Most of the United States is being assailed with extreme winter weather this week as Arctic air blasts south from Canada, snow tracks up the Northeast coast and a potentially crippling winter storm takes aim at the South.

It's been a while since it last snowed in Mobile, but snow is in the forecast for the city on Tuesday, and a winter storm watch is in effect. The photo above is from the Mobile office of the National Weather Service from a rare south Alabama snow in December of 1996. Joe Maniscalco/National Weather Service

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

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.

A winter storm will affect New York and the surrounding area starting Sunday. From 1 p.m. Sunday to 4 a.m. Monday, the tri-state area is expected to be hit with snow, according to the National Weather Service.

The entire Delaware Valley will see snow Sunday, with 3-6 inches expected in Philadelphia. On Monday and Tuesday, temps plummet into the teens and single digits.

Snowfall forecasts have increased for a winter storm expected to blanket New Jersey with widespread areas of 4 to 8 inches of snow. Winter storm warning areas were expanded early Sunday and a state of emergency is in effect. National Weather Service and AccuWeather

The good news/bad news is that bitterly cold air will move into the state overnight Sunday, dropping morning lows into the mid-teens for north Alabama and the upper teens as far south as Montgomery. Daytime highs may not get out of the 30s in central Alabama until Wednesday,