Tens of millions of Americans are preparing as the ingredients come together for Winter Storm Jonas to evolve into a crippling snowstorm later Friday into the weekend. With Winter Storm Jonas organizing over the Southeast and moisture surging into cold air to the north, rain is changing over to snow on the northwest side of the system.

Conditions will go downhill rapidly through Saturday with blizzard conditions, heavy ice accumulations, strong winds and coastal flooding developing across the East, reported Weather.

As of Thursday night, more than 85 million people – or roughly one in every four Americans – in at least 20 states were covered by either a blizzard watch, blizzard warning, winter storm watch, winter storm warning, winter weather advisory, or freezing rain advisory from Arkansas to the Carolinas to the New York City area.

Governments in Washington, D.C., Virginia and Maryland have declared states of emergency in preparation for the storm, which could dump near-record amounts of snow in some regions, and may bring high winds and flooding along the coast.

As of Thursday morning, the National Weather Service had a winter storm watch in effect for a vast region “stretching from the Tennessee Valley into the interior Carolinas and up into the Central Appalachians / mid-Atlantic region.”

“The heaviest snow should start falling in the mid-Atlantic” region as early as Friday afternoon, and it will “steadily progress” northward toward New York City through Saturday.

“We expect the wind to be very strong with this storm system,” Uccellini said, and forecasts anticipate coastal flooding in many areas, including “in the Delaware Bay area, all the way up the New Jersey Coast to Long Island and New York City.”

He urged people to pay close attention to local forecasts, especially in flood-prone regions.

Washington, Baltimore, Virginia and West Virginia all stand to be “measuring snow in feet,” and there is likely to be “significant icing” further south from there, according to the National Weather Service.

Two feet of snow in D.C. would be close to the record of 28 inches set in 1922, according to NBC News.

Snowfall this winter has so far been light, as the National Weather Service noted in a tweet Jan. 7.