By Alana Wise
NEW YORK (Reuters) - Airlines canceled thousands of flights in the U.S. Northeast on Wednesday as a swirl of strong winds, snow, sleet and ice from the fourth major storm this month crippled the region.
Airlines scrapped more than 4,400 flights to and from the United States, according to flight tracking website FlightAware, and more than 2,600 other flights were delayed as the latest "nor'easter" dumped snow and ice on New York, Boston, Philadelphia and Washington.
The cancellations piled on to thousands more canceled flights this season due to an unrelenting series of late-winter storms.
In addition to creating headaches for passengers, these storms can rack up millions of dollars in costs for airlines, as carriers reallocate aircraft and crew, and swallow the cost of passengers who don't re-book travel for when the storm passes.
"This has been a much harsher late winter than we've seen for quite some time. It does have an impact on carriers' bottom lines," CFRA Research analyst Jim Corridore said.
While the full financial impact of the storms was not yet known, Corridore said accurate weather forecasts helped carriers quickly move planes and crew as well as plan for resuming normal operations.
"There is a small silver lining in that it does help load factors and yields," he said, noting that passengers from canceled flights often help fill later flights that would have otherwise sat empty.
U.S. carriers are offering change-fee waivers from flights in the affected regions, including from New York's three major airports, Philadelphia International and Boston Logan International.
LaGuardia Airport in New York City said on Twitter on Wednesday afternoon that airlines had canceled all remaining flights at the facility for the rest of the day.
(Additional reporting by Alex Dobuzinskis in Los Angeles,; Editing by James Dalgleish and Sandra Maler)