New York, New York - New York Mayor Zohran Mamdani on Sunday ordered the shutdown of the city's entire traffic network for all but emergency travel as a massive snowstorm began to hit the Northeast.

Tens of millions of Americans from Washington DC to Maine prepared for up to two feet of snow forecast in some areas.

The National Weather Service (NWS) said blizzard conditions would "quickly materialize" from Maryland up to southeastern New England, making travel "extremely treacherous."

Snow could fall at a rate of two to three inches per hour at the peak of the storm, with nearly 54 million people in its path, it said.

On Sunday evening, the storm had already begun to hit New York, slashing visibility to the extent that the skyscrapers of Wall Street were barely visible from the adjacent borough of Brooklyn.

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The heavy snow and strong wind gusts are expected to cause major power outages. As of early Monday, over 83,000 customers were without power in New Jersey, according to poweroutage.us.

In New York, Mayor Zohran Mamdani said streets, highways, and bridges would be shut down from 9:00 pm Sunday until noon Monday.

"New York City has not faced a storm of this scale in the last decade," he said, explaining the state of emergency. "We are asking New Yorkers to avoid all non-essential travel."

The ban will not apply to essential workers or New Yorkers needing to travel due to emergencies.

The NWS warned heavy snow, high winds and low visibility were "expected to cause dangerous to impossible travel" conditions.

Gusts of up to 60 miles per hour were expected into Monday, the NWS said.

"The worst is yet to come," New York Governor Kathy Hochul told a press briefing Sunday.

"Whatever you need – any groceries, any medicines you need to be refilled at the pharmacy, any pet food you need to have – do it right now."

Then, she advised, "just settle in."

"Watch some more Olympics, read a book, catch up on the news, call your family members, call your moms – especially your moms."

New Jersey Governor Mikie Sherrill declared a state of emergency beginning midday Sunday, freeing up funds and allowing the swift deployment of resources to address the weather crisis.

In Boston, Mayor Michelle Wu closed all public schools and municipal buildings on Monday.

"We ask everyone to plan ahead, stay safe and warm, and stay off the roads to help our public works and public safety efforts," Wu said.

The NWS said "moderate to major" coastal flooding affecting waterfront roads and properties was possible from Delaware up to Cape Cod in Massachusetts.

The storm comes just weeks after the region recovered from another devastating winter weather system that was linked to more than 100 deaths.