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.

North Florida residents from Pensacola to Jacksonville are bracing for what is expected to be a historic, once-in-a-lifetime winter storm.

The heaviest snowfall in the Sunshine State occurred around Pensacola, where spotters reported measuring amounts of 5 to 12 inches through Tuesday evening. Due to the hazardous weather and a series of crashes, a nearly 70-mile stretch of Interstate 10 was shut down by the Florida Highway Patrol.