Most flights headed to the East Coast from Chicago have been canceled.
"We have something scheduled," Jeremy Hayden who was trying to fly to Washington DC said. "Doesn't look good. That's what I'm hearing-cancelled."
In Boston and other cities in the northeast, they are preparing for the possibility of more than two feet of snow.
Most schools and many businesses will be closed. Forecasters are predicting a storm that rival what is known as the great blizzard of 1978 which stranded thousands of people.
Grocery stores were packed as people tried to stock up in preparation.
While O'Hare passengers are dealing with hundreds of cancellations, it's even worse at East Coast airports where many are trying to get out of town before the storm hits.
Airlines issued "weather waivers," allowing passengers flying in the storm-affected areas to change their flight date without paying a change fee.
In recent years airlines have tried to get ahead of big storms by canceling flights in advance rather than crossing their fingers that they could operate in bad weather.
Travelers can still face dayslong delays in getting home, but the advanced cancellations generally mean they get more notice and can wait out the storm at home or a hotel, rather than on a cot at the airport.
In addition reservation systems have been programmed to automatically rebook passengers when flights are canceled. And travelers now receive notifications by email, phone or text message.
LINK: FLIGHT TRACKER
The Associated Press contributed to this report.