Undulatus asperatus

Asperatus are strange, frightening clouds of a completely new species. This is what the Cloud Appreciation Society advocates, after compiling numerous examples of this unusual phenomenon received from all corners of the world.

"Since they look like the surface of a rough sea from below, we call them the 'Jacques Cousteau cloud' in honor of the legendary French diver and ecologist," they say.

In search of a name that sounded more “official,” they came up with the term “asperatus” from the “rough” Latin used by classical poets to describe seas churned by high winds.

The suggestion for the new classification was made to meteorologists of the British Royal Meteorological Society, which adopted the idea and is seeking more information about the conditions that cause the phenomenon.

"These clouds look very stormy, but some of the reports we get suggest that they tend to fall apart without really turning into a storm," said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society.

Undulatus asperatus (or just asperatus) is a cloud type proposed in 2009 as a separate cloud rating by the founder of the Cloud Appreciation Society. It was the first added cloud formation since the Cirrus intortus type, added in 1951 in the World Meteorological Organization's International Cloud Atlas. Margaret LeMone, a cloud expert, has been taking photos of asperatus clouds for 30 years, and considers it a new type of cloud.

Asperatus are more closely related to undulatus clouds. The appearance of threatening clouds is particularly common on the plains of the United States, often in the morning or noon, followed by convective storm activity. To this day it is not known exactly how they form.