List of cloud types
The list of cloud types groups the tropospheric types as "high" (cirrus, cirrocumulus, cirrostratus), "middle" (altocumulus, altostratus), "multi-level" (nimbostratus, cumulus, cumulonimbus), and "low" (stratocumulus, stratus) according to the altitude level or levels at which each cloud is normally found. Small cumulus are commonly grouped with the low clouds because they do not show significant vertical extent. Of the multi-level genus-types, those with the greatest convective activity are often grouped separately as "towering vertical". The genus types all have Latin names.
List of cloud types
Abbreviation: Cb
Clouds of the genus cumulonimbus have very dark gray to nearly black flat bases and very high tops that can penetrate the tropopause. They develop from cumulus when the airmass is convectively highly unstable. They generally produce thunderstorms, rain or showers, and sometimes hail, strong outflow winds, and/or tornadoes at ground level.