW...BUT
ADDITIONAL RAIN AND LLVL MOISTURE MOVING INTO THE SITE SHOULD PULL
CIGS/VSBY TO IFR. FAVORABLE ESE FLOW AT BOTH KCMX/KSAW WILL LEAD TO
VLIFR CONDITIONS THROUGH MUCH OF THE DAY...ALTHOUGH MIXING FROM
STRONGER RAIN SHOWERS COULD PROVIDE A BRIEF REPRIEVE. AS THE LOW
SHIFTS E TONIGHT...EXPECT WINDS TO INCREASE OUT OF THE NW AND TRY TO
PULL IN DRIER LLVL AIR. THUS...HAVE SHOWED A IMPROVING TREND WITH
CIGS/VSBYS.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM IN MN WILL SLIDE NE TODAY AND ACROSS UPPER
MICHIGAN. THIS WILL PRODUCE EASTERLY WINDS UP TO 30KTS OVER THE NRN
HALF OF LAKE SUPERIOR...WITH A FEW GALE FORCE GUSTS TOP 35KTS NEAR
ISLE ROYALE. AS THE LOW SHIFTS EAST TONIGHT...EXPECT WINDS TO TURN
TO THE NNW. MODELS HAVE TRENDED MUCH WEAKER WITH THE LOW AND THUS
HAVE LIMITED CONFIDENCE IN SEEING WINDS WARRENTING A GALE
WATCH/WARNING. THUS...HAVE DECIDED TO CANCEL THE WATCH SINCE THE
MAIN WINDS WILL BE IN THE 30KT RANGE. BEST CHANCE FOR SOME GALE
FORCE GUSTS WILL COME FROM 09-15Z TONIGHT OVER CENTRAL LAKE SUPERIOR
AND WILL MENTION SOME GUSTS FOR THAT TIME FRAME. WINDS WILL DIMINISH
BELOW 20KTS ON SUN NIGHT DUE TO A WEAK SFC TROUGH. EXPECT ANOTHER
SFC TROUGH TO SLIDE ACROSS LK SUPERIOR ON MONDAY EVENING...WITH ONCE
AGAIN COULD PRODUCE WINDS UP TO 30KTS. CENTRAL LK SUPERIOR COULD
ALSO SEE A FEW GALE FORCE GUSTS TO 35KTS. EXPECT WINDS TO FALL BELOW
25KTS TUES AFTN AND CONTINUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
DISCUSSION...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1218 PM CST SAT NOV 26 2011
.UPDATE...MIDDDAY SURFACE ANALYSIS INDICATES HIGH PRESSURE OVER
THE ROCKY MOUNTAIN RANGE...WITH VERY INTENSE LOW LEVEL PRESSURE
RISES IN PROCESS ACROSS THE CENTRAL PLAINS. STRONG
NORTH/NORTHWESTERLY LOW LEVEL FLOW HAS ESTABLISHED ITSELF ACROSS
THE REGION AS A RESULT. SHORT TERM GUIDANCE CONTINUES TO SUGGEST
THE LOW LEVEL PRESSURE GRADIENT WILL REMAIN VERY STRONG THROUGH
THIS AFTERNOON...THUS PROMOTING STRONG WINDS THROUGH THE REMAINDER
OF THE AFTERNOON. IN ADDITION TO THIS STRONG LOW LEVEL PRESSURE
GRADIENT...RUC UPPER AIR ANALYSIS INDICATES AN 850MB JET STREAK
IN EXCESS OF 60KTS POSITIONED OVER THE WESTERN HALF OF OUR
CWA...WITH SLIGHTLY WEAKER 850MB WINDS NOTED ACROSS OUR EAST. FORECAST
PROXIMITY SOUNDINGS FROM THE RUC...NAM AND OPERATIONAL GFS ALL
SUGGEST AFTERNOON PBL DEPTH WILL LIKELY NEAR 800MB...THUS PROVIDING AN
AFTERNOON GUST POTENTIAL NEAR 55KTS. GIVEN ALL THIS THE CURRENT
POSITION OF THE HIGH WIND WARNING ACROSS OUR WEST AND THE WIND
ADVISORY ACROSS OUR EAST SEEM RIGHT ON AND WILL KEEP THESE
HEADLINES AS IS THROUGH THE REMAINDER OF THE AFTERNOON.
THE AFOREMENTIONED PBL DEPTH AND RESULTANT MIXING WILL ALSO LIKELY
CONTRIBUTE AN ADDITIONAL DECREASE IN AFTERNOON SURFACE DEW
POINTS...BEYOND THE DECREASE WHICH WOULD ALREADY BE OBSERVED WITH
DRY AIR ADVECTION SETTLING IN ACROSS THE AREA. 10-15 DEGREE DROPS
IN DEW POINTS HAVE ALREADY BEEN NOTED THROUGH THE PAST TWO HOURS
AT LOCATIONS SUCH AS KLBF...KBBW AND KTIF...WITH KLXN AND KODX NOT
FAR BEHIND. GIVEN ALL THIS THE CURRENT RFW ACROSS THE WESTERN
TWO-THIRDS OF THE CWA APPEARS TO BE IN GOOD SHAPE AND WILL ALSO
LET THAT RIDE THROUGH THE REMAINDER OF THE AFTERNOON.
&&
.AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. SURFACE WINDS WILL REMAIN VERY STRONG
FROM THE NORTH/NORTHWEST THIS AFTERNOON AT NEAR 30KTS...GUSTING TO NEAR
45KTS AT TIMES. THE LOW LEVEL PRESSURE GRADIENT IS EXPECTED TO
DIMINISH TOWARDS 00Z PER SHORT TERM GUIDANCE...AND THE GUST
POTENTIAL SHOULD ALSO GREATLY DIMINISH AS THE PBL DECOUPLES FROM
THE STRONGER WINDS ALOFT TOWARDS SUNSET. VISIBILITY RESTRICTIONS ARE
NOT EXPECTED THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 307 AM CST SAT NOV 26 2011/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE MAIN CONCERN IN THE
SHORT TERM FORECAST PERIOD WILL BE WINDS TODAY ALONG WITH THE
POSSIBILITY OF RED FLAG CONDITIONS. THE RED FLAG CONCERNS WILL BE
ADDRESSED IN THE FIRE WEATHER PORTION OF THE DISCUSSION LOCATED
BELOW.
A LARGE MID LEVEL TROUGH MOVING ACROSS THE CENTRAL UNITED STATES
THIS MORNING IS PUSHING A STRONG COLD FRONT ACROSS THE REGION.
MSAS 3 HOUR PRESSURE CHANGE ANALYSIS SHOWS PRESSURE RISES NEAR 7
MILLIBARS BEHIND THE FRONT WHICH IS HELPING BRING A NICE SURGE OF
WINDS AS THE BOUNDARY PASSES. WINDS WILL LIKELY SETTLE DOWN TO
SOME DEGREE THIS MORNING BEHIND THE FRONT...HOWEVER IT WILL NOT
TAKE LONG FOR THE WINDS TO INCREASE AGAIN AS MIXING COMMENCES THIS
MORNING. ALL SIGNS STILL POINT TO A DECENT WIND EVENT FOR TODAY
WITH A STRONG SURFACE PRESSURE GRADIENT DEVELOPING DUE TO LOW
PRESSURE TO THE EAST...AND HIGH PRESSURE TO THE WEST.
THE PRIMARY CONCERN SURROUNDS THE GOING HIGH WIND WARNING AND
WIND ADVISORY...AND POTENTIAL CHANGES/ADJUSTMENTS TO THE HEADLINES
FOR TODAY. NAM PROXIMITY SOUNDINGS SUGGEST MIXING TO NEAR H8 IS
LIKELY ACROSS A MAJORITY OF THE FORECAST AREA TODAY...WITH 50 TO
60 KTS OF WIND EXPECTED AT THAT LEVEL. THE FLOW WILL BE FAIRLY
UNIDIRECTIONAL IN THE MIXED LAYER...SO SOME OF THE THE STRONG
WINDS COULD POTENTIALLY TRANSFER TO THE SURFACE. THE HEART OF THE
STRONGER WINDS ARE SHOWN TO RESIDE ACROSS WESTERN PORTIONS OF THE
FORECAST AREA...AND THE CURRENT HIGH WIND WARNING COVERS THAT
WELL. WILL GO AHEAD AND LEAVE THE HEADLINES IN THEIR PRESENT
CONFIGURATION...THOUGH THE NEXT SHIFT WILL OBVIOUSLY HAVE TO WATCH
TRENDS AS THE STRONGER H8 WINDS SHIFT SOUTHEAST THIS AFTERNOON.
A SMALLER CONCERN FOR TODAY WILL BE THE POSSIBILITY OF ANY
LINGERING FLURRIES OR SPRINKLES AS THE LEFT EXIT REGION OF A
100KT UPPER JET SEGMENT SHIFTS THROUGH THE AREA. THE LATEST SREF
AND NCEP 4KM WRF KEEP IT DRY AFTER 12Z TODAY...WHILE THE GFS AND
NOW 26.06Z NAM SUGGESTS THERE COULD BE LINGERING LIGHT
PRECIPITATION IN PARTS OF NORTH CENTRAL KANSAS THIS
MORNING...WHILE THE RUC DEVELOPS LIGHT QPF IN EASTERN PARTS OF THE
FORECAST AREA. CROSS SECTIONS OF RELATIVE HUMIDITY/OMEGA FROM THE
NAM REVEAL DRY LOW LEVELS WHICH WILL BE TOUGH TO
OVERCOME...ESPECIALLY AS THE FORCING WEAKENS...SO WOULD RATHER
CARRY A NON MEASURABLE EVENT SUCH AS SPRINKLES OR FLURRIES. H85
TEMPERATURES QUICKLY FALL BELOW FREEZING THIS MORNING...HOWEVER
ABOVE FREEZING H925 TEMPERATURES WILL PERSIST...SO WILL GO WITH
SPRINKLES/FLURRIES IN THE GRIDS.
THE STRONGEST OF THE WINDS SHOULD SUBSIDE BY EARLY EVENING AS
MIXING BEGINS TO DIMINISH. H5 HEIGHTS BEGIN TO RISE
TONIGHT...WITH WARMER AIR GRADUALLY RETURNING FOR SUNDAY AND
MONDAY. IN FACT...H85 TEMPERATURES RISE FROM -5 DEGREES CELSIUS
TONIGHT...TO NEARLY +10 DEGREES CELSIUS ON MONDAY IN PORTIONS OF
THE FORECAST AREA. WILL AIM FOR HIGHS IN THE MID 40S TO LOWER 50S
ON SUNDAY...WITH 50S ON MONDAY.
ANOTHER MID LEVEL WAVE HELPS KNOCK DOWN THE RIDGE MONDAY AFTERNOON
INTO MONDAY NIGHT...WITH ANOTHER COLD FRONT PLOWING THROUGH THE
AREA. MOISTURE APPEARS LIMITED WITH THE PASSAGE OF THE WAVE/FRONT
AND WILL MAINTAIN A DRY FORECAST AS IT PASSES. WINDS WILL AGAIN
BECOME GUSTY AS THE FRONT PASSES...BUT CURRENTLY IT APPEARS SPEEDS
SHOULD STAY BELOW ADVISORY LEVELS.
LONG TERM...TUESDAY THROUGH FRIDAY.
MODELS NOT IN TOO BAD OF AGREEMENT AT THE START OF THE LONG TERM
PERIOD...WITH NORTHWESTERLY FLOW SET UP IN THE UPPER LEVELS AS A
LOW PRESSURE SYSTEM SPINS OVER THE SOUTHEASTERN CONUS AND A
RIDGE AXIS SETS UP OVER THE WEST COAST. WITH NO DISTURBANCES
EXPECTED TO PUSH THROUGH THE REGION...FORECAST FOR TUESDAY REMAINS
DRY. GETTING INTO TUESDAY NIGHT THROUGH THURSDAY...EXPECTING TO
SEE SHORTWAVE UPPER LEVEL RIDGING BUILD INTO THE CENTRAL PLAINS
EXTENDING FROM THE AREA OF HIGH PRESSURE CENTERED JUST OFF THE SRN
COAST OF CA...BETWEEN THE LOW PRESSURE CONTINUES TO PUSH NORTHEAST
TOWARD THE EAST COAST AND ANOTHER DISTURBANCE MOVING FROM THE PAC
NW INTO THE ROCKIES.
A LITTLE MORE UNCERTAINTY ARISES INTO THURSDAY AND FRIDAY WITH THE
LATEST MODEL RUNS HAVING A FEW DIFFERENCES. THE GENERAL STORY IS
THE DISTURBANCE WHICH HAS SHIFTED INTO THE ROCKIES BECOMES
SPLIT...WITH A CLOSED LOW DEVELOPING OVER THE WRN/SWRN CONUS...BUT
MODELS VARY ON THE TIMING AND LOCATION OF THE LOW AND WHAT HAPPENS
WITH THE NORTHERN ENERGY. THE GFS PUSHES THE NORTHERN ENERGY
FURTHER SOUTH INTO THE REGION...WHILE THE ECMWF SHOWS MORE RIDGING
HELPING TO PUSH IT FURTHER EAST. INTRODUCED SMALL PRECIPITATION
CHANCES ACROSS THE NORTHERN PORTIONS OF THE CWA TO ACCOUNT FOR
THIS DISTURBANCE IN THE REGION...BUT KEPT IT CONFINED TO THE
DAYTIME HOURS ON THURSDAY. TEMPERATURES SUGGEST THE PTYPE WOULD BE
SNOW. ANY PRECIPITATION WOULD NOT STICK AROUND LONG...AND KEPT
THURSDAY NIGHT AND FRIDAY DRY.
WHILE A BUMP UP IN TEMPERATURES IS EXPECTED ON WEDNESDAY WITH THE
RIDGING SET UP AND HIGHS IN THE UPPER 40S TO LOWER/MID
50S...COMPARED TO THE LOWER/MID 40S ON TUESDAY...A COLD FRONT IS
EXPECTED TO PUSH THROUGH THE CWA EARLY THURSDAY. THE COOLER AIR
ACCOMPANYING THE FRONT LOOKS TO DROP HIGHS FOR THURSDAY INTO THE
MID 30S TO LOWER 40S...WITH MID 30S EXPECTED FOR FRIDAY.
FIRE WEATHER...AS STATED ABOVE WINDS TODAY WILL EASILY EXCEED
THE 25 KT GUST CRITERIA NEEDED FOR A RED FLAG WARNING. THE BIGGEST
CONCERN WILL BE RELATIVE HUMIDITY VALUES DROPPING TO 20 PERCENT
OR LESS. THE NAM AND GFS HAVE BOTH COME IN WITH HIGHER SURFACE
DEWPOINTS ON THE 00Z RUNS...AND THIS TREND IS ALSO EVIDENT EVEN
WHEN MIXING DEWPOINTS ALOFT TO THE SURFACE. THAT BEING SAID...AM
STILL CONCERNED ABOUT FIRE WEATHER ISSUES TODAY...ESPECIALLY WITH
THE LATEST ECMWF STILL SUPPORTING LOWER DEWPOINTS THIS AFTERNOON.
WILL HOLD ONTO THE LOWER DEWPOINTS SHOWN BY THE CURRENT FORECAST
AND LATEST ECMWF AND KEEP THE RED FLAG WARNING IN PLACE FOR THIS
AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ041-048-049-063-
064-076-077-086-087.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ039-040-046-
047-060>062-072>075-082>085.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ039-040-046-
047-060>062-072>075-082>085.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ007-019.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005-006-017-
018.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-
017>019.
&&
$$
UPDATE/AVIATION...BRYANT
SHORT TERM/FIRE WEATHER...KING
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1143 AM CST SAT NOV 26 2011
.AVIATION...
18Z TAFS FOR KOFK...KOMA...KLNK.
STRONG NORTHWEST WINDS WITH GUSTS TO 45 KTS AT TIMES THROUGH
00Z. VFR CONDITIONS DEVELOPING WITH BKN LAYER MOVING EAST
00Z-06Z.
&&
.PREV DISCUSSION... /ISSUED 523 AM CST SAT NOV 26 2011/
AVIATION...12Z TAFS FOR KOFK...KOMA...KLNK.
MAIN CONCERN WILL BE VERY GUSTY NORTHWEST SFC WINDS THRU THE DAY.
GUSTS ARE EXPECTED TO INCREASE TO NEAR 40 KTS BY LATE MORNING AND
EARLY AFTERNOON. MVFR CONDITIONS ARE EXPECTED THIS MORNING FOR
KOFK AND KOMA HOWEVER SHOULD IMPROVE TO VFR BY EARLY AFTERNOON.
WINDS WILL BEGIN TO DIMINISH LATER THIS EVENING.
PREV DISCUSSION... /ISSUED 325 AM CST SAT NOV 26 2011/
DISCUSSION...
MAIN FORECAST CONCERN IS WIND TODAY. WATER VAPOR IMAGERY EARLY THIS
MORNING SHOWED A FAIRLY IMPRESSIVE TROUGH EXTENDING FROM SASKATCHEWAN
DOWN INTO MEXICO. 500 MB HEIGHT FALLS WERE AROUND OR IN EXCESS OF
100 METERS FROM SOUTHWEST NEBRASKA TO WEST TEXAS LAST EVENING. A FEW
THUNDERSTORMS WERE NOTED NEAR THE KANSAS/OKLAHOMA BORDER. A COLD
FRONT STRETCHED FROM LOW PRESSURE OVER SOUTHERN MINNESOTA DOWN INTO
WESTERN OKLAHOMA.
THE TROUGH AND FRONT WILL BOTH CONTINUE TO MOVE EAST TODAY...WITH A
TIGHT PRESSURE GRADIENT AND STRONG WINDS SPREADING EAST ACROSS THE
AREA. DELAYED WIND ADVISORY A FEW HOURS FOR PARTS OF THE AREA THIS
MORNING...BUT OTHERWISE WIND FORECAST IS SIMILAR TO PREVIOUS GRIDS.
THE 06Z RUC MODEL DID SHOW SOME LIGHT PRECIPITATION MOVING INTO PARTS
OF NORTHEAST NEBRASKA THROUGH 18Z. OTHERWISE...THE SHOWERS IN FAR
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA SHOULD MOVE OUT VERY EARLY
THIS MORNING. MUCH COLDER AIR WILL MOVE INTO THE AREA TODAY. LOWS
TONIGHT SHOULD BOTTOM OUT IN THE UPPER TEENS TO MID 20S. WINDS WILL
REMAIN BRISK AT LEAST EARLY TONIGHT BUT MOST LIKELY BELOW ADVISORY
LEVELS. AS HIGH PRESSURE AT THE SURFACE BUILDS INTO THE AREA ON
SUNDAY...WINDS WILL DECREASE. EXPECT WEAK RETURN FLOW TO SETUP LATE
SUNDAY NIGHT...BUT IS NOT EXPECTED TO BE STRONG ENOUGH TO KEEP LOWS
UP MUCH ABOVE MOS GUIDANCE.
MILDER AIR SHOULD BE OVER THE AREA MONDAY...WITH HIGHS IN THE UPPER
40S AND LOWER 50S. NEXT COLD FRONT PUSHES THROUGH MONDAY NIGHT...BUT
SHOULD NOT PRODUCE ANY PRECIPITATION. KEPT TUESDAY AND WEDNESDAY DRY
BUT ADDED A SLIGHT CHANCE OF LIGHT SNOW FOR ABOUT THE NORTHERN HALF
OF THE FORECAST AREA THURSDAY. 00Z GFS WAS THE BEST MODEL DEPICTING
THAT SCENARIO.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-015>018-
030>034-042>045-050>053-065>068-078-088>093.
IA...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-055-056-069-
079-080-090-091.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1142 AM CST SAT NOV 26 2011
.AVIATION...
WINDS CONTINUE TO BE THE MAIN IMPACT OF THE AVIATION FORECAST
THROUGH SUNDAY MORNING. THE PRESSURE GRADIENT WILL SLACKEN THROUGH
THE REMAINDER OF THE DAY TODAY AND WITH SUNDOWN EXPECT DECOUPLING
OF THE BOUNDARY LAYER SO SHOULD SEE WINDS DECREASE APPRECIABLY
THIS EVENING. ONE THING TO LOOK FOR THIS EVENING IS THE
POSSIBILITY FOR LOW LEVEL WIND SHEAR AS THE BOUNDARY LAYER
DECOUPLES BEFORE THE WINDS AT OR ABOVE 1K FEET DECREASE. BUFKIT
SOUNDINGS SHOWING 35 TO 45 KT WINDS AT AROUND 1900FT EARLY THIS
EVENING BUT INSERTING LLWS IN THE TAF WILL DEPEND IF THE SURFACE
WINDS HAVE DECREASED BY THEN. WITH LOWER CONFIDENCE... DID NOT ADD
THEM IN THE FORECAST. WILL WATCH TRENDS THROUGH THE AFTERNOON AND
WILL ADD IN IF IT WARRANTS IT.
THROUGH THE REMAINDER OF THE AFTERNOON...LOOKING FOR NORTHWEST
WINDS OF 30 TO 40KTS WITH GUSTS UP TO 55KTS. THEN BY MID
EVENING...THE WINDS SHOULD DROP DOWN BELOW 12KTS FOR ALL AREAS.
HIGH PRESSURE BUILDING INTO THE PLAINS OVERNIGHT WILL KEEP WINDS
RATHER LIGHT THROUGH THE DAY ON SUNDAY AS AFTERNOON MIXING WILL
ONLY LEAD TO WINDS UP TO 12KTS. DRY AIR WILL BE IN PLACE AS WELL
SO EXPECTING CLEAR SKIES THROUGH SUNDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 312 AM CST SAT NOV 26 2011/
DISCUSSION...
SHORT TERM...
BUFKIT IS ON TRIAL TODAY AS IT CONTINUES TO ADVERTISE VERY STRONG
WINDS...40 TO 45 KTS AT 1000 TO 1500 FT AGL. THIS SHOULD TRANSLATE
TO SFC WINDS OF 40 MPH OR STRONGER AND ALL MODELS IN BUFKIT SHOW
THIS.
THE MODEL GUIDANCE AND DIRECT OUTPUT HAVE BEEN WOBBLING SHOWING
WIND SPEEDS RUNNING ABOVE AND BELOW HIGH WIND CRITERIA. BUFKIT HAS
BEEN VERY RELIABLE THOUGH SUGGESTING HIGH WINDS WILL DEVELOP.
THE LATEST MAV MET GUIDANCE WIND SPEEDS HAVE SLOWED
SOME...SUGGESTING A HIGH END WIND ADVISORY ACROSS MOST AREAS. THE
EXCEPTION AT KBBW. THE 06Z NAM HOWEVER INDICATES 65 KT WINDS AT
800MB...THE APPROXIMATE MIXING DEPTH EXPECTED ACROSS NCNTL NEB
THIS AFTN. A CORRIDOR OF HIGH WINDS IS EXPECTED TO DEVELOP FROM
KVTN SSE THROUGH KBBW TODAY. DEEPER VERTICAL MIXING IS EXPECTED TO
PRODUCE HIGH WIND GUSTS ACROSS SWRN NEB THIS AFTERNOON ALSO. A
BLEND OF HRRR AND NAMDNG WIND GUST DATA PRODUCED GUSTS TO 55 MPH.
A FEW KNOTS WERE ADDED TO THE FCST TO BRING GUSTS SPEEDS TO 60 MPH
WHICH IS CERTAINLY REACHABLE GIVEN THE 65 KT WINDS AT 800MB SHOWN
IN THE NAM. ALSO KTIF AND KLBF GUSTED TO 47 MPH BETWEEN 8 AND 9Z
BUT HRRR SUGGESTED GUSTS TO 58 MPH WOULD DEVELOP. THE 06Z NAM
FRH68 DATA SUGGESTED 35 KTS IN LOWEST 35 MB THIS AFTERNOON AT
KLBF...ROUGHLY 35 MPH AT THE SFC. 35 MPH IN THE VALLEY SHOULD
EQUATE TO 40 MPH IN THE SANDHILLS NORTH AND SOUTH OF TOWN.
THE HIGH WIND WARNING APPEARS TO BE ON TRACK ACROSS A GOOD
PORTION OF THE FORECAST AREA. WEAKNESSES IN THE WIND FIELDS WERE
NOTED AT BOYD AND WHEELER COUNTIES AND ACROSS SHERIDAN COUNTY.
WIND SPEEDS SHOULD DROP OFF RAPIDLY BETWEEN 4 AND 6 PM CST AS
VERY DRY AIR WILL MOVE IN THIS AFTN. BY SUNDAY MORNING 1035MB HIGH
PRESSURE SHOULD BE ACROSS THE FCST AREA AND WINDS IN THE VALLEYS
SHOULD FALL OFF TO LESS THAN 10 MPH. LOWS IN THE TEENS SHOULD BE
COMMON.
LONG TERM...
ANOTHER STRONG PACIFIC COLD FRONT WILL MOVE THROUGH THE FCST AREA
MONDAY WITH WINDS INCREASING...PERHAPS TO WIND ADVISORY
CRITERIA...30 MPH. MIX DOWN WIND TOOLS PRODUCED WINDS NEAR 30 MPH
AND GFS AND ECMWF SHOW SOME 50 KT WINDS AT 850MB MONDAY AFTERNOON.
FOR NOW A LIMITER WAS USED FOR 20 TO 30 MPH WIND SPEEDS AND LATER
FCSTS CAN ADJUST UP IF NECESSARY. BY TUESDAY MORNING 1035 MPH HIGH
PRESSURE IS CENTERED SOMEWHERE BETWEEN SD AND NERN COLO WITH LOWS
IN THE TEENS. THIS HIGH WILL THEN MOVE OFF TO THE SOUTHEAST TO BE
FOLLOWED BY A STRONGER MORE ARCTIC TYPE HIGH PRESSURE SYSTEM
WEDNESDAY NIGHT AND THURSDAY. THE FRONT APPEARS TO BE CARRYING
SOME MOISTURE WITH IT FROM THE HIGH LATITUDES. SO WE CONTINUE THE
FORECAST FOR SCATTERED SNOW SHOWERS. TEMPS AHEAD OF THE FRONT
APPEAR TO BE COLD ENOUGH FOR SNOW VS FREEZING DRIZZLE CHANGING TO
SNOW. EITHER WAY VERY LIGHT PCPN AMOUNTS ARE EXPECTED WITH THE
FRONT AND MAINLY ACROSS THE NORTHWEST ZONES.
MAX TEMPS TODAY THROUGH WEDNESDAY WILL BE MOSTLY IN THE 40S TO
LOWER 50S. BEHIND THE ARCTIC FRONT THURSDAY AND FRIDAY HIGHS
REACH ONLY INTO THE 30S.
SO THE GEM...GFS...ECMWF AND GEF ARE IN VERY GOOD AGREEMENT
THROUGH WEDNESDAY. THEREAFTER...TIMING PROBLEMS DEVELOP WITH THE
ARCTIC FRONT WHICH APPEAR TO BE RELATED TO DISTURBANCES UPSTREAM
AND DOWNSTREAM ACROSS THE WRN AND ERN U.S. THE GFS APPEARED TO BE
THE MOST RATIONAL SOLN. TIMING-WISE IT WAS SLOWER THAN THE GEM
AND FASTER THAN THE ECMWF.
FIRE WEATHER... VERY GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH
THE DAY. DRY AIR IS EXPECTED TO ADVECT INTO THE REGION...DROPPING
DEW POINT TEMPS INTO THE TEENS AND SINGLE DIGITS. THIS WILL
COMBINE WITH HIGHS IN THE 40S TO PRODUCE MINIMUM RELATIVE HUMIDITY
VALUES AROUND 20 PERCENT...LOWEST IN SW NEB. WILL CONTINUE THE RED
FLAG WARNING FOR ALL BUT ZONE 208...WHERE RH VALUES CLOSER TO 30
PERCENT ARE EXPECTED. ALTHOUGH THE AREA MAY NOT REACH THE TYPICAL
WIDESPREAD RH MINIMUM PERCENTAGES OF 15 PERCENT NEEDED FOR A RED
FLAG...THE COMBINATION OF WIND GUSTS ABOVE 50 MPH...THE VERY DRY
FUELS AND STILL LOW RH VALUES AROUND 20 PERCENT WARRANT THE
HEADLINE. THERE IS A SMALL CHANCE THE DRIER AIR IS DELAYED...WHICH
WOULD RESULT IN WIDESPREAD MINIMUM RH PERCENTAGES IN THE 30S. LOW
CONFIDENCE ON THIS SCENARIO AND WANT TO ERROR ON THE SIDE OF
CAUTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 6 PM
CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
RED FLAG WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ204-206-209-210-219.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
302 PM CST SAT NOV 26 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
PRIMARY FORECAST CHALLENGES CONCERN CLOUD TRENDS...TEMPERATURES...
PRECIPITATION AND WIND OVER THE NEXT 12 TO 18 HOURS. GFS/NAM/
ECMWF/GEM HEIGHT/PRESSURE FIELDS ARE IN GOOD AGREEMENT...BUT ALL
MODELS ARE OVERDONE ON QPF. FOR PRECIPITATION...WILL USE CURRENT
RADAR TRENDS AND RUC MODEL DATA FOR GUIDANCE.
20 UTC SURFACE OBSERVATIONS SHOW LIGHT SNOW FROM ROSEAU TO FOSSTON
TO ALEXANDRIA AND POINTS EAST. RADAR ECHOES ARE WEAK TO NON-
EXISTENT...SO ANY NEW SNOW ACCUMULATION SHOULD BE MINIMAL. THE
SURFACE LOW HAS MOVED INTO THE UPPER PENINSULA OF MI WITH AN
INVERTED TROUGH INTO SOUTHWEST ONTARIO. KEPT SOME SLIGHT CHANCE
POPS OR FLURRIES ACROSS THE FAR EASTERN FORECAST AREA THIS EVENING
AND OVERNIGHT...BUT ALL AREAS SHOULD DRY OUT BY 12 UTC SUNDAY
MORNING.
OVERCAST SKIES HAVE PLAGUED THE FORECAST AREA ALL DAY WITH THE
CLEARING LINE NOW FROM RUGBY TO ABERDEEN. IT IS THESE CLOUDS THAT
HAVE LIKELY LIMITED BOUNDARY LAYER MIXING AND HIGHER WIND SPEEDS
THIS AFTERNOON. A FEW SPOTS FROM COOPERSTOWN TO VALLEY CITY HAVE
BRIEFLY TOUCHED WIND ADVISORY CRITERIA THIS AFTERNOON. FOR NOW...
WILL LEAVE ADVISORY IN PLACE AS SOME CLEARING WEST OF THE VALLEY
BEFORE SUNSET SHOULD ENCOURAGE 35 KT WINDS NEAR 2000 FT TO MIX TO
THE SURFACE.
TEMPERATURES TONIGHT WILL BE HIGHLY DEPENDENT ON CLOUD COVER. WITH
CLEARING SKIES ALONG AND WEST OF THE VALLEY FOR MUCH OF THE NIGHT
AND CURRENT DEW POINT TEMPERATURES ACROSS CENTRAL ND IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO...EXPECT LOWS TO DIP DOWN INTO THE LOW
TEENS TONIGHT ACROSS EASTERN ND. DEPENDING ON THE FULL EXTENT OF
NEAR SURFACE DRYING THAT TAKES PLACE...TEMPERATURES MAY DROP EVEN
FURTHER. TO THE EAST WHERE CLOUD COVER WILL BE SLOWER TO ERODE...
UPPER TEENS TO LOW 20S SEEM REASONABLE AT THIS TIME.
SUNDAY WILL BE DRY AND SLIGHTLY WARMER AS SURFACE HIGH PRESSURE
NOSES INTO THE NORTHERN PLAINS. A DRY COLD FRONT WILL DROP SOUTH
ACROSS THE FORECAST AREA MONDAY AFTERNOON...BUT TEMPERATURES IN
THE 925 TO 850 HPA LAYER FROM +2 TO +8 C AHEAD OF THE FRONT SHOULD
ALLOW HIGHS TO CLIMB INTO THE MID 30S TO LOWER 40S. SURFACE HIGH
PRESSURE RE-ESTABLISHES ITSELF ON TUESDAY...BUT FULL EXTENT OF
COOLING AFTER FRONTAL PASSAGE WILL TAKE AFFECT WITH HIGHS ONLY IN
THE LOWER TO MID 30S.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
MODELS INITIALIZED WELL THIS RUN AND REMAIN IN RELATIVELY GOOD
AGREEMENT...SO WENT WITH A BLENDED SOLN ATTM. BROAD UPPER RIDGE IS
IN PLACE EARLY IN THE PERIOD SO LOOKING AT SLIGHTLY ABOVE NORMAL
TEMPS AND LITTLE PCPN. A VIGOROUS SHORT WAVE IS EXPECTED TO CROSS
THE AREA LATE WED BRINGING A COLD FRONT...SLIGHTLY COOLER
TEMPS...AND A SLIGHT CHANCE FOR MEASURABLE PCPN. OTHERWISE...THE
UPPER RIDGE QUICKLY REBOUNDS...AND RETURN FLOW AT THE SURFACE WILL
BRING A RETURN TO A BIT WARMER TEMPS BY THE END OF THE PERIOD.
&&
.AVIATION...
VFR CIGS ARE WORKING THEIR WAY ACROSS THE DEVILS LAKE BASIN. OTHER
TAF SITES REMAIN MVFR OR IFR. AS SURFACE LOW PRESSURE CONTINUES TO
MOVE EAST ACROSS THE GREAT LAKES...A SFC RIDGE AND RETURN FLOW WILL
HELP DRY OUT THE BOUNDARY LAYER. CLEARING SHOULD SPREAD FROM WEST TO
EAST OVERNIGHT AND IS REFLECTED IN THE TAFS...WITH THE LAST SITES
SCATTERING OUT BY 09Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-007-014-015-
024-026-028-029-038-039-049-052>054.
MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003-029-040.
&&
$$
ROGERS/HOPKINS
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1148 AM CST SAT NOV 26 2011
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...PRE FRONTAL TROUGH HAS PUSHED THROUGH ALL TAF
SITES...SHIFTING WIND TO THE NORTHWEST. MAIN COLD FRONT IS
TRAILING BEHIND AND WILL PUSH THROUGH THIS AFTERNOON. WINDS WILL
INCREASE BEHIND THE FRONT...GUSTING TO AROUND 30KTS. SHOWERS AND
OCCASIONAL THUNDERSTORMS WILL CONTINUE FOR VCT AND CRP. GENERALLY
MVFR CIGS EXPECTED FOR EASTERN SITES...AND VFR WEST. GUSTY WINDS
CONTINUE OVERNIGHT...AND INCREASE ONCE AGAIN TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 1005 AM CST SAT NOV 26 2011/
DISCUSSION...COLD FRONT IS PROGRESSING THROUGH WEST AND CENTRAL
TEXAS THIS MORNING. WIND SHIFT HAS PUSHED INTO THE CWA BUT FEEL
THIS IS WITH A PRE FRONTAL TROUGH. WITH JUST SLIGHT DPT DROP AND
WINDS REMAIN LIGHT. REAL FRONTAL BOUNDARY A LITTLE TOUGH TO PICK
OUT...BUT SEEMS TO BE JUST THROUGH DALLAS...TO FREDERICKSBURG...TO
DEL RIO. PRECIPITATION ASSOCIATED WITH THE FRONT SO FAR HAS BEEN
RATHER LIMITED IN THE EAST...WITH ISOLATED TO AT TIMES SCATTERED
LIGHT SHOWERS IN THE WEST. LATEST RUC MODEL KEEPS THE BULK OF THE
PRECIP JUST INTO THE NORTHERN PARTS OF THE CWA. HRRR MODEL HOWEVER
SHOWS SCATTERED CONVECTION DEVELOPING ACROSS ENTIRE AREA. BOTH
MODELS INDICATE INCREASING COVERAGE OF MORE STRATIFORM PRECIP
RIGHT ALONG THE FRONT AS IT NEARS THE COAST...WHERE THE DEEPEST
MOISTURE EXISTS...12Z CRP SOUNDING HAD 1.6 PWAT. HAVE ADJUSTED
MORNING POPS SOME TO ACCOUNT FOR LACK OF CONVECTION...HOWEVER
STILL THINK WE SHOULD SEE SOME DEVELOPMENT AS TEMPS INCREASE. HAVE
ALSO ADJUSTED TEMPS TO ACCOUNT FOR WARMER TEMPS FAR EAST WHERE
CLOUDS REMAIN BROKEN AND TEMPS ALREADY APPROACHING 80 DEGREES.
PREV DISCUSSION... /ISSUED 538 AM CST SAT NOV 26 2011/
DISCUSSION...SEE AVIATION SECTION BELOW.
AVIATION...CURRENTLY VFR CIGS/VSBYS ARE ACROSS S TX...HOWEVER SCT
TO NUM SHRA`S/TSRA`S ARE EXPECTED AHD AND ALONG A STRONG COLD
FRONT LATER THIS MORNING INTO THE EARLY AFTERNOON. BEST CHC OF
TSRA`S WILL BE ACROSS VCT AREA WITH LESSER CHCS FARTHER S AND W.
AREAS BEING EFFECTED BY CONVECTION WILL LIKELY LOWER TO MVFR AND
POSSIBLY IFR LEVELS AT TIMES. AS THE COLD FRONT MOVES THROUGH S
TX...CONDITIONS WILL IMPROVE TO VFR AND WINDS WILL SHIFT TO THE N AND
INCREASE TO 20 TO 30 KNOTS WITH GUSTS UP TO AROUND 40
KNOTS...MAINLY FROM LRD TO ALI TO CRP. WENT WITH GUSTS TO AROUND
30-33KT IN THE TAFS AS THIS WILL BE MORE COMMON. NLY WINDS WILL
DECREASE OVRNIGHT BUT RESTRENGTHEN ON SUNDAY.
PREV DISCUSSION... /ISSUED 459 AM CST SAT NOV 26 2011/
SHORT TERM (TODAY THROUGH SUNDAY)...A LONG WAVE TROF DRAPED ACROSS
THE TX PANHANDLE SOUTHWARD INTO MEX WILL MOVE ACROSS THE REGION
TODAY BRINGING WITH IT A STRONG COLD FRONT. AHD OF THE COLD
FRONT...DEEP MOISTURE WILL COMBINE WITH UPPER JET...EMBEDDED SHORT
WAVE...LG OMEGA...AND DECENT LOW LEVEL CONVERGENCE TO PRODUCE
SCT/NUM SHRA`S/TSRA`S. THE ACTIVITY IS EXPECTED TO INCREASE IN
COVERAGE AS IT MOVES E TOWARD THE COAST DUE TO LOW TO MOD CAPE ALONG
THE COAST AND OVER THE GULF WATERS. THE CAPE AND THE LI`S ARE NOT
IMPRESSIVE AND THERE WILL BE LITTLE TO NO SHEAR...THEREFORE AM NOT
EXPECTING ANY ORGANIZED SVR STORMS. SOME STORMS COULD BECOME STRONG
WITH GUSTS TO AROUND 40KT AND SMALL HAIL. THE BEST CHC FOR PRECIP
WILL BE ACROSS THE NW CWA THRU MID MORNING THEN MOVG E WITH INCREASING
CHCS ACROSS THE E AND NE CWA BY AROUND NOON INTO EARLY AFTERNOON.
THE SYSTEM WILL THEN EXIT THE AREA THRU LATE AFTERNOON.
THE MAIN ISSUE BEHIND THE COLD FRONT WILL BE WINDS. THE MODELS SHOW
40KT OFF THE DECK ALONG WITH DECENT LAPSE RATES THIS AFTERNOON INTO
TONIGHT...ESPECIALLY ACROSS THE SRN CWA AND ALONG THE COASTAL
COUNTIES. THEREFORE WENT WITH A WIND ADVISORY FOR THOSE AREAS WHERE
GUSTS TO 40 MPH WILL BE MOST FREQUENT. IT WILL BE WINDY ACROSS THE
NRN CWA AS WELL...BUT SHOULD REMAIN BELOW ADVISORY LEVELS. WINDS
RELAX SOMEWHAT OVERNIGHT BUT THEN RESTRENGTHEN ON SUNDAY BUT THE WINDS
SHOULD REMAIN BELOW ADVISORY LEVELS.
WITH ONGOING CAA INTO TONIGHT...MN TEMPS ARE EXPECTED TO DIP INTO
THE MID 30S ACROSS THE NW CWA TO MID 40S ALONG THE COAST. THE
OVERNIGHT WINDS WILL REMAIN ELEVATED AND NOT ALLOW THE TEMPS TO DROP
MUCH MORE THAN THAT. DESPITE SUNNY SKIES...HIGHS ON SUNDAY WILL BE
MUCH COOLER WITH AREA WIDE 60S.
MARINE...SCT TO NUM SHRA`S/TSRA`S CAN BE EXPECTED TODAY AHD AND
ALONG A STRONG COLD FRONT THAT WILL MOVE ACROSS THE BAYS AND COASTAL
WATERS THIS AFTERNOON. WINDS WILL SHIFT TO THE N AND RAPIDLY
INCREASE TO ADVISORY LEVELS ACROSS THE BAYS AND GALE FORCE ACROSS
THE COASTAL WATERS. A GALE WARNING IS IN EFFECT FOR THE GULF WATERS
AND AN SCA IS IN EFFECT FOR THE BAYS. THE GALE FORCE WINDS ARE
EXPECTED TO DECREASE BY SUN MORNING BUT REMAIN HIGH END SCA THROUGH
SUNDAY NIGHT.
FIRE WEATHER...A COLD FRONT IS EXPECTED TO PUSH ACROSS S TX LATE
TODAY WITH STRENGTHENING N WINDS DVLPG IN ITS WAKE. ALTHOUGH DRIER
AIR WILL BE FILTERING INTO S TX...RH VALUES ARE EXPECTED TO REMAIN
ABV CRITICAL THRESHOLDS THROUGH TODAY AND TONIGHT. THEREFORE AM NOT
EXPECTING FIRE WEATHER CONDITIONS THRU TONIGHT. HOWEVER...MUCH LOWER
RH VALUES IN THE TEENS WILL BE IN PLACE ON SUNDAY AND WINDS WILL BE
BREEZY TO WINDY LEADING TO CRITICAL FIRE DANGER CONDITIONS. A FIRE
WEATHER WATCH IS IN EFFECT FOR SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...COLD DRY AIRMASS WILL
REMAIN OVER SOUTH TEXAS SUNDAY NIGHT WITH WINDS RELAXING. WENT CLOSE
TO THE COLDER MET GUIDANCE FOR MINIMUMS WITH BELOW FREEZING TEMPS
EXPECTED FOR THE INLAND COASTAL PLAINS UP INTO THE NORTHERN BRUSH
COUNTRY. WENT AHEAD AND ISSUED A FREEZE WATCH FOR THESE AREAS FOR
LATE SUNDAY NIGHT. THE ANOMALOUS DEEP UPPER LOW WILL MOVE ACROSS THE
SOUTHEAST UNITED STATES MONDAY AND TUESDAY. THE OFFSHORE FLOW WILL
WEAKEN MONDAY BUT INCREASE AGAIN ON TUESDAY. HIGH PRESSURE WILL
SURGE DOWN THE PLAINS AFTER A NORTHERN STREAM SHORT WAVE TROUGH
MOVES INTO THE UPPER MIDWEST TUESDAY WITH AN INCREASE IN WINDS
EXPECTED TUESDAY AFTERNOON. TEMPERATURES WILL ALMOST BE BACK TO
NORMAL MONDAY/TUESDAY BUT WILL FALL BACK TO BELOW NORMAL FOR
WEDNESDAY. A BRIEF WARM UP IS EXPECTED FOR THURSDAY. MEDIUM RANGE
MODELS SHOW ENERGY DIVING OUT OF THE GULF OF ALASKA INTO THE PACIFIC
NORTHWEST WEDNESDAY BUT THE MODELS DIVERGE FROM THERE ON EVOLUTION
OF THE UPPER LOW BECOMING CUTOFF FROM THE NORTHERN STREAM AND MOVING
INTO THE DESERT SOUTHWEST BY FRIDAY. POLAR AIRMASS IS EXPECTED TO
MOVE DOWN THROUGH THE PLAINS INTO SOUTH TEXAS ON FRIDAY. INCREASING
ISENTROPIC LIFT SHOULD LEAD TO AN INCREASED CLOUD COVER. 00Z GFS
GENERATED TOO MUCH PRECIP WITH THE UPPER SYSTEM EXPECTED TO BE WELL
TO THE WEST. KEPT POPS AT 10 PERCENT FOR NOW FOR FRIDAY BUT SHOWED
TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL WITH WINDS INCREASING FROM
THE NORTHEAST. FIRE WEATHER CONCERNS WILL PERSIST FROM MONDAY AND
TUESDAY DUE TO A VERY DRY AIRMASS AND MODEST NORTHWEST WINDS MONDAY
AND GUSTY NORTH WINDS TUESDAY. AN ELEVATED FIRE DANGER RISK IS
EXPECTED FOR BOTH DAYS.
89/TMT
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 81 46 64 33 71 / 50 10 0 0 0
VICTORIA 75 39 61 29 67 / 70 10 0 0 0
LAREDO 76 42 65 36 75 / 30 10 0 0 0
ALICE 75 43 64 32 73 / 40 10 0 0 0
ROCKPORT 79 49 62 40 67 / 60 10 0 0 0
COTULLA 71 36 63 30 73 / 30 10 0 0 0
KINGSVILLE 81 45 64 30 73 / 50 10 0 0 0
NAVY CORPUS 80 51 63 42 68 / 50 10 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FREEZE WATCH LATE SUNDAY NIGHT FOR THE FOLLOWING ZONES: BEE...
CALHOUN...GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE
OAK...MCMULLEN...NUECES...REFUGIO...SAN PATRICIO...VICTORIA.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...
GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...
MCMULLEN...NUECES...REFUGIO...SAN PATRICIO...VICTORIA...
WEBB.
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARANSAS...CALHOUN...DUVAL...JIM WELLS...KLEBERG...
NUECES...REFUGIO...SAN PATRICIO...WEBB.
GM...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM CST SUNDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST SUNDAY
FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY
TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO
PORT O`CONNOR.
&&
$$
PZ/83...SHORT TERM/AVIATION
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1145 AM CST SAT NOV 26 2011
.AVIATION...
WINDS WILL BE THE CONCERN OF THE DAY AT BOTH TERMINALS WITH GUSTS
APPROACHING 50KTS. WE WILL SEE LOW LEVEL BLOWING DUST MOST
PREDOMINANTLY BELOW 500 FT OR SO. WINDS WILL TAPER LATE THIS
AFTERNOON BUT REMAIN BREEZY ALL NIGHT. MAY PERIODICALLY SEE
VISIBILITIES DROP BRIEFLY TO IFR AT KLBB THIS AFTERNOON. VERTICAL WIND
SHEAR SHOULD NOT BE TOO MUCH OF AN ISSUE THIS AFTERNOON ALTHOUGH
IT MAY BECOME AN ISSUE OVERNIGHT AS THE BOUNDARY LAYER DECOUPLES
AND WE WILL HAVE TO MONITOR TRENDS.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST SAT NOV 26 2011/
..VERY STRONG WINDS DEVELOPING TODAY...
AVIATION...
TWO CHALLENGES OF CONCERN TODAY...THE FIRST IS THE DEVELOPMENT OF
SOME POST-FRONTAL MVFR LAYERS FROM CLOVIS EAST TO NEAR CHILDRESS
AND THE SECOND AND MORE PROLONGED THREAT IS THAT OF STRONG
NORTHERLY WINDS FOR MUCH OF THE DAY. BEHAVIOR OF MVFR CIGS IS SUCH
THAT THEY QUICKLY TREND VFR AS COLDER AND DRIER AIR PUSHES
SOUTH...SO WILL ONLY CARRY A TEMPO GROUP AT LBB THIS MORNING. CDS
HAS ALREADY RISEN TO VFR LAYERS IN THIS DRIER AIR.
GREATEST AVIATION HAZARD IS STRONG NORTHERLY WINDS INCREASING TO
BETWEEN 30 AND 40 KNOTS LATER THIS MORNING. THUS FAR WE HAVE LITTLE
REASON TO DOUBT THE FEW MODELS INDICATING SUCH HIGH WINDS AS 50
KNOTS WAS RECENTLY SAMPLED BY THE LBB WSR-88D VAD WIND PROFILE A
MERE 1K FEET AGL. ONCE MIXING LAYERS DEEPEN AROUND 15Z...EXPECT
OCCASIONAL GUSTS TO APPROACH 50 KNOTS WITH SUSTAINED SPEEDS
RESIDING BETWEEN 30 AND 35 KNOTS. AN AIRPORT WX WARNING FOR HIGH
WINDS WILL BE ISSUED SHORTLY FOR LBB STARTING ~15Z. BLOWING DUST
SHOULD NOT BE AS SEVERE AS WITH A WESTERLY WIND EVENT...BUT TEMPO
5SM APPEARS REASONABLE AT LBB. EXPECT WINDS AND STRONG GUSTS TO
QUICKLY SUBSIDE AROUND SUNSET.
PREV DISCUSSION... /ISSUED 407 AM CST SAT NOV 26 2011/
SHORT TERM...
SHARP UPPER TROUGH CURRENTLY BISECTING THE CONUS WILL INTENSIFY
TODAY AS A VORTICITY MAXIMUM SLIDES SOUTHWARD FROM NERN COLORADO
AND INTO THE BASE OF THE TROUGH. THIS PROCESS IS ALREADY SENDING
A POLAR FRONT SOUTH FROM THE PANHANDLE WHICH SHOULD CLEAR THE CWA
BY MID-MORNING. OF GREATER INTEREST IS A STRONG HEIGHT GRADIENT
TAKING AIM ON MUCH OF THE HIGH PLAINS BY MIDDAY RESULTING IN
NEARLY 100 KNOTS AND 50-60 KNOTS AT 500MB AND 700MB RESPECTIVELY.
DEEP SUBSIDENCE ON THE BACKSIDE OF THE UPPER TROUGH WILL FOSTER
STRONG LOW-LEVEL DRYING TO THE TUNE OF SINGLE-DIGIT DEWPOINTS ON
THE CAPROCK BY EARLY AFTERNOON. EVEN THOUGH MAX TEMPS WILL BE
STUNTED 10 DEG BELOW NORMAL...DEWPOINT DEPRESSIONS RISING TO 40
DEG SHOULD ONLY AID IN DEEPER DRY ADIABATIC LAPSE RATES AND HIGHER
MOMENTUM TRANSFER OVER TIME. CONSIDERING THE MID-LEVEL JET CORE
WILL RESIDE NEAR/JUST WEST OF I-27 AND MAX PRESSURE RISES WILL BE
FAVORABLY TIMED...WE FEEL A HIGH WIND WARNING IS IN ORDER FOR MUCH
OF THE CAPROCK WITH A WIND ADVISORY ELSEWHERE. ALTHOUGH OUR LOCAL
HIGH WIND CHECKLIST FALLS A BIT SHORT OF SOLID HIGH WIND
CRITERIA...THIS PATTERN OF CAA AND DEEP NORTHERLY FLOW COMBINED
WITH SHARP LOW-LEVEL DRYING IS ENOUGH TO TIP THE SCALE IN FAVOR OF
A LOW-END HIGH WIND WARNING SCENARIO. IF THE RUC AND GFS ARE
CORRECT...THE HIGH WIND WARNING MAY NEED TO BE EXPANDED AREA WIDE
THIS MORNING. THE MEMPHIS WTM SITE IS ALREADY ATTEMPTING TO CRASH
THIS PARTY WITH A RECENT GUST TO 55 MPH...HOWEVER CONFIDENCE IN
SUCH A WIDESPREAD AND PROLONGED HIGH WIND THREAT AREA IS NOT
SUFFICIENTLY HIGH AT THIS TIME...BUT LATER FORECASTS WILL REVISIT
THIS POTENTIAL.
A BROAD SURFACE RIDGE WILL THEN OVERSPREAD THE CAPROCK TONIGHT
RESULTING IN LIGHTER WINDS THAN IN THE ROLLING PLAINS. EXPECT
STRONG RADIATIONAL COOLING ON THE CAPROCK TO GARNER SOME OF
COLDEST OVERNIGHT LOWS IN SEVERAL DAYS.
LONG TERM...
REMAINDER OF THE FORECAST PACKAGE IS RELATIVELY QUIET COMPARED
WITH ISSUES FOR TODAY. DEEP NORTHERLY FLOW ALOFT WILL REMAIN IN
PLACE BUT SURFACE WINDS WILL GRADUALLY TRANSITION TO THE WEST LATE
SUNDAY INTO MONDAY. HIGHS TOMORROW WILL AT OR A TICK UNDER NORMAL
FOR THIS TIME OF YEAR BUT WILL REBOUND TO AROUND 10 DEGREES ABOVE
NORMAL ON MONDAY AS DECENT DOWNSLOPE FLOW AND AMPLE SUNSHINE HELP
TO BOOST HIGH TEMPS.
A SECOND COLD FRONT WILL ARRIVE LATE MONDAY INTO TUESDAY ONCE
AGAIN DROPPING HIGH TEMPERATURES BELOW NORMAL FOR TUESDAY FOR
TUESDAY AND POSSIBLY BUMPING WIND SPEEDS UP INTO THE BREEZY
RANGE. RIGHT NOW IT APPEARS THAT WIND SPEEDS WILL NOT BE AS HIGH
AS WE ARE EXPECTING FOR TODAY. SIMILAR CYCLE WILL THEN ENSUE WITH
WEST TO SOUTHWEST WINDS ON WEDNESDAY HELPING TO BRING TEMPERATURES
BACK ABOVE NORMAL FOR A DAY.
STILL ARE SOME CONSIDERABLE DIFFERENCES FOR THE END OF NEXT WEEK
AND THE END OF THIS FORECAST. ALL MODELS ARE NOW DEVELOPING A
CLOSED LOW SOMEWHERE IN THE WESTERN PART OF THE COUNTRY WITH A
STRONG COLD FRONT EXPECTED TO ARRIVE SOMETIME LATE THURSDAY INTO
FRIDAY. GFS IS A FULL DAY FASTER WITH THE COLD FRONT ARRIVAL AND
BRINGS A PRETTY COLD ARCTIC AIRMASS INTO THE REGION. THE ECMWF IS
NOT AS COLD AS THE GFS AND RAPIDLY MIXES OUT THE COLD AIR IN
ADVANCE OF THE APPROACHING CLOSED LOW AND RAPIDLY PULLS IN GULF
MOISTURE. GFS KEEPS THE COLD AIRMASS OVER THE REGION EVEN WITH THE
ADVANCING LOW HEADING TOWARDS THE REGION. WILL HOLD OFF MAKING
CHANGES TO THE LAST TWO DAYS OF THE FORECAST UNTIL THE MODELS
SETTLE DOWN A BIT AND COME INTO BETTER AGREEMENT...BUT THE
POTENTIAL IS THERE FOR SOME PRETTY CHILLY DAYS BY THE END OF NEXT
WEEK INTO NEXT WEEKEND.
JORDAN
FIRE WEATHER...
STRONG LOW-LEVEL DRYING BEHIND A COLD FRONT TODAY COMBINED WITH
NORTHERLY WINDS OF 25-35 MPH AT THE 20-FOOT LEVEL WILL CREATE
PERIODS OF CRITICAL FIRE WEATHER CONDITIONS PRIMARILY OVER THE
SOUTHERN SOUTH PLAINS. ALTHOUGH WIND SPEEDS ARE MORE THAN
SUFFICIENT...BELOW NORMAL TEMPERATURES AND MARGINAL RELATIVE
HUMIDITY VALUES ARE NOT FULLY SUPPORTIVE OF A RED FLAG WARNING. WE
HAVE INSTEAD ISSUED A FIRE DANGER STATEMENT TO HIGHLIGHT PERIODS
THIS AFTERNOON WHEN RELATIVE HUMIDITIES SHOULD BRIEFLY DIP TO
AROUND 15-20 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 46 22 57 32 66 / 0 0 0 0 0
TULIA 46 24 58 31 70 / 0 0 0 0 0
PLAINVIEW 47 24 58 32 70 / 0 0 0 0 0
LEVELLAND 49 24 59 32 69 / 0 0 0 0 0
LUBBOCK 49 26 59 32 69 / 0 0 0 0 0
DENVER CITY 51 26 59 35 69 / 0 0 0 0 0
BROWNFIELD 49 26 60 32 70 / 0 0 0 0 0
CHILDRESS 52 30 57 30 66 / 0 0 0 0 0
SPUR 52 27 59 34 70 / 0 0 0 0 0
ASPERMONT 54 30 58 32 69 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ026-031-032-037-038-043-044.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>025-027>030-033>036-039>042.
&&
$$
99/99/26
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1005 AM CST SAT NOV 26 2011
.DISCUSSION...COLD FRONT IS PROGRESSING THROUGH WEST AND CENTRAL
TEXAS THIS MORNING. WIND SHIFT HAS PUSHED INTO THE CWA BUT FEEL
THIS IS WITH A PRE FRONTAL TROUGH. WITH JUST SLIGHT DPT DROP AND
WINDS REMAIN LIGHT. REAL FRONTAL BOUNDARY A LITTLE TOUGH TO PICK
OUT...BUT SEEMS TO BE JUST THROUGH DALLAS...TO FREDERICKSBURG...TO
DEL RIO. PRECIPITATION ASSOCIATED WITH THE FRONT SO FAR HAS BEEN
RATHER LIMITED IN THE EAST...WITH ISOLATED TO AT TIMES SCATTERED
LIGHT SHOWERS IN THE WEST. LATEST RUC MODEL KEEPS THE BULK OF THE
PRECIP JUST INTO THE NORTHERN PARTS OF THE CWA. HRRR MODEL HOWEVER
SHOWS SCATTERED CONVECTION DEVELOPING ACROSS ENTIRE AREA. BOTH
MODELS INDICATE INCREASING COVERAGE OF MORE STRATIFORM PRECIP
RIGHT ALONG THE FRONT AS IT NEARS THE COAST...WHERE THE DEEPEST
MOISTURE EXISTS...12Z CRP SOUNDING HAD 1.6 PWAT. HAVE ADJUSTED
MORNING POPS SOME TO ACCOUNT FOR LACK OF CONVECTION...HOWEVER
STILL THINK WE SHOULD SEE SOME DEVELOPMENT AS TEMPS INCREASE. HAVE
ALSO ADJUSTED TEMPS TO ACCOUNT FOR WARMER TEMPS FAR EAST WHERE
CLOUDS REMAIN BROKEN AND TEMPS ALREADY APPROACHING 80 DEGREES.
&&
.PREV DISCUSSION... /ISSUED 538 AM CST SAT NOV 26 2011/
DISCUSSION...SEE AVIATION SECTION BELOW.
AVIATION...CURRENTLY VFR CIGS/VSBYS ARE ACROSS S TX...HOWEVER SCT
TO NUM SHRA`S/TSRA`S ARE EXPECTED AHD AND ALONG A STRONG COLD
FRONT LATER THIS MORNING INTO THE EARLY AFTERNOON. BEST CHC OF
TSRA`S WILL BE ACROSS VCT AREA WITH LESSER CHCS FARTHER S AND W.
AREAS BEING EFFECTED BY CONVECTION WILL LIKELY LOWER TO MVFR AND
POSSIBLY IFR LEVELS AT TIMES. AS THE COLD FRONT MOVES THROUGH S
TX...CONDITIONS WILL IMPROVE TO VFR AND WINDS WILL SHIFT TO THE N AND
INCREASE TO 20 TO 30 KNOTS WITH GUSTS UP TO AROUND 40
KNOTS...MAINLY FROM LRD TO ALI TO CRP. WENT WITH GUSTS TO AROUND
30-33KT IN THE TAFS AS THIS WILL BE MORE COMMON. NLY WINDS WILL
DECREASE OVRNIGHT BUT RESTRENGTHEN ON SUNDAY.
PREV DISCUSSION... /ISSUED 459 AM CST SAT NOV 26 2011/
SHORT TERM (TODAY THROUGH SUNDAY)...A LONG WAVE TROF DRAPED ACROSS
THE TX PANHANDLE SOUTHWARD INTO MEX WILL MOVE ACROSS THE REGION
TODAY BRINGING WITH IT A STRONG COLD FRONT. AHD OF THE COLD
FRONT...DEEP MOISTURE WILL COMBINE WITH UPPER JET...EMBEDDED SHORT
WAVE...LG OMEGA...AND DECENT LOW LEVEL CONVERGENCE TO PRODUCE
SCT/NUM SHRA`S/TSRA`S. THE ACTIVITY IS EXPECTED TO INCREASE IN
COVERAGE AS IT MOVES E TOWARD THE COAST DUE TO LOW TO MOD CAPE ALONG
THE COAST AND OVER THE GULF WATERS. THE CAPE AND THE LI`S ARE NOT
IMPRESSIVE AND THERE WILL BE LITTLE TO NO SHEAR...THEREFORE AM NOT
EXPECTING ANY ORGANIZED SVR STORMS. SOME STORMS COULD BECOME STRONG
WITH GUSTS TO AROUND 40KT AND SMALL HAIL. THE BEST CHC FOR PRECIP
WILL BE ACROSS THE NW CWA THRU MID MORNING THEN MOVG E WITH INCREASING
CHCS ACROSS THE E AND NE CWA BY AROUND NOON INTO EARLY AFTERNOON.
THE SYSTEM WILL THEN EXIT THE AREA THRU LATE AFTERNOON.
THE MAIN ISSUE BEHIND THE COLD FRONT WILL BE WINDS. THE MODELS SHOW
40KT OFF THE DECK ALONG WITH DECENT LAPSE RATES THIS AFTERNOON INTO
TONIGHT...ESPECIALLY ACROSS THE SRN CWA AND ALONG THE COASTAL
COUNTIES. THEREFORE WENT WITH A WIND ADVISORY FOR THOSE AREAS WHERE
GUSTS TO 40 MPH WILL BE MOST FREQUENT. IT WILL BE WINDY ACROSS THE
NRN CWA AS WELL...BUT SHOULD REMAIN BELOW ADVISORY LEVELS. WINDS
RELAX SOMEWHAT OVERNIGHT BUT THEN RESTRENGTHEN ON SUNDAY BUT THE WINDS
SHOULD REMAIN BELOW ADVISORY LEVELS.
WITH ONGOING CAA INTO TONIGHT...MN TEMPS ARE EXPECTED TO DIP INTO
THE MID 30S ACROSS THE NW CWA TO MID 40S ALONG THE COAST. THE
OVERNIGHT WINDS WILL REMAIN ELEVATED AND NOT ALLOW THE TEMPS TO DROP
MUCH MORE THAN THAT. DESPITE SUNNY SKIES...HIGHS ON SUNDAY WILL BE
MUCH COOLER WITH AREA WIDE 60S.
MARINE...SCT TO NUM SHRA`S/TSRA`S CAN BE EXPECTED TODAY AHD AND
ALONG A STRONG COLD FRONT THAT WILL MOVE ACROSS THE BAYS AND COASTAL
WATERS THIS AFTERNOON. WINDS WILL SHIFT TO THE N AND RAPIDLY
INCREASE TO ADVISORY LEVELS ACROSS THE BAYS AND GALE FORCE ACROSS
THE COASTAL WATERS. A GALE WARNING IS IN EFFECT FOR THE GULF WATERS
AND AN SCA IS IN EFFECT FOR THE BAYS. THE GALE FORCE WINDS ARE
EXPECTED TO DECREASE BY SUN MORNING BUT REMAIN HIGH END SCA THROUGH
SUNDAY NIGHT.
FIRE WEATHER...A COLD FRONT IS EXPECTED TO PUSH ACROSS S TX LATE
TODAY WITH STRENGTHENING N WINDS DVLPG IN ITS WAKE. ALTHOUGH DRIER
AIR WILL BE FILTERING INTO S TX...RH VALUES ARE EXPECTED TO REMAIN
ABV CRITICAL THRESHOLDS THROUGH TODAY AND TONIGHT. THEREFORE AM NOT
EXPECTING FIRE WEATHER CONDITIONS THRU TONIGHT. HOWEVER...MUCH LOWER
RH VALUES IN THE TEENS WILL BE IN PLACE ON SUNDAY AND WINDS WILL BE
BREEZY TO WINDY LEADING TO CRITICAL FIRE DANGER CONDITIONS. A FIRE
WEATHER WATCH IS IN EFFECT FOR SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...COLD DRY AIRMASS WILL
REMAIN OVER SOUTH TEXAS SUNDAY NIGHT WITH WINDS RELAXING. WENT CLOSE
TO THE COLDER MET GUIDANCE FOR MINIMUMS WITH BELOW FREEZING TEMPS
EXPECTED FOR THE INLAND COASTAL PLAINS UP INTO THE NORTHERN BRUSH
COUNTRY. WENT AHEAD AND ISSUED A FREEZE WATCH FOR THESE AREAS FOR
LATE SUNDAY NIGHT. THE ANOMALOUS DEEP UPPER LOW WILL MOVE ACROSS THE
SOUTHEAST UNITED STATES MONDAY AND TUESDAY. THE OFFSHORE FLOW WILL
WEAKEN MONDAY BUT INCREASE AGAIN ON TUESDAY. HIGH PRESSURE WILL
SURGE DOWN THE PLAINS AFTER A NORTHERN STREAM SHORT WAVE TROUGH
MOVES INTO THE UPPER MIDWEST TUESDAY WITH AN INCREASE IN WINDS
EXPECTED TUESDAY AFTERNOON. TEMPERATURES WILL ALMOST BE BACK TO
NORMAL MONDAY/TUESDAY BUT WILL FALL BACK TO BELOW NORMAL FOR
WEDNESDAY. A BRIEF WARM UP IS EXPECTED FOR THURSDAY. MEDIUM RANGE
MODELS SHOW ENERGY DIVING OUT OF THE GULF OF ALASKA INTO THE PACIFIC
NORTHWEST WEDNESDAY BUT THE MODELS DIVERGE FROM THERE ON EVOLUTION
OF THE UPPER LOW BECOMING CUTOFF FROM THE NORTHERN STREAM AND MOVING
INTO THE DESERT SOUTHWEST BY FRIDAY. POLAR AIRMASS IS EXPECTED TO
MOVE DOWN THROUGH THE PLAINS INTO SOUTH TEXAS ON FRIDAY. INCREASING
ISENTROPIC LIFT SHOULD LEAD TO AN INCREASED CLOUD COVER. 00Z GFS
GENERATED TOO MUCH PRECIP WITH THE UPPER SYSTEM EXPECTED TO BE WELL
TO THE WEST. KEPT POPS AT 10 PERCENT FOR NOW FOR FRIDAY BUT SHOWED
TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL WITH WINDS INCREASING FROM
THE NORTHEAST. FIRE WEATHER CONCERNS WILL PERSIST FROM MONDAY AND
TUESDAY DUE TO A VERY DRY AIRMASS AND MODEST NORTHWEST WINDS MONDAY
AND GUSTY NORTH WINDS TUESDAY. AN ELEVATED FIRE DANGER RISK IS
EXPECTED FOR BOTH DAYS.
89/TMT
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 78 46 64 33 71 / 50 10 0 0 0
VICTORIA 75 39 61 29 67 / 70 10 0 0 0
LAREDO 76 42 65 36 75 / 30 10 0 0 0
ALICE 78 43 64 32 73 / 40 10 0 0 0
ROCKPORT 76 49 62 40 67 / 60 10 0 0 0
COTULLA 73 36 63 30 73 / 30 10 0 0 0
KINGSVILLE 78 45 64 30 73 / 50 10 0 0 0
NAVY CORPUS 76 51 63 42 68 / 50 10 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FREEZE WATCH LATE SUNDAY NIGHT FOR THE FOLLOWING ZONES: BEE...
CALHOUN...GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE
OAK...MCMULLEN...NUECES...REFUGIO...SAN PATRICIO...VICTORIA.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...
GOLIAD...JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...
MCMULLEN...NUECES...REFUGIO...SAN PATRICIO...VICTORIA...
WEBB.
WIND ADVISORY UNTIL 8 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARANSAS...CALHOUN...DUVAL...JIM WELLS...KLEBERG...
NUECES...REFUGIO...SAN PATRICIO...WEBB.
GM...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM CST SUNDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST SUNDAY
FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY
TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO
PORT O`CONNOR.
&&
$$
PZ/83...SHORT TERM
TT/89...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
219 PM CST SAT NOV 26 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
219 PM CST SAT NOV 26 2011
MAIN FORECAST CONCERNS ARE WITH PRECIPITATION TONIGHT AND THEN
TEMPERATURES THROUGH THE REST OF THE SHORT TERM PERIOD.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGES OVER BOTH THE WEST AND EAST COASTS OF THE U.S. AND
TROUGHING IN-BETWEEN FROM MANITOBA SOUTHWARD THROUGH TEXAS. BULK OF
THE ENERGY ASSOCIATED WITH THE UPPER TROUGHING HAS BEEN DROPPING
SOUTH INTO TEXAS PER PRESSURE VALUES ON THE 1.5 PV SURFACE. STILL...
GRADUAL HEIGHT FALLS ON THE EAST SIDE OF THE UPPER TROUGH AND
SHORTWAVES MOVING THROUGH THE SOUTHWEST FLOW...COMBINED WITH LOW
LEVEL MOISTURE TRANSPORT...HELPED BRING THE LIGHT TO MODERATE RAIN
TO MUCH OF THE FORECAST AREA THIS MORNING. THIS PRECIPITATION IS
NOW ONLY AFFECTING THE FAR SOUTHEASTERN PORTION OF THE FORECAST
AREA DUE TO A DRY SLOT IN THE MID TO UPPER LEVELS PUNCHING IN
ELSEWHERE. MEANWHILE...VERY WEAK COLD CONVEYOR BELT AROUND A
1006MB SURFACE LOW IN NORTHEAST WISCONSIN IS REFLECTED BY LIGHT
RADAR RETURNS ACROSS CENTRAL MN INTO NORTHWEST WI. A MIX OF LIGHT
RAIN AND SNOW HAS BEEN REPORTED WITH THESE RADAR RETURNS...THANKS
TO SURFACE TEMPERATURES THAT HAVE BEEN FALLING ON GUSTY NORTHWEST
WINDS. OFF TO THE WEST... EVEN COLDER AIR WAS EVIDENT OVER THE
DAKOTAS INTO MONTANA WHERE 12Z 850MB TEMPS WERE OBSERVED AT -5 TO
-7C. COMPARE THIS TO OBSERVED 4-6C OVER THE AREA AT 12Z TODAY.
SKIES DO CLEAR OUT OVER THE WESTERN DAKOTAS...THOUGH...THANKS TO A
DRY 12Z GLASGOW MT SOUNDING.
TONIGHT AND SUNDAY...UPPER TROUGH OVER THE PLAINS IS FORECAST TO
GRADUALLY TRACK EAST DURING THIS PERIOD...WITH THE 500MB AXIS
SITUATED OVER LA CROSSE AT 12Z SUNDAY AND THEN OVER EASTERN
WISCONSIN AT 00Z MONDAY. SINCE THIS UPPER TROUGH IS COMING THROUGH
POSITIVELY TILTED AND AGAIN MOST OF THE ENERGY DROPPING SOUTH INTO
THE SOUTHERN PLAINS...VERY LITTLE IN THE WAY OF FORCING IS EXPECTED.
MAIN PRECIPITATION LOOKS TO BE THE CURRENT WEAK COLD CONVEYOR BELT
OVER CENTRAL MINNESOTA WHICH SHOULD SLIDE THROUGH MUCH OF THE
FORECAST AREA THIS EVENING. CANNOT RULE OUT A FEW HUNDREDTHS OF
QPF...AS INDICATED BY THE 26.12Z NAM/26.00Z ECMWF...BUT THE
PROBABILITY SEEMS TOO LOW TO GO MORE THAN A 50 PERCENT CHANCE GIVEN
NEARLY DRY 26.09Z SREF MEAN/26.12Z GFS AND GIVEN WEAK APPEARANCE OF
CONVEYOR BELT ON RADAR. PRECIPITATION TYPE WILL BE DETERMINED BY THE
SURFACE TEMPERATURE GIVEN THE WARMEST LAYER AT THE SURFACE...MAKING
IT A RAIN/SNOW SCENARIO. HOWEVER...THERE ARE SOME HINTS OF LOSS OF
ICE DUE TO SOME DRIER AIR IN THE 10000-15000 FT LAYER...WHICH COULD
ALLOW FOR JUST A LITTLE MORE LIQUID VS SNOW. NOT ENOUGH CONFIDENCE
EXISTS TO MENTION ANY FREEZING PRECIPITATION...THOUGH...DUE TO
QUESTION MARKS ON AMOUNT OF PRECIPITATION IN GENERAL AND SURFACE
TEMPERATURES LIKELY TAKING AWHILE TO FALL BELOW FREEZING. ANY
SNOW ACCUMULATION LIKELY TO BE VERY LIGHT IF AT ALL TOO. OVERNIGHT
HOURS THROUGH SUNDAY LOOK MOSTLY DRY AS THE UPPER TROUGH PUSHES
EAST AND SUBSIDENCE COMES IN. CERTAINLY MUCH COOLER WEATHER DURING
THIS PERIOD AS 850MB TEMPS TANK TO -4 TO -8C BY 12Z SUNDAY...ALONG
WITH THE BLUSTERY NORTHWEST WINDS. NOT A WHOLE LOT OF MODIFICATION
EXPECTED TOMORROW WITH CLEARING NOT COMING IN UNTIL LATE AND 850MB
TEMPS STAYING BELOW -2C. IN FACT...ANY CLEARING MAY ONLY OCCUR IN
THE FAR WESTERN FORECAST AREA.
SUNDAY NIGHT THROUGH TUESDAY...QUIET WEATHER LOOKS TO DOMINATE THE
FORECAST AREA DESPITE A FRONTAL PASSAGE LIKELY TO MOVE THROUGH VERY
LATE MONDAY. THINGS WILL BE MORE ACTIVE TO OUR SOUTHEAST AS AN UPPER
LOW FORMS OVER THE SOUTHEASTERN U.S....BUT ANY PRECIPITATION
WRAPPING BACK AROUND THIS UPPER LOW LOOKS TO STAY EAST AND SOUTH OF
CHICAGO. REGARDING THE FRONTAL PASSAGE...A NORTHERN STREAM UPPER
LEVEL TROUGH CURRENTLY OVER THE EASTERN PACIFIC IS FORECAST TO CROSS
THE DAKOTAS ON MONDAY...BRINGING A SURGE OF DOWNSLOPED WARMED AIR
INTO THE FORECAST AREA. 850MB TEMPS ACTUALLY CLIMB UP TO 4-6C BY 00Z
TUESDAY. PROBLEM IS THAT A LOT OF THE WARMING TAKES PLACE ALOFT AND
WE WILL NOT BE ABLE TO MIX UP TO IT...DUE TO THE LOW SUN ANGLE AND
LIGHT WINDS FORECAST. STILL...MIXING UP TO 925MB IS LIKELY WITH FULL
SUNSHINE RESULTING IN HIGHS IN THE UPPER 30S TO LOW 40S. THIS SHOULD
BE A NICE REBOUND AFTER SUNDAY NIGHT LOWS LIKELY IN THE MID TEENS TO
MID 20S...COLDEST IN THE TYPICAL COLD SPOTS. DRY WEATHER EXPECTED
WITH THE FRONTAL PASSAGE DUE TO LACK OF MOISTURE...THEN COOLER
TEMPERATURES COME IN AGAIN AS HIGH PRESSURE BUILDS BACK OVER THE
PLAINS FOR MONDAY NIGHT AND TUESDAY. 850MB TEMPS THIS TIME DO NOT
FALL AS MUCH...ONLY TO -2 TO -4C...SO TUESDAY SHOULD END UP A LITTLE
WARMER THAN SUNDAY. MAY HAVE SOME THICKER HIGH CLOUDS TO DEAL WITH
IN THE MORNING COMING OFF THE SOUTHEASTERN UPPER LOW TO LIMIT
FIXING...BUT THESE LOOK TO START CLEARING OUT IN THE AFTERNOON.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
219 PM CST SAT NOV 26 2011
SIMILAR TO THE SUNDAY NIGHT THROUGH TUESDAY TIME PERIOD...MUCH OF
THE EXTENDED LOOKS QUIET...THOUGH PLENTY OF UNCERTAINTY EXISTS WITH
THE UPPER LEVEL PATTERN HEADING INTO NEXT WEEKEND. LONGWAVE PATTERN
FEATURES UPPER RIDGING BUILDING INTO THE AREA ON WEDNESDAY BETWEEN
THE UPPER LOW LIFTING UP THE EAST COAST AND TROUGHING DIGGING DOWN
THE WEST COAST. SHOULD SEE WARMER TEMPERATURES ON WEDNESDAY
ASSOCIATED WITH THE UPPER RIDGING...THOUGH NOT MUCH ABOVE NORMAL
GIVEN 850MB TEMPS ONLY 2-4C. THIS TROUGHING LOOKS TO SPLIT INTO
TWO...WITH THE NORTHERN STREAM PORTION CROSSING THE FORECAST AREA
THURSDAY NIGHT. MODELS HAVE BEEN SPLIT WHETHER OR NOT FRONTOGENESIS
AND DPVA FORCING AHEAD OF THE NORTHERN STREAM TROUGH CAN PRODUCE
LIGHT SNOW...MOSTLY DUE TO LACK OF MOISTURE WITH IT. CONSENSUS OF
GUIDANCE SUGGESTS JUST A 10-15 PERCENT CHANCE FOR BOTH THURSDAY AND
THURSDAY NIGHT...WHICH RESULTS IN A DRY FORECAST. MORE IMPORTANTLY
IS THE 850MB TEMPS ACCOMPANYING THE TROUGH. MODELS HAVE BEEN
INCONSISTENT INCLUDING RUN TO RUN ON HOW COLD THE AIR IS WITH IT.
CURRENT CONSENSUS IS BETWEEN -8 TO -12C...BUT HAVE SEEN MODELS BOTH
WARMER AND COLDER. THIS SHOULD SET UP TEMPERATURES BELOW NORMAL FOR
FRIDAY AS AN AREA OF HIGH PRESSURE BUILDS IN. HEADING INTO THE
WEEKEND...MODELS ARE IN AGREEMENT OF RIDGING BUILDING UP IN THE
EASTERN PACIFIC. QUESTION IS WHERE SHORTWAVES DIG DOWN TO ON THE
EAST SIDE OF THIS RIDGE. THE 26.12Z GFS AND SOME GFS ENSEMBLE
MEMBERS ALLOW SHORTWAVES TO DIG DOWN INTO THE WESTERN U.S....
RESULTING IN DOWNSTREAM RIDGING OVER THE FORECAST AREA. OTHERS LIKE
THE 26.00Z/26.12Z ECMWF AND OTHER GFS ENSEMBLE MEMBERS DIG THE
SHORTWAVES DOWN MORE OVER THE NORTHERN PLAINS INTO OUR REGION BY
MAINTAINING NORTHWEST FLOW. FOLLOWED A SOMEWHAT OF CONSENSUS
APPROACH WHICH JUST PLACES SOME 10-20 PERCENT CHANCES OVER THE AREA
ON SATURDAY...MAINLY NORTH OF I-90 WITH A SHORTWAVE TROUGH GOING
THROUGH THERE. SLIGHTLY WARMER TEMPERATURES WOULD OCCUR ON SATURDAY
AS WELL WITH WARM ADVECTION ASSOCIATED WITH THE SHORTWAVE TROUGH.
IN SUMMARY...EXTENDED LOOKS AROUND NORMAL ON TEMPERATURES WITH
MAINLY DRY CONDITIONS.
&&
.AVIATION...THIS AFTERNOON THROUGH SUNDAY
1125 AM CST SAT NOV 26 2011
MVFR/IFR CLOUDS WILL PERSIST OVER THE AREA THRU TONIGHT AND WELL
INTO SUNDAY. A COLD FRONT NEAR KEAU-KLSE-KPDC AT 17Z WILL CONTINUE
TO PUSH EAST ACROSS THE AREA THIS AFTERNOON. WINDS WILL INCREASE
FROM THE NORTHWEST FOR THE AFTERNOON AND TONIGHT...SLOWLY SCOURING
OUT THE MVFR/LCL IFR VSBYS IN BR. VSBYS NOT EXPECTED TO IMPROVE TO
VFR UNTIL LATE IN THE AFTERNOON OR EARLY THIS EVENING AS THE SHARPLY
COLDER AIR BEHIND THE FRONT INTERACTS WITH THE MOIST BOUNDARY
LAYER/WET GROUND PRODUCING BR WELL BEHIND THE FRONT. MVFR/IFR CLOUD
DECKS BEHIND THE FRONT AND A LOW IN NORTHEAST WI WRAP ALL THE WAY
BACK INTO THE EASTERN DAKOTAS. WITH THIS MOISTURE BECOMING TRAPPED
UNDER AN INCREASING INVERSION NEAR 900MB TONIGHT...WILL LIKELY HAVE
TO WAIT FOR THE MOISTURE/CLOUDS TO BODILY ADVECT EAST AND OUT OF THE
AREA. PRESENT MODEL TRENDS/TIMING INDICATE THIS WILL NOT OCCUR AT
KRST/KLSE UNTIL EARLY SUN AFTERNOON AT KRST AND LATER SUN AFTERNOON
AT KLSE. PRESSURE GRADIENT WILL REMAIN TIGHT AT THE TAF SITES
TONIGHT/SUN...WITH NORTHWEST WINDS OF 10-20KTS AND GUSTY EXPECTED TO
PREVAIL UNTIL LATER SUN AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
219 PM CST SAT NOV 26 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RRS