The Chicago area and parts of Indiana are experiencing their first snowfall of the season, starting with cold rain Saturday night that transitioned into snow overnight.
The National Weather Service has issued a Winter Storm Warning for Cook County, parts of Will County, and northwest Indiana counties for the potential of high-impact lake effect snow from late Sunday into Monday.
The Winter Storm Warning is in effect through noon Monday for the entirety of Cook County, as well as eastern Will County. In Kankakee County, the warning begins at midnight Monday morning and also continues through noon Monday.
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The warning is in effect through 6 p.m. Monday for Lake and Porter counties in Indiana.
For LaPorte County, Indiana, a Winter Storm Warning was already in effect as of midday Sunday and continues until midnight Tuesday morning.
Chief Meteorologist Albert Ramon gave us a timeline of what to expect.
Sunday night through Monday
Through 1 a.m. Monday, snow will be increasing right off the lake. Snow-covered roads were reported in La Porte County. Heavy snow is picking up in northern Porter and northeast Lake County, Indiana.
The band should reach Chicago and the North Shore by around 10:30-11 p.m., then gradually expand south and west overnight.
Lake effect snow bands continue to strengthen overnight, producing snowfall rates up to 3 inches per hour.
From 4-6 a.m., the snow band focuses from the North Shore to Chicago.
Then, from 6-10 a.m., it’ll move its focus from Chicago to the south suburbs. Snow then pivots east to Northwest Indiana until noon.
Snow to impact Monday morning commute
Wherever the snow band is during the morning commute, expect extremely difficult to nearly impossible travel conditions.
Chief Meteorologist Albert Ramon said forecasting its exact location is tough, but the best models have it most likely affecting areas from near downtown Chicago into Lake County, Indiana.
How much snow is expected to fall?
About 6 to 8 inches, with isolated higher amounts are expected. Totals reaching 12 inches or more are still on the table for Sunday night.
The extreme snowfall amount would likely be somewhere near the lakeshore in either Cook or Lake County, Indiana.
Significant delays are expected at O’Hare and Midway international airports.
Widespread power outages are not expected, though some localized issues may occur.
Check back with CBS News Chicago for updates.
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