BOSTON (AP) — A storm with wind gusts near hurricane force lashed the Northeast on Saturday, dropping heavy snow, causing coastal flooding and threatening widespread power outages while forecasters warned conditions would worsen and then be followed by bitter cold.

The nor’easter thrashed parts of 10 states and some major population centers, including Philadelphia, New York and Boston. By midday, more than 18 inches (45 centimeters) of snow had fallen on parts of New Jersey’s shore and eastern Long Island.

Areas closest to the Atlantic coast bore the brunt. Boston, in the nor’easter’s crosshairs, could get more than 2 feet (61 centimeters) of snow. Winds gusted at 70 mph (113 kph) or higher at several spots in Massachusetts, including Nantucket Island and Provincetown, at the tip of Cape Cod.

Most flights into and out of the airports serving New York, Boston and Philadelphia were canceled Saturday, according to FlightAware. More than 4,500 flights were canceled across the U.S. Amtrak canceled all its high-speed Acela trains between Boston and Washington and canceled or limited other service.

Across the region, residents hunkered down to avoid whiteout conditions and stinging snow hurled by fierce winds. Business closed or opened late.

“My boyfriend is out driving a plow, and I had a bunch of cleaning to do at home, and I want a drink while I’m doing it,” she said, as she called the store to find out if it planned to open at all. “It’s a good day to stay inside and clean.”

Video on social media showed wind and waves battering North Weymouth, south of Boston, flooding streets with a slurry of frigid water. Other video showed a street underwater on Nantucket and waves crashing against the windows of a building in Plymouth.

In the seaside town of Newburyport, near the New Hampshire border, officials encouraged residents along the shore to move to higher ground.

Over 100,000 homes and businesses lost power in Massachusetts, with failures mounting. No other states reported widespread outages.

The storm had two saving graces: Dry snow less capable of snapping trees and tearing down power lines, and its timing on a weekend, when schools were closed and few people were commuting.

Parts of 10 states were under blizzard warnings: Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York and New Jersey, along with much of the Delmarva Peninsula in Delaware, Maryland and Virginia. Officials in all those states warned people to stay off the roads.

Rhode Island, all of which was under a blizzard warning, banned all nonemergency road travel.

In West Hartford, Connecticut, a tractor-trailer jackknifed on Interstate 84, closing several lanes. Massachusetts banned heavy trucks from interstate highways.

New York Gov. Kathy Hochul advised people to stay home as the storm lingered longer than expected, and she warned of below-zero windchills after it passes. The state had declared a state of emergency Friday evening.

“This is a very serious storm, very serious. We’ve been preparing for this. This could be life-threatening,” Hochul said. “It’s high winds, heavy snow, blizzard conditions — all the elements of a classic nor’easter.”

In Philadelphia, where 6 inches (15 centimeters) fell by early Saturday, few drivers ventured onto streets covered in knee-high drifts.

Delaware allowed only essential personnel to drive in two of its three counties.

Virginia, where a blizzard this month stranded hundreds of motorists for hours on Interstate 95, did not hesitate to get resources at the ready.

Ocean City, Maryland, recorded at least a foot (30 centimeters) of snow. Maryland State Police tweeted that troopers had received more than 670 calls for service and responded to over 90 crashes by midmorning.

Hardy New Englanders took the storm in stride.

Dave McGillivray, race director for the Boston Marathon, jokingly invited the public to his suburban Boston home on Saturday for a free snow-shoveling clinic.

“I will provide the driveway and multiple walkways to ensure your training is conducted in the most lifelike situation,” he said.

Washington and Baltimore got some snow but were largely spared. The worst of the nor’easter was expected to blow by Sunday morning into Canada, where several provinces were under warnings.