MESOSCALE DISCUSSION 1806
   NWS STORM PREDICTION CENTER NORMAN OK
   1210 PM CDT SAT JUL 31 2004
   
   AREAS AFFECTED...ERN DAKOTAS...WRN MN
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 311710Z - 311945Z
   
   RISK FOR SEVERE STORMS WILL INCREASE THROUGH THE AFTERNOON...AND WW
   COULD BECOME NECESSARY WITHIN NEXT 2 TO 3 HOURS.
   
   AHEAD OF LOW AMPLITUDE SHORT WAVE TROUGH DIGGING IN THE LEE OF THE
   CANADIAN ROCKIES...LOWER/MID-TROPOSPHERIC WARM ADVECTION HAS BECOME
   FOCUSED ACROSS PARTS OF THE EASTERN DAKOTAS/WESTERN MINNESOTA. THIS
   APPEARS TO BE STRONGEST...BENEATH NORTHWESTERLY UPPER FLOW REGIME...
   IN A CORRIDOR NORTH/NORTHEAST OF ABERDEEN SD INTO THE REDWOOD FALLS
   MN AREA.  LARGE-SCALE ASCENT /STEEPENING LAPSE RATES/...IN
   CONJUNCTION WITH STRONG SURFACE HEATING...IS SUPPORTING FAIRLY RAPID
   DESTABILIZATION...AND MEAN MIXED LAYER CAPE IS PROGGED TO EXCEED
   2000 J/KG BY PEAK HEATING.
   
   ON NORTHEASTERN PERIPHERY OF STRONGER MID-LEVEL CAP...FORCING IS
   EXPECTED TO SUPPORT SURFACE-BASED CONVECTIVE INITIATION AS SURFACE
   TEMPERATURES APPROACH/EXCEED 80F THIS AFTERNOON.  THIS APPEARS
   POSSIBLE AS EARLY AS THE 19-20Z TIME FRAME...WITH FURTHER
   INCREASE/INTENSIFICATION LIKELY THROUGH THE REMAINDER OF THE
   AFTERNOON.  SHEAR PROFILES ON NOSE OF SOUTHERLY LOW-LEVEL JET ARE
   ALREADY FAVORABLE FOR SUPERCELLS...AND THERMODYNAMIC ENVIRONMENT
   WILL BECOME INCREASINGLY FAVORABLE FOR LARGE HAIL/DAMAGING WIND
   GUSTS...POSSIBLY ISOLATED TORNADOES BY LATE AFTERNOON.
   
   ..KERR.. 07/31/2004
   
   
   ATTN...WFO...MPX...DMX...FGF...FSD...ABR...BIS...
   
   46729737 46739590 45849456 44469395 43819378 43289453
   43379605 44249655 45159739 45549838