

000 

WWUS20 KWNS 181622

SEL7

SPC WW 181622

FLZ000-CWZ000-190300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 837

NWS STORM PREDICTION CENTER NORMAN OK

1225 PM EDT MON AUG 18 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTH FLORIDA

       COASTAL WATERS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1225 PM UNTIL

1100 PM EDT.



TORNADOES...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS

LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE

MILES EAST AND WEST OF A LINE FROM 45 MILES WEST NORTHWEST OF

WEST PALM BEACH FLORIDA TO 35 MILES SOUTH SOUTHWEST 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...VERTICAL WIND SHEAR CONTINUES TO INCREASE OVER SOUTH FL

IN ADVANCE OF TROPICAL STORM FAY.  A FEW CELLS HAVE BEGUN TO SHOW

MORE PERSISTENT ROTATION OFFSHORE...SUGGESTING THE THREAT OF

ISOLATED TORNADOES IS INCREASING.  THREAT WILL PERSIST AT LEAST

THROUGH 03Z.



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

TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI

WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 13020.





...HART

