Weather hampers Chicago travel

CHICAGO (AP) A developing storm threatened heavy snow across parts of the Midwest on Monday, leading United Airlines to cancel about half its flights at O'Hare International Airport. The city had more than 250 snow plows on the streets, with 60 more on standby, said Ray Padvoiskis of the Streets and Sanitation Department. 

A blizzard warning was posted across northern Illinois and northern Indiana, with up to a foot of snow forecast Monday in the Chicago area and southeastern Wisconsin, and 20 inches possible by Tuesday morning in northern Indiana, the National Weather Service said. 

Snow also fell from central Nebraska to Michigan. Most school districts in Iowa canceled classes Monday after the weather service issued a cold weather advisories and winter storm warnings. 

At O'Hare, the Federal Aviation Administration says the weather is causing some arriving flights to be delayed an average of 4 hours and 30 minutes with some arrivals delayed as much as 8 hours. 

The weather also means flights will not be allowed to depart Chicago Midway until noon CT, the FAA says.

United usually has 440 departures and an equal number of arrivals at O'Hare each day, United spokesman Joe Hopkins said Sunday. 

Also, American Airlines began canceling flights to and from O'Hare late Sunday, according to airline spokeswoman Sonja Whitemon. About 60 flights were canceled Monday out of 171 American flights in and out of the airport, she said. 

Because O'Hare is United's largest hub, cancellations are expected to affect flights across the country, Hopkins said. Travelers from both coasts will be routed through United's Denver hub or other airports. 

''Passengers should check ahead before they leave home,'' he said. 

Temperatures varied by almost 50 degrees from northern Illinois to the southern parts of the state, and while snow fell in Chicago, thunderstorms rattled southern Illinois during the morning. Central Illinois had freezing rain, with up to a half-inch of ice on the ground at Springfield, said weather service meteorologist Paul Merzlock. 

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