Clouds of the Day - Tuesday, December 21, 2021

Cumulus

Cumulus is one of 10 principal cloud types. Its name refers to the puffy or heaped shape caused by upward motion as air warmer than the surrounding air rises. As it rises it expands because the surrounding air at higher levels is under less pressure. As it expands it cools and the invisible water vapor in the air condenses. The level where it condenses is called the condensation level.

The two photos below show cumulus clouds with different shapes and sizes in a group. The clouds were moving from the northwest to southeast in a cold air mass. The afternoon sunshine was warming the earth creating masses of warmer air rising to the condensation level where the moisture condensed into puffy clouds.

Cumulus

Cumulus