292
FXUS62 KTAE 191532
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1032 AM EST THU DEC 19 2024
..NEW UPDATE
UPDATE
ISSUED AT 1023 AM EST THU DEC 19 2024
MAIN ISSUE TODAY IS DEALING WITH THE STRATUS DECK THAT HAS MOVED
INTO THE NORTHWESTERN HALF OF THE FORECAST AREA THIS MORNING
BEHIND THE DEPARTING COLD FRONT. MODEL GUIDANCE CONTINUES TO
STRUGGLE WITH HOW LONG THIS CLOUD DECK WILL HANG AROUND (OR SOME
MODELS JUST DON'T EVEN SEE IT ALL). HOWEVER, LOOKING AT VISIBLE
SATELLITE IMAGERY AND SURFACE DATA, IT SEEMS THAT THE EASTWARD
EXPANSION OF THE CLOUD DECK IS BEGINNING TO SLOW OR STOP AS
INSOLATION AHEAD OF THE CLOUD DECK IS ALLOWING FOR SUFFICIENT
MIXING IN A STEADILY WARMING AIRMASS. HOWEVER, BACK TO THE NORTH
AND WEST, WITHIN THE STRATUS FIELD, THE CONTINUED LOW LEVEL COOL
ADVECTION WILL HELP REINFORCE THE STABILITY OF THE LOCAL AIRMASS
AND WITH RELATIVELY WEAK DRY ADVECTION OCCURRING, I'M DOUBTFUL THE
CLOUD DECK WILL DISSIPATE VERY MUCH, IF AT ALL, BY THE END OF THE
DAY. AS A RESULT, HAVE UPDATED THE NEAR TERM FORECAST TO ACCOUNT
FOR A LONGER DURATION OF CLOUD COVER AND LOWER MAXTS TODAY AND
WILL MONITOR TRENDS INTO THE AFTERNOON AND MAKE ADJUSTMENTS AS
NECESSARY. ASIDE FROM THIS, NO OTHER CHANGES WERE MADE TO THE
FORECAST.
SYNOPSIS
ISSUED AT 405 AM EST THU DEC 19 2024
A COLD FRONT WAS CROSSING THE REGION EARLY THIS MORNING. AN EVEN
STRONGER BUT DRY REINFORCING COLD FRONT WILL SWEEP THROUGH ON
FRIDAY, BRINGING A COLD AIR MASS AND BELOW NORMAL TEMPERATURES
FROM FRIDAY NIGHT THROUGH MONDAY. A TURN TO SOUTHEAST LOW-LEVEL
FLOW ON TUESDAY AND WEDNESDAY WILL BRING A RETURN OF MILDER AND
MOISTER AIR. A WEAK TROUGH TRYING TO APPROACH FROM THE WEST WILL
BRING THE NEXT CHANCE OF RAIN ON CHRISTMAS DAY.
NEAR TERM
(THROUGH TONIGHT)
ISSUED AT 612 AM EST THU DEC 19 2024
THE FIRST COLD FRONT OF THE COLD SNAP HAS MOVED ITS WAY THROUGH
THE AREA THIS MORNING. OUTSIDE OF DIXIE COUNTY, THE DENSE FOG HAS
NEARLY DISSIPATED. A LARGE STRATUS DECK THAT HAS NOT BEEN WELL
ACCOUNTED FOR IN THE MODELS IS MOVING INTO THE WIREGRASS THIS
MORNING. WE'LL SEE HOW LONG THIS STICKS AROUND AND HOW FAR SOUTH
AND EAST IT MOVES. BUT, THIS WILL HELP PIN TEMPERATURES DOWN A BIT
OVER OUR NORTHEASTERN AREAS. THE THINKING IS THAT THIS WILL MIX
OUT ONCE WE GET INTO THE LATE MORNING OR EARLY AFTERNOON, BUT
THESE STRATUS DECKS TEND TO BE RATHER STUBBORN.
ONCE THE MORNING CLOUDS CLEAR THE AREA, SUNSHINE WILL DOMINATE THE
AFTERNOON. THE AIR MASS BEHIND THIS FIRST COLD FRONT ISN'T
PARTICULARLY COLD. HOWEVER, IN LOOKING AT THE GUIDANCE, NBM IS A
BIT OF A WARM OUTLIER FOR TODAY. WE WILL BE IN A COLD AIR
ADVECTION REGIME, WHICH LEANS ME TOWARD UNDERCUTTING NBM BY A
COUPLE DEGREES, WHICH IS MORE IN LINE WITH SOME OF THE MOS
GUIDANCE. HIGHS WILL RANGE FROM THE LOW TO MID-60S IN THE
WIREGRASS TO THE MID-70S IN THE SOUTHEAST BIG BEND. THE COLD AIR
ADVECTION CONTINUES INTO TONIGHT WITH LOWS GENERALLY IN THE 40S.
SHORT TERM
(FRIDAY THROUGH SUNDAY NIGHT)
ISSUED AT 405 AM EST THU DEC 19 2024
AN EVEN STRONGER REINFORCING COLD FRONT WILL SWEEP ACROSS THE
REGION DURING THE DAY ON FRIDAY. IT WILL ENCOUNTER A DRY AIR MASS
ON ITS TREK ACROSS THE SERVICE AREA, SO IT WILL BE A DRY FRONT. YOU
WILL MAINLY NOTICE AN INCREASE IN NORTHERLY WINDS ON FRIDAY WHEN
IT PASSES. IN ITS WAKE, A LONG FETCH OF NORTHERLY WINDS WILL BE
SLIDING DOWN THE EAST SIDE OF A MERIDIONAL SURFACE RIDGE EXTENDING
FROM MANITOBA INTO EASTERN TEXAS. WITH AIR ORIGINATING SO FAR
NORTH, THIS WILL BE A COLD AIR MASS, SIMILAR IN CHARACTER TO WHAT
WE HAD AROUND HERE DURING THE FIRST WEEK OF DECEMBER. BELOW NORMAL
TEMPERATURES ARE FORECAST FROM FRIDAY NIGHT THROUGH MONDAY. THE
COLDEST DAY WILL BE SATURDAY, WHEN HIGH WILL ONLY REACH THE 50S.
THE COLDEST NIGHT WILL BE SATURDAY NIGHT, WHEN THE N-NE WINDS WILL
WEAKEN ENOUGH TO SUPPORT BETTER RADIATIONAL COOLING. WIDESPREAD
LIGHT FREEZING TEMPERATURES AND FROST ARE EXPECTED AT SUNRISE ON
SUNDAY, EXCEPT AT THE BEACHES.
SURFACE HIGH PRESSURE WILL REACH THE NORTHEAST U.S. LATE SUNDAY,
CAUSING OUR SURFACE WINDS TO GRADUALLY CLOCK AROUND FROM NORTH TO
NORTHEAST. THIS WILL ARREST THE COOLING TREND, BUT THERE WILL NOT
YET BE ENOUGH EASTERLY COMPONENT FOR MUCH MODERATION YET ON
SUNDAY. THE INTRODUCTION OF A LITTLE MARINE INFLUENCE CROSSING THE
NORTHERN FL PENINSULA ON SUNDAY NIGHT WILL BRING THE BIGGEST
MODERATION OF LOW TEMPERATURES ON SUNDAY NIGHT TO THE SE BIG BEND
REGION AND THE COAST.
LONG TERM
(MONDAY THROUGH WEDNESDAY)
ISSUED AT 405 AM EST THU DEC 19 2024
THE COLD-WEATHER INDUCING LONGWAVE TROUGH WILL QUICKLY EXIT OFF
THE U.S. EAST COAST ON SUNDAY NIGHT, EXITING OUR WEATHER PICTURE
ON MONDAY. UPPER FLOW ACROSS THE EASTERN U.S. WILL THEN BECOME
LESS CONSOLIDATED AND MORE ZONAL. IN FACT, A WEAK FLAT UPPER RIDGE
WILL PASS ACROSS OUR REGION ON MONDAY, AND THEN A WEAK SOUTHERN
STREAM SHORTWAVE WILL MOVE FROM THE SOUTHERN HIGH PLAINS EARLY
TUESDAY ACROSS THE NORTHERN GULF COAST ON WEDNESDAY (CHRISTMAS
DAY). THIS WILL BE PRECEDED BY SOUTHWEST FLOW ALOFT. A TURN TO
LOW-LEVEL SOUTHEAST FLOW WILL BRING A RETURN OF MILDER AND MOISTER
AIR FROM MONDAY THROUGH WEDNESDAY.
BY TUESDAY NIGHT OR CHRISTMAS DAY, RAIN CHANCES WILL INCREASE INTO
THE 20-40 PERCENT RANGE. BY THEN, PRECIPITABLE WATER WILL HAVE
INCREASED TO WELL OVER 1 INCH, AND THE AIR MASS WILL BE MILD. A
CONFLUENT BAND OF SHOWERS AND THUNDERSTORMS WILL PROBABLY DEVELOP
SOMEWHERE NEAR THE CENTRAL GULF COAST IN SOUTHERLY LOW-LEVEL FLOW.
THERE ARE STILL SIGNIFICANT MODEL DIFFERENCES IN WHETHER IT SETS
UP FURTHER WEST TOWARD LOUISIANA, OR FURTHER EAST OVER THE FL
PANHANDLE. IF THIS FEATURE TRIES TO MOVE TOO FAR EAST, THE
CONVECTIVE ACTIVITY WOULD WEAKEN OVER THE COOLER WINTER WATERS OF
THE FAR EASTERN GULF. THEREFORE, RAIN CHANCES DECREASE AS YOU MOVE
EAST AND NORTHEAST FROM THE PANHANDLE.
AVIATION
(12Z TAFS)
ISSUED AT 612 AM EST THU DEC 19 2024
THE FOG HAS CLEARED OUT OF ALL TAF SITES THIS MORNING WITH THE
COLD FRONT EXITING OUR AREA. MEANWHILE, A LARGE STRATUS DECK IS
MOVING SOUTHWARD OUT OF CENTRAL ALABAMA AND GEORGIA TOWARD DHN. IN
THE NEXT HOUR OR SO, EXPECT LOW-END MVFR CIGS TO PREVAIL FOR MUCH
OF THE MORNING. IT'S UNCERTAIN HOW FAR EAST AND SOUTH THIS STRATUS
FIELD MOVES. THUS, HAVE INCLUDED TEMPOS FOR BOTH ECP AND ABY JUST
IN CASE FOR SOME MVFR CIGS. OTHERWISE, VFR CONDITIONS ARE EXPECTED
WITH NW WINDS AROUND 5-8 KTS.
MARINE
ISSUED AT 405 AM EST THU DEC 19 2024
GENTLE TO MODERATE NORTHERLY BREEZES WILL FOLLOW A COLD FRONT THAT
IS PASSING ACROSS THE WATERS THIS MORNING. THE FRONT WILL ALSO
PUSH OUT THE SEA FOG THAT WAS PREVALENT OVER APALACHEE BAY EARLY
THIS MORNING. A REINFORCING COLD FRONT ON FRIDAY WILL BE FOLLOWED
BY A A SURGE OF STRONG NORTHERLY BREEZES ON FRIDAY EVENING. HIGH
PRESSURE WILL PASS BY WELL TO THE NORTH THROUGH THE WEEKEND,
ALLOWING MODERATE BREEZES TO GRADUALLY CLOCK AROUND FROM NORTHERLY
TO NORTHEASTERLY ON SUNDAY, BECOMING EASTERLY BY MONDAY NIGHT.
FIRE WEATHER
ISSUED AT 405 AM EST THU DEC 19 2024
AREAS OF FOG THIS MORNING OVER FAR SOUTHERN GEORGIA AND THE FLORIDA
BIG BEND WILL DISSIPATE BY MID-MORNING AS A COLD FRONT CLEARS THE
AREA. WITH THE PASSAGE OF THE FRONT, WINDS WILL BE NORTHWESTERLY
TODAY. A SECOND, STRONGER COLD FRONT MOVES THROUGH THE AREA DURING
THE DAY FRIDAY, WHICH WILL BRING STRONGER NORTHWESTERLY WINDS AND
DRIER AIR. HOWEVER, RELATIVE HUMIDITY WILL REMAIN ABOVE CRITICAL
LEVELS THROUGH THE PERIOD. DISPERSIONS AREA-WIDE WILL GENERALLY BE
FAIR TO GOOD TODAY, THEN GOOD FRIDAY AND SATURDAY.
HYDROLOGY
ISSUED AT 405 AM EST THU DEC 19 2024
NO FLOODING IS EXPECTED THROUGH CHRISTMAS DAY.
SPOTTER INFORMATION STATEMENT
SPOTTER ACTIVATION IS NOT REQUESTED. HOWEVER, SPOTTERS ARE ALWAYS
ENCOURAGED TO SAFELY REPORT SIGNIFICANT WEATHER CONDITIONS WHEN THEY
OCCUR BY CALLING THE OFFICE OR TWEETING US @NWSTALLAHASSEE.
PRELIMINARY POINT TEMPS/POPS
TALLAHASSEE 71 44 64 36 / 0 0 0 0
PANAMA CITY 66 46 65 36 / 0 0 0 0
DOTHAN 60 41 62 32 / 0 0 0 0
ALBANY 63 41 62 32 / 0 0 0 0
VALDOSTA 71 45 64 35 / 0 0 0 0
CROSS CITY 76 49 68 37 / 0 0 0 0
APALACHICOLA 70 49 65 38 / 0 0 0 0
TAE WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
UPDATE...GODSEY
NEAR TERM...YOUNG
SHORT TERM...HANER
LONG TERM....HANER
AVIATION...YOUNG
MARINE...HANER
FIRE WEATHER...YOUNG
HYDROLOGY...HANER
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