MESOSCALE DISCUSSION 0912
   NWS STORM PREDICTION CENTER NORMAN OK
   0634 PM CDT MON JUN 01 2009
   
   AREAS AFFECTED...CNTRL/NRN SECTIONS OF IL/IND/OH AND EXTREME SRN LWR
   MI
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 318...320...
   
   VALID 012334Z - 020100Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   318...320...CONTINUES.
   
   VSBL SATL SHOWS EVIDENCE OF AN MCV OVER NWRN IL THAT WILL LIKELY
   ENHANCE UVV DOWNSTREAM ACROSS THE MIDWEST THIS EVENING.  TSTMS HAVE
   BEEN FAVORING OUTFLOW BOUNDARIES LEFT BY THIS MORNING/S ACTIVITY
   WHERE AIR MASS HEATED CONSIDERABLY TODAY.  DEEP LAYER SHEAR WAS ON
   THE LOWER MARGIN TO SUPPORT SUSTAINED SUPERCELLS...BUT MLCAPES TO
   2000 J/KG AND FAVORABLE MID-LVL LAPSE RATES HAVE CONTRIBUTED TO
   BRIEF ROTATING UPDRAFTS WITH LARGE HAIL.  TROPOSPHERE STILL CONTAINS
   CONSIDERABLE DRY LAYERS AND EVAPORATIVE COOLING WILL ENHANCED
   DOWNDRAFTS WITH DMGG WIND GUSTS...ESPECIALLY ACROSS WCNTRL OH/MIAMI
   VLY AND UPSTREAM ACROSS CNTRL IL.
   
   ISOLD STG TSTMS THAT APCH CHICAGOLAND...ASSOCD WITH CORE OF THE
   MCV...WILL LIKELY WEAKEN THROUGH 00Z AS THEY ENCOUNTER A LAKE
   BREEZE.
   
   ..RACY.. 06/01/2009
   
   
   ATTN...WFO...CLE...ILN...IWX...IND...LOT...ILX...DVN...
   
   LAT...LON   40879078 41878852 41818561 41358345 40838277 40158278
               39948382 40068530 40308708 40318831 40328972 40879078