MESOSCALE DISCUSSION 1987
   NWS STORM PREDICTION CENTER NORMAN OK
   0347 PM CDT MON AUG 15 2011
   
   AREAS AFFECTED...PARTS OF SE MONTANA...NWRN SOUTH DAKOTA AND WRN/SRN
   NORTH DAKOTA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 152047Z - 152145Z
   
   A WATCH LIKELY WILL BE NEEDED AT SOME POINT LATE THIS AFTERNOON OR
   EVENING...BUT TIMING REMAINS A BIT UNCERTAIN.
   
   PRIMARY MID/UPPER FORCING FOR UPWARD VERTICAL MOTION DOES NOT APPEAR
   LIKELY TO IMPACT THE REGION UNTIL LATER THIS EVENING...PERHAPS AFTER
   02-03Z.  BUT LATEST RUC GUIDANCE SUGGESTS THAT INHIBITION IS
   WEAKENING FOR MOIST BOUNDARY LAYER PARCELS...WITH MIXED LAYER CAPE
   NOW IN EXCESS OF 3000 J/KG ACROSS PARTS OF WESTERN AND SOUTHERN
   NORTH DAKOTA.  DEEPENING CONVECTIVE DEVELOPMENT IS EVIDENT ACROSS
   THE BLACK HILLS...AS WELL AS PARTS OF SOUTHEASTERN MONTANA...NEAR
   BAKER.  THIS LATTER ACTIVITY APPEARS TO BE NEAR THE INTERSECTION OF
   THE LEE SURFACE TROUGH AND A WEAKENING SURFACE COLD POOL /WHICH HAS
   ADVANCED EASTWARD THROUGH MUCH OF NORTHWEST AND WEST CENTRAL NORTH
   DAKOTA/...AND MAY OFFER THE BEST POTENTIAL FOR STORM INITIATION
   THROUGH 22-00Z.  THIS SEEMS MOST PROBABLE AROUND THE DICKINSON ND
   AREA...WHERE VEERING WINDS FROM LIGHT NORTHEASTERLY/EASTERLY NEAR
   THE SURFACE TO MODEST WESTERLY AT MID LEVELS IS PROVIDING SUFFICIENT
   VERTICAL SHEAR FOR SUPERCELLS.
   
   ..KERR.. 08/15/2011
   
   
   ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...
   
   LAT...LON   46540465 46760374 47600346 48090262 48020153 47660115
               46960069 46480069 45590155 45050247 44020331 44620428
               45250447 45900455 46220462 46540465