April 15: Tornado Watch #7

URGENT - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH NUMBER 146
   NWS STORM PREDICTION CENTER NORMAN OK
   745 PM CDT FRI APR 15 2011
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   TORNADO WATCH FOR PORTIONS OF 
   
          CENTRAL AND SOUTHERN ALABAMA
          THE WESTERN FLORIDA PANHANDLE
          EXTREME SOUTHEAST MISSISSIPPI
          COASTAL WATERS
   
   EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 745 PM
   UNTIL 300 AM 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 90 STATUTE
   MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHWEST OF LA
   GRANGE GEORGIA TO 20 MILES EAST OF MOBILE ALABAMA.  FOR A
   COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
   UPDATE (WOUS64 KWNS WOU6).
   
   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 141. WATCH NUMBER 141 WILL NOT BE IN EFFECT AFTER
   745 PM CDT. CONTINUE...WW 142...WW 143...WW 144...WW 145...
   
   DISCUSSION...CLUSTERS OF SUPERCELLS IN CENTRAL/SRN AL AND SE MS WILL
   CONTINUE TO SPREAD EWD THROUGH THE OVERNIGHT HOURS IN ADVANCE OF THE
   MS VALLEY MIDLEVEL TROUGH AND SURFACE BOUNDARY.  WEAK-MODERATE
   INSTABILITY AND STRONG VERTICAL SHEAR WILL BE MAINTAINED OVER THIS
   AREA...AND THE TORNADO/SEVERE THREAT WILL EXPAND EWD TONIGHT AS THE
   LOW LEVELS MOISTEN FARTHER E INTO SE AL AND THE FL PANHANDLE.  A
   STRONG TORNADO OR TWO WILL REMAIN POSSIBLE FOR THE NEXT SEVERAL
   HOURS...GIVEN THE PRESENCE OF DISCRETE SUPERCELLS IN A MOIST
   ENVIRONMENT WITH EFFECTIVE SRH NEAR 500 M2/S2.
   
   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
   550. MEAN STORM MOTION VECTOR 27030.