000
FXUS62 KTAE 171826
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
220 PM EDT WED MAR 17 2010

.SYNOPSIS...
AT 2 PM EDT...SKIES WERE CLOUDY ACROSS THE REGION. LOCAL RADARS
SHOWED WIDESPREAD LIGHT RAIN EAST OF THE APALACHICOLA RIVER DOWN TO
SPRINKLES/DRIZZLE WEST OF THE RIVER. TEMPS RANGED FROM AROUND 50
SE ALA TO MID 50S ELSEWHERE. WINDS WERE GENERALLY N/NW 5-10 MPH.

AT UPPER LEVELS...
THE LARGE SCALE CONUS PATTERN REMAINS AMPLIFIED HIGHLIGHTED BY A
TROUGH ACROSS EXTREME ERN PAC...A RIDGE OVER WRN HALF OF CONUS WITH
AXIS FROM DAKOTAS SWWD TO DESERT SW...AND TROUGHINESS ACROSS EASTERN
HALF OF CONUS. THIS INCLUDES A 556MB LOW NE OK BORDER AND AN
UPPER TROUGH OVER GULF OF MEX WITH A WEAK H5 558MB LOW CONTINUING TO
ROTATE ALONG N FL COAST.

WATER VAPOR LOOP SHOWED ABUNDANT MID AND UPPER LEVEL MOISTURE ON THE
N PERIPHERY OF FL LOW. SEVERAL SHORTWAVES/H5 TROUGHS ARE ROTATING
AROUND BOTH LOWS CONTRIBUTING TO A BROAD REGION OF LOWER HEIGHTS
DOWN INTO THE GULF COAST STATES. LOOKING SOUTH...SBTRPCL JET
CONTINUES TO ADVECT MOISTURE FROM THE PACIFIC NEWD TO CNTRL FLA. SO
DRIEST AIR CONTINUES TO BE THAT WRAPPING S OF GULF LOW...NORTH OF
SBTRPCL JET AND SOUTH OF SHORTWAVES.

THE FIRST SHORT WAVE WILL MOVE THROUGH OUR AREA REST OF THIS
AFTN/EVE SHUNTING UPPER TROUGH EWD TO ERN SEABOARD. THIS WILL
PROVIDE MODEST DIVERGENCE AND LIGHT RAIN OR SPRINKLES TAPERING
OFF FROM WEST TO EAST THIS EVE AS THE SHORT WAVES MOVE TO OUR EAST.
THE NEXT SHORTWAVE MOVES INTO THE NORTHERN GULF TONIGHT AND BEGIN TO
PHASE WITH THE DEPARTING SHORTWAVE OVER THE EXTREME ERN FL. AS THESE
LOWS ARE NEARLY CUT OFF FROM THE N JET...THIS PHASING WILL BE A SLOW
PROCESS WITH TROUGH/LOW NOT OFF THE EAST COAST UNTIL LATE TONIGHT
WHERE IT INTERACTS WITH WARM GULF WATERS TO DEVELOP SOME TSTMS.
THUS...THE GUIDANCE INDICATES THAT THERE WILL BE ENOUGH DEEP LAYER
MOISTURE REMAINING INTO EARLY THURSDAY FOR A SMALL CHANCE OF SHOWERS
SPRINKLES OR DRIZZLE MAINLY NE TIER GA COUNTIES.

ON THURS...SHORTWAVE DIGS SEWD FROM PAC NW INTO GREAT BASIN. WRN
RIDGE SHUNTED EWD AND ERN UPPER TROF LIFTS OUT ALLOWING MID LEVEL
HEIGHT RISES TO PUSH EASTWARD ACROSS THE NRN GULF. EXPECT CLEARING
AND WARMING FRIDAY INTO EARLY SATURDAY. THE RIDGE ADVANCES QUICKLY
EASTWARD OFF THE EAST COAST ON SATURDAY WHILE THE NEXT STORM SYSTEM
DEVELOPS OVER THE SRN PLAINS. THIS SETS UP A RETURN FLOW PATTERN OFF
THE GULF BY LATE SAT ALLOWING FOR A MODEST INCREASE IN DEEP LAYER
MOISTURE OVERNIGHT SAT AND THRU SUN. ALL INDICATIONS ARE THAT THIS
WILL NOT BE A MAJOR WX NOR RAIN PRODUCER. THIS IS REFLECTED IN MODEL
SOUNDINGS. I.E. GFS TAE WITH 0.91 INCH PWAT AT 18Z WED...HOVERING
AROUND .07 AND .08 INCHES THRU 06Z FRI BEFORE SLOWLY DECREASING TO
1/2 INCH RANGE THRU SAT EVE BEFORE INCHING UP AGAIN INTO SUN.

AT LOWER LEVELS...
ANALYSIS SHOWED A TROUGH/DIFFUSE LOW EXTENDING FROM SRN GA THROUGH
THE FL BIG BEND. THE COMBINATION OF ABOVE PASSING SHORTWAVE AND THIS
TROUGH WAS PRODUCING INCREASING ISENTROPIC INDUCED MAINLY LIGHT
RAIN. THIS TROUGH WILL MOVE SLOWLY EWD BY TONIGHT HELPING TO DRAG IN
SOME DRIER AIR INTO THE LOWER LEVELS. STILL THE PASSING SHORTWAVE
WILL ALLOW FOR SMALL CHANCE OF RAIN TONIGHT DECREASING FROM W-E. BY
TOMORROW...RIDGING WILL BE PROMINENT ACROSS MUCH OF THE GULF OF
MEXICO.

A FAIRLY DEEP LOW IS PROGGED TO MIGRATE SSE THROUGH THE SRN PLAINS
ON FRIDAY PUSHING THE RIDGE EASTWARD TOWARD THE ATLANTIC. AS THIS
OCCURS...A BROADENING BELT OF MODESTLY STRONG SOUTHERLY FLOW WILL
DEVELOP OFF THE GULF OF MEXICO. HOWEVER...A RELATIVELY DRY BOUNDARY
LAYER OVER THE GULF OF MEXICO WILL TAKE TIME TO MODIFY AND THE LACK
OF A RETURN FLOW WILL SUPPRESS ANY CHANCES OF LOCAL RAIN UNTIL
ASSOCD COLD FRONT IS DRAGGED ESE ACROSS LOCAL AREA ON SUNDAY.

.SHORT TERM...TONIGHT THROUGH SATURDAY
TONIGHT...WITH THE LOW LEVEL TROUGH AND UPPER SHORTWAVES ACROSS
LOCAL REGION...EXPECT CLOUDY ALL NIGHT. LINGERING LIGHT RAIN/
SPRINKLES RAIN DECREASING FROM SW-NE. PER WRF4KM AND RUC...GREATEST
COVERAGE AND BEST CHANCE FOR RAIN IS 00Z-05Z AND ACROSS NE TIER GA
COUNTIES. WILL GO WITH A 20-40 PCT SW-NE POP GRADIENT TONIGHT.
EXPECT DRIZZLE OR SPRINKLES ACROSS MUCH OF BIG BEND AND AND S/CNTRL
GA AND WILL INCLUDE IN GRIDS. TEMPS TONIGHT WILL BE IN THE LOW-MID
40S. LOW STRATUS A GOOD BET TONIGHT ESPECIALLY EAST OF THE
APALACHICOLA RIVER. DESPITE ABUNDANT CLOUD COVER...LINGERING
MOISTURE SHOULD CONTRIBUTE TO AREAS OF FOG ESPECIALLY OVER GA ZONES
LATE TONIGHT. THIS REFLECTED IN SREF PROGS.

THURSDAY...AOB 20 PCT POPS. UNDER CLOUDY SKIES...HIGHS LOW-MID 60S.
LOWS FROM LOW 40S NORTH TO UPPER 40S COAST.

FRIDAY...NO POPS. UNDER MOSTLY SUNNY SKIES...MAX TEMPS RISE TO NEAR
70 COAST TO MID 70S INLAND.

SATURDAY...NO POPS. HIGHS FROM LOW 70S SE ALA TO MID 70S ERN
COUNTIES.

.LONG TERM...
SATURDAY NIGHT THROUGH NEXT WEDNESDAY AT THE START OF THE
PERIOD...THE DEEP LAYER RIDGING WILL BE EAST OF THE AREA. THE NEXT
UPPER TROF AND ASSOCIATED COLD FRONT WILL APPROACH AND MOVE THROUGH
SUNDAY. THE LATEST GFS AND 16/12Z EURO CONTINUE TO SHOW SOME
DIFFERENCES IN THE STRENGTH AND POSITION OF SURFACE AND UPPER LEVEL
FEATURES. BOTH SHOW A CLOSED UPPER LOW OVER SOUTHEAST MISSOURI AT
12Z SUNDAY WITH THE EURO SLIGHTLY STRONGER. DURING THIS SAME TIME
THE STRONGER SURFACE LOW OF THE EURO IS OVER CENTRAL ILLINOIS WHILE
THE GFS IS OVER SOUTHERN INDIANA. DESPITE THE GFS SURFACE LOW
POSITION BEING FURTHER EAST...THE SOUTHWARD EXTENDING COLD FRONT
CONTINUES TO LAG BY ABOUT 6 HOURS BEHIND THE EURO AS IS IT SWEEPS
FROM WEST TO EAST ACROSS OUR CWA SUNDAY. THE EURO BRINGS THE FRONT
ACROSS THE AREA SUNDAY MORNING WITH THE FRONT EAST OF OUR ZONES BY
18Z...WHILE THE GFS SHOWS THE FROPA ENTERING OUR GA AND FLORIDA BIG
BEND ZONES AT 18Z. WILL CONTINUE TO LEAN TOWARD THE SLOWER GFS AND
SHOW POPS IN THE UPPER CHANCE RANGE FOR ALL ZONES SUNDAY WITH
LINGERING SLIGHT POPS FOR MOST ZONES IN THE EVENING. SURFACE HIGH
PRESSURE AND A MUCH DRIER AIRMASS BUILD IN BEHIND THE FRONT MONDAY
INTO TUESDAY. ON WEDNESDAY THE HIGH SHIFTS EAST MAKING WAY FOR THE
NEXT COLD FRONT SLATED TO ARRIVE JUST AFTER THIS EXTENDED RANGE.
TEMPERATURES WILL BE NEAR OR JUST UNDER SEASONAL LEVELS THROUGH MOST
OF THE PERIOD. THE AVERAGE HIGH TEMPERATURE FOR MID TO LATE MARCH IS
IN THE MID 70S WITH AVERAGE MIN TEMPS IN THE MID TO UPPER 40S.

.AVIATION...LIGHT TO MODERATE SHOWER ACTIVITY CONTINUES ACROSS THE
MAJORITY OF THE CWA AFFECTING ALL TERMINALS. LATEST RADAR IMAGERY
SHOWS THE SHIELD OF RAIN HAS BEGUN LIFTING OFF TO THE NORTH AND
EAST. THIS TREND IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON WITH
RAIN EVENTUALLY TAPERING OFF FROM WEST TO EAST INTO THE EVENING.
SHOWERS MAY CAUSE VSBYS TO DROP TO MVFR/IFR LEVELS BEFORE ENDING.
RAINFALL HAS MOISTENED THE LOW LEVELS ALLOWING FOR THE FORMATION OF
LOW STRATUS OVER MUCH OF THE REGION. LIFR/IFR CIGS ARE IN PROGRESS
OVER ALL TERMINALS BUT VLD. CIGS WILL REMAIN IN THE MVFR/IFR AND
OCCASIONAL LIFR RANGE OVERNIGHT. IN ADDITION TO LOW CIGS...FOG WILL
BE LIKELY AT DHN...ABY...TLH AND VLD. FOG MAY DROP VSBYS TO IFR/LIFR
LEVELS. FOG WILL LIFT BY MID MORNING THURSDAY WITH A CHANCE OF
SHOWERS AGAIN THURSDAY AFTERNOON AND SUBSTANTIAL MID-LEVEL
CLOUDINESS.

.MARINE...
OFFSHORE WINDS WILL REMAIN MODERATE THRU TONIGHT...BUT THEN SUBSIDE
THURSDAY AND FRIDAY AS THE PRESSURE GRADIENT WEAKENS. FOR
TONIGHT...WILL GO WITH NW 10 TO 15 KNOTS WITH SEAS UP TO 4 FEET
OFFSHORE. WINDS WILL SUBSIDE THURS AND FRI AS HIGH PRESSURE BUILDS
EAST ACROSS THE NRN GULF REGION. WINDS WILL VEER TO ONSHORE AND
BEGIN TO INCREASE ON SAT AHEAD OF NEXT FRONT. THIS FRONT WILL CROSS
ON SUNDAY WITH WINDS INCREASING AND VEERING TO WEST AND THEN NW AND
MAY APPROACH OR REACH ADVISORY LEVELS.

.FIRE WX...NO CONCERNS THROUGH THURSDAY. AIRMASS WILL SUFFICIENTLY
DRY OUT ON FRIDAY AFTN THAT SEVERAL HOURS BELOW 35 PERCENT RELATIVE
HUMIDITY ARE POSSIBLE ACROSS INLAND FL. HOWEVER...AT THIS TIME
DURATIONS ARE NOT EXPECTED. WILL MENTION SAME IN REMARKS SECTION.

.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE   44  65  43  74  44/  30  30  10  0  0
PANAMA CITY   49  62  49  67  48/  20  20  10  0  0
DOTHAN        44  64  44  74  46/  30  20  10  0  0
ALBANY        42  65  43  75  45/  30  20  10  0  0
VALDOSTA      43  64  43  74  43/  40  20  10  0  0
CROSS CITY    45  65  42  73  45/  30  20  10  0  0
APALACHICOLA  48  61  48  69  47/  20  20  10  0  0

.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...NONE.
GM...NONE.

BLOCK/AUSTIN