As a weak upper-level disturbance moves off to the east, light snow (some freezing drizzle in counties along and south of Interstate-80) will diminish from the west by mid-late this Sunday morning. Untreated roads side streets and sidewalks could be slick, so take precautions if you are out and about.
Most of the Chicago area is under a Winter Storm Watch Monday/Monday night into Tuesday. From 6 to 9-inches of snow is expected to accumulate across most of the counties along and north of Interstate-80, beginning during the day Monday and continuing Monday night, gradually ending from the west Tuesday. Farther south a Winter Weather Advisory will likely be issued for a wintry mix of snow, freezing rain and sleet Monday changing over to all wet snow Monday night, accumulating a few inches before ending from the west later Tuesday.
There could be some impacts southernmost portions of the area during the Monday morning commute, but strongest influence of the storm will be experienced Monday evening, overnight and Tuesday morning when snow will be enhanced by strong northeast winds 20 to 40 mph flowing over Lake Michigan. Waves building to 10 to 12-feet will cause considerable Lakeshore Flooding along the Illinois and NW Indiana Lake Michigan shoreline.
Low pressure developing in the Texas Panhandle will move northeast during the day Monday, tracking through southern Illinois Monday night before gradually weakening as it moves off to the east of our area Tuesday. The pictorial below prepared by the Chicago National Weather Service will likely be updated, but gives a good idea where the heaviest snowfall in excess of 6-inches should occur.