MESOSCALE DISCUSSION 1943
   NWS STORM PREDICTION CENTER NORMAN OK
   0149 PM CDT THU AUG 11 2011
   
   AREAS AFFECTED...SOUTH DAKOTA AND PARTS OF SOUTHERN NORTH DAKOTA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 111849Z - 112015Z
   
   TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT THAT
   COULD REQUIRE A WW WITHIN THE NEXT COUPLE OF HOURS.
   
   AS A FAIRLY STRONG MID/UPPER JET STREAK...40+ KT AROUND 500
   MB...NOSES INTO THE NORTHERN ROCKIES...A DOWNSTREAM SHORT WAVE
   IMPULSE CONTINUES TO PROGRESS EASTWARD INTO THE NORTHERN PLAINS. 
   FORCING ASSOCIATED WITH THIS FEATURE APPEARS TO BE CONTRIBUTING TO
   ONGOING SCATTERED THUNDERSTORM ACTIVITY ACROSS THE BLACK HILLS AND
   POINTS NORTHWARD INTO AREAS NORTHWEST OF BISMARCK.  CONVECTION
   ALREADY APPEARS TO BE IN THE PROCESS OF SLOWLY INTENSIFYING...AND
   THIS TREND IS EXPECTED TO CONTINUE THROUGH 21-22Z.  AS INHIBITION
   CONTINUES TO WEAKEN...STORMS WILL BECOME INCREASINGLY ROOTED IN A
   BOUNDARY LAYER CHARACTERIZED BY MODERATELY LARGE CAPE IN EXCESS OF
   2000 J/KG.  WESTERLY MID-LEVEL FLOW WILL REMAIN SOMEWHAT MODEST...ON
   THE ORDER OF 30 KT...BUT VEERING FROM A SOUTH SOUTHEASTERLY
   COMPONENT AT LOWER LEVELS SHOULD PROVIDE SUFFICIENT SHEAR FOR
   SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL AND LOCALLY DAMAGING WIND
   GUSTS...PERHAPS AN ISOLATED TORNADO.
   
   ..KERR.. 08/11/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...UNR...
   
   LAT...LON   47380257 47650115 46619809 45499822 44839966 43890006
               43300264 43810368 45130353 46400254 47380257