GLOBE Cloud Exploration: Cumulus
Cumulus of great depth
Cumulus clouds have a flat base, and range in size from very shallow to a dense, mound-shaped top that resembles a large cauliflower. Where the sun hits these clouds it it a brilliant white. They generally do not produce precipitation.
These cumulus are very large and deep (congestus) at sunset on 3 August 1993 at Norman, Oklahoma. The cumulus on the left is maintaining its rounded cumulus shape and has a thin horizontal layer on it (pileus). The cumulus on the right has started to become diffuse and therefore is just reaching the cumulonimbus stage. Photo © 1993 Ronald L. Holle.