Another blast of winter storms in the U.S. on Thursday closed schools, snarled flights and put millions of residents across the South under warnings of snow and freezing rain that could cause dangerous travel conditions.

Schools as far south as El Paso, Texas, closed due to a polar vortex that has brought historically low temperatures and snowfall to parts of the U.S.

Storm Cora will bring a round of snow and ice to many southern cities, including Dallas, Atlanta, Memphis and Raleigh. Several inches of snow and some ice will fall from Texas to Georgia and the Carolinas through Saturday.