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785 

WWUS20 KWNS 181819

SEL7

SPC WW 181819

FLZ000-CWZ000-190200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 867

NWS STORM PREDICTION CENTER NORMAN OK

220 PM EDT TUE OCT 18 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTH FLORIDA

       COASTAL WATERS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 220 PM UNTIL

1000 PM EDT.



TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES NORTHEAST OF FORT

MEYERS FLORIDA TO 50 MILES EAST SOUTHEAST OF MARATHON FLORIDA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



DISCUSSION...A LINE OF INTENSE THUNDERSTORMS OFF THE SOUTHWEST COAST

OF FL WILL MOVE EASTWARD AND INLAND THIS AFTERNOON.  HIGH THETA-E

VALUES AND MODERATE CAPE...COMBINED WITH SUFFICIENT AND INCREASING

LOW LEVEL WIND FIELDS WILL PROMOTE SUPERCELL STRUCTURES CAPABLE OF

DAMAGING WINDS AND ISOLATED TORNADOES.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 24030.





...HART

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