An arctic air mass sprawling across the eastern, central and parts of the western U.S. on Monday will channel temperatures 20-30 degrees below already historically cold January averages and was poised to slam parts of the South with a disruptive winter storm.

The National Weather Service has issued a Winter Storm Watch for parts of northern and northeast Florida, as well as southeast Georgia, effective from late Tuesday night through Wednesday afternoon.

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.