cumulonimbus

[ kyoo-myuh-loh-nim-buhs ]

noun

, Meteorology.

, plural cu·mu·lo·nim·bus.

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.

cumulonimbus

/ 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

cumulonimbus

/ kyo̅o̅m′yə-lō-nĭm′bəs /

, Plural cumulonimbi kyo̅o̅m′yə-lō-nĭm′bī

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

Word History and Origins

Origin of cumulonimbus¹

First recorded in 1885–90; cumulo- + nimbus

Example Sentences

The worst of these atmospheric disturbances create severe thunderstorms with giant cumulonimbus clouds that flatten out against the stratosphere.

From Science News