The latest bout of extreme weather came about a week after a monster storm pummeled a wide swath of the United States, killing more than 100 people and leaving many communities struggling to dig out from snow and ice.

Heavy snow fell in North Carolina and neighboring states Saturday, as authorities urged residents to stay off the roads and warned oceanfront structures were threatened by the storm.

All of North and South Carolina, and portions of Georgia, eastern Tennessee and Kentucky, as well as southern Virginia were under a winter storm warning.

North Carolina saw 750 car crashes on Saturday, the highway patrol said.

Faust, North Carolina recorded 14.5 inches (37 cm) of snow, while West Critz, Virginia got 12.5 inches. Harrisburg, Tennessee received more than nine inches of accumulation.

In the North Carolina town of Cape Carteret, high winds sent thick snow blowing sideways, prompting the National Weather Service to warn that travel was "Treacherous and Potentially Life-Threatening especially if you become stranded."

In dramatic footage released by police in Gastonia, North Carolina, a train plowed at high speed into a semi-truck that had gotten stuck on the tracks, crushing the vehicle. No one was hurt.

The weekend storm forced more than 1,800 flight cancellations Saturday and Sunday at Charlotte Douglas International Airport in North Carolina, a major hub for American Airlines, data from the tracker FlightAware showed.

A 300-strong "snow team" was working to clear runways, taxiways, roads and sidewalks, the airport said Saturday.

More than 600 flights were cancelled Saturday at Atlanta's international airport, the world's busiest. About 50 flights in and out of Atlanta were cancelled in the early hours of Sunday.

"An explosively deepening coastal cyclone will continue to bring moderate to heavy snow, high winds, and possibly blizzard conditions for the Carolinas," the National Weather Service said Saturday.

"An intense surge of arctic air behind the coastal storm will send below freezing temperatures down toward South Florida by Sunday morning."

Davis, West Virginia recorded the lowest temperature in the lower 48 states on Saturday -- a frigid minus 28F (minus 33C).

About 156,000 customers remained without power early Sunday, mostly in the south, according to poweroutage.us, with Mississippi, Tennessee and Louisiana hardest hit.

In North Carolina, the National Park Service announced the closure of campgrounds and some beaches at the Outer Banks, a series of barrier islands off the coast of the southern state that are vulnerable to storms.

It said oceanfront structures were threatened, and a section of highway that threads through its dunes was closed.

In Mississippi, Governor Tate Reeves said the US Army Corps of Engineers helped to install generators at critical sites, and authorities were opening 79 shelters and warming centers across the state.

The freezing weather forced NASA to postpone a key fueling test over the weekend of the 322-foot (98-meter) rocket that is on the Cape Canaveral launch pad in Florida.

That in turn is likely to push back by at least a couple of days a planned manned Moon flyby slated for this month.