Storm Prediction Center Mesoscale Discussion 104

   Mesoscale Discussion 0104
   NWS Storm Prediction Center Norman OK
   0113 AM CST Wed Feb 02 2022

   Areas affected...parts of northeastern Missouri...central and
   northeastern Illinois...and northwestern Indiana

   Concerning...Heavy snow 

   Valid 020713Z - 021315Z

   SUMMARY...Snowfall rates of 1" per hour to locally/occasionally 1
   1/2" per hour are expected from parts of northeastern Missouri,
   northeastward to northwestern Indiana through the overnight hours.

   DISCUSSION...Latest radar loop shows a band of precipitation to the
   north of a surface baroclinic zone that currently extends from the
   Ozark Plateau of southern Missouri northeastward to central Indiana.
   Rainfall is occurring near and just north of the front, with a
   narrow transition zone stretching from northeastern Missouri
   northeastward to far northwestern Indiana -- north of which moderate
   to heavy snowfall is occurring.

   As a 1050mb high centered over Saskatchewan moves
   south-southeastward with time, the cold front -- at the leading edge
   of this advance of cold Canadian air -- will gradually shift
   southward, as will the aforementioned liquid-to-frozen precipitation
   transition zone.

   Model height fields indicate very weak short-wave ridging crossing
   the mid Mississippi Valley at this time.  However, subtle short-wave
   troughing -- embedded within southwesterly flow aloft on the eastern
   fringe of the synoptic-scale central Canada to southwestern U.S.
   trough -- will continue to shift out of Kansas/Oklahoma toward the
   Midwest overnight.  This -- in tandem with low-level warm advection
   atop the surface front -- will result in an increase in QG-induced
   ascent, and corresponding maintenance of a band of heavy snow which
   will remain largely in place over the same areas for the next
   several hours.  Snowfall rates reaching or exceeding 1" per hour
   across a rather large area, and local rates reaching 1 1/2" per
   hour, can be expected.

   ..Goss.. 02/02/2022

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...IWX...LOT...ILX...LSX...DVN...EAX...

   LAT...LON   39959213 41019015 41758778 41818646 41148646 40238808
               39349030 39169153 39309257 39959213