

820 

WWUS20 KWNS 190152

SEL8

SPC WW 190152

FLZ000-CWZ000-191000-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 868

NWS STORM PREDICTION CENTER NORMAN OK

955 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 NIGHT AND WEDNESDAY MORNING FROM 955 PM

UNTIL 600 AM EDT.



TORNADOES...HAIL TO 1 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 65 STATUTE

MILES EAST AND WEST OF A LINE FROM 65 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 WOU8).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 867...



DISCUSSION...SUBTROPICAL DISTURBANCE OVER THE ERN GULF WAS BEGINNING

TO ACCELERATE ENE AS IT BECOMES ABSORBED INTO LARGER SCALE UPR

SYSTEM OVER THE SERN CONUS.  BANDS OF TSTMS WILL CONTINUE TO FORM

ALONG PRE-FRONTAL CONFLUENCE ACROSS SRN FL THROUGH THE NIGHT AS THE

DISTURBANCE MOVES ACROSS THE REGION.  ALTHOUGH LLVL WIND PROFILES

WILL TEND TO VEER SOMEWHAT OVERNIGHT AS THE PRIMARY LLJ AXIS

DEVELOPS OVER THE SW ATLC...SUFFICIENT DIRECTIONAL/SPEED SHEAR WILL

EXIST FOR SUPERCELLS AND/OR LEWPS TO BE EMBEDDED WITHIN LINE

SEGMENTS FOR SVRL MORE HOURS.  ISOLD TORNADOES AND DMGG WIND GUSTS

WILL BE THE PRIMARY THREATS.



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

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.

MEAN STORM MOTION VECTOR 24035.





...RACY

