MESOSCALE DISCUSSION 0049
   NWS STORM PREDICTION CENTER NORMAN OK
   0743 AM CST SUN FEB 01 2015

   AREAS AFFECTED...PORTIONS OF NRN ILLINOIS...NRN INDIANA...SRN LOWER
   MICHIGAN...NWRN OHIO

   CONCERNING...HEAVY SNOW 

   VALID 011343Z - 011915Z

   SUMMARY...AREAS OF HEAVY SNOW WITH RATES TO 1 INCH PER HOUR WILL
   SPREAD ACROSS THE REGION THROUGH THE DAY.

   DISCUSSION...SFC PRESSURE FALLS OF 2-3 MB PER 2 HOURS ARE ANALYZED
   ACROSS THE MID-MS VALLEY TO PORTIONS OF NRN IL/INDIANA...REFLECTING
   THE LOW-LEVEL WAA REGIME IN PLACE AHEAD OF SFC LOW PRESSURE ANALYZED
   NEAR KANSAS CITY. RELATED ISENTROPIC ASCENT IS SUPPORTING WIDESPREAD
   PRECIPITATION IN THIS REGIME...WITH MODERATE TO OCCASIONALLY HEAVY
   SNOW BEING REPORTED ACROSS PARTS OF NRN IL. AS THE SFC LOW DEVELOPS
   EWD/ENEWD WHILE DEEPENING AND LOW-LEVEL FRONTOGENESIS
   CORRESPONDINGLY BECOMES ENHANCED...PRECIPITATION WILL FURTHER
   INCREASE IN COVERAGE AND INTENSITY ACROSS THE DISCUSSION
   AREA...WHERE WET-BULB ZERO HEIGHTS WILL REMAIN SUFFICIENTLY LOW/AT
   THE GROUND IN SUPPORT OF SNOW PER THE 12Z ILX RAOB AND RAP FORECAST
   SOUNDINGS. THE STRONGER WAA AND ASSOCIATED LLJ-ENHANCED ASCENT WILL
   SHIFT EWD THROUGH THE DAY. AS SUCH...SNOWFALL RATES TO 1 INCH PER
   HOUR WILL GRADUALLY SPREAD EWD AS WELL -- REACHING NWRN OHIO
   AROUND/AFTER 18Z. ALSO OF NOTE...STRENGTHENING NELY WINDS TO THE NW
   OF THE SFC CYCLONE WILL COMBINE WITH LINGERING LIGHT TO MODERATE
   SNOW ACROSS NERN IL TO ENCOURAGE BLOWING/DRIFTING OF SNOW AND VERY
   LOW VISIBILITIES BY THIS AFTERNOON. THIS INCLUDES THE CHICAGO AREA
   AND SURROUNDING COMMUNITIES.

   ..COHEN/CARLAW.. 02/01/2015


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

   LAT...LON   41988761 41538935 40778913 40438808 40588673 40838506
               41118383 41828431 42068552 41988761