Cumulus clouds are a genus-type of low-level cloud that can have noticeable vertical development and clearly defined edges. Cumulo- means "heap" or "pile" in Latin. They are often described as "puffy" or "cotton-like" in appearance, and generally have flat bases. Cumulus clouds, being low-stage clouds, are generally less than 2,000 metres (6,600 ft) in altitude unless they are the more vertical cumulus congestus form. Cumulus clouds may appear by themselves, in lines, or in clusters.
Cumulus Clouds of May. Photo copyright by CGC.
Cumulus clouds are often precursors of other types of cloud, 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 vapor, 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 includecumulonimbus 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. There are also cumuliform clouds of limited convection that comprise stratocumulus clouds (low-étage), altocumulus clouds (middle-étage) and cirrocumulus clouds (high-étage).Read more: Cumulus clouds