MESOSCALE DISCUSSION 0892
   NWS STORM PREDICTION CENTER NORMAN OK
   0317 PM CDT FRI MAY 29 2009
   
   AREAS AFFECTED...CNTRL IL/IND
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 292017Z - 292145Z
   
   ISOLATED TSTMS SHOULD INITIATE BY 22Z ALONG TRAILING PORTION OF COLD
   FRONT SINKING SLOWLY SWD THROUGH THE MIDWEST. ALTHOUGH STRONG
   MID-LEVEL NWLYS WILL GENERALLY REMAIN POST-FRONTAL...MODERATE
   DEEP-LAYER SHEAR AND MODEST INSTABILITY WILL SUPPORT POTENTIAL FOR
   SEVERE HAIL AND GUSTY WINDS. OVERALL THREAT APPEARS RELATIVELY
   MARGINAL FOR A SEVERE TSTM WATCH...ALTHOUGH TRENDS WILL BE
   MONITORED.
   
   20Z SUBJECTIVE SURFACE ANALYSIS PLACED A COLD FRONT FROM THE THUMB
   OF LOWER MI ACROSS NRN IND INTO NRN MO/NERN KS. HI-RES AND
   OPERATIONAL MODEL GUIDANCE ARE FAIRLY CONSISTENT WITH PRODUCING AT
   LEAST ISOLATED QPF ALONG THE BOUNDARY AT PEAK HEATING. WINCHESTER IL
   AND WOLCOTT IND PROFILERS INDICATE MODERATE DEEP-LAYER NWLYS ATTM
   /WITH 0-6 KM SHEAR AROUND 30 KT/. SOME INCREASE IN MID-LEVEL FLOW
   ALONG THE BOUNDARY WILL OCCUR /OWING TO APPROACH OF STRONG MID-LEVEL
   JET FROM THE UPPER MS RIVER VALLEY/...BUT MORE SIGNIFICANT INCREASES
   SHOULD REMAIN CONFINED N OF THE BOUNDARY. CONTINUED HEATING COMBINED
   WITH SURFACE DEW POINTS IN THE 50S WILL RESULT IN MODEST INSTABILITY
   WITH MLCAPE NEAR 1000 J/KG. OVERALL SETUP SHOULD YIELD A FEW STORMS
   PRODUCING SEVERE HAIL AND STRONG TO LOCALLY SEVERE WINDS.
   
   ..GRAMS.. 05/29/2009
   
   
   ATTN...WFO...ILN...IWX...IND...LOT...ILX...LSX...
   
   LAT...LON   41308546 41308497 41028464 40438459 40058513 39668680
               39408784 38889060 39419137 39679137 40059099 40828766
               41308546