MESOSCALE DISCUSSION 1765
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 PM CDT WED JUL 27 2011
   
   AREAS AFFECTED...WY...SD...NE
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 272049Z - 272215Z
   
   A FEW STORMS HAVE RECENTLY INITIATED NEAR INVERTED/THERMAL TROUGH
   AXIS AND OVER HIGHER TERRAIN ACROSS NERN WY AND THE BLACK HILLS IN
   WRN SD. THERMODYNAMIC ENVIRONMENT IS EXPECTED TO SUPPORT A COUPLE OF
   BETTER ORGANIZED STORMS/SUPERCELLS WITH HAIL/HIGH WINDS POSSIBLE
   THROUGH THE EVENING HOURS AND A WATCH IS POSSIBLE IF COVERAGE
   CONTINUES TO INCREASE.
   
   PERSISTENT LOW LEVEL CONVERGENCE INVOF TROUGH AND DIFFERENTIAL
   HEATING ACROSS THE HIGHER TERRAIN HAVE LIKELY CONTRIBUTED TO RECENT
   STORM DEVELOPMENT ACROSS THE AREA GIVEN RELATIVELY SUBSTANTIAL
   INHIBITION. STRONG HEATING WITHIN LOW LEVEL MOIST AXIS TO THE EAST
   OF THE ONGOING STORMS IN WY HAS RESULTED IN A WEST TO EAST AXIS OF
   GREATER INSTABILITY WHERE MLCAPE VALUES OF 1000-1500 J PER KG ARE IN
   PLACE PER LATEST OBJECTIVE DATA. OTHER THAN THE LOW LEVEL FORCING
   MECHANISMS ALREADY MENTIONED...ONLY WEAK LARGER SCALE ASCENT IS
   INDICATED BY MODEL GUIDANCE AND SATL IMAGERY. HOWEVER...A WEAK UPPER
   WAVE/TROUGH MAY BE PASSING ACROSS THE AREA WITH MID LEVEL FLOW OF
   ABOUT 40KT.
   
   INGREDIENTS APPEAR TO SUPPORT A CONTINUATION OF AT LEAST AN ISOLATED
   SUPERCELL THREAT WITH HAIL AND HIGH WIND POTENTIAL SPREADING FROM
   NERN WY AND ACROSS PORTIONS OF WRN SD INTO THE EVENING HOURS.
   CURRENT UNCERTAINTIES REGARDING STORM COVERAGE SUGGEST THAT A WATCH
   IS NOT IMMINENT BUT MAY BE NEEDED FOR SOME OF THIS AREA IN THE NEXT
   2-3 HOURS.
   
   ..CARBIN.. 07/27/2011
   
   
   ATTN...WFO...UNR...CYS...BYZ...RIW...
   
   LAT...LON   44640645 44880581 44870332 44590276 43880221 43120256
               42870323 42820387 43080443 43260531 43180619 43660647
               43960649 44640645