Severe Thunderstorm Warning 35, NWS Jacksonville, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
247 AM EST THU MAR 13 2003

CURRENTLY...WATER VAPOR IMAGERY SHOWS INCREASING MID AND UPPER LEVEL
MOISTURE ACROSS THE CWA...DOWNSTREAM FROM AN AREA OF SHOWERS AND
THUNDERSTORMS AFFECTING THE GULF COAST FROM MS TO FL PANHANDLE AND
SWRN GA. ISOLD SHOWERS SHOULD MOVE INTO GA COUNTIES IN NEXT FEW HRS
AND ALREADY SEEING ISOLD SHOWERS FORM IN ERN MARION CO. MID-UPPER
TROUGH LOCATED FROM GREAT LAKES TO TX RESULTING IN WEAK TO MODERATE
DIVERGENCE ALOFT OVER THE SE STATES. ONE SHORTWAVE WAS LOCATED NEAR
SRN MS/AL AREA AND ANOTHER ONE OVER SE TX. AT SFC...SFC RIDGING FROM
ATLC TO SRN GA WITH A DIFFUSE WARM FRONT BOUNDARY ORIENTED NW TO SE
OVER N CENTRAL FL. TEMPS WERE MAINLY IN THE MID 60S TO AROUND 70 AT
OCF WITH DEWPOINTS IN THE LOWER 60S. PWATS NOTED FROM GPS DATA
AROUND 1.3-1.4 INCHES FOR GNV AND JAX.

TODAY...MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT THAN YESTERDAY
WITH REGARD TO POPS AND TEMPS TODAY. ALL GUIDANCE PLACES HIGHEST
QPFS IN CENTRAL AND ERN GA AS SHORTWAVE TROUGH MOVES THROUGH THAT
AREA IN THE MORNING AND EARLY AVN. AVN STILL SEEMS QUITE HIGH WITH
RAINFALL AND LIKELY SUFFERING FROM CONVECTIVE FEEDBACK.
NONETHELESS...RELATIVELY STRONG UVV ASSOCD WITH PVA AND LI ABOUT -3
TO -5 WITH SBCAPES ON THE ORDER OF 1000-1500 J/KG ARGUES FOR LIKELY
POPS OVER SE GA AND STILL CHANCE POPS IN WEAKER UVV FIELD OVER NE
FL. SHOULD SEE A LATER DEVELOPMENT THAN YESTERDAY OF ATLC SEA BREEZE
DUE TO WLY LOW LVL WIND COMPONENT. THIS MAY KICK OFF A FEW SHOWERS
AND STORMS OVER COASTAL AREAS BY LATE AFTN.

TONIGHT...FRONTAL BOUNDARY OVER TN VALLEY CONTS PRESSING SWD
OVERNIGHT AND FIRST SHORTWAVE WILL BE WELL E OF THE AREA. WILL ONLY
GO WITH SLIGHT POPS AT MOST. MODELS CONT TO HAVE PROBLEMS WITH
TIMING SECOND SHORTWAVE WAVE MOVING ACROSS THE CENTRAL GULF COAST.

FRI-FRI NIGHT...ETA AND GFS DEVELOP LOW PRES CENTER OVER SRN AL
ALONG COLD FRONT FRI MORNING...SUPPORTED BY SHORTWAVE OVER MS. FRONT
BECOMES STNRY OVER SRN GA AND EWD INTO ATLC. MID AND UPPER LEVEL LOW
APPEARS TO BECOME CUT-OFF OVER LOW MS VALLEY WITH A GOOD FETCH OF SW
FLOW AT 500 MB. HIGH PRES RIDGE SETTLES OVER CAROLINAS...WITH MODELS
HINTING AT COOL AIR SURGE AFFECTING THE SE GA COUNTIES BUT GIVEN
FLOW ALOFT THIS SHOULD BE SHORT-LIVED. LOW LEVEL THICKNESSES DROP
KEEPING TEMPS SLIGHTLY COOLER THAN TODAY. DEEP LAYER MOISTURE IN PLACE
WITH PWATS AROUND 1.3 TO 1.6 INCHES.

SAT...GFS APPEARS TO LIFT 5H LOW PRES NE AND WEAKEN WITH SFC HIGH
NEAR NEW ENGLAND WATERS PUSHING FURTHER OFFSHORE OVER ATLC WATERS.
THIS LEAVES NEARLY STNRY FRONTAL BOUNDARY AROUND SRN GA OR N
FL...AGAIN WEAK SFC LOW MAY DEVELOP OVER GA WATERS SAT AND MOVE NE.
WILL CONT CHANCE POPS IN FORECAST.

MARINE...DUE TO PROBABLE CONVECTIVE FEEDBACK PROBLEMS WITH THE GFS...
FEEL THE MODEL IS OVER DEVELOPING A WAVE ACROSS GEORGIA AND INCREASING
THE WINDS TOO MUCH. WILL LEAN TOWARDS WEAKER MESO-ETA GIVEN THAT THE
MODEL HAS A BETTER HANDLE. APPEARS NE SURGE WILL BE SHORT LIVED FRIDAY
NIGHT AND SATURDAY AS HIGH PRESSURE BUILDS FROM NEW ENGLAND TO MID
ATLANTIC...BUT RAPIDLY MOVING EAST RESULTING IN WINDS VEERING.
NO HEADLINES EXPECTED FOR NOW.

FIRE WX...NO CONCERNS.

EXTDD...FRONT BECOMES DIFFUSE WITH LITTLE TO NO SUPPORT ALOFT AND
EVENTUALLY LIFTS NWD. SE TO S WINDS DEVELOP AS A FAIRLY STRONG
FRONT PUSHES INTO CENTRAL U.S. ONLY SLIGHT CHANGES EXPECTED FROM
CURRENT FORECAST.

PRELIM...
AMG   75  59  72  55 /  60  20  60  50
SSI   72  60  71  57 /  60  20  60  50
JAX   80  60  77  58 /  50  20  50  40
SGJ   78  63  75  62 /  40  20  40  40
GNV   82  60  80  58 /  40  20  40  30
OCF   83  61  80  58 /  40  20  40  30

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

PUBLIC...SHASHY
MARINE/FIRE WX...PETERSON

FLZ020>025-030>033-035>038-040-GAZ132>136-149>154-162>166-131700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
600 AM EST THU MAR 13 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST FLORIDA AND SOUTHEAST
GEORGIA.

.DAY ONE...TODAY AND TONIGHT...
...RIVER FLOODING CONTINUES ACROSS THE AREA...

AREA RIVERS WILL CONTINUE ABOVE FLOOD STAGE TODAY AND TONIGHT.
ADDITIONAL RAINFALL OVER PORTIONS OF SOUTHEAST GEORGIA AND NORTHEAST
FLORIDA WILL OCCUR TODAY AND LIKELY AFFECT RIVER LEVELS AGAIN.
PLEASE REFER TO THE LATEST RIVER FLOOD WARNINGS AND STATEMENTS FOR
MORE INFORMATION.

SCATTERED THUNDERSTORMS EXPECTED TODAY. AN ISOLATED STRONG
THUNDERSTORM IS POSSIBLE WITH GUSTY WINDS AND SMALL HAIL.

NO OTHER HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
SCATTERED THUNDERSTORMS ARE EXPECTED FRIDAY AND SATURDAY. THERE IS A
SLIGHT RISK OF SEVERE STORMS ON FRIDAY. A FEW STORMS COULD CONTAIN
STRONG GUSTY WINDS AND HAIL. IN ADDITION...LOCALLY HEAVY RAINFALL
IS POSSIBLE FROM FRIDAY THROUGH SUNDAY.

AREA RIVERS WILL LIKELY CONTINUE AT OR ABOVE FLOOD STAGE THROUGH
THE PERIOD.

NO OTHER HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN
JACKSONVILLE WEBSITE ON THE INTERNET AT WWW.SRH.NOAA.GOV/JAX.

FLZ032-037-131130-

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
604 AM EST THU MAR 13 2003

...STRONG THUNDERSTORMS WILL IMPACT PUTNAM AND CLAY COUNTIES THROUGH
630 AM...

AT 604 AM EST NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CENTERED OVER HOLLISTER...OR ABOUT 5 MILES EAST
OF INTERLACHEN...MOVING NORTH AT 20 MPH. THIS STRONG THUNDERSTORM
WILL ALSO AFFECT AREAS AROUND MANNVILLE...INTERLACHEN...HOLLISTER...
FLORAHOME...CARRAWAY AND BOSTWICK THROUGH 630 AM EST. HAIL UP TO ONE
HALF INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY
WINDS OF 45 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE.

SHASHY

FLZ032-033-131215-

SIGNIFICANT WEATHER ALERT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
639 AM EST THU MAR 13 2003

...STRONG THUNDERSTORMS WILL IMPACT CLAY AND ST JOHNS COUNTIES
THROUGH 715 AM...

AT 639 AM EST NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CENTERED 9 MILES NORTH OF PALATKA MOVING
NORTH AT 20 MPH. THIS THUNDERSTORM MAY PRODUCE SMALL HAIL OVER
SOUTHERN CLAY COUNTY AND SOUTHWEST ST JOHNS COUNTY. EXCESSIVE CLOUD-
TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 MPH CAN BE EXPECTED ALONG
WITH POSSIBLE MINOR DAMAGE.

SHASHY