MESOSCALE DISCUSSION 1124
   NWS STORM PREDICTION CENTER NORMAN OK
   0731 PM CDT MON JUN 22 2015

   AREAS AFFECTED...SRN LOWER MI...NWRN OH...NRN INDIANA...NERN IL

   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

   VALID 230031Z - 230130Z

   PROBABILITY OF WATCH ISSUANCE...80 PERCENT

   SUMMARY...TORNADO WATCH MAY BE REQUIRED BY 01Z FROM LOWER MI SWWD
   INTO NERN IL.

   DISCUSSION...LARGE SCALE ASCENT APPEARS TO BE INCREASING ACROSS
   LOWER MI PER EXPANDING ELEVATED CONVECTION THAT IS EVOLVING ATOP
   BOUNDARY LAYER STRATUS.  WHILE 00Z SOUNDING AT DTX IS NOTABLY
   CAPPED...800MB TEMPERATURE IS 7C COOLER AT GRB IN CLOSER PROXIMITY
   TO SHORT-WAVE TROUGH.  COOLING PROFILES ACROSS THIS REGION SHOULD
   CONTRIBUTE TO WEAKER INHIBITION OVER THE NEXT FEW HOURS AND ELEVATED
   CONVECTION IS EXPECTED TO STRENGTHEN AND NEAR-SFC BASED TSTMS WILL
   LIKELY EVOLVE WITH TIME...ESPECIALLY OVER SRN LOWER MI INTO NRN
   INDIANA.  SHEAR PROFILES STRONGLY SUPPORT DEEP ROTATING UPDRAFTS AND
   GIVEN THE INSTABILITY OBSERVED SUPERCELLS SHOULD EVOLVE. 
   ADDITIONALLY...DISCRETE SUPERCELL OVER NRN IL IS EXPECTED TO TRACK
   SEWD ALONG DECAYED OUTFLOW BOUNDARY TO THE SOUTH SIDE OF THE CHICAGO
   METRO AREA OVER THE NEXT FEW HOURS.  THIS ACTIVITY COULD SPREAD INTO
   NWRN INDIANA LATER THIS EVENING.

   ..DARROW/CARBIN.. 06/23/2015


   ATTN...WFO...CLE...DTX...IWX...GRR...IND...LOT...ILX...

   LAT...LON   42128801 43908330 42748214 41588379 40368769 42128801