The water droplets at the top of the cloud tower have not frozen to become ice crystals. Cumulonimbus calvus - the top of the cumulonimbus is puffy, like a cumulus cloud.How do we categorise cumulonimbus clouds?Ĭumulonimbus clouds have 3 distinct 'species' which describe the appearance of the head of the cloud: If there is thunder, lightning or hail, the cloud is a cumulonimbus, rather than nimbostratus. However, multicell or supercell storms contain many cumulonimbus clouds and the intense rainfall may last much longer. Individual cumulonimbus cells will usually dissipate within an hour once showers start falling, making for short-lived, heavy rain. What weather is associated with cumulonimbus clouds?Ĭumulonimbus clouds are associated with extreme weather such as heavy torrential downpours, hail storms, lightning and even tornadoes. They can also form along cold fronts as a result of forced convection, where milder air is forced to rise over the incoming cold air. They get taller and taller until they represent huge powerhouses, storing the same amount of energy as 10 Hiroshima-sized atom bombs. How do cumulonimbus clouds form?Ĭumulonimbus clouds are born through convection, often growing from small cumulus clouds over a hot surface.

The base of the cloud is often flat, with a very dark wall-like feature hanging underneath, and may only lie a few hundred feet above the Earth's surface. More commonly known as thunderclouds, cumulonimbus is the only cloud type that can produce hail, thunder and lightning.

Precipitation: heavy rain and thunderstormsĬumulonimbus clouds are menacing looking multi-level clouds, extending high into the sky in towers or plumes.

Latin: cumulus - heap nimbus - rain cloud.

Anvil of dawn maps