Heavy snow is expected to blanket large portions of the Eastern U.S. while much of the country will endure dangerously cold temperatures in the coming days.

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.

Millions of people in the East are bracing for a powerful winter storm packing heavy snow that’s expected to cause major travel disruptions in cities like Washington, Baltimore, Philadelphia, New York City and Boston.