More than 4,000 flights were canceled in the US on Saturday ahead of a monster winter storm that has already cut power to more than 160,000 electricity customers as far west as Texas, and threatened to paralyze eastern states with heavy snowfall.
Forecasters said snow, sleet, and freezing rain, accompanied by dangerously frigid temperatures, would sweep the eastern two-thirds of the nation on Sunday and into next week.
Calling the storms "historic," US President Donald Trump on Saturday approved federal emergency disaster declarations in South Carolina, Virginia, Tennessee, Georgia, North Carolina, Maryland, Arkansas, Kentucky, Louisiana, Mississippi, Indiana, and West Virginia.
"We will continue to monitor, and stay in touch with all States in the path of this storm. Stay Safe, and Stay Warm," Trump wrote in a post on Truth Social.
Seventeen states and the District of Columbia have declared weather emergencies, the Department of Homeland Security said.
"We do have tens of thousands of people in affected states in the South that have lost power. We have utility crews that are working to restore that as quick as possible," DHS Secretary Kristi Noem said late Saturday afternoon.
The number of power outages continued to rise. As of 10:17 p.m. EST, more than 160,000 US customers had no electricity, the bulk of them in Louisiana and Texas, according to PowerOutage.com.
The US Department of Energy on Saturday said it issued an emergency order authorizing the Electric Reliability Council of Texas to deploy backup generation resources at data centers and other major facilities, aiming to limit blackouts in the state.
The US National Weather Service warned of an unusually expansive and long-duration winter storm that will bring widespread, heavy ice accumulation in the southeast US, where "crippling to locally catastrophic impacts" can be expected.
Weather service forecasters predicted record cold temperatures and dangerously cold wind chills descending further into the Great Plains region of the US by Monday.
As of 10:21 p.m. EST, more than 4,000 US flights scheduled for Saturday had been canceled, according to flight tracking website FlightAware. More than 9,400 US flights originally set for Sunday have also been canceled.
Major US airlines warned passengers to stay alert for abrupt flight changes and cancellations.
In an update on Saturday morning, Delta Air Lines said it was continuing to make schedule adjustments, with additional cancellations in the morning for Atlanta and along the East Coast, including in Boston and New York City.
It added it was relocating experts from cold-weather hubs to support de-icing and baggage teams at several southern airports.
JetBlue said that as of Saturday morning it had canceled about 1,000 flights through Monday, with additional cancellations possible.
United Airlines said in an email that its weather preparations included proactively canceling some flights in places with the worst weather.
Frigid weather stresses US electric grid
U.S. electric grid operators on Saturday stepped up precautions to avoid rotating blackouts.
Dominion Energy, whose Virginia operations include the largest collection of data centers in the world, said if its ice forecast holds, it could be among the largest-ever winter events to affect the utility's operations.
Noem, speaking at a news conference about US government preparations for the storm, warned Americans to take precautions.
"It’s going to be very, very cold," Noem said. "So we'd encourage everybody to stock up on fuel, stock up on food, and we will get through this together.
'Take the storm seriously,' National Weather Service warns
This follows a warning from the NWS on Friday that the storm would be set to affect 40 states throughout the weekend, including heavy snow, freezing rain, and sleet.
According to the data shared by the NWS, people in the North-East coast and the center of the country are expected to see heavy rains and snow in the coming days, with a warning of "considerable disruptions to daily life" issued by the authorities.
"Take this storm seriously, folks," said the NWS in a statement, and added, "Hazardous to impossible driving conditions are expected. Avoid travel if at all possible. Widespread closures and disruption to infrastructure may also occur."