SEL8
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 578
   NWS STORM PREDICTION CENTER NORMAN OK
   1210 PM CDT TUE JUL 6 2004
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          NORTHEAST ARKANSAS
          SOUTHERN ILLINOIS
          SOUTHWEST INDIANA
          WESTERN KENTUCKY
          SOUTHEAST MISSOURI
          NORTHWEST MISSISSIPPI
          WESTERN TENNESSEE
   
   EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1210 PM UNTIL
   600 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 ALONG AND 95 STATUTE MILES
   EAST AND WEST OF A LINE FROM 65 MILES EAST OF LITTLE ROCK ARKANSAS
   TO 25 MILES NORTHEAST OF MOUNT VERNON ILLINOIS.
   
   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.
   
   DISCUSSION...VERY UNSTABLE AND UNCAPPED AIR MASS OVER WATCH AREA. 
   WITH 20-25 KT OF SHEAR...PULSE TYPE SEVERE STORMS EXPECTED TO
   DEVELOP DURING NEXT SEVERAL HOURS. PRIMARY THREAT WILL BE LARGE HAIL
   AND DAMAGING DOWNBURST WINDS.
   
   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 550. MEAN STORM
   MOTION VECTOR 22020.
   
   
   ...HALES