At least three people were dead, hundreds of flights were canceled and millions of Americans faced a messy commute Monday as a winter storm brought snow and ice across the East and Midwest.
A stretch of low pressure "associated" with the same winter storm was wreaking havoc from Louisiana to Alabama, the Weather Channel reported, with possible tornadoes, severe thunderstorms, hail and powerful wind gusts leaving thousands without power.
Much of the region was still shivering after a bitter blast of arctic air brought record-smashing temperatures to several cities over the weekend.
The freeze was joined by snow Sunday, with up to a foot expected through Tuesday from western Pennsylvania to northern New England, according to The Weather Channel. '
Freezing rain, ice and lesser snow accumulations were also anticipated across much of the Eastern Seaboard, with a blanket of winter storm warnings and freezing rain advisories in effect from Georgia to Maine.
Snow was also forecast in Michigan.
North of Boston, the coastal community of Revere was grappling with severe flooding: the city's floodgates were left open during the polar vortex, and frozen solid by the blast of arctic air, NBC affiliate WHDH reported.
When high tide arrived, water spilled onto the streets and surged under raised homes, creating a sheet of ice that froze pipes and sent residents to hotels, the station reported.
In Mississippi, at least two tornadoes were reported, the Weather Channel meteorologist Greg Forbes reported,and 14,000 people were in the dark,according to NBC affiliate WLBT. More than an inch of hail fell north of Baton Rouge, the Weather Channel reported, and the roof was blown off a Pizza Hut in the central part of Louisiana.
As of 2:30 pm ET, nearly 4,000 flights had been delayed or canceled across the nation. Ronald Reagan Washington National Airport, Newark Liberty and Baltimore-Washington were the worst affected, suffering nearly 1,000 cancellations and delays, according to Flight Aware.
The snow looked likely to be short-lived in the East, however, with much of it turning to rain overnight and temperatures expected to spike to the mid-50s in Boston by Tuesday, the Weather Channel reported.
Cold weather records across the Northeast were shattered on Valentine's Day after the polar vortex shot a mass of Canadian arctic air south.
Valentine's Day saw temperature records tumble across the region. In Boston, thermometers dipped to minus 9 degrees — the coldest day since Jan. 15, 1957 — while in New York City, Central Park registered minus 1, the lowest reading in 22 years.
Monday looked likely to be warmer — but only just — with lows between 10 to 20 degrees below average and subzero temperatures already recorded across New England in the early hours of the morning.
This article originally appeared on NBCNews.com.