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

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.

Heavy snow and freezing temperatures are hitting parts of Texas and the Gulf Coast, causing travel disruptions and prompting a number of Southern governors to declare states of emergency. Winter weather — including low temperatures and storms — involves a number of risks,