More than 1,350 flights are canceled on Sunday alone and 2,165 were canceled on Saturday as Harper moved from the Midwest into the Northeast Saturday night.

JetBlue has already canceled 770 flights through Monday, and Delta Airlines has issued travel waivers for passengers affected by the storm, according to CNN. The storm first brought 10 inches of snow to the Midwest before traveling east to deposit less snow—but it will wreak more havoc in combination with rain likely to turn to ice amid low temperatures later and strong winds.

Chicago’s O’Hare International Airport was one of the worst hit on Saturday, with more than 650 flights canceled. Cancellations in Chicago continued through Sunday, joined by 100 canceled flights at New York’s John F. Kennedy International Airport. Smaller regional airports—in Albany, Syracuse, Rochester, and Connecticut—are seeing about half each day’s flights canceled. Boston, however, looks to face the worst cancellations in the Northeast, with about 450 total flights canceled or half the day’s flights at an even larger airport.

These travel disruptions are made worse by the ongoing government shutdown, with federal TSA employees going unpaid and security lines at airports stretching longer than usual.