MESOSCALE DISCUSSION 1191
   NWS STORM PREDICTION CENTER NORMAN OK
   1107 PM CDT WED JUN 17 2009
   
   AREAS AFFECTED...PARTS OF NERN IA / SERN MN / WRN WI
   
   CONCERNING...TORNADO WATCH 449...
   
   VALID 180407Z - 180500Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 449 CONTINUES.
   
   LARGE HAIL WILL BE THE MOST LIKELY THREAT ACROSS PARTS OF NERN
   IA/SERN MN/WRN WI BUT AN ISOLD TORNADO REMAINS POSSIBLE...MAINLY
   OVER PARTS OF NERN IA.
   
   LATEST RADAR IMAGERY SHOWS A STOUT SUPERCELL OVER HOWARD/CHICKASAW
   COUNTIES IN NERN IA.  NEWLY DEVELOPED CONVECTION HAS FORMED ALONG
   THE SERN MN/NERN IA BORDER WITH ADDITIONAL DISCRETE STORMS NEAR MPX
   AND EAU.  THE LATTER CONVECTION MAY BE AIDED IN PART TO WEAK
   ISENTROPIC ASCENT ALONG RESIDUAL WARM FRONTAL SEGMENT OVER THE
   MID-UPPER MS RIVER VALLEY.  THESE STORMS ARE BEGINNING TO INTENSIFY
   NEAR THE MS RIVER AND NEAR EAU...WITH STORMS SPLITS RECENTLY
   OBSERVED NEAR EAU.  
   
   MODIFYING 00Z MPX RAOB AND RUC FORECAST SOUNDINGS FOR OBSERVED
   TEMP/DEWPOINT IN THE LOW 70S/MID-UPPER 60S RESPECTIVELY...INDICATES
   EFFECTIVE PARCELS ARE STILL ROOTED AT THE SURFACE AND WILL REMAIN SO
   FOR THE NEXT FEW HOURS.  MPX VWP DATA SHOWS 0-1 KM SRH AROUND 200 M2
   PER S2 ACCORDING TO OBSERVED STORM MOTIONS ACROSS SERN MN SUGGESTING
   SUFFICIENT SHEAR EXIST FOR LOW LEVEL STORM ROTATION.  ALTHOUGH LARGE
   HAIL /PERHAPS SIGNIFICANT/ WILL BE THE LIKELY THREAT WITH THE
   STRONGER STORMS...AN ISOLD TORNADO REMAINS A POSSIBILITY FOR THE
   NEXT FEW HOURS.
   
   ..SMITH.. 06/18/2009
   
   
   ATTN...WFO...ARX...MPX...DMX...
   
   LAT...LON   42649189 43289263 44649337 44849341 44959326 45049209
               45119155 45039106 44759084 43609070 42899092 42659117
               42649189