- American, Delta, JetBlue, Southwest and United are waiving ticket-change fees.
- Newark and Boston airports are being hit the hardest.
- New York's JFK airport suspended operations due to "whiteout" conditions.
- The powerful storm is bringing heavy winds, snow, ice and then brutal cold to the East Coast of the U.S.
A powerful winter storm grounded more than 4,000 flights and halted operations at New York City airports Thursday.
New York's John F. Kennedy International Airport and LaGuardia Airport suspended flights because of whiteout conditions and high winds.
Newark Liberty International Airport in New Jersey, a United Airlines hub, was most affected by cancellations, with more than 1,000 canceled flights, close to 80 percent of its schedule, according to FlightAware, a plane-tracking website. At Boston Logan International Airport, a hub of JetBlue Airways and an important airport for business travel, 720 flights were canceled.
Travel disruptions will continue into Friday, capping off a shortened back-to-work week for business travelers. Airlines canceled more than 600 flights on Friday because of the storm, according to FlightAware.
American Airlines scrubbed its entire Thursday schedule in and out of the three main New York-area airports. It said operations would resume on Friday.
The Port Authority of New York and New Jersey said Wednesday it had 524 pieces of snow equipment at the area's airports that can melt up to 500 tons of snow an hour, but they will soon be faced with a new challenge: ice. Forecasters said bone-chilling temperatures are expected in the storm's wake.
Long-haul international flights are often among the last flights airlines cancel, because they generate much more revenue than short, domestic flights and are serviced by much larger aircraft.
The cancellation of an international flight can make logistical problems snowball into disruptions lasting more than a day because both aircraft and crews are out of position. U.S. airlines have much greater access to aircraft and crews within the country.
More than 100 flights were diverted after airports closed runways, according to FlightAware. Some of those included international flights. Singapore Airlines was forced to land an Airbus A380, the largest passenger plane, at a small New York airport after J.F.K. was closed.
It was unclear how much the storm will cost airlines. Last year, a string of strong hurricanes that hit airlines' hubs cost airlines hundreds of millions of dollars in lost revenue, but clearing runways from a snowstorm is a much faster process than recovering from the floods, power outages, structural damage to airports and other infrastructure damage that 2017's storms caused.