A powerful winter storm that pushed into northwest Oklahoma Friday knocked out power for hundreds residents and dropped heavy snow across several counties, prompting the closure of major highways.

Gov. Brad Henry declared a state of emergency for much of Oklahoma, allowing state agencies to make emergency purchases to deal with the storm and starting the process of seeking federal assistance should it be necessary.

“Ice and snow resulting from this winter storm poses serious challenges to everything from roads to power lines, and so it is critical that we be prepared for the worst,” Henry said.

Forecasters predicted “unprecedented levels” of snow for late March and travel problems as far south as the Interstate 44 corridor as the storm moved through the state.

“Conditions have really deteriorated rapidly in the last hour or so,” Woodward County Emergency Management Director Matt Lehenbauer said early Friday. “We’ve had pretty steady mix of precipitation since last night that has turned to sleet and snow in the last hour or so.”

Lehenbauer said several rollover accidents have been reported, including some with injuries in Woodward County.

Transportation officials shut down Interstate 40 in the Texas Panhandle to the Oklahoma state line due to heavy snow. The Oklahoma Department of Transportation also announced the closure of portions of State Highway 285 and U.S. Highway 56 in the Oklahoma Panhandle, and State Highway 171 from Keyes south to the Texas state line. ODOT said travel conditions west of Woodward were “treacherous.”

The storm knocked out power briefly to nearly 1,000 customers of Northwestern Electric Cooperative, mostly in and near the town of Buffalo in Harper County, but electricity had been restored by 10:30 a.m. Friday, said Sid Sperry, a spokesman with the Oklahoma Association of Electric Cooperatives.

About 300 customers across the Panhandle were without power late Friday morning, Sperry said.

“It’s classic Oklahoma winter weather — thundersnow, sleet, winds between 50 and 60 mph, the classic conditions are setting in,” Sperry said.

Before it’s done, the early spring storm could leave a half-foot to a foot or more of snow and snow drifts as high as 10 to 20 feet in the Oklahoma Panhandle, the National Weather Service reported.

Visibility in that area, where a blizzard warning was in effect for Cimarron and Texas counties, began deteriorating as strong winds whipped around light snow, a dispatcher for the Texas County Sheriff’s office said.

The weather service said four highways in the Texas Panhandle were closed late Thursday because of low visibility from snow and blowing snow. Forecasters warned that the storm could be “crippling” and “potentially life threatening” for Panhandle residents.

Four to 8 inches of snow or more was possible in areas under a winter storm warning, including the eastern Panhandle, adjacent counties in northwest Oklahoma and counties bordering the Texas Panhandle.

Public works officials in Woodward started preparing on Thursday.

“We’re just getting all of our equipment ready to push snow,” said Kevin Kornele, Woodward’s street superintendent. “As soon as there is enough to push, we will push and we will keep pushing until it stops.

“Everybody works overtime in a storm like this. It’s never a good thing to have 12 or 14 inches of snow, but I think we can keep up with it, or I hope we can.”

According to a winter storm watch for counties near I-44, including Oklahoma and Tulsa counties, more than 4 inches of snow may accumulate. Southeastern Oklahoma is expected to be largely spared from the storm.

“When these systems intensify, and the track this one is going to take, from southern New Mexico northeast over Oklahoma, that’s just a perfect track for heavy snow in Oklahoma,” said meteorologist Kevin Brown with the National Weather Service office in Norman.

While heavy snow is expected, it should melt fairly quickly, Brown said.

“We may get 6 inches of snow but 12 hours later, it may dwindle down to 2 to 3 inches,” he said. “It looks like temperatures won’t be bitterly cold filtering in behind the system, so we’ll warm up gradually Sunday, Monday and into Tuesday.

“By the first part of next week, especially by midweek, this storm should be a memory.”

The weather pattern responsible for the snow involves moisture moving into Oklahoma from the south and cold air dropping into the state from the north, Brown said.

The warm side of the storm produced strong to severe thunderstorms in southern and eastern Oklahoma on Thursday.

A storm that moved through LeFlore County destroyed a barn and downed power lines near Pocola, according to the weather service’s Web site. There were no reports of injuries.