Another blast of winter storms is closing schools, snarling flights and putting millions of residents on alert across parts of the Deep South and south-central U.S. The storm started dumping a mix of sleet and heavy snow Thursday morning in north Texas and Oklahoma, where schools canceled classes for more than 1 million students.

An area stretching from Texas to Tennessee is bracing for an expected snowstorm even as some other parts of the U.S. hit by the plunging polar vortex this week are beginning to shake off its icy effects.

In Virginia, state vaccine coordinator Dr. Danny Avula said the state could hit Biden’s goal earlier. But several governors cautioned it must come with a dramatic increase in vaccine supply. “It could be a delay for people to actually get a vaccine because of the operational constraints," she said. We can’t disappoint people who eagerly want a vaccine,” said Pat Allen, director of the Oregon Health Authority. Elsewhere, governors met Biden's goal with enthusiasm.