CUMULUS

Imagine laying on your back in the grass on a warm, sunny day. You and your friends are looking up into the bright blue sky dotted with white, fluffy clouds. You see one that looks like a horse, and your friend sees one that looks like an ice cream cone. And there's one that looks like a rabbit! You are watching cumulus clouds!

Cumulus clouds are puffy clouds that sometimes look like pieces of floating cotton. The base of each cloud is often flat and may be only 1000 meters (3300 feet) above the ground. The top of the cloud has rounded towers. Cumulus clouds are often precursors of other types of clouds, such as cumulonimbus, when influenced by weather factors such as instability, moisture, and temperature gradient. Normally, cumulus clouds produce little or no precipitation, but they can grow into the precipitation-bearing congestus or cumulonimbus clouds. Cumulus clouds can be formed from water vapour, supercooled water droplets, or ice crystals, depending upon the ambient temperature. They come in many distinct subforms, and generally cool the earth by reflecting the incoming solar radiation. Cumulus clouds are part of the larger category of free-convective cumuliform clouds, which include cumulonimbus clouds. The latter genus-type is sometimes categorized separately as cumulonimbiform due to its more complex structure that often includes a cirriform or anvil top.