cumulonimbus

American  

[kyoo-myuh-loh-nim-buhs] / ˌkyu myə loʊˈnɪm bəs /

noun

Meteorology.

plural

cumulonimbus

1. a cloud of a class indicative of thunderstorm conditions, characterized by large, dense towers that often reach altitudes of 30,000 feet (9,000 meters) or more, cumuliform except for their tops, which appear fibrous because of the presence of ice crystals: occurs as a single cloud or as a group with merged bases and separate tops.

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cumulonimbus British  

/ ˌkjuːmjʊləʊˈnɪmbəs /

noun

1. meteorol a cumulus cloud of great vertical extent, the top often forming an anvil shape and the bottom being dark coloured, indicating rain or hail: associated with thunderstorms

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cumulonimbus Scientific  

/ kyo̅o̅m′yə-lō-nĭm′bəs /

plural

cumulonimbi

1. An extremely dense, vertically developed cloud with a low, dark base and fluffy masses that tower to great heights. Cumulonimbus clouds usually produce heavy rains, thunderstorms, or hailstorms.

2. Also called thundercloud

3. See illustration at cloud

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Etymology

Origin of cumulonimbus

First recorded in 1885–90; cumulo- + nimbus

Example Sentences

Cumulonimbus clouds producing thunder have very strong air currents - they can carry the same amount of energy as 10 Hiroshima-sized atom bombs.

From BBC • May 22, 2024

High clouds streaking upward of 45,000 feet above the ground are called Cirrus, Cirrocumulus or Cirrostratus, while lower-lying Cumulus or Cumulonimbus clouds are usually spotted anywhere from the Earth’s surface to 6,500 feet above land.

From Reuters • Jul. 25, 2019

“He doesn’t paint Cumulonimbus or Cirrus or any of the others,” he says, adding that the overcast sky isn’t entirely colorless.

From Reuters • Jul. 25, 2019

The Cloud Appreciation Society’s “Cloud-a-Day” app calls the Cumulonimbus “the King or Queen of Clouds” and praises its impressive size and ability to form storms.

From Reuters • Jul. 25, 2019

Rather more dramatic is "king of clouds" the Cumulonimbus.

From BBC • Jun. 6, 2012