MESOSCALE DISCUSSION 1765
   NWS STORM PREDICTION CENTER NORMAN OK
   1040 PM CDT MON AUG 03 2009
   
   AREAS AFFECTED...PORTIONS SERN SD...CENTRAL-ERN NEB.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 040340Z - 040545Z
   
   CLUSTER OF STG-SVR TSTMS HAS EVOLVED OVER CHERRY COUNTY NEB...FROM
   COMBINATION OF EARLIER...DISCRETE/PREFRONTAL TSTMS MOVING SSEWD OUT
   OF SD...AND CONVECTION ASSOCIATED WITH COLD POOL THAT MOVED EWD FROM
   WY.  ERN PORTION OF RESULTING MCS MAY ABSORB RIGHT-MOVING SUPERCELL
   -- EVIDENT OVER SD/NEB BORDER AT 330Z AND MOVING TOWARD WRN HOLT
   COUNTY NEB.  ALTHOUGH MODIFIED RAOBS AND RUC SOUNDINGS SUGGEST
   INCREASING MLCINH FROM DIABATIC SFC HEATING...DAMAGING WIND WILL
   REMAIN LIKELY ESPECIALLY OVER WRN PORTIONS WW...WHERE ORGANIZED COLD
   POOL SHOULD FORCE ASCENT OF SFC-BASED AIR ALONG ITS LEADING EDGES. 
   EFFECTIVE SHEAR MAGNITUDES 40-50 KT SHOULD CONTINUE TO COVER MOST OF
   WW AREA AND WILL SUPPORT CONTINUING THREAT OF SUPERCELLS...WITH
   SIGNIFICANT-SVR HAIL IN ADDITION TO LOCALIZED WIND DAMAGE.
   
   SPECIFIC TRACK OF MCS EVOLUTION REMAINS SOMEWHAT UNCERTAIN...BUT
   PORTIONS OF SRN/ERN NEB MAY NEED ADDITIONAL WW ISSUANCE BEFORE
   SCHEDULED 08Z EXPIRATION OF WW 652.  ISOLATED TO WIDELY SCATTERED
   TSTMS ALSO MAY DEVELOP INVOF SFC COLD FRONT OVER SERN SD AND MOVE
   SEWD ACROSS NERN/ERN PORTIONS WW.
   
   ..EDWARDS.. 08/04/2009
   
   
   ATTN...WFO...FSD...OAX...ABR...GID...LBF...UNR...
   
   LAT...LON   40670122 42440237 42840204 42950029 44039862 43969759
               42519652 42009665 41579698 40949778 40489886 40360014
               40670122