The severe winter weather moving through Chicago is causing delays averaging over two hours for arriving flights at O'Hare International Airport, according to the Federal Aviation Administration.
At Midway, most flights are delayed an average of 20 minutes.
The first major snow storm of the season brought 200 flight cancellations at O'Hare International Airport alone this morning.
Passengers are advised to check their airline's web site or call to confirm their flight status.
The inclement weather is expected to continue through 3 a.m. this morning.
A mixture of rain, sleet and snow are expected south and east of I-55 Tuesday night that will change to rain, according to the weather service. Three to four inches of snow are expected to fall on the North Shore and through out north central Illinois, including the northwest suburbs, Rockford and Dekalb.
Weather service maps show snow total amounts ranging from 4 1/2 in the Chicago area to 10 inches in Lake County and the far northwest suburbs. Strong winds will cause blowing and drifting, particularly on north-south highways.
A winter weather advisory remains in effect until 6 p.m. Wednesday and includes Cook, DuPage and Kendall counties.
Check in with NBCChicago for up to the minute weather alerts, traffic alerts, airport delays and school closings related to the coming storm.