SEL9
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 179
   NWS STORM PREDICTION CENTER NORMAN OK
   440 PM CDT THU APR 21 2005
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          CENTRAL AND NORTH TEXAS
   
   EFFECTIVE THIS THURSDAY AFTERNOON FROM 440 PM UNTIL MIDNIGHT CDT.
   
   HAIL TO 3 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 50
   STATUTE MILES EAST AND WEST OF A LINE FROM 70 MILES NORTH
   NORTHEAST OF FORT WORTH TEXAS TO 75 MILES SOUTH SOUTHWEST OF SAN
   ANGELO TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
   ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
   
   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 176...WW 177...WW 178...
   
   DISCUSSION...ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG
   SURFACE DRYLINE ACROSS CENTRAL AND NORTH TX DURING THE EVENING. 
   MODERATE INSTABILITY...COOL TEMPERATURES ALOFT...AND STEEP LAPSE
   RATES SUGGEST THAT LARGE HAIL WILL BE LIKELY WITH STRONGER STORMS.
   
   AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
   TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
   KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
   MOTION VECTOR 26030.
   
   
   ...HART