IE 11 is not supported. For an optimal experience visit our site on another browser.

Snow Storm Forecast to Wallop East Coast Takes Shape Over Plains

A colossal winter storm forecast to bring heavy snow to at least 15 states over the weekend was taking shape early Thursday.

A colossal winter storm gathered strength over the central United States on Thursday and began moving east, where it was expected to dump heavy snow on at least 15 states, with a bulls eye on the nation's capital.

The impact of the storm was daunting: 80 million people were under either a blizzard watch, winter storm watch, winter storm warning, winter weather advisory or freezing rain advisory.

Washington, D.C. may get the worst of it: about 2 feet of snow and dangerous blizzard conditions from Friday through Sunday. The impact on the city — as well as Baltimore, Maryland, and Charlotte, North Carolina — could be "historic," NBC meteorologist Bill Karins said.

But a much wider swath of the country will be impacted in some way. A patchwork of winter storm watches and advisories were in effect over a 1,300-mile area from New Jersey to Mississippi to Nebraska. Other major cities in the watch area included Philadelphia; Richmond, Virginia; and Memphis and Nashville in Tennessee.

"This will be bad," said Kevin Roth, lead meteorologist at The Weather Channel. "It is going to snow hard and it's going to be hard for road crews to keep up so driving will be difficult."

Roth added that the weather would likely impact air travel.

The storm began building over the central Plains on Wednesday night, scattering snow across South Dakota, Nebraska, Kansas, Missouri, and Arkansas. This system was expected to move eastward through Thursday and Friday before intensifying on Friday night.

In Washington D.C., a precursor to the storm — a relatively light snowfall on Wednesday night — snarled traffic and forced Mayor Muriel Bowser to apologize for the city's slow response. She promised better preparation for Friday, declaring a state of emergency and announcing that public schools would be closed.

Related: 1 Inch of Snow Paralyzes D.C. — and There's 24 More on Way

If the projected 2 feet of snow actually falls in the nation's capital, it will be the city's second-biggest snowstorm ever: The largest was a 1922 storm that produced 28 inches.

The U.S. Senate preemptively postponed Monday votes in anticipation of record snow.

Maryland road crews were also caught unprepared by Wednesday's snow, which Gov. Larry Hogan said frustrated him. He declared a state of emergency and outlined ramped-up preparations for the coming storm, which could dump 1 to 2 feet of snow across the state, making it the worst since 2010.

States of emergency were also declared in Pennsylvania, North Carolina and Virginia.

GALLERY: Will East Coast Storm Top These Monsters?

Elizabeth Chuck and Jon Schuppe contributed.