Residents across parts of the Gulf Coast and South are bracing for a rare winter storm expected to drop heavy snow and create treacherous conditions.

Another Arctic blast of freezing temperatures will test the ERCOT grid during this Martin Luther King Jr. holiday weekend and early next week.

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 accustomed to hurricane dismissals than snow days.