FXUS62 KTAE 252008
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
308 PM EST FRI DEC 25 2009
.SYNOPSIS...COLD FRONT IS NOW PAST JAX AND SAV MOVING OFF THE
COAST. SURFACE WINDS ARE MAINLY WEST TO WEST SOUTHWEST 10 TO 15
KNOTS WITH A FEW HIGHER GUSTS. TEMPS IN OUR CWA AT 19Z RANGED FROM
UPPER 40S NORTHWEST TO MID 60S SOUTHEAST. DEWPOINTS VARIED FROM
NEAR 40 TO THE MID 50S AT CTY. MUCH OF THE AREA WAS COVERED BY
STRATOCUMULUS WITH CLEARING IN SOUTHWEST ALABAMA AND THE WESTERN
PANHANDLE. HAVE ANALYZED A 1007-MB SURFACE LOW IN SOUTH CAROLINA
WHERE THE WARM FONT MEETS THE COLD FRONT. ON THE LARGER SCALE...THE
SURFACE LOW BACK IN THE MIDWEST WAS STILL LOCATED IN IOWA WITH SNOW
FALLING IN MISSOURI AND ILLINOIS BACK INTO THE DAKOTAS...AND THEN
WEST INTO WYOMING. THE LOWEST 12Z HEIGHT I SAW ON THE UPPER AIR PLOTS
WAS 525DM SUGGESTING POSSIBLY A 520DM OBLONG UPPER LOW SITUATED
ACROSS KANSAS AND NEBRASKA. AS I SAID EARLIER...500-MB CLOSED
CONTOURS COVERED ALL OF THE NATIONS MID SECTION. RIDGING WAS LOCATED
ON BOTH COASTS. SUBTROPICAL JET APPEARS TO EXTEND ACROSS MEXICO
EASTWARD RIGHT OVER US.
HAVE HEARD OF NO REPORTS OF SEVERE WEATHER OVERNIGHT IN OUR CWA.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...STAGNANT PATTERN DURING
THE SHORT TERM. BLOCKING RIDGES ON BOTH SIDES OF THE UPPER LOW IN
THE MIDWEST WILL SLOW ITS PROGRESS. MODELS ARE IN PRETTY GOOD
AGREEMENT THAT THE LOW WILL WOBBLE AROUND CHICAGO FOR THE NEXT COUPLE
OF DAYS...AND THEN BEGIN TO MOVE EAST SUNDAY NIGHT AND FILL AS IT
COMES UNDER THE INFLUENCE OF THE UPPER LOW OVER HUDSON BAY. HIGH
PRESSURE WILL BUILD INTO OUR AREA TONIGHT AND INFLUENCE OUR WEATHER
THROUGH THE WEEKEND. ALL MODELS AGREE THAT SOME SORT OF IMPULSE WILL
DEVELOP IN THE WESTERN GULF ON SATURDAY AFTERNOON AND PROCEED
EASTWARD INCREASING MOISTURE AND THE CHANCE OF RAIN ON SUNDAY
ASSOCIATED WITH A WEAK UPPER DISTURBANCE. THE FEATURE WEAKENS
SIGNIFICANTLY ON MONDAY MORNING AS IT MOVES INTO THE ATLANTIC. OUR
NEXT WEATHER MAKE WILL BE ASSOCIATED WITH A SHORT WAVE MOVING UNDER
THE UPPER RIDGE AND WILL BE APPROACHING BAJA CALIFORNIA SUNDAY
EVENING. ONE THING TO NOTE...I TOOK THE MIDDLE GROUND ON TEMPS ON
SUNDAY AFTERNOON BETWEEN THE MAV AND MET GUIDANCE. THROUGH THE
PERIOD...TEMPS WILL BE COOL...NEARLY 18 TO 10 DEGREES BELOW NORMAL
WITH 30S EACH MORNING AND MID 50S OR SO EACH AFTERNOON.
.LONG TERM (MONDAY THROUGH FRIDAY)...
THE OVERALL LONG TERM PERIOD IS DOMINATED BY FAST MID LEVEL FLOW
ACROSS THE EASTERN CONUS AND GENERALLY BELOW NORMAL TEMPERATURES.
THE PERIOD BEGINS WITH A DEEP TROF OVER THE EASTERN CONUS WITH
RELATIVELY COOL AIR IN PLACE ACROSS MUCH OF THE EAST. THE TROF AXIS
SWINGS THROUGH THE REGION MONDAY MORNING...AND MIGHT PROVIDE ENOUGH
FORCING FOR A FEW ISOLATED SHOWERS...BUT WITH THE AIRMASS PROGGED TO
BE QUITE DRY...WILL KEEP POPS OUT OF THE FORECAST FOR NOW.
COLD HIGH PRESSURE BUILDS IN ACROSS THE REGION ON MONDAY AFTERNOON
AND REMAINS IN PLACE UNTIL WEDNESDAY MORNING. BOTH THE 25/00Z EURO
AND GFS SHOW A GULF LOW DEVELOPING ALONG THE TEXAS COAST ON
WEDNESDAY AFTERNOON...THOUGH THE MODELS DIFFER ON THE TRACK AND
SPEED OF THIS FEATURE...WITH THE GFS BEING THE SLOWER OF THE TWO.
WITH THE GFS GENERALLY BEING A LITTLE FASTER IN THE DAY 5 PERIOD AND
BEYOND...WILL TREND THE GFS SOLUTION A LITTLE CLOSER TO THE EURO
PROG...BUT FAVOR A STORM TRACK SLIGHTLY FURTHER SOUTH...WHICH KEEPS
OUR REGION SQUARELY IN THE STABLE CONTINENTAL AIRMASS.
THE EURO IS SHOWING THE POTENTIAL FOR A BIG COOL AIR OUTBREAK BY THE
END OF THE PERIOD AND EXTENDING INTO THE WEEKEND. THE GFS GENERALLY
VECTORS THE MUCH COOLER AIR INTO THE MID ATLANTIC. DUE TO
UNCERTAINTIES AT THESE TIME SCALES...WILL GENERALLY STAY CLOSE TO
SLIGHTLY BELOW CLIMO VALUES...BUT IF FUTURE MODEL RUNS TREND TOWARD
THE EURO SOLUTION...TEMPERATURE FORECASTS FOR FRIDAY AND BEYOND WILL
NEED TO BE LOWERED SEVERAL DEGREES.
&&
.AVIATION...HIGH PRESSURE WILL BUILD OVER THE SE US INTO THE
WEEKEND BRINGING CLEARING SKIES AND WEAKER LOW LEVEL WINDS. VFR
CONDITIONS WILL BE THE RULE AFTER RESIDUAL CLOUDINESS ERODES DURING
THIS AFTERNOON AND EVENING. CRITICAL RELATIVE HUMIDITIES COULD BE
POSSIBLE NEXT TUESDAY.
&&
.MARINE...WINDS ARE WESTERLY TO WEST NORTHWEST THIS AFTERNOON WITH
REPORTED WINDSPEEDS AROUND 20 KNOTS WITH HIGHER GUSTS. SEAS ARE
RUNNING BETWEEN 6 AND 8 FEET. WINDS ARE FORECAST TO WEAKEN SLIGHTLY
OVERNIGHT AND VEER TO THE NORTHWEST TONIGHT AND NORTHEAST TOMORROW
AFTERNOON. WILL ALLOW THE SCA TO EXPIRE THIS EVENING FOR OUR
EASTERN LEGS WHILE THE REMAINING SCA SHOULD EXPIRE TOMORROW MORNING.
WITH HIGH PRESSURE BUILDING IN...DO NOT EXPECT ANY ADVISORY
CONDITIONS UNTIL EARLY NEXT WEEK.
&&
.FIRE WEATHER...HAVE GONE AHEAD AND ISSUED A FIRE WEATHER WATCH
FOR ALL OUR FLORIDA ZONES FOR SATURDAY. RIGHT NOW...IT APPEARS THAT
WE COULD SEE 3 HOURS OF CRITICAL RELATIVE HUMIDITIES. SO..IT IS
JUST TOO CLOSE TO CALL ON A RED FLAG WARNING. FOR SUNDAY...
DEWPOINTS WILL SUFFICIENTLY RECOVER SO AS RELATIVE HUMIDITIES WILL
NOT REACH CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 35 54 34 55 34 / 10 10 10 30 20
PANAMA CITY 36 54 40 56 38 / 10 10 20 40 20
DOTHAN 31 52 35 56 34 / 10 10 20 30 10
ALBANY 32 54 36 56 32 / 10 10 10 20 10
VALDOSTA 37 57 33 55 36 / 10 10 10 20 20
CROSS CITY 36 61 38 58 38 / 10 10 10 20 20
APALACHICOLA 38 54 40 54 42 / 10 10 10 40 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
BAY...CALHOUN...COASTAL WALTON...DIXIE...FRANKLIN...
GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON...
JEFFERSON...LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR...
WAKULLA...WASHINGTON.
HIGH SURF ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: BAY...COASTAL WALTON...GULF.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM OCHLOCKONEE RIVER TO
APALACHICOLA FL OUT TO 20 NM...COASTAL WATERS FROM
APALACHICOLA TO DESTIN FL OUT 20 NM...WATERS FROM SUWANNEE
RIVER TO APALACHICOLA FL FROM 20 TO 60 NM...WATERS FROM
APALACHICOLA TO DESTIN FL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR THE
FOLLOWING ZONES: APALACHEE BAY OR COASTAL WATERS FROM
KEATON BEACH TO OCHLOCKONEE RIVER FL OUT TO 20 NM...COASTAL
WATERS FROM SUWANNEE RIVER TO KEATON BEACH OUT 20 NM.
&&
$$
AVIATION/FIRE WEATHER...GOREE
LONG TERM...GODSEY
REST OF DISCUSSION...WATSON
