Snow was falling in the Mid-Atlantic and New York City on Sunday. The coldest air in several years will descend across much of the country starting Monday, forecasters said.

The updated forecast on timing and track of the storm calls for the snow to end from southwest to northeast as midnight approaches. “The heaviest precipitation looks to occur between roughly 4 and 9 p.m. during which time snowfall rates could reach or exceed 1 inch per hour,” the National Weather Service said.

The snow is likely to fall on Sunday from the Appalachians to New England. New York City may see its largest snowfall in years.

A winter storm warning has been issued for New York, New Jersey and Connecticut as the entire region could get blanketed in snow.

A fast-moving winter storm will sweep across the US Northeast on Sunday, snarling travel and creating frigid windchills that linger into the work week.

Storm Demi is forecast to bring snow to some of the nation’s largest cities, including Washington D.C., New York, and Boston, on Sunday. The winter storm will also usher in cold temperatures in its wake.