National Weather Service Weather Forecast Office

Area Forecast Discussion

000
FXUS62 KJAX 221430
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
930 AM EST SUN NOV 22 2009

...POSSIBILITY OF ISOLATED STRONG STORMS...

.UPDATE...A WARM FRONT STRETCHES NE-SW ACROSS OUR N FL ZONES WITH A
BROADENING SURFACE LOW NEAR THE MS/AL GULF COAST. A SURFACE HIGH
PRESSURE WEDGE CONTINUES DOWN THE SE ATLANTIC SEABOARD WITH COOL ENE
FLOW ACROSS OUR GA ZONES (TEMPS & DEW PTS IN THE LOW/MID
60S)...WHILE SOUTH OF THE WARM FRONT ACROSS OUR FL ZONES WARM AIR
ADVECTION HAS RAISED TEMPS AND DEW PTS INTO THE MID/UPR 60S AT MOST
LOCATIONS. CONVECTION HAS IMPACTED MOST OF OUR GA CWA THIS MORNING
WITH A BAND OF RAIN STRETCHING INLAND FROM THE GOMEX ACROSS OUR FL
ZONES FROM GNV TOWARD NIP. HAD AN ELEVATED STORM LAST HOUR WITH
DECENT MID LEVEL REFLECTIVITIES AND INBOUND VELOCITIES ACROSS WAYNE
AND INLAND GLYNN COUNTIES...BUT IT HAS LIFTED NE OUT OF OUR CWA.
WILL CONTINUE TO MONITOR PERSISTENT SUPERCELL IN THE GOMEX AND
POSSIBLE POP-UP TS THROUGH THE MORNING...BUT INITIAL FEELING IS THAT
THERE CONTINUES TO BE LIMITED SFC BASED INSTABILITY...THUS LIMITING
SVR WX POTENTIAL THROUGH EARLY AFTN.

FORECAST CHALLENGE WILL CONTINUE TO BE THE BATTLE BETWEEN THE WEDGE
AND THE WARM FRONT. WILL CONTINUE TO LEAN TOWARD THE NAM12 WHICH DID
A GOOD JOB YESTERDAY POSITIONING THE WARM FRONT ACROSS N FL THIS
MORNING. THIS AFTN THE BOUNDARY MAY SHIFT SLIGHTLY FARTHER N...BUT
IT WILL BE WEAKENING AND LIKELY NOT MOVE MUCH FARTHER N THAN THE
FL-GA STATELINE. IF SOME INSOLATION CAN OCCUR ALONG AND SOUTH OF THE
WARM FRONT TODAY ACROSS NE FL...THERE REMAINS THE POSSIBILITY OF
ISOLATED SEVERE STORMS DUE TO MODEST SFC BASED CAPES AROUND
1000-1200 J/KG AND SRH VALUES OF 150-200 M2/S2. SO...ALTHOUGH THREAT
OF SVR WX IS LOW...IT WILL EXIST THIS AFTN UNTIL FRONTAL INVERSION
DEVELOPS AS LOW PRESSURE RE-DEVELOPS OFFSHORE OF THE SE ATLANTIC
COAST THIS EVENING. WILL CONTINUE TO HEADLINE SVR WX POSSIBILITY IN THE
HWO.

&&

.AVIATION...SHOWERS ARE CURRENTLY EXPANDING ACROSS THE AREA...WITH
RAIN-COOLED ENVIRONMENT YIELDING LOWERING CEILINGS...WITH CEILING
HEIGHTS MAINLY BETWEEN 2500 AND 4000 FEET AS OF 9 AM EST. THE
EXCEPTION IS AT KSSI WHERE CEILINGS ARE AROUND 1000 FEET AGL AS
STRONG NORTHEAST WEDGE CONTINUES TO IMPACT THE SOUTHEAST GEORGIA
COAST. A WARM FRONT CURRENTLY RESIDES NEAR THE STATE LINE AS THIS
FEATURE IN CONCERT WITH INCREASING ENERGY WITH APPROACHING LOW
PRESSURE SYSTEM WILL LIKELY PROMOTE EVEN LOWER CEILINGS DURING THE
COURSE OF THE DAY AND HAVE INCLUDED MVFR/IFR CONDITIONS FOR THIS TAF
CYCLE. ADDITIONALLY...CANNOT RULE OUT ISOLATED THUNDERSTORMS
TODAY.

&&

.MARINE...NORTHEAST WEDGE REMAINS STRONG ACROSS THE SOUTHEAST
GEORGIA COASTAL WATERS WITH BUOY 41008 RESORTING 21G27KT. A SURFACE
WARM FRONT CURRENTLY RESIDES NEAR THE STATE LINE...WITH BUOY 41012
REPORTING SOUTHEAST WINDS 15 KNOTS. THIS FRONTAL BOUNDARY WILL
CONTINUE TO ADVANCE SLOWLY NORTHWARD THE BALANCE OF TODAY...WITH AN
OPEN WAVE/SURFACE LOW FORECAST TO DEVELOP OVER THE SOUTHEAST U.S.
ATLANTIC WATERS...ALONG AFOREMENTIONED FRONTAL BOUNDARY. WILL
CONTINUE TO SEGMENT NEARSHORE/OFFSHORE LEGS AS WELL AS SEGMENTING
FL/GA MARINE ZONES DUE TO VARIABLE WIND DIRECTION/WIND SPEED.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  59  48  64  47 /  90  30  10  10
SSI  65  57  68  52 /  70  50  10  10
JAX  69  57  75  51 /  70  50  10  10
SGJ  75  64  76  57 /  50  50  10  10
GNV  77  59  78  53 /  60  50  10  10
OCF  79  61  79  55 /  60  50  20  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

$$

ENYEDI/ZAPPE/WALKER