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.

Electric Reliability Council of Texas (ERCOT) told Newsweek: "ERCOT has issued a Weather Watch from January 20-23 due to predicted extreme cold weather across the ERCOT region, higher electrical demand, and the potential for lower reserves. Winter precipitation is also expected across parts of the state.