Cumulus cloud
Subforms

Cumulus clouds come in four distinct species, cumulus humilis, mediocris, congestus, and fractus. These species may be arranged into the variety, cumulus radiatus; and may be accompanied by up to seven supplementary features, cumulus pileus, velum, virga, praecipitatio, arcus, pannus, and tuba.

The species Cumulus fractus is ragged in appearance and can form in clear air as a precursor to cumulus humilis and larger cumulus species-types; or it can form in precipitation as the supplementary feature pannus (also called scud) which can also include stratus fractus of bad weather. Cumulus humilis clouds look like puffy, flattened shapes. Cumulus mediocris clouds look similar, except that they have some vertical development. Cumulus congestus clouds have a cauliflower-like structure and tower high into the atmosphere, hence their alternate name "towering cumulus". The variety Cumulus radiatus forms in radial bands called cloud streets and can comprise any of the four species of cumulus.

Cumulus supplementary features are most commonly seen with the species congestus. Cumulus virga clouds are cumulus clouds producing virga (precipitation that evaporates while aloft), and cumulus praecipitatio produce precipitation that reaches the Earth's surface. Cumulus pannus comprise shredded clouds that normally appear beneath the parent cumulus cloud during precipitation. Cumulus arcus clouds have a gust front, and cumulus tuba clouds have funnel clouds or tornadoes. Cumulus pileus clouds refer to cumulus clouds that have grown so rapidly as to force the formation of pileus over the top of the cloud. Cumulus velum clouds have an ice crystal veil over the growing top of the cloud. There are also cumulus cataractagenitus, which are formed by waterfalls.
punctuation:no_comma, startend:end_checker, change_case:english_lowercase