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   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 171
   NWS STORM PREDICTION CENTER NORMAN OK
   230 PM CDT SUN MAY 9 2004
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          CENTRAL AND SOUTHWEST MINNESOTA
          EASTERN SOUTH DAKOTA
   
   EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 800
   PM CDT.
   
   HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
   MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
   
   THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 65 STATUTE MILES
   EAST AND WEST OF A LINE FROM 60 MILES SOUTHWEST OF SIOUX FALLS
   SOUTH DAKOTA TO 55 MILES NORTH NORTHEAST OF SAINT CLOUD MINNESOTA.
   
   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 170...
   
   DISCUSSION...COLD FRONT MOVING SEWD ACROSS ERN SD WITH AIR MASS IN
   ADVANCE BECOMING STRONGLY UNSTABLE AND WEAKLY CAPPED.  WITH 40-50 KT
   OF DEEP LAYER COUPLED WITH THE INSTABILITY AND STEEP LAPSE
   RATES...THUNDERSTORMS WILL RAPIDLY DEVELOP ALONG AND AHEAD OF FRONT.
    POTENTIAL EXISTS FOR SUPERCELLS ENHANCING LARGE HAIL AND WIND
   THREAT.
   
   AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
   TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
   KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
   MOTION VECTOR 26035.
   
   
   ...HALES