Photo by Eric Brady | The Roanoke Times

Krissy Agosto walks across Jefferson Street in downtown Roanoke with her hair blowing with the wind Thursday afternoon.

Kevin Myatt is The Roanoke Times' weather columnist.

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Wind roared through the bare February trees Thursday morning, knocking a few down, breaking branches and flickering the lights for some.

Widespread power outages and significant structural damage occurred in West Virginia. A hotel roof was blown onto a restaurant in Princeton, W.Va., as winds clocked at up to 68 mph rushed through the southern part of the state early Wednesday evening, according to the National Weather Service in Blacksburg. Those winds were boosted by a line of thunderstorms that weakened to gusty showers as it moved east.

At one time, nearly 1,500 customers were without power in Pulaski County, but generally power outages were sporadic in the New River and Roanoke valleys.

In most of Southwest Virginia, Thursday's tempest was a breeze compared with what happened a year and three days ago.

The Feb. 10, 2008, windstorm will likely be the standard to which all wind events are compared for a generation. It was roughly the equivalent of a cold tropical storm on a deceivingly sunny day, with hours of 35 to 50 mph winds and gusts sometimes reaching up to 74 mph in some parts of Southwest Virginia. By comparison, Thursday's winds in Roanoke were generally 20 to 35 mph with a peak gust of 55 mph.

"We frequently get gusty and sometimes isolated damaging winds behind many cold fronts every single year," Stephen Keighton, the science officer at the National Weather Service in Blacksburg, said in an e-mail. But in the Feb. 10, 2008, windstorm, "all the pieces happened to come together just right," Keighton said.

The Feb. 10 windstorm and Thursday's gusts had some common causes -- a cold frontal passage; westerly winds blowing perpendicular to the Appalachian mountain ridges, causing the winds to break into waves of gusts; and a strong gradient between high pressure and low pressure systems.

But two factors boosted last year's windstorm to another level: a pocket of extremely strong winds a little more than a mile above the surface, and daytime heating that caused warmer air near the surface to rise as colder air aloft sank. The layers of air mixed into one, and thus, the fast-moving air just above the mountaintops became a hard wind roaring through the mountains and valleys.

The ground and air were both extremely dry on Feb. 10, 2008. Fires became rampant. Statewide, 351 wildfires were reported, according to the Virginia Department of Forestry, by far the most on any single day in Virginia's history. That one day accounted for almost 30 percent of the state's wildfires for all of 2008.

"What we had on February 10th, was Virginia's equivalent to Southern California, prolonged wind, fire, and people trying to either save their homes or get out of the way of the approaching fire front," Phillip Manuel, a forecaster at the National Weather Service in Blacksburg, said in an e-mail.

Wind damage was reported in all 40 counties of the Blacksburg office's forecast area, an unprecedented extent of damage. At the Feb. 10 storm's peak, more than 100,000 homes were without power across Virginia.

Thursday was another reminder that big wind is something we just have to deal with from time to time here in the mountains.

"Wind episodes will always be common here," Manuel said. "We live at the base of a dam ... the Appalachian Mountains. When water flows over a dam, the turbulent flow occurs at the base. Since our prevailing wind flow is from the west, our mountains will act as a dam, the wind accelerating as it crosses the higher peaks and crashing into the foothills just east of the mountains ... simple fluid dynamics."