The next round of bitter cold is set to envelop the southern U.S. on Tuesday, after the first significant winter storm of the year blasted a huge swath of the country with ice, snow and wind

The plunging polar vortex brought subfreezing temperatures Tuesday to some of the southernmost points of the U.S., threatening to dump snow on parts of Texas and Oklahoma in coming days and contributing to a power outage in Virginia's capital that made the water unsafe to drink.

Temperatures are plummeting to the 20s for the rest of the week. Overnight lows will drop to the single digits.

Bitterly frigid conditions will blanket southern Louisiana, with temperatures today, tomorrow, and Thursday topping out in the mid- to upper-40s.

For tonight, expect mostly clear skies with lows near 21 degrees. McDonald's says it is rolling back some of its diversity practices 12 Best Shade Perennials That Won’t Take Over Your Garden What to Know About Trudeau’s Resignation Adrien Brody Nears Tears During Golden Globe Win: ‘I Felt This May Never Be a Moment Afforded to Me Again' I've been on 50 cruises.

The winter storm is over and now the Arctic deep freeze clamps down through midweek. After a few morning flurries we'll end up mostly cloudy with highs in the mid to upper 20s Tuesday.