An impressive storm system moving across the Central U.S. will impact Northern Illinois and the Chicago metro area tonight, bringing significant snowfall to the region. The center of the low pressure system will be tracking well south of the area, but strong south/southeasterly flow will transport abundant moisture northward to bring snow to the region.
The onset of snow looks to begin across the Chicago area right around rush hour, which could impact the evening commute as snow should easily accumulate on pavement through this event. The image below shows the HRRR-model simulated radar reflectivity, which projects snow to be reaching Chicago around 6pm local time (image source: tropicaltidbits.com).
A steady snowfall can be expected for Chicago metro from early this evening through Saturday morning, with many areas likely to pick up 6″ or more of snow. In general, the heaviest amounts are expected north of I-88, but banded snowfall could result in varying amounts.
Road conditions will quickly deteriorate tonight through Saturday morning, and strong winds from the east/northeast at 15-25mph with gusts to 35mph will result in areas of blowing and drifting snow. The heaviest snow should come to an end during the morning hours Saturday with additional lingering light snow showers.
However, the potential for lake effect snow will arrive from late Saturday through early Sunday, with additional snow accumulations possible during the overnight period Saturday night-Sunday morning. The additional lake effect snow along with breezy north/northeast winds will continue to impact travel conditions through Sunday.
Snowfall should eventually come to an end by Sunday afternoon or early evening, but cold air arriving Sunday night will keep high temperatures in the teens on Monday.