Severe Thunderstorm Warning 92, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
230 PM EDT SUN AUG 19 2001

DURING THE EARLY AFTERNOON...EARLIER CONVECTION ACROSS NE APALACH
BAY AND SE BIG BEND FIZZLED OUT AS ASSOCD CLOUDS PREVENTED DIURNAL
HEATING FROM GETTING STARTED HERE. CIRRUS SHIELD MOVED NWD ALSO
SERVING TO INHIBIT INLAND ACTIVITY. THUS CLOUDS STRATIFIED IN
MODIFIED AIRMASS AND SEABREEZE CANT SEEM TO GET GOING...ALTHO MAY
DEVELOP ACROSS BIG BEND LATER TODAY. HOWEVER ACROSS PANHANDLE
COAST...WITHIN UNMODIFIED AIR...SEABREEZE DEVELOPED AND UNDER WSW
FLOW SHUD MOVE NNE THRU AFTERNOON. ALSO...SMALL MCS MOVING SE ACROSS
SW ALA AROUND 30 MPH AND WILL REACH WRN SECTIONS OF LOCAL AREA LATER
THIS AFTERNOON AND ER MOST SECTIONS THIS EVENING. GREATEST CONCERN
IS MCS/SEA BREEZE CLASHES. ALTHO WIDESPREAD SEVERE NOT EXPECTED...
ISOLD SEVERE...ESPECIALLY DAMAGING WIND GUSTS REMAINS POSSIBLE. THUS
WILL INSERT EXTRA PERIOD THIS EVENING TO ACCOUNT FOR HIER POPS AND
POTENTIALLY STRONG STORMS AND LOWER POPS FROM W TO E TONIGHT.

MONDAY AND TUESDAY...
THE BIG PIX SHOWS UPPER TROF OVER ERN CONUS AND SURFACE RIDGE OVER
CNTRL FLA. CURRENTLY WEAK COLD FRONT N TENN TO SW MISS APPEARS TO BE
MAKING LITTLE SWD PROGRESS AND LOOKING LESS AND LESS THAT IT WILL
MAKE IT THRU CWFA...AND IF IT DOES MAINLY AS WIND SHIFT LINE AND MON
EVENING (SE ALA/GA) TO EARLY TUES FLORIDA. THUS AT LEAST HALF OF
LOCAL AREA MAY REMAIN IN SW FLW MUCH OF TOMORROW. TYPE 4 OR 5 SEA
BREEZE REGIME (W/SW AROUND 10 MPH) FAVORS MID-HI SCT POPS FOR
FLA...LESS ELSEWHERE. 12Z FWC/MAV/AVN GUIDANCE CONT TO BACK OFF
OVERALL POPS WITH AVN ABOUT 10 PCT HIGHER ACROSS THE BOARD. TLH ETA
MODEL SOUNDING DROPS OFF FROM AROUND 2 INCH PWAT THIS AFTERNOON TO
1.37 BY TUES EVENING. THUS WILL GO ON HIGH SIDE (40-50PCT)  POPS FOR
FLORIDA 2ND PERIOD...LOWER ELSEWHERE. AS FRONT FIZZLES AND HIGH
BUILD SWD INTO LOCAL AREA...1000-700 MB STEERING FLOW BECOMES WNW
AOA 10 MPH (TYPE 9) WHICH FAVORS AOB WDLY SCT POPS. SO FORECAST POPS
DROP OFF TO ISOLD TO WIDELY SCT 4TH PERIOD.

EXTENDED: UPPER TROF LIFTS INTO ATLC REPLACED BY UPPER RIDGE
ALLOWING DRY AIR TO FILTER IN FROM NW TO SE AND PLACE LOCAL AREA IN
BLO NORMAL CLIMO REGIME FOR AT LEAST SEVERAL DAYS. THEN RIDGE
WEAKENS AND RETURN TO NORMAL CLIMO (SCT AFTN CONVECTION) BY
THURSDAY. ALTHO THE ABOVE PATTERN FAVORS CONT TS CHANTAL TRACK AWAY
FROM LOCAL AREA...ITS STILL EARLY AND BOTH LAND AND SEA FORECAST
STILL UNCERTAIN AND DEPENDENT ON FINAL PATH OF CHANTAL.

MARINE: WITH APALACH BAY CONVECTION DYING...WILL REGROUP ALL ZONES
INTO ONE SIZE FITS ALL. WILL ACCOUNT FOR ABOVE MCS BY INTORDUCING
SCT-NMRS CONVECTION THIS EVENING AND LOWERING TO WDLY SCT POPS BY
MIDNIGHT. AFTERNOON BUOYS CONT TREND OF SW AOB 10 KNOTS...SEAS AOB 2
FEET. AS STATED ABOVE...AT THIS MOMEMENT WILL NOT INCREASE
SEAS/WINDS DAY 5 TO ACCOUNT FOR CHANTAL UNTIL I SEE CONTRASTING
EVIDENCE.

FIRE WEATHER...NO HEADLINES.

PRELIMINARY NUMBERS:

TLH 072 092 070 093 5532
PFN 078 089 077 090 3431
DHN 073 092 072 093 2311
ABY 073 091 070 093 232-
VLD 073 092 072 073 5421

.TLH...
AL...NONE.
GA...NONE.
FL...NONE.

BLOCK

ALZ065-066-068-FLZ007>009-192100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
414 PM EDT SUN AUG 19 2001

AT 413 PM EDT(313 PM CDT)...NATIONAL WEATHER SERVICE DOPPLER RADAR
INDICATED A LINE OF STRONG THUNDERSTORMS OVER COVINGTON ALABAMA AND
OKALOOSA COUNTY FLORIDA...MOVING EAST AT 25 MPH.

THESE STORMS ARE CAPABLE OF PRODUCING WIND GUSTS TO 50 MPH...PEA
SIZED HAIL...FREQUENT CLOUD TO GROUND LIGHTNING...AND TORRENTIAL
DOWNPOURS WHICH MAY CAUSE LOCALIZED FLOODING OF STREETS AND LOW
LYING AREAS.

PEOPLE IN WALTON AND HOLMES COUNTIES OF FLORIDA...GENEVA...COFFEE
AND DALE COUNTIES OF SOUTHEAST ALABAMA SHOULD REMAIN ALERT FOR
THREATENING WEATHER THE NEXT 45 MINUTES.

MME