A rare frigid storm charged through Texas and the northern Gulf Coast on Tuesday, blanketing New Orleans and Houston with snow that closed highways, grounded nearly all flights and canceled school for more than a million students more used to hurricane dismissals than snow days.

A rare winter storm charging through Texas and the northern Gulf Coast on Tuesday has closed highways and airports and prompted the first blizzard warning for southeast Texas and southwest Louisiana.

Dangerous below-freezing temperatures with even colder wind chills were also expected to last over much of the week in the region. Authorities say three people have died in the cold weather.