PHILADELPHIA -- Thousands of flights were cancelled, students got an extra day off from school or were being sent home early, and the federal government closed its offices in the Washington area Tuesday as another winter storm bore down on the U.S. Mid-Atlantic and Northeast.

The National Weather Service said the storm could bring 10 to 14 inches (25 to 35 centimetres) of snow to Philadelphia and southern New England and up to a foot (30 centimetres) in New York City, to be followed by bitter cold. An arctic air mass will plunge the eastern half of the United States into a deep freeze, with wind chills as low as 40 degrees Fahrenheit below zero (-40 Celsius), the weather service said.

It warned of heavy winds and hazardous driving conditions as the storm moved up the East Coast.

With federal workers told to stay home on Tuesday, Tom Ripley, who works at a Washington hardware store, said his morning commute was cut in half because "there was almost no one on the road."

He said the store was jammed Monday as customers stocked up on ice melt and shovels.

"Nobody prepares because we never get any snow, so the slightest chance of it, everybody freaks out," Ripley said.

Nearly 2,200 flights were cancelled and thousands more delayed Tuesday, with airports from Washington to Boston affected, according to flight-tracking site Flightaware.com. An additional 450 flights for Wednesday were already cancelled.

Schools in Pennsylvania, New Jersey, Connecticut, Virginia, West Virginia and Kentucky stayed closed for an extra day after the Martin Luther King Jr. Day holiday, or planned to send students home early. Some parents kept their kids home even if their schools were open, unwilling to put them on slippery roads.

New Jersey Gov. Chris Christie was forced to modify his schedule of inaugural events -- cancelling an evening party on Ellis Island -- because there was fear snow would make travel dangerous.