SEL1
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 411
   NWS STORM PREDICTION CENTER NORMAN OK
   500 PM CDT TUE JUN 8 2004
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          WESTERN AND NORTHERN IOWA
          NORTHEAST NEBRASKA
          EXTREME SOUTHEAST SOUTH DAKOTA
   
   EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 500 PM UNTIL
   1100 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 50 STATUTE MILES
   NORTH AND SOUTH OF A LINE FROM 45 MILES NORTH OF GRAND ISLAND
   NEBRASKA TO 25 MILES EAST NORTHEAST OF MASON CITY IOWA.
   
   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 409...WW 410...
   
   DISCUSSION...SCATTERED INTENSE CONVECTION IS EXPECTED TO DEVELOP
   LATE THIS AFTERNOON AND EVENING ALONG FRONT FROM NORTHEAST NEB INTO
   NORTHERN IA.  EXTREMELY MOIST/UNSTABLE AIRMASS AND STEEP MID LEVEL
   LAPSE RATES WILL PROMOTE A RISK OF LARGE HAIL AND DOWNBURST WINDS IN
   STRONGER CELLS.
   
   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 26025.
   
   
   ...HART