Airlines have already begun canceling flights ahead of the latest nor'easter to menace the Northeast.
More than 1,600 flights have been preemptively grounded for Wednesday and another 180 on Thursday, flight-tracking service FlightAware counted as of 10:35 p.m. ET on Tuesday. Combined, about 500 of those came on JetBlue, which operates its busiest bases at New York JFK and Boston.
The wave of preemptive cancellations comes as the second powerful nor'easter in a week takes aim at the Mid-Atlantic and Northeast. Winds aren't expected to be as strong as in last week's storm – which forced airlines to cancel 4,000 flights – but snow is expected be heavier and fall over a larger, more populated area.
Among the cities expected to receive significant snow accumulations are New York, Philadelphia and Boston.
Not surprisingly, many of the preemptive cancellations announced so far have come at airports serving those cities.
he three New York City-areas were the hardest hit as of Tuesday evening. More than 450 combined departures and arrivals had been canceled for Wednesday at Newark Liberty and more than 400 at JFK. That account for more than a third of the entire day's schedule at each airport. At LaGuardia, about a 25% of Wednesday's flights had already been canceled as of Tuesday evening.
To the north, more than 190 flights had already been grounded on Wednesday at Boston and another 85 for Thursday.
Those totals were almost certain to rise at both airports as more airlines start to pare schedules ahead of the storm. JetBlue – which accounted for the bulk of the preemptive cancellations as of Tuesday afternoon – operates its two busiest hubs at JFK and Boston.
Other airports seeing major Wednesday and Thursday cancellations included Philadelphia, Albany, N.Y. and Hartford, Conn.
Even airports in Florida were seeing preemptive cancellations. More than two dozen arrivals had been canceled at both the Orlando and Fort Lauderdale airports, likely the result of cancellations being made on flights that had been scheduled to arrive from northern airports like New York JFK, Boston and Hartford.
Most big airlines had put weather waivers in place by Monday night, allowing fliers scheduled to fly though the region to change their plans without paying change fees or additional charges.
The waivers included airports from Pennsylvania and New Jersey north through New England.
Among the major airports included in the various waivers: New York JFK, Newark Liberty, New York LaGuardia, Boston, Philadelphia, Hartford and Providence. Smaller airports included Albany, N.Y.; Harrisburg, Pa.; Islip/Long Island, N.Y.; New Haven, Conn.; Newburgh, N.Y.; State College, Pa.; Watertown, N.Y.; and Wilkes-Barre/Scranton, Pa.
Some carriers, such as Southwest and Alaska Airlines, included the airports in the Washington and Baltimore metro areas. JetBlue's waiver went as far north as Portland, Maine.
The details varied by carrier, but they generally allowed eligible customers to make one change to their itineraries without paying a change fee or fare difference. Dates covered by the waivers also varied by airline; most covered flights on Wednesday and Thursday, though some included Tuesday flights. Customers should check with their carriers for specific date and airport eligibility.
Regardless of the details of the flexible rebooking policies, fliers traveling to or through the region later this week should expect widespread delays and cancellations.
Scroll down for links to the flexible rebooking policies currently in place at big U.S. carriers: