A strong winter storm moved east across the United States, bringing very different weather to different regions. Parts of the Upper Midwest and Great Lakes saw heavy snow and strong winds, with whiteout or blizzard conditions making travel dangerous and snowfall reaching more than a foot in some areas.

At the same time, the South experienced warm, springlike temperatures, but that warmth is ending fast as a sharp cold front moves in, bringing thunderstorms, rain, and a sudden drop in temperatures. Cities like Atlanta, Dallas, and Little Rock are expected to go from record highs to near-freezing conditions within days.

Forecasters say this powerful storm is fueled by cold air from Canada colliding with unusually warm air in the South, causing snow, ice, rain, and strong winds across much of the country. The storm has already led to many flight delays during the busy holiday travel season, while California, after recent deadly storms and flooding, enjoyed a brief break with drier weather.