The National Weather Service has issued a winter storm watch now in effect through late Friday evening for parts of east-central and northeastern Illinois.
Officials warned snowstorms could make travel dangerous, with gusts of up to 55 mph. Falling and drifting snow can lead to whiteout conditions with sometimes zero visibility, officials said.
Roads could become icy as temperatures plummet Thursday afternoon.
Bitter cold chills are expected to be as low as 25 to 30 below zero Thursday night through Friday. Frostbite of exposed skin can occur within 20 minutes under these conditions, officials warned.
Isolated river jams are also possible.
Power outages could occur due to wind gusts, officials warn and ask the public to prepare for the dangerous conditions.
In a briefing last week, city officials asked residents to check on the elderly and homeless.
Officials also reminded that district heating centers are available to residents. Chicagoans can call 311 if they see people struggling in the elements or to seek help for those in need.
The snow is expected to begin on Thursday, with road conditions rapidly deteriorating Thursday afternoon. Heavy snowfall is expected on Friday, when dangerous chills are expected to begin. The snow is expected to ease on Saturday, but blowing snow and chills may remain a factor.