Blizzard warnings were posted for much of the Northeast, with predictions of wind gusting up to 50 mph, the National Weather Service said. Heavy snow warnings were in place from eastern Kentucky to New England.
The weather service predicted as much as 2 feet of snow across the New York metro region. By 8 a.m., a foot had accumulated in Central Park as the flakes fell at a rate of about 2 inches an hour. Philadelphia's northern and western suburbs measured up to 18 inches, the weather service said.
Columbia, Maryland, reported 21 inches of snow by late morning and thousands of customers in that state had no electricity.
The possible accumulation of 16 to 24 inches in New York would make it one of the top 10 snowstorms in city history, the weather service said. The current No. 10 is a storm in February 1961 that dumped 17.4 inches. The record is 26.4 inches in two days following Christmas 1947.
"We seem to be in the heart of the storm," Sanitation Commissioner John Doherty said Sunday morning.
In a rare display, lightning lit up the falling snow in some parts.
Radar showed snow falling from eastern Virginia to Maine as the storm known as a nor'easter crawled up the coast. Behind the storm, pockets of snow were scattered across the Great Lakes and Ohio Valley, south to Tennessee and North Carolina.
Whiteout conditions were reported around Philadelphia and Trenton, N.J., with northerly wind gusting to 40 mph.
Most people stayed indoors, but some were determined to be out and about, including Petter Jorunn of Oslo, Norway, who was visiting New York City. He said he was surprised to see people so affected by the weather, saying New Yorkers are "not wimpy at all, but ill-prepared especially with tires and stuff."
Emil Krupczyn, a mechanic for the U.S. Postal Service, didn't let the snow interfere with his 200-mile drive home to upstate New York from Manhattan, but he figured the journey would take about six hours.
"There's no rushing in this stuff and if you don't have no place to go, don't go," he said as he waited in his car for a street to get plowed.
More than 80,000 customers were without power in Maryland, according to Baltimore Gas & Electric Co. spokeswoman Linda Foy. She said it could be at least 24 hours before power is fully restored.
"It's taking us a long time to even get to the locations where we can begin the restoration process," Foy said.
Power also was out at thousands of homes and businesses in New Jersey, New York's Long Island and Connecticut.
New Jersey Transit suspended all bus service statewide, although most rail service continued operating. Amtrak reported a few cancellations and delays but said most Northeast Corridor trains remained in service.
Most airlines canceled all flights until Sunday afternoon at LaGuardia Airport. Delta, Delta Shuttle and American Airlines canceled all flights at the airport until Monday, said Steve Coleman, spokesman for The Port Authority of New York and New Jersey. Hundreds of flights were canceled at Kennedy and Newark airports.
Delta said it also canceled Sunday arrivals and departures at several other airports including Washington, Philadelphia, Boston, Baltimore, Newark, Providence, Rhode Island, and Hartford, Connecticut.
But the storm was good news for ski resorts after an unseasonably warm January dragged down business, said Betsy Strickler at Jiminy Peak ski resort in western Massachusetts.
"The best PR (public relations) is when people look up in the sky, see the snow start to fall," she said.