

182 

WWUS20 KWNS 231832

SEL9

SPC WW 231832

FLZ000-CWZ000-240100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 499

NWS STORM PREDICTION CENTER NORMAN OK

235 PM EDT TUE JUN 23 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FLORIDA

       COASTAL WATERS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

900 PM EDT.



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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTHEAST OF

OCALA FLORIDA TO 55 MILES SOUTH OF MIAMI FLORIDA.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU9).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

SEVERE THUNDERSTORM WATCH NUMBER 495. WATCH NUMBER 495 WILL NOT

BE IN EFFECT AFTER 235 PM EDT. CONTINUE...WW 496...WW 497...WW

498...



DISCUSSION...SEASONABLY STRONG NLY FLOW ALOFT WILL CONTINUE ACROSS

FL THIS AFTERNOON/EVENING AS DEEP MID LEVEL TROUGH DIGS OFF THE NERN

FL COAST.  AIR MASS REMAINS VERY UNSTABLE...DESPITE EARLIER LINEAR

MCS...WITH SUFFICIENT SHEAR FOR ORGANIZATION INTO LINES/CLUSTERS AND

PERHAPS A BRIEF SUPERCELL OR TWO.  DAMAGING WINDS AND ISOLATED LARGE

HAIL WILL REMAIN PRIMARY THREATS...ALTHOUGH A BRIEF

WATERSPOUT/TORNADO COULD ACCOMPANY STORMS ALONG RESIDUAL SURFACE

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 500. MEAN STORM

MOTION VECTOR 33030.





...EVANS

