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.

---

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

---

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

---

Etymology

Origin of cumulonimbus

First recorded in 1885–90; cumulo- + nimbus

Example Sentences

Tornadoes — or rotating funnels of air connected to the Earth and either a cumulonimbus or the base of a cumulus cloud — are dangerous because of their immense power, which Houser barely escaped.

From Salon

But wrapped around it is the eyewall, a ring of cumulonimbus clouds also known as a wall cloud.

From New York Times

North America’s only monsoon — and the reason the Sonoran Desert is billed as the world’s “wettest desert”— brings billowing cumulonimbus clouds that drench the land in rain.

From Seattle Times

Thunderstorm clouds are called cumulonimbus clouds — the nimbus part of the name comes from the Latin for “dark cloud,” because the moisture within nimbus clouds can block or reduce incoming sunlight.

From Los Angeles Times

The clouds typically form as a result of air turbulence within large cumulonimbus structures.

From Fox News