SEL1
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 231
   NWS STORM PREDICTION CENTER NORMAN OK
   430 AM CDT FRI APR 21 2006
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          MIDDLE-UPPER TEXAS COASTAL PLAIN
          COASTAL WATERS
   
   EFFECTIVE THIS FRIDAY MORNING FROM 430 AM UNTIL 900 AM CDT.
   
   HAIL TO 1.5 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 55
   STATUTE MILES EITHER SIDE OF A LINE FROM 45 MILES SOUTH OF
   VICTORIA TEXAS TO 40 MILES NORTHEAST OF HOUSTON TEXAS. FOR A
   COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
   UPDATE (WOUS64 KWNS WOU1).
   
   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 229...WW 230...
   
   DISCUSSION...QUASI-LINEAR MCS IS FCST TO CONTINUE MOVING GENERALLY
   ESEWD FROM WW 230 TOWARD MID/UPPER TX COAST.  FOREGOING AIR MASS IS
   FAVORABLY SHEARED...AND ALSO SUFFICIENTLY BUOYANT WITH MLCAPES UP TO
   AROUND 1500 J/KG.  INCREASING CINH WITH SWD EXTENT SHOULD LIMIT
   BACKBUILDING...SO COMPLEX WILL FORWARD-PROPAGATE WITH FORCED LIFT
   ALONG LEADING OUTFLOW EDGE.
   
   AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
   TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
   KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
   MOTION VECTOR 29035.
   
   
   ...EDWARDS/thompson