MESOSCALE DISCUSSION 1557
   NWS STORM PREDICTION CENTER NORMAN OK
   0639 AM CDT SUN JUL 10 2011
   
   AREAS AFFECTED...PORTIONS SERN MN...WI.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 101139Z - 101245Z
   
   EXPANDING MCS MOVING EWD ABOUT 35 KT...FROM SERN MN INTO SWRN
   WI...MAY CONTINUE ACROSS WRN/CENTRAL WI WITH MAIN CONCERN BEING
   DAMAGING DOWNDRAFTS.  POTENTIAL EXISTS FOR ISOLATED SVR GUSTS AOA 50
   KT...AS WELL AS MORE COMMON SUBSEVERE GUSTS STILL CAPABLE OF DAMAGE
   TO SOME TREES. APEX OF BOW PRODUCED ONLY 31 KT GUST AT RGK AT
   1109Z...WITH 35 KT AT GYL AND MKT EARLIER...BUT ALSO WIND DAMAGE
   REPORT IN DAKOTA COUNTY MN.
   
   SFC MESOANALYSIS INDICATES QUASISTATIONARY FRONTAL ZONE EXTENDING
   EWD FROM LOW N RWF...ACROSS AUW AREA.  MOST FAVORABLE CORRIDOR FOR
   CONTINUED FORWARD PROPAGATION MAY EXIST ALONG AND NEAR THIS
   BOUNDARY...WHERE MODIFIED FCST SOUNDINGS SUGGEST CHANNEL OF
   RELATIVELY MINIMIZED MLCINH 50-75 J/KG AND MAXIMIZED LOW-LEVEL
   VORTICITY.  MEAN WIND AND DEEP-LAYER SHEAR VECTORS -- INCLUDING
   ABOUT 40 KT PRE-STORM EFFECTIVE SHEAR MAGNITUDE -- ARE ALIGNED
   NEARLY PARALLEL TO BOUNDARY AND ORTHOGONAL WITH RESPECT TO APEX OF
   BOW ECHO...OFFERING KINEMATIC SUPPORT FOR CONTINUED
   FORWARD-PROPAGATION.  THERMODYNAMICALLY...VERY MOIST BOUNDARY LAYER
   WILL CONTRIBUTE TO 1000-1500 J/KG MLCAPE FOR PARCELS THAT CAN BE
   FORCED THROUGH CINH LAYER.  HOWEVER...POTENTIAL FOR GENERATION OF
   SUBSTANTIAL THETAE/PRESSURE DEFICITS WITH COLD POOL APPEAR SOMEWHAT
   LIMITED ATTM GIVEN LACK OF STEEPER SUBCLOUD LAPSE RATES.  EARLIEST
   VIS IMAGERY INDICATES BKN CLOUDS IN PROJECTED PATH OF COMPLEX...WITH
   SOME POTENTIAL FOR DIABATIC HEATING TO STEEPEN LOW-LEVEL LAPSE RATES
   OVER CENTRAL-ERN WI IF CONVECTION DOES NOT WEAKEN IN MEANTIME.
   
   ..EDWARDS.. 07/10/2011
   
   
   ATTN...WFO...GRB...MKX...DLH...ARX...MPX...
   
   LAT...LON   43819253 44259212 44689213 44979230 45209269 45649211
               45739043 45628913 45428810 45048786 44478820 43928930
               43879007 43799137 43819253