A major winter storm slammed the southern US Tuesday, blanketing parts of the Gulf Coast with record-breaking snowfall in a region largely unaccustomed to extreme winter weather.

A rare frigid storm is charging through Texas and the northern Gulf Coast, blanketing New Orleans and Houston with snow, closing highways and grounding nearly all flights.

The latest closure means that nearly three-quarters of Louisiana’s portion of the coast-to-coast highway is shut. A rare winter storm brought record snowfall to the state on Tuesday.