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.

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.

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.