BOSTON — Tens of millions of residents along the East Coast are bracing for several inches of snow Sunday followed by dangerously cold temperatures that will take hold in 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 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 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 hazards warning in the coming days including in New England and the Mid-Atlantic. Large cities like Philadelphia, New York and Boston could see several inches of snow this evening with the highest totals being 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.”

New York City Mayor Eric Adams urged city residents to take the subway and buses if they have to travel during the storm, to make it 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 as we navigate through this cold weather condition we expect.”

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 set to host 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 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 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 half of the United States will be enduring some of the coldest temperatures this winter, if not for several years.

An area from the Rockies into the Northern Plains will see colder than normal temperatures starting Sunday into the coming week, with temperatures dropping to minus 30 degrees F to minus 55 F on Sunday and Monday. Wind chills of minus 40 F were already being clocked in parts of North Dakota and Minnesota. Sub-zero wind chills are forecast to reach as far south as Oklahoma and the Tennessee Valley.

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.