Airlines already canceling flights into Monday from Winter Storm Harper

SUNDAY UPDATE: It’s been a rough holiday weekend for air travel. Airlines have canceled more than 4,100 flights in the United States since Friday, with disruptions already extending into Monday. The hardest-hit for Sunday: Boston's Logan airport. Full update: Storm: 4,100 flights already axed as cancellations stretch into Monday

PREVIOUS UPDATE (Saturday, 8:25 p.m.): Flight headaches were on the rise Saturday as a potent winter storm moved from the Midwest into the Northeast.

Airline cancellations mounted, with some flights on Monday already off the books. In total, about 3,900 flights had been canceled from Friday through Monday. That number was likely to grow as the storm moved into the Northeast. All big U.S. airlines were waiving change fees at many airports in the storm’s path.

For Saturday, more than 2,125 flights had been canceled nationwide and another 2,570 delayed as of 8:25 p.m. ET, according to flight-tracking service FlightAware.

Even for Sunday, airlines already had pre-emptively canceled nearly 1,160 flights in the anticipation of poor weather. Even Monday flights were affected, with about 100 already canceled. Those totals came on top of 522 mostly-storm-related cancellations on Friday.

The storm, dubbed Winter Storm Harper by The Weather Channel, was dumping snow, ice and rain across the Great Lake and Ohio Valley early Saturday morning. By evening, poor conditions were forecast to expand into the Mid-Atlantic and Northeast.

TODAY IN THE SKY: Southwest's Herb Kelleher: Five innovations that shaped U.S. aviation

The hardest-hit airport on Saturday was Chicago O’Hare, where a combined 1,080 departures and arrivals had been axed as of 8:25 p.m. ET. That accounted for close to a half of the entire day’s schedule there, by FlightAware’s count.

Saturday’s flight problems were widespread. Among the dozens of airports where FlightAware showed significant cancellations were New York JFK, New York LaGuardia, Newark Liberty, Chicago Midway, Boston, Indianapolis, Washington Reagan National, Baltimore/Washington, Buffalo, Detroit and Cleveland.

Looking to Sunday, Boston had the most pre-emptive cancellations, with more than 465 combined departures and arrivals already off the schedule. That accounted for about half of the Sunday’s entire schedule at Boston, according to FlightAware. New York JFK had about 100 combined arrival and departure cancellations for Sunday.

Many of those came on JetBlue, which counts Boston and JFK as its two busiest hubs. JetBlue had already canceled about 430 for Sunday and another 46 for Monday, FlightAware showed.

TODAY IN THE SKY: Sun Country Airlines adds 19 routes, 7 cities in its largest expansion ever

Numerous other airports were already seeing dozens of cancellations for Sunday, including Newark; Washington Reagan National; Philadelphia; Charlotte, North Carolina; and Hartford, Connecticut. Even Florida airports were feeling the effects; dozens of Sunday were already canceled at airports like Orlando and Fort Lauderdale, with the disruptions coming mostly on flights that had been scheduled to operate to airports in the Midwest and Northeast.

Flyers on all airlines should brace for a spike in cancellations and delays at least through Monday. Using previous storms as a yardstick, flight cancellations seem likely to continue to spike into early next week if current forecasts hold.

Flight delays could last even after the storm. Bitter cold is predicted to blast into the Midwest and Northeast in the storm’s wake, bringing the possibility of de-icing delays at busy airports that could last at least through Monday.

TODAY IN THE SKY: Air France to pull plug on Joon, its airline for millennials

IN PICTURES: 40 cool photos: Planespotting, behind the scenes at Washington Dulles

This article originally appeared on USA TODAY: Airlines already canceling flights into Monday from Winter Storm Harper