MESOSCALE DISCUSSION 1798
   NWS STORM PREDICTION CENTER NORMAN OK
   0256 PM CDT SAT JUL 30 2011
   
   AREAS AFFECTED...PORTIONS WI...MI...LM.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 703...
   
   VALID 301956Z - 302200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 703
   CONTINUES.
   
   QUASI-LINEAR CONVECTIVE SYSTEM IS MOVING SEWD ABOUT 40 KT ACROSS WW
   AREA...WITH WIDELY SCATTERED REPORTS OF DAMAGING WIND DURING PAST
   1.5 HOURS OVER ONTONAGON COUNTY MI AND PRICE/ONEIDA/LINCOLN COUNTIES
   WI.  POTENTIAL FOR OCNL DAMAGING GUSTS WILL CONTINUE WITH THIS
   SYSTEM AT LEAST TO LM SHORE...BEFORE MOVING OVER SHALLOW/STABLE
   MARINE LAYER.
   
   SFC MESOANALYSIS SHOWS LAKE BREEZE BOUNDARIES VERY CLOSE TO
   SHORELINE OF LM BETWEEN CHI-RUE...THEN NEWD ACROSS WRN ALGER COUNTY
   MI.  AIR MASS TRANSITION OVER MI PORTION WILL REMAIN MORE GRADUAL
   GIVEN DIABATIC HEATING EFFECTS ON LM AIR ADVECTED NWD ACROSS ERN
   UPPER MI.  ACCORDINGLY...MLCAPE AND DCAPE EACH DECREASE MORE
   GRADUALLY WITH EWD EXTENT OVER UPPER MI THAN FROM WI-LM..AND
   DAMAGING WIND THREAT SHOULD DO LIKEWISE.  IN MEANTIME...PROSPECTIVE
   INFLOW LAYER WILL REMAIN CHARACTERIZED BY HIGHLY FRAGMENTED SFC DEW
   POINT FIELD AVERAGING IN MID 60S F...AND SUPPORTING MLCAPE NEAR 1500
   J/KG...BENEATH MRGL EFFECTIVE SHEAR VALUES OF 25-35 KT. 
   HOWEVER...COLD POOL IS WELL-DEVELOPED...WITH 15-20 DEG C THETAE
   DEFICITS VERSUS HIGHEST WARMS-ECTOR VALUES.  THIS ALONG WITH NEARLY
   ORTHOGONAL ALIGNMENT OF CONVECTION TO MEAN FLOW VECTOR INDICATE
   CONTINUED FORWARD PROPAGATION OF COMPLEX...AND FORCED ASCENT OF
   BUOYANT AIR ALONG ITS LEADING EDGE...AT LEAST TO LM.  AREAS E OF LM
   IN WRN LOWER MI WILL NEED TO BE MONITORED FOR SVR THREAT AND
   POSSIBLE WW ISSUANCE IF CONVECTION SURVIVES TREK ACROSS
   LM...ALTHOUGH CONFIDENCE IN THAT SCENARIO IS LOW ATTM GIVEN
   RELATIVELY WEAK BOUNDARY LAYER THETAE THERE VERSUS W OF LAKE.
   
   ..EDWARDS.. 07/30/2011
   
   
   ATTN...WFO...APX...GRR...MQT...GRB...MKX...ARX...MPX...
   
   LAT...LON   45099188 44939024 45298913 46308884 46848824 46858775
               46548737 46568651 46608568 46028582 44858566 43528612
               43118724 43789001 45099188