

000 

WWUS20 KWNS 131758

SEL1

SPC WW 131758

FLZ000-CWZ000-140000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 21

NWS STORM PREDICTION CENTER NORMAN OK

1255 PM EST TUE FEB 13 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL FLORIDA

       COASTAL WATERS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL

700 PM EST.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES EITHER SIDE OF A LINE FROM 20 MILES NORTH OF OCALA

FLORIDA TO 50 MILES EAST OF FORT MEYERS FLORIDA.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU1).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 20...



DISCUSSION...TSTM CLUSTER OFF THE W CST OF FL...AND ADDITIONAL

STORMS LIKELY TO FROM IN HEATED ENVIRONMENT OVER THE INTERIOR...MAY

POSE A THREAT FOR HIGH WIND AND HAIL AS REGION CONTINUES TO

DESTABLIZE DOWNSTREAM FROM 50 KT WLY MID LEVEL JET STREAK.  WHILE

LOW LEVEL SHEAR IS WEAK OVER MOST OF WW AREA...LOW LEVEL DIRECTIONAL

SHEAR WILL BE ENHANCED INVOF E CST SEA BREEZE BOUNDARY AND OUTFLOWS

FROM EARLIER STORMS.  PART OF WATCH NUMBER 21 ALONG THE IMMEDIATE E

CST MAY REQUIRE UPGRADE TO TORNADO IF IT APPEARS THAT DISCRETE

STORMS WILL INDEED INTERACT WITH THOSE BOUNDARIES.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 26035.





...CORFIDI

