Millions of people across the northern Gulf Coast braced Tuesday for a rare winter storm that’s expected to scatter heavy snow, sleet and freezing rain around the Deep South as a blast of Arctic air plunges much of the eastern U.S. into a deep freeze.

Millions of Americans face an artic blast, including the first-ever blizzard warning for parts of the Gulf Coast.

The snowstorm currently lashing the Gulf Coast is being described as a once in a generation weather event, the National Weather Service said Monday.