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

Frigid temperatures engulfed the South on Monday ahead of a winter storm that's expected to spread heavy snow and disruptive ice around a region from Texas to north Florida that rarely sees such weather,

Preparations are underway from Houston to Atlanta as a rare winter storm sets its sights on the southern U.S., where it's expected to bring a messy mix of heavy snow, sleet and freezing rain that could have a major impact on travel and daily life.