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000 

WWUS20 KWNS 111959

SEL8

SPC WW 111959

ALZ000-GAZ000-TNZ000-120200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 198

NWS STORM PREDICTION CENTER NORMAN OK

300 PM CDT FRI APR 11 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND NORTHEAST ALABAMA

       NORTHWEST GEORGIA

       EASTERN TENNESSEE



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 900

PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

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

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF KNOXVILLE

TENNESSEE TO 45 MILES SOUTHWEST OF BIRMINGHAM ALABAMA.  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...THIS TORNADO WATCH REPLACES TORNADO

WATCH NUMBER 195. WATCH NUMBER 195 WILL NOT BE IN EFFECT AFTER

300 PM CDT. CONTINUE...WW 196...WW 197...



DISCUSSION...SUPERCELLS IN MIDDLE TN AND NRN/CENTRAL AL WILL

CONTINUE TO SPREAD EWD THROUGH THE AFTERNOON/EVENING.  VERTICAL

SHEAR REMAINS SUFFICIENT FOR SUPERCELLS WITH SOME TORNADO

THREAT...THOUGH THE ERN BOUNDARY OF THIS THREAT IS IN QUESTION GIVEN

THE DECREASING LOW-LEVEL MOISTURE WITH EWD EXTENT.

OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH BOTH

SUPERCELLS AND EMBEDDED BOWING SEGMENTS.



AVIATION...TORNADOES AND 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 24040.





...THOMPSON

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