This image made available by NOAA shows storm systems over the eastern half of the United States on Thursday, Feb. 7, 2013 at 11:15 EST. A blizzard of potentially historic proportions threatened to strike the Northeast with a vengeance Friday, Feb. 8, 2013 with 1 to 2 feet of snow feared along the densely populated Interstate 95 corridor from the New York City area to Boston and beyond. (AP Photo/NOAA)
Airlines have already canceled more than 2,700 Friday flights as they get ready for a storm that threatens to dump up to 3 feet of snow from New York City to Boston.
Flight-tracking website FlightAware shows 728 cancellations at the three big airports in the New York area. Another 191 flights to or from Boston have been scrubbed, and 137 in Toronto.
Airlines issued so-called "weather waivers," allowing passengers flying in the storm-affected areas to change their flight date without paying a change fee.
Airlines try to get ahead of big storms by canceling flights in advance rather than crossing their fingers that they can operate in bad weather.