MESOSCALE DISCUSSION 1741
   NWS STORM PREDICTION CENTER NORMAN OK
   0328 PM CDT TUE JUL 20 2004
   
   AREAS AFFECTED...EXTREME ERN MT...WRN AND CENTRAL ND...NRN AND
   N-CENTRAL SD
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 202028Z - 202230Z
   
   THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE
   AFTERNOON AND EVENING HOURS.  A FEW DAMAGING WIND GUSTS WILL BE THE
   MAIN SEVERE THREAT...BUT LOW END SEVERE HAIL WILL BE POSSIBLE AS
   WELL.
   
   SHORTWAVE TROUGH NOW OVER CENTRAL MT WILL CONTINUE MOVING EWD. 
   ASSOCIATED LIFT AHEAD OF THIS WAVE IS ALREADY CAUSING THUNDERSTORMS
   TO DEVELOP OVER ERN MT WHERE INSTABILITY IS MINIMAL. WIND GUSTS IN
   EXCESS OF 40 KTS HAVE ALREADY BEEN REPORTED WITH WEAK CONVECTION
   OVER SERN MT.
   
   STORMS WILL LIKELY STRENGTHEN AS THEY MOVE INTO LARGER INSTABILITY
   ACROSS OVER WRN/CENTRAL DAKOTAS. WIND PROFILES ARE FAVORABLE FOR
   FORWARD PROPAGATING SYSTEMS WITH STRONG OUTFLOW.  STEEP LOW LEVEL
   LAPSE RATES AND FORECAST STORMS MOTIONS IN EXCESS OF 30 KTS TO THE
   SE FURTHER SUGGEST DAMAGING WIND THREAT.
   
   ..JEWELL.. 07/20/2004
   
   
   ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...
   
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