MESOSCALE DISCUSSION 1076
   NWS STORM PREDICTION CENTER NORMAN OK
   1007 PM CDT THU JUN 02 2011
   
   AREAS AFFECTED...PARTS OF WRN/CNTRL NORTH AND SOUTH DAKOTA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 421...
   
   VALID 030307Z - 030430Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 421
   CONTINUES.
   
   A NEW WW MAY BE NEEDED EAST OF THE CURRENT WATCH PRIOR TO 05-06Z.
   
   UPSCALE CONVECTIVE GROWTH APPEARS UNDERWAY NORTH AND EAST OF THE
   BLACK HILLS...WITH A SMALL ORGANIZED MESOSCALE CONVECTIVE SYSTEM
   ALREADY EVOLVING NEAR PHILIP.  THIS ACTIVITY MAY IMPACT PIERRE BY
   THE 04-05Z TIME FRAME...WITH FURTHER EXPANSION LIKELY IN THE
   PRESENCE OF LINGERING MODERATELY LARGE BOUNDARY LAYER CAPE ON THE
   ORDER OF 1500-3000 J/KG.  AN AREA OF ENHANCED MID/UPPER FORCING FOR
   UPWARD VERTICAL MOTION AHEAD OF BROADER SCALE UPSTREAM TROUGHING IS
   ENHANCING ACTIVITY...CONTRIBUTING TO WEAKENING OF MID-LEVEL
   INHIBITION.  THERMODYNAMIC PROFILES CHARACTERIZED BY SIZABLE
   MID-LEVEL AND SUB-CLOUD TEMPERATURE/DEW POINT SPREADS PROBABLY WILL
   CONTINUE TO SUPPORT DOWNBURSTS AND SURFACE COLD POOL DEVELOPMENT. 
   AND IT APPEARS POSSIBLE THAT STRONG SURFACE GUST POTENTIAL MAY
   INCREASE THROUGH 05-06Z...AS A SOUTHERLY 850 MB JET STRENGTHENS
   /PERHAPS WELL IN EXCESS OF 50 KTS/ FROM THE CENTRAL PLAINS TOWARD
   THE EASTERN DAKOTAS.  ACCELERATION OF THE EVOLVING MESOSCALE
   CONVECTIVE SYSTEM MAY NECESSITATE ADDING COUNTIES EAST OF THE
   CURRENT WW...OR PERHAPS A NEW WW INCLUDING NORTHEASTERN SOUTH DAKOTA
   AND SOUTHEASTERN NORTH DAKOTA WITHIN THE NEXT HOUR OR TWO.
   
   ..KERR.. 06/03/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...UNR...
   
   LAT...LON   45040220 46360129 47149966 46849821 45009868 43499983
               43250178 45040220