Types of clouds

The World Meteorological Organisation has classified clouds into ten principle groups which then have a number of varieties:

Low clouds

Cumulus

• humilis
• fractus
• congestus
• mediocris
• radiatus

Cumulonimbus

• calvus
• capilatus

Stratocumulus

• cumulogenitus
• stratiformis
• castellanus
• lenticulari
• tranlucidus
• perlucidus
• opacus
• duplicatus
• undulatus
• radiatus
• lacunosus

Stratus

• nebulosus
• fractus
• opacus
• translucidus
• undualtus

Medium clouds

Altostratus

• translucidus
• opacus (nimbostratus)

Nimbostratus

Altocumulus

• lenticularis
• stratiformis
• cumulogenitus
• castellanus
• floccus
• translucidus
• duplicatus

High clouds

Cirrus

• uncinus
• fibratus
• floccus
• castellanus
• spissatus
• intortus
• radiatus
• vertebratus
• dupolicatus

Cirrostratus

• nebulosus
• fibratus
• duplicatus
• undulatus

Cirrocumulus

• stratiformis
• lenticularis
• castellanus
• floccus
• undulatus
• lacunosus