Kevin Myatt is The Roanoke Times' weather columnist.

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Wildfires raged through central Oklahoma on Thursday, scorching scores of homes. Meanwhile, not far to the east, tornadoes wrecked communities in eastern Oklahoma and western Arkansas.

Those seemingly very diverse tragedies resulted from a common factor: a dry line.

A dry line is a feature that often develops in the spring in the central United States when extremely dry air -- originating from the deserts of the Southwest and downsloping winds off the Rockies -- moves eastward to meet warm and humid air moving northward from the Gulf of Mexico.

The difference across the dry line is astounding. Dew points can be as low as the single digits on one side and as high as the 70s on the other. I've heard about people driving through the dry line with their windows rolled down, experiencing an immediate change.

The dry line is a boundary along which thunderstorms often develop, on the east side where the moisture is thick.

On Thursday, a strong low pressure system cranking up in the region also supplied strong winds at the surface. These winds whipped flames in the tinderbox conditions that developed behind the dry line, in addition to pulling in moist southeasterly winds ahead of the dry line that ramped up thunderstorms and spun tornadoes.

While boundaries between relatively dry and moist air can develop in our region, a truly extreme dry line is another item on the list of weather events Southwest Virginia doesn't have to worry about.