See a rare 'roll cloud' appear like an apocalyptic vision

An ominous roll cloud formed over Texas, giving the National Weather Service a good look at an unusual formation in the sky.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser

Ah, clouds. Some look like fluffy sheep. Some look like artful veils. And some look like an oncoming apocalypse rolled up into a startling tube. 

You could go your whole life and never see a rare "roll cloud" in person, but the US National Weather Service office in San Angelo, Texas, snapped a photo of the strange formation in the sky and posted it to social media Monday.

A roll cloud is a type of arcus cloud, which is a low-lying horizontal formation. 

"These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud," NASA explains

Despite the dramatic formation's resemblance to a massive funnel cloud laying on its side, NASA says roll clouds aren't thought to be able to morph into a tornado. 

The Facebook version of the NWS photo lets you explore the space in 360, which is the next best thing to being there. Weather-watching Texas residents described the cloud in the comments as stunning, cool and "kinda weird."   

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