A rare formation called asperitas clouds appeared over the Santa Barbara Channel in Southern California on Nov. 15.
Channel Islands National Park
A rare, wave-like cloud formation blanketing the sky off the coast of Southern California left some people mesmerized — and wondering what it was.
They were asperitas clouds, the Channel Islands National Park shared Nov. 15 on Facebook. A park ranger captured a photo of the phenomenon while traveling from Anacapa Island to the mainland.
The newly named clouds are “known for their dramatic wave like appearance on the underside of the cloud.”
Asperitas clouds are the latest formation to be documented in the International Cloud Atlas, according to the Met Office in the U.K. They were added in 2017 as the first addition to the atlas in nearly 70 years. The most recent clouds to be introduced prior to that were cirrus intortus in 1951.
The word asperitas comes from Latin and translates to “roughness,” the park said.
“I was wondering what they were called!” one person commented on the park’s Facebook post identifying the clouds. “I saw them and said it looks like the Ocean in the sky.”
Others said the clouds hanging over the water looked like “waves on waves,” a lava lamp or a Vincent van Gogh painting.
The “dramatic” clouds create the effect of “viewing a roughened sea surface from below,” according to the International Cloud Atlas.
The clouds don’t just occur over water. Photos of the undulating waves in the sky have been captured everywhere from Midwest states to other countries.
“Saw these driving out of Ojai yesterday — was so trippy!” another person wrote on Facebook. “I took a few photos myself as I had never seen anything like that before.”
Researchers don’t know exactly what causes the clouds to form, but the U.K. meteorology center says the clouds can form after thunderstorms and don’t typically produce rain themselves.
One person summed it up simply by calling the clouds “stunning.”
Channel Islands National Park is off the coast of Los Angeles.
