BOSTON — A blizzard of potentially mammoth proportions threatened to strike the Northeast with a vengeance Friday, with up to 2 feet of snow feared along the densely populated Interstate 95 corridor from the New York City area to Boston and beyond.

From Pennsylvania to Maine, people rushed to stock up on food, shovels and other supplies, and road crews readied salt and sand, halfway through what had been a merciful winter.

Before the first snowflake had even fallen, Boston, Providence, R.I., Hartford, Conn., and other New England cities canceled school Friday, and airlines scratched more than 2,600 flights through Saturday, with the disruptions certain to ripple across the U.S.

Forecasters said this could one for the record books.

"This one doesn't come along every day. This is going to be a dangerous winter storm," said Alan Dunham, meteorologist for the National Weather Service in Taunton, Mass. "Wherever you need to get to, get there by Friday afternoon and don't plan on leaving."

The snow is expected to start Friday morning, with the heaviest amounts falling at night and into Saturday. Wind gusts could reach 65 mph. Widespread power failures were feared, along with flooding in coastal areas still recovering from Superstorm Sandy in October.

Boston could get more than 2 feet of snow, while New York City was expecting 10 to 14 inches. Mayor Michael Bloomberg said plows and 250,000 tons of salt were being put on standby. To the south, Philadelphia was looking at a possible 4 to 6 inches.

"We hope forecasts are exaggerating the amount of snow, but you never can tell," Bloomberg said, adding that at least the bad weather is arriving on a weekend, when the traffic is lighter and snowplows can clean up the streets more easily.

Amtrak said its Northeast trains will stop running Friday afternoon. The organizers of New York's Fashion Week — a closely watched series of fashion shows held under a big tent — said they will have extra crews to help with snow removal and will turn up the heat and add an extra layer to the venue.

Blizzard warnings were posted for parts of New Jersey and New York's Long Island, as well as portions of Massachusetts, Rhode Island and Connecticut, including Hartford, New Haven, Conn., and Providence. The warnings extended into New Hampshire and Maine.

In New England, it could prove to be among the top 10 snowstorms in history, and perhaps even break Boston's record of 27.6 inches, set in 2003, forecasters said. The last major snowfall in southern New England was well over a year ago — the Halloween storm of 2011.

Dunham said southern New England has seen less than half its normal snowfall this season, but "we're going to catch up in a heck of a hurry." He added: "Everybody's going to get plastered with snow."

Diane Lopes was among the shoppers who packed a supermarket Thursday in the coastal fishing city of Gloucester, Mass. She said she went to a different grocery earlier in the day but it was too crowded. Lopes said she has strep throat and normally wouldn't leave the house but had to stock up on basic foods — "and lots of wine."

She chuckled at the excitement the storm was creating in a place where snow is routine.

"Why are us New Englanders so crazy, right?" she said.

At a Shaw's supermarket in Belmont, Mass., Susan Lichtenstein stocked up, with memories of a 1978 blizzard on her mind. "This is panic shopping, so bread, milk, a snow shovel in case our snow shovel breaks," she said.

In New Hampshire, Dartmouth College student Evan Diamond and other members of the ski team were getting ready for races at the Ivy League school's winter carnival.

"We're pretty excited about it because this has been an unusual winter for us," he said. "We've been going back and forth between having really solid cold snaps and then the rain washing everything away."

But he said the snow might be too much of a good thing this weekend: "For skiing, we like to have a nice hard surface, so it will be kind of tough to get the hill ready."

The governors of Connecticut and Massachusetts ordered nonessential state workers to stay home Friday.

Terrance Rodriguez, a doorman at a luxury apartment complex in Boston, took the forecast in stride.

"It's just another day in Boston. It's to be expected. We're in a town where it's going to snow," he said. "It's like doomsday prep. It doesn't need to be. People just take it to the extreme."