BOSTON (AP) — Tens of millions of residents along the East Coast are bracing for several inches of snow Sunday followed by dangerously cold temperatures that will grip much of the country from the Northern Plains to the tip of Maine.

Winter storm warnings issued by the National Weather Service have already gone into effect for parts of the Mid-Atlantic through Monday morning, with the forecast projecting up to a half foot (15 centimeters) of snow. Warnings will begin in New England on Sunday afternoon, with parts of Massachusetts, New Hampshire, Maine and Connecticut seeing as much as 10 inches (25 centimeters) of snow.

Marc Chenard, a meteorologist with the National Weather Service in College Park Maryland, projected that as many as 70 million residents will be under some kind of winter storm warning in the coming days including in New England and the Mid-Atlantic. Large cities such as Philadelphia, New York and Boston could see several inches of snow this evening with the highest totals accumulating outside of major cities.

“There will certainly be some more hazardous road conditions anywhere from D.C. up the whole I-95 corridor and then inland from there later today and tonight,” Chenard said. “Then it gets quite cold behind that. By Monday morning, any roads that haven’t been treated or cleared will still likely be some hazardous travel conditions.”

The snowfall was disrupting airline flights along the Eastern Seaboard. Nearly 130 flights at New York City-area airports were canceled and nearly 90 others were delayed, according to the FlightAware flight tracking service. Dozens of flights also were canceled or delayed at airports around Washington, D.C., and Boston.

In New York City, Mayor Eric Adams urged city residents to take the subway and buses if they have to travel during the storm, making the task easier for crews to clear the streets. He said people who need help with heating or frozen pipes can call 311, and he asked residents to check on their neighbors during the frigid weather.

“Cold temperatures, high winds tomorrow, could be dangerous,” Adams told reporters on Saturday afternoon. “We have to be here for each other and make sure our pets and other parts of New York are safe.”

The weather service said there was a chance of snow showers Sunday afternoon and evening in western New York state, where the Buffalo Bills are hosting the Baltimore Ravens in an NFL playoff game starting at 6:30 p.m.. Heavier, lake-effect snow was expected in that part of the state Monday through Wednesday morning, with 2 feet to 3 feet (about 60 to 90 centimeters) possible in some areas including Oswego along Lake Ontario.

New Jersey Gov. Phil Murphy declared a state emergency for all 21 counties in the Garden State. A winter storm warning was in effect for 10 counties in the northern part of the state, where 6 to 8 inches (15 to 20 centimeters) of snow is expected to fall from Sunday afternoon through the late evening.

Cities and towns were opening warming centers for the next several days to protect people from the freezing temperatures.

Return of the Arctic blast

But the snow is just the start of a chaotic week of weather.

Much of the Eastern Seaboard will be enduring some of the coldest temperatures this winter.

An area from the Rockies into the Northern Plains will see colder than normal temperatures over several days with temperatures dropping to minus 30 degrees F (minus 34 degrees C) to minus 55 F (minus 48 C) on Sunday and Monday. Wind chills of minus 40 F (minus 40 C) were already recorded in parts of North Dakota and Minnesota. Sub-zero wind chills are forecast to reach as far south as Oklahoma and the Tennessee Valley.

Minnesota residents were urged to wear appropriate clothing and carry a survival kit for travel. Kristi Rollwagen, director of homeland security and emergency management at the Minnesota Department of Public Safety, also urged motorists to drive with a full tank of gas and a fully charged cellphone to keep in touch with loved ones.

“It’s not something we haven’t experienced before, it’s just a good reminder that it does get cold in Minnesota,” Rollwagen said.

The cold weather forecasted for Monday for Washington, D.C., prompted President-elect Donald Trump's inaugural ceremony to be moved inside the U.S. Capitol Rotunda.

“It’s going to be a cold day in Washington, D.C. on Monday. That's for sure,” Chenard said, noting temperatures will be in the 20s with wind gust upwards of 30 mph (48 kph).

As happened earlier this month, this latest cold snap comes from a disruption in the polar vortex, the ring of cold air usually trapped about the North Pole.

The cold air will moderate as it moves southward and eastward, but the Central and Eastern U.S. will still experience temperatures in the teens and 20s Monday into Tuesday, Chenard said. The Mid-Atlantic and Northeast also will have highs in the teens and 20s, lows in the single digits and below zero degrees F (minus 18 C) and wind chills below zero.

Unusual mix of snow, sleet and freezing rain

The colder temperatures will dip into the South early this week, where as many as 30 million people starting Monday could see a wintry mix of snow, sleet and freezing rain. The unusual conditions are expected to stretch from Texas into northern Florida and the Carolinas. Impacts are expected starting Monday night in Texas and then spreading across the Gulf Coast and Southeast on Tuesday into Wednesday.

Frigid air combined with a low-pressure system over the Gulf is behind the storm, which could bring heavy snow just south of the Interstate 20 corridor across northern Louisiana and into Mississippi and a mix of snow, sleet, and freezing rain near the Interstate 10 corridor from Houston to Mobile, Alabama.

Louisiana Gov. Jeff Landry on Saturday issued a state of emergency ahead of the severe weather, urging residents to prepare and keep watch on the forecast.

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Julie Walker contributed to this report from New York. She can be reached at https://x.com/jwalkreporter. Dave Collins contributed from Hartford, Connecticut. Bruce Shipkowski contributed from Toms River, New Jersey.

A light snow shrouds the skyline as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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A motorist struggles to move along Pearl Street as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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A motorist clears snow off his vehicle parked along First Avenue as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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Electric scooters covered in snow sit idle along Galapago Street as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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A motorist clears ice and snow from the windshield of a vehicle as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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A person takes a break from clearing a walkway along Bannock Street as a winter storm sweeps over the intermountain West, plunging temperatures into the single digits and bringing along a light snow in its wake Saturday, Jan. 18, 2025, in Denver. (AP Photo/David Zalubowski)

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A man walks around Culler Lake in Frederick, MD during the snowfall on Sunday, Jan. 19, 2025. (Ric Dugan/The Frederick News-Post via AP)

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Snow is cleared as the first half ends of an NFL football NFC divisional playoff game between the Philadelphia Eagles and the Los Angeles Rams on Sunday, Jan. 19, 2025, in Philadelphia. (AP Photo/Matt Slocum)

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Philadelphia Eagles linebacker Nolan Smith Jr. sticks his tongue out as it snows before an NFL football NFC divisional playoff game against the Los Angeles Rams on Sunday, Jan. 19, 2025, in Philadelphia. (AP Photo/Matt Slocum)

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