Cumulus clouds are clouds which have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance. Their name derives from the Latin cumulo-, meaning heap or pile.

What does the name cumulus mean?

Cumulus. From the Latin cumulus, which means an accumulation, a heap, a pile. Cumulonimbus.

What do cumulonimbus clouds mean?

Cumulonimbus clouds are associated with extreme weather such as heavy torrential downpours, hail storms, lightning and even tornadoes. ... If there is thunder, lightning or hail, the cloud is a cumulonimbus, rather than nimbostratus.