MESOSCALE DISCUSSION 1795
   NWS STORM PREDICTION CENTER NORMAN OK
   1128 AM CDT SAT JUL 30 2011
   
   AREAS AFFECTED...PORTIONS MN...NRN WI...WRN UPPER MI...WRN LS.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 301628Z - 301900Z
   
   SVR POTENTIAL MAY INCREASE THROUGH EARLY AFTERNOON OVER THIS
   REGION...WITH DAMAGING GUSTS AND LARGE HAIL POSSIBLE.  THOUGH
   CURRENTLY MORE ISOLATED...CONVECTION MOVING SEWD FROM ND ULTIMATELY
   MAY POSE BETTER-ORGANIZED SVR THREAT OVER MN. 
   HOWEVER...ISOLATED/SPORADIC SVR MAY OCCUR S OF LS AS WELL.
   
   SFC MESOANALYSIS SHOWS OUTFLOW BOUNDARY FROM EARLIER CONVECTION
   EXTENDING FROM NEAR STC SWWD ACROSS KANDIYOHI COUNTY MN THEN SRN
   MARSHALL COUNTY SD...WHERE IT IS BEING OVERTAKEN BY FRESH OUTFLOW
   FROM CONVECTION OVER EXTREME SERN ND.  AHEAD OF BOUNDARY...TSTMS
   HAVE DEVELOPED IN INITIALLY ELEVATED LAYER OF FAVORABLE
   BUOYANCY...IN LOOSE/BKN ARC FROM MN IRON RANGES TO NWRN WI TO ENE
   STC.  AS OF 1530Z...COMPOSITE REFLECTIVITY ANIMATIONS INDICATE MCV
   OVER N-CENTRAL MN NEAR BRD...MOVING GENERALLY EWD 35-40 KT WITH SOME
   NEWD TURN POSSIBLE TOWARD WRN LS AREA.  THIS FEATURE MAY ENHANCE
   LARGE SCALE ASCENT SUBTLY ACROSS ERN MN AND NWRN WI...WHICH APPEARS
   TO BE COMBINING WITH LOW-LEVEL WAA IN CONTRIBUTING TO FAVORABLE
   ENVIRONMENT ALOFT.  MEANWHILE SFC DEW POINTS UPPER 60S TO LOW 70S F
   CONTRIBUTE TO MINIMAL MLCINH AND MLCAPE 2000-3500 J/KG...BASED ON
   MODIFIED MPX RAOB AND MODEL SOUNDINGS.  LS LAKE BREEZE MAY ACT BOTH
   AS NRN BOUND AND LOCALIZED FOCUS FOR SVR POTENTIAL AS WELL. 
   MODIFIED RUC SOUNDINGS SUGGEST ONLY 20-30 KT EFFECTIVE SHEAR OVER
   REGION...CONSISTENT WITH VALUES OBSERVED AT MPX VWP...ALTHOUGH THESE
   MAY NOT ADEQUATELY SAMPLE MESONET-SCALE HEIGHT-GRADIENT ENHANCEMENTS
   FORCED BY MCV.  ANTECEDENT COLD POOL IS PRESENT BEHIND THIS
   ACTIVITY...BUT WITH RATHER LOOSE SFC THERMAL GRADIENT AND WEAK
   PRESSURE RISES.  GIVEN THAT...AND CLUSTERED TO QUASI-LINEAR MODE
   ALREADY EVIDENT...MAIN CONCERN THEREFORE WILL BE DAMAGING WIND
   PRIMARILY S OF LS WHERE LOW-LEVEL THETAE IS RELATIVELY MAXIMIZED.
   
   BY CONTRAST...STG PRESSURE FALLS ARE EVIDENT IN WAKE OF COLD
   POOL...OVER W-CENTRAL MN.  THIS IS RELATED BOTH TO WAKE-DEPRESSION
   EFFECTS AND LOW-LEVEL WAA N OF OUTFLOW BOUNDARY...AND IS IMMEDIATELY
   AHEAD OF ISOLATED CLUSTER OF TSTMS MOVING SEWD ABOUT 35 KT FROM SERN
   CORNER ND.  BILLOW CLOUDS IN VIS IMAGERY SUPPORT OBJECTIVELY
   ANALYZED RELATIVE MAX IN MLCINH NEAR BOUNDARY OVER NERN SD. 
   HOWEVER...THIS ACTIVITY MAY GROW UPSCALE AND DEVELOP COLD POOL AS IT
   MOVES ALONG THERMAL/INSTABILITY GRADIENT ASSOCIATED WITH OUTFLOW
   BOUNDARY...AND EVENTUALLY INTO VERY STRONGLY HEATED AND MOIST
   BOUNDARY LAYER OF CENTRAL/SRN MN WHERE CINH IS NEGLIGIBLE.  GIVEN
   PRONOUNCED LOW-LEVEL FOCUS FOR ASCENT AND FAVORABLY DESTABILIZING
   AIR MASS IN ITS PATH...SVR THREAT SHOULD INCREASE WITH TIME AND
   EXPAND IN AREA.  ADDITIONAL DEVELOPMENT ALSO IS POSSIBLE ALONG
   OUTFLOW BOUNDARY BETWEEN CURRENT CONVECTIVE REGIMES.
   
   ..EDWARDS.. 07/30/2011
   
   
   ATTN...WFO...MQT...GRB...DLH...ARX...MPX...FGF...ABR...
   
   LAT...LON   46269658 45679533 45719363 46449231 47729208 47919118
               47689054 46999059 46749031 46808908 46348844 45788862
               45138961 44559199 44139457 45159630 45869653 46269658