Cumulus castellanus cloud

Cumulus castellanus
Cumulus castellanus low on the horizon
Appearance	Flat on the bottom, though has multiple "towers" on top
Precipitation cloud?	Usually, but not always

Cumulus castellanus (from Latin castellanus, castle) is a type of cumulus cloud that is distinctive because it displays multiple towers arising from its top, indicating significant vertical air movement. They are so named because they somewhat resemble the crenellation on medieval castles. Cumulus castellanus clouds are associated with the formation of towering cumulus or cumulonimbus clouds, and correspondingly can be an indicator of forthcoming showers and thunderstorms. The World Meteorological Organization and the American Meteorological Society do not recognize cumulus castellanus as a distinct species, but instead classify all towering cumulus clouds as Cumulus congestus.