First snow event of the season in Chicago expected this week

CHICAGO (CBS) — The Chicago area can expect its first wet snowflakes of the season on Thursday, but roadways are not expected to be impacted as temperatures remain too warm.

By mid-morning Thursday, a band of snowfall is expected to rotate around a low-pressure system in Wisconsin into our area. 

Periods of light to moderate snowfall will be widespread across northern Illinois and northwest Indiana through Thursday afternoon. Then, milder winds turning off the lake could transition snow back to light rain late in the day as precipitation wraps up. 

Additional light showers on Friday in northwest Indiana should remain liquid rain.

While Chicago will likely see its first freeze Thursday morning with a forecast low temperature of 31 degrees, much of the daytime snow will fall while area temperatures are between 32 to 34 degrees – cold enough for snowflakes to reach the ground, but not cold enough for roadway accumulations. 

Roads will remain wet or a bit slushy at worst, grassy areas and elevated surfaces may see up to 1 inch of snow away from the lake. Parts of northwest Indiana can expect 1-2 inches on the grass by Thursday afternoon. Lakeside communities can expect only a dusting as record-warm water temperatures in the mid-50s keep air temperatures slightly milder.

If Chicago O'Hare records its first freeze on Thursday morning (Nov. 21), it will be one full month overdue compared to the average. It would also be the Chicago area's fourth-latest first freeze on record. Chicago's latest first freeze was Nov. 24, 1931.

Chicago's first measurable snow of the year typically comes on Nov. 20, and the last measurable snow comes Apr. 3.