SEL4
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 374
   NWS STORM PREDICTION CENTER NORMAN OK
   335 PM CDT SUN MAY 21 2006
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          NORTHERN ALABAMA
          NORTHWESTERN GEORGIA
          WESTERN AND SOUTHERN TENNESSEE
   
   EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 335 PM UNTIL
   1000 PM CDT.
   
   HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
   MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
   
   THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 40
   STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES NORTH OF
   MEMPHIS TENNESSEE TO 55 MILES EAST OF CHATTANOOGA TENNESSEE.  FOR
   A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
   OUTLINE UPDATE (WOUS64 KWNS WOU4).
   
   REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
   FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
   DO PRODUCE TORNADOES.
   
   OTHER WATCH INFORMATION...CONTINUE...WW 372...WW 373...
   
   DISCUSSION...THUNDERSTORMS EXPECTED TO INCREASE IN COVERAGE AND
   INTENSITY ACROSS SRN TN DURING THE NEXT HOUR OR SO WHERE AIR MASS
   HAS BECOME MODERATELY UNSTABLE SOUTH OF STATIONARY SURFACE FRONT. 
   ACTIVITY MAY BE AIDED BY WEAK MID LEVEL IMPULSE NOW MOVING INTO WRN
   TN AS IT SHIFTS SEWD ACROSS THE TN RIVER VALLEY THIS EVENING.  SHEAR
   WILL BE MARGINAL...BUT STILL SUFFICIENT...FOR SUPERCELLS GIVEN
   AMOUNT OF INSTABILITY. ACTIVITY WILL LIKELY CONSOLIDATE INTO
   CLUSTERS/MCS DURING THE EVENING.  LARGE HAIL AND DAMAGING WINDS
   EXPECTED TO BE PRIMARY SEVERE THREATS.
   
   AVIATION...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 29025.
   
   
   ...EVANS