MESOSCALE DISCUSSION 2197
   NWS STORM PREDICTION CENTER NORMAN OK
   0345 PM CDT TUE SEP 20 2011
   
   AREAS AFFECTED...NORTHERN MN/WESTERN WI
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 202045Z - 202245Z
   
   AN ISOLATED SEVERE THREAT...IN THE FORM OF WIND/HAIL AND/OR A BRIEF
   TORNADO...MAY BE POSSIBLE LATE THIS AFTERNOON ACROSS NORTHEAST
   MN/WESTERN WI.
   
   WATER VAPOR IMAGERY REFLECTS A NEARLY STACKED CYCLONE CENTERED NEAR
   THE ND/MN BORDER AT MID-AFTERNOON...WITH SURFACE ANALYSIS INDICATIVE
   OF AN ARCING CONFLUENCE ZONE ACROSS NORTHERN MN SOUTHWARD TO
   NEAR/WEST OF THE MS RIVER. THE PREVALENCE OF CLOUD COVER AND A
   RELATIVELY COOL/MODESTLY MOIST AIRMASS IS EXPECTED TO LIMIT THE
   OVERALL EXTENT/LIKELIHOOD OF SEVERE POTENTIAL. THAT SAID...POCKETS
   OF MODEST CLEARING ARE OCCURRING /SUCH AS CURRENTLY NOTED ACROSS
   NORTHEAST MN/ ALONG THE EAST-NORTHEAST ADVANCING SURFACE
   BOUNDARY...AND SOME ADDITIONAL LOW-LEVEL HEATING IN THE PRESENCE OF
   LOWER TO MIDDLE 50S F SURFACE DEWPOINTS MAY PROVE SUFFICIENT FOR
   SUSTAINED/LIGHTNING-PRODUCING UPDRAFTS LATE THIS AFTERNOON/EARLY
   EVENING. IN THE PRESENCE OF AMPLE AMBIENT VERTICAL
   VORTICITY/RELATIVELY STRONG VERTICAL SHEAR/SRH AS OBSERVED PER
   REGIONAL WSR-88D VWPS...A BRIEF TORNADO AND/OR STRONG WIND GUSTS
   COULD OCCUR ASIDE FROM SMALL HAIL. ANY SUCH SEVERE THREAT IS
   CURRENTLY EXPECTED TO BE MARGINAL/LOCALIZED IN NATURE...BUT
   CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.
   
   ..GUYER.. 09/20/2011
   
   
   ATTN...WFO...MQT...GRB...DLH...ARX...MPX...
   
   LAT...LON   47389392 48269386 47539140 46548994 44468969 44009183
               45369209 46429257 47389392