For the first time in thirty years, there is a new class of clouds.
Actually, there are 11 new cloud classifications, just added to the International Cloud Atlas, the recognized source on clouds in the meteorology community.
These clouds aren't exactly "new", as they have likely been around just as long as the more commonly known cumulus, cirrus, and stratus clouds. However, the increased use of personal technology like cellphone cameras have allowed the newly named clouds to be photographed and discussed more often, which led to the recent additions.
Here are a sampling of the new cloud classifications. See if you recognize any and have seen them in the skies over South Jersey lately:
- Asperitus: Wave-like clouds that appear to ripple across the sky
- Murus: Formerly known as a "wall" cloud, usually observed during severe thunderstorms. Extends from the base of a cumulonimbus cloud.
- Cavum: Commonly called a "hole-punch" or "fall-streak" hole, a cavum is a circular hole in a blanket of altocumulus or cirrocumulus clouds.
- Fluctus: Usually a short-lived series of structures typically on the top of clouds, in the form of curls or breaking waves. Called Kelvin-Helmholtz waves before this new cloud classification.
- Volutus: Commonly referred to as a roll cloud, a volutus is a long, typically low, horizontal, detached, tube-shaped cloud, often appearing to roll slowly about a horizontal axis. Often comes in advance of thunderstorms or severe weather.
- Homogenitus: You may know them as contrails, or cirrus clouds that result from the exhaust of airplanes flying overhead.
- Homomutatus: If contrails persist for awhile while under the influence of strong upper winds, they can grow and spread out over a larger portion of sky, and undergo internal transformation such that the cloud eventually takes on the appearance of more natural cirri-form clouds.
- Silvagenitus: Clouds that form over a forest as a result of evaporation from the moisture over the tree canopy.
- Flammagenitus: Also known as a pyrocumulus cloud or fire cloud, is a dense cumuliform cloud associated with fire or volcanic eruption that may produce dry lightning (lightning without rain).
- Cataractagenitus: Clouds that may develop locally in the vicinity of large waterfalls as a consequence of water broken up into spray by the falls.
- Flumen: Well-known to tornado chasers, this cloud will now have the Latin name flumen. Chasers call it a "beaver's tail," owing to its shape and placement within a severe thunderstorm.
The International Cloud Atlas was first created in 1896 and has been a resource of cloud types and photos that has helped train meteorologists for decades.
For a look at all possible cloud types, you can visit the International Cloud Atlas here.