The classification of clouds has ten main groups, called genera. Each observed cloud is a member of one, and only one, genus.
Cirrus (Ci)
Cirrocumulus (Cc)
Cirrostratus (Cs)
Altocumulus (Ac)
Altostratus (As)
Nimbostratus (Ns)
Stratocumulus (Sc)
Stratus (St)
Cumulus (Cu)
Cumulonimbus (Cb)
