More than 30 million Americans are under a winter storm warning in the Southern US after historic snow storms hit Louisiana and Texas late Monday night into Tuesday morning. The National Oceanic and Atmospheric Administration's Weather Prediction Center reported "life-threatening cold and wind chills".

A rare winter storm churned across the U.S. Gulf Coast on Tuesday, bringing heavy snow, ice and wind gusts to a region where flurries are unusual, while much of the United States remained in a deep freeze.

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.