Airlines also protectively canceled nearly 2,800 flights on Wednesday, FlightAware reported. Nearly 800 flights were canceled Monday.

Dallas-Fort Worth airport, a major hub, was closed briefly Tuesday morning due to the ice storm and delays were averaging about three hours once it reopened.

Chicago's O'Hare, among the busiest airports in the world, had the most cancelations with more than 1,100 flights affected Tuesday as airlines prepared for blizzard conditions to strike in the afternoon.

Another 100 flights were canceled at the city's secondary airport, Midway.

"Airlines at both O'Hare and Midway anticipate canceling additional flights throughout the day," cautioned Karen Pride, a spokeswoman for the Chicago Department of Aviation.

Some 900 flights were canceled in Dallas, 650 in Newark, and nearly 1,100 at New York's LaGuardia and JFK airports.

"This storm is going to have a significant impact on airlines, particularly those with hubs in Chicago (United, American) and Newark (Continental)," the website warned.