What term describes clouds that appear puffy or heap-like?

The term that describes clouds that appear puffy or heap-like is "Cumulus." This type of cloud is characterized by its distinct, fluffy appearance, resembling cotton balls with a rounded shape. Cumulus clouds typically form in fair weather conditions and are associated with rising warm air, which leads to the build-up of moisture in the atmosphere. This moisture condenses into the visible, puffy cloud formations you observe. Cumulus clouds can indicate nice weather, although larger, more developed cumulus clouds can evolve into cumulonimbus clouds, which are associated with thunderstorms.

The other terms do not describe clouds with this character. Stratus clouds tend to form in layers covering the sky, creating a gray overcast. Nimbus refers to rain-bearing clouds and is often combined with other types to describe specific cloud types that produce precipitation. Cirrus clouds are thin, wispy clouds high in the sky, lacking the puffy, heap-like structure of cumulus clouds. Understanding these differences helps in recognizing cloud types and predicting weather conditions effectively.