A storm that toppled power lines, closed major highways and buried parts of the southern Plains in heavy ice and snow began moving into the South on Friday, leaving tens of thousands of people in the dark — possibly for several more days.

Winter storm warnings were in effect from New Mexico to North Carolina, and Arkansas Gov. Mike Beebe declared a state of emergency. The storm threatened to dump up to a foot of snow across the region after leaving 13 inches in the northern Texas Panhandle, where nearly all of Interstate 40 from the Texas-Oklahoma line to New Mexico was closed.

The closure stranded dozens of people at the Travel Centers of America truck stop along I-40 in Sayre in far western Oklahoma. Ken Halford of Nashville, Tenn., who was driving to Las Vegas with his wife, was stranded in Oklahoma City after officials closed the interstate.

"Our goal was to be in Vegas by Sunday, and we were going to stop in Flagstaff, (Ariz.) and do the Grand Canyon tour, but we'll probably have to cut that out," Halford said. "We'll just sit tight here until we get the word that I-40 is back open, and then we'll head on west."

Heavy ice brought down electrical lines and trees limbs, leaving nearly 142,000 homes and businesses in Oklahoma without power Friday, according to the Oklahoma Department of Emergency Management.

"In some places, as far you can see there are hundreds of utility poles on the ground," said Andrea Chancellor, spokeswoman for Public Service Co. of Oklahoma. She said it could be five days before electricity is restored to all customers.

Flights were canceled Friday morning at airports in Oklahoma City and Little Rock, Ark.

Arkansas State Police warned people who were driving to work on Friday to be prepared to be stranded. Spokesman Bill Sadler encouraged motorists to bring blankets, water and snacks with them and to line up a hotel room within walking distance or make other plans for an overnight stay.

The snow, sleet and freezing rain were expected to crawl east through Friday. Up to a foot of snow was expected in Arkansas near the Missouri state line, northern Tennessee near the Kentucky and Virginia borders and western North Carolina, according to the National Weather Service.

Freezing rain began falling in Memphis shortly after dawn Friday, and by midmorning it was snowing steadily in Nashville, 200 miles to the east.

Jeff Hooker, who manages a Piggly Wiggly in the Memphis area, said some employees were afraid to drive in the snow, so he offered to pick them up in his truck. Customers were waiting outside to buy groceries when the store opened at 7 a.m.

"People here in Memphis, if there's just a little flight of bad weather they think they're going to get snowed in for a week," he said.

More snow also was expected in Texas and Oklahoma, where dozens of shelters were opened for those who needed a warm place to stay, including First United Methodist Church in Hobart, about 120 miles southwest of Oklahoma City. Pastor Kyle Clark said downed trees and utility poles littered the slick roadways and most of the town of about 4,000 residents had no electricity.

"We've got gas heat and we are illuminating the place with candles," Clark said late Thursday.

Farther southwest in Altus, home to about 7,000 residences and businesses, power was out except at the hospital and other emergency operations with generators, said emergency management director Lloyd Colston.

More than two dozen flights were canceled Friday morning at Will Rogers World Airport in Oklahoma City following the cancellation of more than 100 flights Thursday because of concerns about ice buildup on planes, according to the airport's Web site. In Arkansas, Little Rock National Airport reported that a number of flights were canceled.

Flights also were canceled Thursday in Tulsa and in Texas out of Lubbock, Amarillo and Wichita Falls.

The Texas Department of Transportation closed I-40 east and west of Amarillo on Friday and a few other major roadways. Downed power lines and icy, dangerous road conditions also temporarily closed a 50-mile stretch of I-44 southwest of Oklahoma City and parts of I-40 in far western Oklahoma and eastern New Mexico on Thursday.