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 historic and deadly winter storm that stretches over 1,500 miles blanketed the southern U.S. on Tuesday with historic snow totals, including the first-ever Blizzard Warning for the Gulf Coast.

Heavy snow, sleet and ice are making travel conditions treacherous across the region, stretching from Houston into the Florida panhandle.