Vicious storms turned a white Christmas into a nationwide nightmare for travelers across the U.S. as blizzards bore down on the Plains and Midwest, rains battered the South, and heavy snows stranded truckers near Texas, where the governor activated emergency resources on a frightful Christmas Eve.

The massive stormfront blowing through the nation's midsection left many residents without power and threatened travelers crawling along the slick, icy roads, while others were forced to contend with delayed and canceled flights.

The worst of the storm was heading northeast across the region Thursday, where a foot or two of snow was expected in some areas by Christmas Day. Well to the south, dozens of truckers and other motorists were forced to seek shelter at an Oklahoma truck stop after being forced off the road by howling winds as a winter storm blows through the state.

The National Weather Service issued blizzard warnings early Thursday for Kansas, western North Dakota, northern Minnesota and northwestern Nebraska. It cautioned that travel would be extremely dangerous in those areas through the weekend and that anyone taking to the road should pack a winter survival kit including flashlight and water in case of emergency.

It also warned of strong winds and more snow with poor visibility in South Dakota, particularly in the west. Rain, sleet and snow were forecast in western Iowa and Wisconsin.

And the weather took a life near the Gulf of Mexico, as powerful thunderstorms swept across Louisiana, producing high winds and possible tornadoes. Louisiana police said a man died and his wife was injured when the wind toppled a tree onto their home Thursday morning.

Scott Blair, a National Weather Service meteorologist in Topeka, Kan., said the wind was becoming a serious issue in central Kansas, with wind speeds of up to 25 mph and gusts reaching 40 mph.

"We're going to see blowing snow," Blair said. "The big concern comes later when we see snowfall with the wind, causing reduced visibility."

Road conditions were particularly bad in northwest Kansas, where 8 inches of snow had fallen overnight. Interstate 70 was completely ice-packed in western Kansas.

"It's kind of hard to stay on the roads. You've got to go slow," Jason Juhan, a clerk at the Love's truck stop in Goodland, Kan. said Wednesday. "People are just trying to get through and get to where they need to as fast as they can."

Still, he saw an upside: "It's been a few years since we've actually had a white Christmas out this way."

The storm began in the southwest — where blizzard-like conditions shut down roads and caused a pileup involving 20 vehicles in Arizona on Tuesday — and spread east and north, prompting weather advisories from the Rocky Mountains to Lake Michigan. Rain, freezing drizzle and snow that fell in parts of the Plains and Midwest on Wednesday were just a precursor to what was expected later in the week.

Slippery roads were blamed for at least six deaths — three in accidents on Interstate 80 in Nebraska, two in a crash on I-70 in Kansas and one near Albuquerque, N.M. South of Phoenix, a dust storm set off a series of collisions that killed at least three people Tuesday.

Early Thursday, nearly 100 scheduled flights from Minneapolis-St. Paul International Airport were canceled and dozens more were slated as delayed, according to the airport's Web site. Scheduled flights out of Bismarck Airport did not appear to be significantly disrupted.

On Wednesday, more than 200 flights at Chicago's O'Hare International Airport were canceled, along with about 60 flights out of Midway International Airport, the city's Aviation Department said.

With temperatures in the low 30s early Thursday, the Iowa Association of Electric Cooperatives said more than 1,300 customers statewide were without power.

The storm forced the closure of the Mount Rushmore National Memorial in South Dakota, and prompted that state's governor, Mike Rounds, to cancel travel plans and stay in Pierre for Christmas. Rounds declared a state of emergency Tuesday before the storm even hit.

The winter blasts follow a weekend storm that dropped record snowfall and interrupted holiday shopping and travel on the East Coast. Tens of thousands of customers in West Virginia and Virginia remained without power.