(NEW YORK) -- The South is bracing for a potentially major winter storm this weekend, impacting Texas, Oklahoma, Louisiana, Arkansas, Mississippi, Alabama and Tennessee.
The storm is still several days away, so exact timing and locations are not yet clear. But as of now, more than 70 million people are under a winter storm watch, from Dallas to Little Rock, Arkansas, to Huntsville, Alabama, to Nashville, Tennessee.
The storm will begin Friday afternoon and evening, bringing snow and ice from Wichita, Kansas, to Oklahoma City to Dallas to Little Rock.
Saturday and Saturday night are expected to be the most dangerous time on the roads, because that's when significant icing and heavy snow are expected.
This kind of ice accumulation from Texas to the Carolinas could cause widespread power outages and downed trees.
The governors of North Carolina and South Carolina have declared a state of emergency ahead of the storm.
Texas Gov. Greg Abbott said he was activating state emergency response resources ahead of the storm, saying the freezing rain, sleet and snow "could create hazardous travel conditions into the weekend and cause impacts to infrastructure."
The system will reach the East Coast by Sunday. The forecast is not yet clear, but up to 6 to 12 inches of heavy snow is possible in some areas.
Besides the snow and ice, another threat will be the dangerously cold temperatures.
Extreme cold alerts have been issued in cities including Minneapolis, Chicago, Oklahoma City, Dallas and Houston.
For some Southern cities – including Dallas, Little Rock and Memphis, Tennessee – the prolonged, bitter cold is expected to continue well after the winter storm passes, and the power outages from the storm could leave residents without heat for some time.
"Please prepare and take precautions in the event of power outages, pipe-bursts, road closures, airport delays, flight cancellations, and freezing temperatures," Department of Homeland Security Secretary Kristi Noem said in a statement. "Federal emergency management is positioning to effectively respond to these conditions, and is prepared to provide aid across the affected areas."
Many airlines are issuing travel alerts and waiving rebooking fees ahead of the storm.
American Airlines and Delta Air Lines have waived rebooking fees, allowing passengers to rebook their flight at no additional cost.
United has issued travel waivers for cities expected to be affected, allowing those who bought tickets on or before Tuesday to rebook without a fee if their travel is affected.
Southwest said its monitoring the weather and will issue any advisories or make any changes as needed.
ABC News' Ayesha Ali contributed to this report.