Severe Thunderstorm Warning 294, NWS Jacksonville, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
210 PM EDT SUN SEP 3 2000

ZONES...WELL THE STAGE IS SET FOR AN INSTANT REPEAT OF LAST EVENING
WITH SHWRS/TSTMS ERUPTING IN CLUSTERS/WAVES AND MOVING ARND THE
UPR TROF FROM SSW TO NNE. WITH A RELATIVELY MOIST SOUNDING...PW'S
OF 1.75-2 INCHES...A COLD H5 THERMAL TROF...AND CAPES IN THE 2400-
2600 J/KG RANGE ( BASED ON MESO-ETA MODEL SOUNDINGS) THIS LOOKS TO BE
A SAFE BET. WE'VE CERTAINLY SEEN ENOUGH OF THE SUNSHINE TO
DESTABILIZE THE ATMOSPHERE OVER THE FA AND THOSE CAPES ARE A LIKELY A
BIT LOW RIGHT NOW. ISOLATED STORMS COULD BE STRONG.

THE MODELS ARE ALL BASICLY IN GOOD AGREEMENT CONTINUING TO OPEN UP
THE UPR LOW AND DROP THE COMPLEX SWWD INTO THE NE GULF. STILL LIKE
THE ETA/MESO-ETA MOISTURE FIELDS OVER NGM/AVN AND WILL GO WITH A
PERSISTENCE FORECAST DROPPING THE PCPN BACK INTO THE NE GULF/SWRN
ZONES OVERNIGHT AND THEN RETURN THE PCPN ACROSS THE BALANCE OF THE FA
TOMORROW AFTN. WITH THE S-SW DEEP LEVEL FLOW CONTINUING ON MONDAY
SUSPECT WE'LL SEE THE SAME PATTERN WHERE THE NOCTURNAL STORMS MOVE
INLAND TO TRAIL RIDGE/LAKE CITY/LIVE OAK DURING THE EARLY AM HOURS
...WE GET A LULL FROM 10-11 AM THROUGH EARLY AFTN AND THEN ALL HECK
BREAKS LOOSE MID AFTN-EVE. EAST COAST WILL LIKELY SEE A BIT LESS
COVERAGE AS THE TRAJ OF MOISTURE SURGE SHOULD BE MORE TWD INTERIOR SE
GA. WILL DROP EAST COAST POPS BACK TO 40 PCNT TMRW. MONDAY NIGHT IS A
BIT MORE INTERESTING AS THE SFC TROF MIGRATES BACK OVER THE FA. DON'T
LIKE AVN'S LOW OVER THE AQQ AREA...PREFERRING THE MORE SWRLY PSN OF
ETA/MESO-ETA/NOGAPS/COAMPS. ALL OF THE MODELS DO SPORT A TROF
ACROSS THE REGION...THEREFORE WILL HOLD THE POPS OPEN ALL NIGHT FOR
ALL OF THE ZONES AND LET FUTURE SHIFTS ADJUST THIS IF NECESSARY.
TUESDAY WE'LL BE LOOKING FOR THE APPROACH OF A STRONG COLD FRONT AND
WILL GO WITH A GOOD CHNC MOST AREAS. PERSISTENCE TEMPS WILL BE BEST
THRU THE FORECAST PD.

MARINE...WILL DECREASE THE NEAR SHORE WINDS TO NEAR 15 KTS AND
WILL KEEP WINDS OFFSHORE WINDS 15 TO 20 KTS OVERNIGHT. WILL GIVE
THE DEVIL HIS AND GO WITH THE AVN GUID AS THAT MODEL DOES SEEM TO
PICK UP ON THE NOCTURNAL WIND SURGE BETTER THAN MESO-ETA. ALL OF THE
MODELS DROP THE WINDS ON LABOR DAY AND WILL DO SO WITH 10 KNOTS
NEAR SHORE AND 10-15 OFFSHORE. LOOK FOR AN REPEAT OF TONIGHT'S
FORECAST FOR MONDAY NIGHT...FOR THE SAME REASONS.

EXTENDED...ALL OF THE MEDIUM RANGE MODELS...NOGAPS...ECMWF...UKMET
AND MRF ARE BUILDING A 1028+ MB HIGH OVER NEW ENGLAND TUE-THU WITH A
WEDGE EXTENDING DOWN THE COAST. LIKE I SAID YDA...DON'T REALLY CARE
WHAT HAPPENS WITH ERNESTO...GULF LOWS OR ANY POTENTIAL LOW DVLPMNT
OVER THE WRN ATLC/BAHAMAS AS THEY AREN'T THE MAIN PLAYERS AT THIS
POINT THE WEDGE IS. EXPECT A STRONG WEDGE/"LOCAL NORTHEASTER" TO
BUILD IN TUESDAY NIGHT THROUGH THURSDAY WITH SCA CONDITIONS...SPEED
CONVERGENT BANDS OF CONVECTION DEVELOPING OVER THE COASTAL WATERS AND
MOVING INLAND OVER XTRM SE GA AND N FL. AS WITH MOST WARM SEASON
"NORTHEASTERS" THE COASTAL RAINFALL WILL LIKELY BE WIDELY
SCATTERED...BUT WILL INCREASE IN AERIAL COVERAGE BEYOND 10 MILES
INLAND AS THE POTENT SEPT SUN PROVIDES PLENTY OF SFC HEATING AND
DESTABLIZATION OF THE LLVL AIR MASS. DUE TO THE WARM SST'S (82+) OVER
THE COASTAL WATERS/GULF STREAM WILL INCREASE MIN TEMPS OVER THE MODEL
GUID AND INDICATE A RANGE OF TEMPS FOR THE COASTAL COUNTIES. A 350
MILE LONG FETCH SHOULD ALLOW FOR A FULLY ARISEN SEA AND POSSIBLY
SOME...MINOR...PROBLEMS ALONG THE IMMD COAST...BUT THIS REMAINS TO BE
SEEN. WILL CALL'EM LIKE I SEE'EM AND WILL WRITE THE EXTENDED PORTIONS
OF THE FORECASTS WITH THE ABOVE IN MIND.

PRELIM

AMG 72/85/73/86 4545
SSI 75/85/75/85 3435
JAX 74/88/75/89 3435
GNV 74/88/74/89 4535 05

.JAX...
.FL...NONE.
.GA...NONE.

SANDRIK