The storm, which complicated travel Saturday and upended plans for the three-day weekend across much of the country, had already caused problems from Kansas, where the governor declared an emergency, to Chicago, where a United Airlines plane slid off the pavement.
Flights have been canceled by the thousands, and rapidly dropping temperatures Sunday in parts of the Northeast would freeze anything wet, creating “extremely dangerous” conditions on the roadways.
By late Saturday afternoon, the worst of the storm was crossing the Appalachian Mountains and advancing toward the East Coast, where the brunt of the snowfall was expected overnight Saturday and into Sunday. But the scope of the extreme weather remained impressive, with precipitation falling from southeast Missouri to upstate New York.
In Alabama, a tornado tore through the town of Wetumpka, about 15 miles northeast of Montgomery. Images of the devastation showed the remains of homes and churches, and Jerry Willis, the mayor, told reporters that a senior citizens center had been destroyed.
Some areas of New York were expected to get a wintry cocktail of snow, sleet, rain and ice, followed by plummeting temperatures.
Rich Otto, a National Weather Service meteorologist, said he expected the worst of the storm to move past New York City, where only 2 or 3 inches were forecast, by Sunday morning. In New England, the storm was expected to pass by Sunday night.
A United Airlines plane slid off the pavement at Chicago O’Hare International Airport on Saturday while it was turning off a runway. No injuries were reported. The night before, at Eppley Airfield in Omaha, Nebraska, a Southwest Airlines plane slid off the runway after landing.
Two people died in Kohler, Wisconsin, on Friday night after a car they were riding in slid off a slick, snow-covered interstate and struck a tree, police said. In Kansas, the state Department of Transportation said one of its drivers died Saturday in a crash south of Kansas City.
This article originally appeared in The New York Times.