The storm was forecast to bring the heaviest snow so far this winter along the New England coast, threatening power and transport links for tens of millions of people.

By late Friday, New York, one of the world's busiest air travel hubs, was cut off from the skies as snow and wind led airlines to suspend all operations at LaGuardia, Newark Liberty and John F. Kennedy International airports.

In Massachusetts alone, more than 255,000 homes and businesses were without power by late evening and the number was expected to rise, the Boston Herald reported.

A gust of 74 miles (119 kilometers) per hour winds was reported on Nantucket Island.

LaGuardia general manager Tom Bosco told NY1 television that the airport was "battling" the storm and would strive to remain open even after the airlines shut down for the night.

He estimated that if a foot (30 centimeters) of snow fell -- the worst-case scenario forecast for New York -- flights would resume "probably by mid-morning."

The heaviest impact of the storm was expected overnight in and around Boston, and Governor Deval Patrick temporarily ordered all normal traffic off Massachusetts roads, with the threat of up to a year in jail for violators.

"There are a number of exemptions for... emergency workers and the like. Please exercise caution and use common sense," Patrick said at his emergency center in Framingham.

In Connecticut, Governor Dannel Malloy issued a "ban on motor vehicle travel on limited access highways" to free up emergency services traffic and suspended commuter train service between New York and New Haven, Connecticut.

Rhode Island, where some of America's most exclusive summer homes are located, also instituted driving restrictions.

In addition to the road and air snarl-ups, the rail service Amtrak said trains from New York northbound and also southbound to the capital Washington were being suspended.

The storm came a little over three months after Hurricane Sandy devastated swathes of New York and New Jersey, killing 132 people and causing damage worth some $71.4 billion.

Snow began in light flurries across the region early Friday, but thickened and by Saturday was expected to leave depths of between half and one foot in New York and as much as two feet in Boston.

"In addition to the heavy snowfall, wind gusts of up to hurricane force are possible, especially near the coast," the National Weather Service warned. "This will result in blizzard conditions with drifting and blowing snow."

Travel at night "will be extremely hazardous, if not impossible," it added.

Among the more glamorous victims of the travel upsets was designer Marc Jacobs, who said he had to reschedule his two shows at New York Fashion Week due to storm-related "production problems."

New York Mayor Michael Bloomberg, who came under withering criticism for the city's flat-footed response to a blizzard in 2010, said residents should stock up with vital supplies and prepare for the worst.

"Stay off the city streets, stay out of your cars," he said at a news conference. "Staying off the streets will make it easier for city workers to clear the streets of snow."

New York's four zoos also announced they were closing for the duration of the storm.

"You can't take nature too lightly. Hopefully it won't be anything too drastic," Bloomberg said.

The good news was that the storm's peak was due as the weekend began, meaning far fewer people would be on the roads. Forecasters said the system should blow through on Saturday, with milder temperatures to follow.

Locals were comparing the coming storm to the ferocious blizzard of 1978, which killed 100 people and buried Boston in more than 27 inches (69 centimeters) of snow and Providence, Rhode Island in nearly 28 inches.

During that storm, people were forced to abandon cars stuck on highways and made their way around Boston on cross country skis and snowshoes.