A rare frigid storm charged through Texas and the northern Gulf Coast on Tuesday, blanketing New Orleans and Houston with snow, closing highways, grounding nearly all flights and canceling school for millions of students more used to hurricane dismissals than snow days.

A rare winter storm churned across the U.S. Gulf Coast on Tuesday, breaking snowfall records more than a century old in a southern region where flurries are unusual, as much of the United States remained in a dangerous deep freeze.