Roughly 40 million people from Texas to the Carolinas are under winter weather alerts, as a rare winter storm brings bone-chilling temperatures and potentially historic snowfall to cities unused to harsh cold weather.

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

These weather conditions are expected to cause disruptive winter storm in areas of the South. Freeze warnings were issued for parts of the Gulf Coast and north Florida. Cold air and a developing low-pressure system are predicted to cause a “rare and significant winter storm” in the region,