MESOSCALE DISCUSSION 0406
   NWS STORM PREDICTION CENTER NORMAN OK
   0104 AM CDT MON APR 06 2009
   
   AREAS AFFECTED...SRN LOWER MI...FAR NRN IND...FAR NE IL
   
   CONCERNING...HEAVY SNOW 
   
   VALID 060604Z - 061000Z
   
   HEAVY SNOW WILL CONTINUE ACROSS SRN LOWER MI AND FAR NRN IND TONIGHT
   FOR THE REMAINDER OF THE NIGHT. SNOWFALL RATES OF 1 INCH PER HOUR
   WILL BE COMMON WITH LOCALLY UP TO 2 INCHES PER HOUR POSSIBLE IN
   SHORT BURSTS IN THE HEAVIER BANDS.
   
   LATEST SFC ANALYSIS SHOWS A 993 MB SFC LOW OVER SERN OH WITH AN
   UPPER-LEVEL TROUGH LOCATED OVER THE LOWER OH VALLEY ACCORDING TO
   WATER VAPOR IMAGERY. A WELL-DEFINED COMMA CLOUD IS LOCATED AROUND
   THE SFC LOW WITH A PRONOUNCED DRY SLOT ASSOCIATED WITH A IMPRESSIVE
   90 TO 100 KT MID-LEVEL JET LOCATED FROM NRN MS NEWD INTO CNTRL OH.
   LARGE-SCALE ASCENT IS LIKELY BEING ENHANCED ACROSS THE GREAT LAKES
   REGION DUE TO THE LEFT EXIT REGION OF THE MID-LEVEL JET. IN
   ADDITION...MODEL FORECASTS MAINTAIN A ZONE OF STRONG ISENTROPIC LIFT
   ACROSS THE MCD AREA TONIGHT. THIS SHOULD SUPPORT HEAVY SNOW FOR THE
   REST OF THE NIGHT ACROSS LOWER MI AND NRN IND. SFC TEMPS ARE
   CURRENTLY NEAR OR JUST ABOVE FREEZING ACROSS MOST OF THE MCD AREA
   WHICH SHOULD LESSEN SNOWFALL ACCUMULATIONS UNTIL LATER TONIGHT.
   SNOWFALL RATES SHOULD GRADUALLY DECREASE OVER NE IL AS THE SYSTEM
   MOVES SLOWLY EWD ACROSS THE OH VALLEY.
   
   ..BROYLES.. 04/06/2009
   
   
   ATTN...WFO...DTX...IWX...GRR...LOT...
   
   LAT...LON   42028311 41418544 40888731 41058789 41568789 42348688
               43428431 43468342 43198279 42768252 42028311