SEL4
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 644
   NWS STORM PREDICTION CENTER NORMAN OK
   1210 PM EST MON JUL 18 2005
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          EASTERN ILLINOIS
          NORTHERN INDIANA
          NORTHWEST OHIO
          LAKE MICHIGAN
   
   EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1210 PM UNTIL 700
   PM EST.
   
   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 95
   STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF FORT
   WAYNE INDIANA TO 25 MILES SOUTH OF LAFAYETTE INDIANA.  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 643...
   
   DISCUSSION...THUNDERSTORMS WILL DEVELOP ALONG/AHEAD OF COLD FRONT
   NOW PUSHING EWD ACROSS NRN IL. WITH VERY UNSTABLE AND WEAKLY CAPPED
   AIR MASS AVAILABLE...COUPLED WITH 30-40KT OF MID LEVEL FLOW
   ASSOCIATED WITH UPPER TROUGH MOVING ACROSS WRN GREAT LAKES...STORMS
   EXPECTED TO DEVELOP INTO SHORT LINES/BOWS WITH PRIMARY SEVERE THREAT
   DAMAGING WINDS.
   
   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 550. MEAN STORM
   MOTION VECTOR 25030.
   
   
   ...HALES