The big storm heading for the Northeast is already disrupting air travel.
United Airlines said it has canceled 900 flights for Friday in advance of the storm. Delta Air Lines Inc. canceled 740.
New England could get smacked with up to two feet of snow on Friday, while New York City is under a blizzard warning for as much as a foot or more.
The airports with the most cancellations on Friday are Newark Liberty, Boston's Logan International and LaGuardia, in that order, according to airline tracking website FlightAware.
American Airlines canceled 50 flights today and was scrapping 50 more on Friday. A spokesman said more flights were likely to be canceled as the night goes on.
Today, the biggest weather problems are in Chicago. O'Hare has seen 85 canceled departures.
Airlines issued so-called "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.