Video: Rare roll cloud stretches across Texas sky

AOL Travel

A truck driver managed to capture amazing footage of a rare roll cloud stretching right across the horizon in Texas.

Bonnie Mask had the day off and captured the video at sunrise last week from her deck in Timbercreek Canyon.

The tube-like formation is caused when cool and warm air fronts meet and are rolled into shape by winds.

According to the Daily Mail, Todd Mask described the cloud in his wife's footage as, "rolling like an ocean wave" and "like a horizontal vortex".

Although they can be associated with thunderstorms, the Huffington Post reports that NASA says roll clouds are not dangerous and are not thought to be able to turn into tornadoes.

Kim Cunningham, a meteorologist for the Weather Channel, told Yahoo News: "This is fairly rare, by the way, to have these things and see these things - especially when not associated with a thunderstorm... It's pretty cool though, and it probably freaked a lot of people out."

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