Fast moving winter storm Niko has already prompted US airlines to pre-emptively cancel more than 2,300 flights for Thursday.
Winter storm warnings have been posted for large swathes of the Northeast from Pennsylvania to New England with most airlines issuing change fee waivers.
"The New York and Boston areas are most impacted with 40% of their flight operations cancelled. We expect Thursday’s numbers to continue to rise as airlines finalize their plans and then assess the impact on how quickly they can recover," said FlightAware CEO Daniel Baker.
By early Wednesday, JetBlue had already cancelled more than 580 flights which is nearly 60% of its entire schedule nationwide.
Its two major hubs at New York JFK and Boston are expected to get more than a foot of snow which could linger at Boston until late evening on Thursday.
American Airlines, Southwest, United and Delta have all cancelled at least 200 flights each.
