Rare "Roll Cloud" Wows Texas, And Then The Rest Of Us

A rare "roll cloud" rolled right over the community of Timbercreek Canyon Texas this week, and it's getting a lot of attention because it was so dramatic.

The dramatic, rare, scary but harmless and beautiful
roll cloud over Texas this week.  

Bonnie Mack took what is becoming a viral video of the roll cloud as it passed over her Timbercreek Canyon home, not far from Amarillo.

You can see the video at the bottom of this post. The cloud stretches as far as the eye can see.

Roll clouds look freaky and scary and otherworldly, and something like a horizontal tornado but they're never dangerous.

They often form some distance from a thunderstorm, when a cool air downdraft blowing out of the storm hits the ground, kind of rises again and puts a horizontal spin in the air. That horizontal spin sometimes forms into what are known as roll clouds.

The air needs precisely the right amount of spin and moisture to make a roll cloud. Almost always, a cool downdraft doesn't form a roll cloud. In rare instances, it does.

You don't necessarily need a thunderstorm to make a roll cloud. But as rare as roll clouds are, they are even more infrequent when there's no thunderstorms around.

You do need an influx of cold air and that's what you see in Bonnie Mack's video. There were no nearby thunderstorms as she filmed.

A cold front apparently came in and displaced some warmer air, and the atmospheric conditions were just right to produce the horizontal spin the air that became the roll cloud.

Mack reported that a gust of cool air blew through her property as the roll cloud passed overhead, which is to be expected near such a phenomenon.

After all the weather disasters the world has seen lately, it is refreshing to see a dramatic weather phenomenon caught on tape that did no harm to anybody, and is not a sign of anything ominous to come.

Here's the roll cloud video: