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493 

WWUS20 KWNS 171627

SEL5

SPC WW 171627

FLZ000-CWZ000-180000-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 5

NWS STORM PREDICTION CENTER NORMAN OK

1125 AM EST MON JAN 17 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHERN FLORIDA

       COASTAL WATERS



EFFECTIVE THIS MONDAY MORNING AND EVENING FROM 1125 AM UNTIL 700

PM EST.



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 50 STATUTE

MILES EITHER SIDE OF A LINE FROM 10 MILES WEST OF KEY WEST

FLORIDA TO 40 MILES SOUTHEAST OF WEST PALM BEACH FLORIDA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU5).



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...SHOWERS AND A FEW TSTMS EXPECTED TO PERSIST INVOF

SHALLOW WARM FRONT EDGING NE ACROSS S FL THROUGH THIS AFTN.  LOW LVL

SHEAR EXPECTED TO REMAIN STRONGEST ALONG AND JUST NE OF FRONT...WITH

SFC-BASED INSTABILITY MAXIMIZED TO ITS WEST.  LARGE SCALE FORCING

FOR ASCENT WILL REMAIN WEAK.  BUT COMBINATION OF SIZABLE LOW LVL

DIRECTIONAL SHEAR/LOW LCLS NEAR FRONT...PRESENCE OF A FEW LONG-LIVED

UPDRAFTS...AND POTENTIAL FOR ADDITIONAL DEVELOPMENT AS AREA OF

STORMS NOW OFF THE SE FL CST CONTINUES ENE SUGGESTS RISK FOR A

COUPLE TORNADOES AND/OR LOCALLY DMGG WIND THROUGH EARLY EVE.



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

400. MEAN STORM MOTION VECTOR 24030.





...CORFIDI

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