MESOSCALE DISCUSSION 1456
   NWS STORM PREDICTION CENTER NORMAN OK
   0807 PM CDT THU JUN 30 2011
   
   AREAS AFFECTED...GREATER CHICAGO METRO
   
   CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON 
   
   VALID 010107Z - 010130Z
   
   THREAT FOR LARGE HAIL/DMGG WINDS WILL LIKELY INCREASE OVER THE NEXT
   HOUR OR TWO ACROSS FAR NERN IL AND PERHAPS FAR NWRN IND /GREATER
   CHICAGO METRO/.  
   
   SURFACE ANALYSIS PLACES A LAKE BREEZE BOUNDARY SLOWLY MOVING WWD
   ACROSS SERN WI AND NERN IL.  00Z GRB RAOB SHOWED AMPLE ELEVATED
   POTENTIAL INSTABILITY /2400 J/KG MUCAPE/ ON THE ERN PERIPHERY OF A
   STOUT PLAINS ELEVATED MIXED LAYER.  SLY SURFACE FLOW VEERING TO NLY
   IN THE MID-UPPER LEVELS IS CONTRIBUTING TO A STRONG DEEP LAYER SHEAR
   PROFILE ACROSS THIS REGION...SUPPORTIVE OF ORGANIZED
   STORMS--INCLUDING SUPERCELLS.  RADAR IMAGERY LOOP SHOWS THE STORMS
   OVER SRN LAKE MICH DEVIATING TO A WEST OF SOUTH COMPONENT...FAVORING
   THE EVENTUAL MOVEMENT OF THESE STORMS INTO THE GREATER CHICAGO METRO
   OVER THE NEXT 1-2 HRS.  KRAC RECENTLY MEASURED A 57 KT WIND GUST. 
   LARGE TO PERHAPS VERY LARGE HAIL/DMGG WINDS WILL PROBABLY IMPACT THE
   NEAR LAKE MICHIGAN AREAS OF THE CHICAGO METRO.
   
   ..SMITH.. 07/01/2011
   
   
   ATTN...WFO...LOT...
   
   LAT...LON   41498818 42028826 42418803 42448778 42378738 41978716
               41538725 41328773 41498818