Undulatus asperatus
© Agathman, via Wikimedia CommonsUndulatus asperatus, photographed in Pocahontas, Mo., in 2008.
Undulatus asperatus isn't some obscure anatomical structure next to your peritoneum, nor is it a minor character from the movie Gladiator.

No, it's actually a type of cloud formation that weather fanciers have proposed for inclusion in the next edition of the World Meteorological Organization's "International Cloud Atlas," the ultimate reference source on the varieties of clouds.

Undulatus asperatus is Latin for "agitated waves," and it basically resembles an enormous, rumpled blanket stretched out across the sky. If accepted into the atlas, it would be the first newly designated cloud formation since 1951. Below is a strikingly beautiful video of an Undulatus asperatus formation, recorded by cloud watcher Alex Schueth over Lincoln, Neb., on July 9.

The new formation is being championed by Gavin Pretor-Pinney, founder of the Cloud Appreciation Society, an international group of more than 36,000 meteorological buffs from countries across the globe.


In a recent article in The Verge, Pretor-Pinney explained that he was moved to propose the new formation after he received pictures of the sky taken from the 12th floor of an office building in Cedar Rapids, Iowa, a few years ago. The cloud formation in the photos "struck me as being rather different from the normal undulates clouds," said Pretor-Kinney, whom the article describes as an author, graphic designer and former absinthe importer. "They were more turbulent, more confused - as if you were underneath the water looking up toward the surface, when the sea is particularly disturbed and chaotic."

Pretor-Kinney subsequently received other pictures of similar-looking clouds, and he began to think that it was a new type of formation.

Undulatus asperatus was recommended for consideration in a November 2013 report issued by the task force assigned to review the cloud atlas. WMO official Roger Atkinson told The Verge that the chances of the formation being included are "very high," but said that the name might be changed. "We need advice from a proper Latin scholar," he explained.