Around 40 million people in the U.S. are under a winter storm warning from an unusual blast of severe cold weather and snow across the South.

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

A historic, dangerous and deadly winter storm stretching over 1,500 miles is blanketing the southern U.S. with heavy snow, including areas of the Texas and Louisiana Gulf coasts under their first-ever Blizzard Warnings.