MESOSCALE DISCUSSION 0929
   NWS STORM PREDICTION CENTER NORMAN OK
   1220 PM CDT WED MAY 30 2007
   
   AREAS AFFECTED...PARTS OF ERN DAKOTAS...WRN MN
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 301720Z - 301845Z
   
   TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT AND THE
   POSSIBILITY OF A WW.
   
   COLD CORE OF UPPER TROUGH LAGS TO THE SOUTH/WEST OF THE WARM SECTOR
   OF SURFACE LOW CENTER...NOW SOUTHWEST OF WATERTOWN SD.  THIS WILL
   TEND TO LIMIT MAGNITUDE OF DESTABILIZATION THIS AFTERNOON.  BUT...
   THE LOW-LEVEL ENVIRONMENT IS RELATIVELY MOIST...AND ENOUGH
   INSOLATION IS OCCURRING TO INCREASE MIXED LAYER CAPE IN EXCESS OF
   500 J/KG.  THIS COULD APPROACH 1000 J/KG BY PEAK AFTERNOON HEATING.
   
   DEEPENING CONVECTIVE DEVELOPMENT IS ALREADY EVIDENT...LIKELY
   ASSOCIATED WITH FORCING ACCOMPANYING A LOBE OF CYCLONIC VORTICITY
   LIFTING TO THE EAST OF UPPER TROUGH AXIS...THROUGH EASTERN SOUTH
   DAKOTA...TOWARD THE RED RIVER VALLEY.  AS DESTABILIZATION
   PROCEEDS...INTENSIFICATION INTO LOW TOPPED THUNDERSTORMS WILL
   CONTINUE ACROSS THE EASTERN DAKOTAS/MINNESOTA.  WHILE HAIL POTENTIAL
   SEEMS MINIMAL...BELT OF 30-40 KT MEAN CLOUD BEARING FLOW WILL
   CONTRIBUTE TO RELATIVE FAST STORM MOTIONS...AND A RISK FOR GUSTY
   WINDS WHICH COULD APPROACH SEVERE LIMITS.  PRIMARY SEVERE THREAT MAY
   BE A RISK FOR GENERALLY SHORT-LIVED TORNADOES... SUPPORTED BY
   SIZABLE LOW-LEVEL VERTICAL SHEAR... SHEAR ALONG WEAK BOUNDARY
   EXTENDING NORTHEAST OF LOW INTO THE INTERNATIONAL FALLS AREA...AND
   PRESENCE OF FAVORABLE AMBIENT VERTICAL VORTICITY.
   
   ..KERR.. 05/30/2007
   
   
   ATTN...WFO...DLH...MPX...DMX...FGF...FSD...ABR...BIS...
   
   45769859 47089738 48169668 48419531 47749424 46149458
   44899415 43189451 43009589 44039689 44899748