Weather Factory

Weather Factory, originally uploaded by MS4JAH.

This is a terrific example of a dense cumulus cloud. It has the characteristic appearance of a cauliflower and is fuelled by intense updrafts of moist air. As in all clouds, the predominant process is cooling and condensation of the rising air mass. This particular cloud looks like it might develop into a cumulonimbus - a thunderhead, but for now it's just a cumulus congestus.

Cumulus congestus clouds are characteristic of unstable areas of the atmosphere which are undergoing convection. They are often characterized by sharp outlines and great vertical development. Because cumulus congestus is produced by strong updrafts, it is typically taller than it is wide, and cloud tops can reach 5,000 metres (15,000 ft). Cumulus congestus clouds are formed by the development of cumulus mediocris generally, though they can also be formed from altocumulus castellanus or stratocumulus castellanus as well.

Cumulus congestus will mature into cumulonimbus calvus under conditions of sufficient instability. This transformation can be seen by the presence of smooth, fibrous, or striated aspects assumed by the cloud's upper part. This cloud type produces precipitation, often in abundance. The congestus species of cloud can only be found in the genus cumulus. (Wikipedia)