Cumulus under altocumulus

Photo by Craig Johnson - August 2019

There are two cloud layers in this photo. The lowest contains cumulus clouds which are below 6,000 feet. The upper layer is altocumulus - a middle layer cloud found above 6,000 feet but below 18,000 feet. Both cloud types form individual cells. the cells are made up of a core of rising air where water vapor has become visible due to condensation. These clouds are entirely separate from each other. The air around these cumulus is sinking as the air in the cloud is rising. The mid-level clouds are also cells of rising air surrounded by sinking air but the cells are closer together. The mid-level clouds resemble more of a layer cloud while still featuring the cell structure of cumulus. Cumulus in the lower layer are called “cumulus” but when they form in the middle layer are referred to altocumulus (high cumulus).