Mammatus Clouds

Facts for Prelims

Mammatus Clouds

News: NASA has released pictures of Mammatus clouds that appear like bubbles from the bottom hovering over Nebraska, a state in the Midwestern region of the United States.

What are Mammatus clouds?
 Mammatus clouds are some of the most unusual and distinctive cloud formations with a series of bulges or pouches emerging from the base of a cloud.
 The shape of mammatus formations can vary widely from the classic protruding shape to a more elongated tube hanging from the cloud above.
 They generally form in the most unstable cumulonimbus, meaning that there is also a chance of hail, heavy rain and lightning in the vicinity, and if the air is cold enough during winter they can produce snow.

How are they formed?
 Mammatus clouds are usually formed in association with large cumulonimbus clouds. Typically, turbulence within the cumulonimbus cloud will cause mammatus to form, especially on the underside of the projecting anvil as it rapidly descends to lower levels.
 This reverses the usual cloud-forming process of upward growth, making for an uneven cloud base.