Update 8:45AM CDT…
A center of low pressure will slowly move east into Lake Superior later today while the associated warm front shifts across and north of the Chicago area late this Friday morning, followed closely by a cold front that will move quickly from west to east across northern Illinois and cross Lake Michigan this afternoon. Cloudiness and scattered showers will precede and accompany the warm and cold fronts – winds will shift from south to west-southwest with showers ending from the west, as the cold front passes through.
Untreated roads especially could become wet and slick in spots overnight across the Chicago area as a band of mixed precipitation precedes and accompanies an influx of warmer air into the Chicago area. If you are out walking/driving late tonight, be aware of potentially slick/dangerous conditions, if you happen upon wet spots or encounter precipitation. The road/sidewalk temperatures should be above freezing in most cases and the mixed precipitation will be light, but there may be spots cool enough to create slippery problems on the roads, streets, sidewalks and parking lots.
Most temperatures will initially fall into the middle 30s tonight, before warming toward morning. Places with an existing snow cover could easily drop below freezing. Precipitation in the form of snow aloft will be falling into a warm area a few hundred feet above the ground, thus snow may make it to the ground as wet snow or possibly in the form of sleet or rain. There could even be a period of freezing rain where temperatures drop temporarily below 32-degrees.
The band of precipitation is expected to change over to all rain as temperatures eventually level off and then rise back into the upper 30s by Friday morning.
Follow the current progression of the precipitation on the Metro Weather Radar map below…