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.

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

Millions of people living along the Gulf Coast and into the Southeast are bracing for a rare, significant winter storm that’s expected to significantly impact travel and lead to power outages due to heavy snow and ice starting Monday evening.