A powerful blizzard dropped more than a foot of snow (30 centimetres) across parts of the U.S. Northeast on Monday, bringing travel to a near-standstill for millions of residents as the treacherous conditions closed roads, shut train service and forced the cancellation of some 5,700 flights.

Thousands of homes and businesses were without power, and officials, including New York City Mayor Zohran Mamdani, ordered residents to stay off the roads so emergency crews could clear the streets. Many schools were closed throughout the region.

“I’m urging every New Yorker to please stay home,” Mamdani said.

More than 15 inches (38 centimetres) of snow had fallen on New York City’s Central Park by 8 a.m. Eastern time on Monday and another 5 to 6 more inches (13-15 centimetres) are expected to fall before the storm tapers off by late afternoon, said Bob Oravec, a meteorologist with the National Weather Service’s Weather Prediction Centre.

Winds can blow snowdrifts several feet high.

“It’s a pretty big storm, and it’s definitely a blizzard” with wind gusts of 40 to 60 mph (64-100 kph) from Delaware to New York City to Boston, Oravec said. “It’ll probably take a week to dig out.”

Boston has received about 6 inches so far, but much of Delaware and southern New England have already received 12 to 18 inches, and Philadelphia has already received a foot of snow.

The storm is expected to taper off in New York City by Monday afternoon but Boston and upper New England will see snow through Monday night.

Many were astounded by the depth of the snowfall. In her 20 years or so living in New Hyde Park, on hard-hit Long Island, Sandra Wu has never seen a winter storm this bad. Her family cannot open the front door and can barely see out of some windows because of the high snowdrifts.

“My husband went out early through the garage to start digging us out, but it was pointless,” Wu said.

Wu, 53, a veterinarian, said the storm, which had dropped about 18 inches of snow, reminds her of the storms in the 1990s when she lived in Buffalo, New York, which gets an average annual snowfall of 92 inches.

Her two children, ages 13 and 5, were thrilled to have a snow day off from school, so they slept in.

“We thought we’d lose power, thankfully not,” she said. “So we’re baking today. There’s nothing else to do while we wait for the snow to stop.”

REGIONAL EMERGENCIES

At least seven U.S. states had declared states of emergency in response to the storm as of Monday.

Airlines had cancelled more than 5,700 flights by Monday morning and delayed another 900, according to the tracking site FlightAware.com. More than 1,600 Tuesday flights had already been cancelled, according to the site. Most of the cancellations and delays were in the northeastern U.S., including New York’s John F. Kennedy International and LaGuardia airports, Boston’s Logan Airport, and New Jersey’s Newark Liberty International Airport.

New York Governor Kathy Hochul said she had activated 100 National Guard members to assist in Long Island, New York City and the lower Hudson Valley, areas expected to bear the brunt of the heavy snow and coastal winds. The storm forced the closure of the U.N. headquarters complex in Manhattan on Monday.

Parts of the Northeast could see up to two feet of snow, and wind gusts could reach 70 mph, raising the risk of falling trees and power outages, according to the Department of Homeland Security.

In an update on Sunday, the agency said despite its ongoing funding lapse, the Federal Emergency Management Agency’s disaster‑response work continues uninterrupted, including staff travel, emergency operations and critical assistance for people affected by active disasters, with life safety and property protection remaining top priorities.

Last week, Reuters reported the Trump administration had ordered FEMA to suspend the deployment of hundreds of aid workers to disaster-affected areas around the country while the DHS is shut down.

Massachusetts Governor Maura Healey declared an emergency and told state workers to stay home. Connecticut barred commercial vehicles from limited-access highways, exempting only emergency and essential deliveries.

Train and bus commuter lines in New Jersey were halted, while the Rhode Island Public Transit Authority said it would suspend all service from Sunday night through Monday and would announce plans to resume service only when conditions improve.

Even some ships were caught by the storm. Wu said her elderly in-laws were stuck on a cruise ship docked in New York Harbour, which cannot start sailing to the Bahamas on a planned vacation.

But Wu said they were enjoying themselves despite the delay.

“They are having the best time with 20 of their friends, eating well with plenty of entertainment,” while they wait for the storm to pass, Wu said.