This website may use up to three names for a cloud. However, It is perfectly correct to call a cloud only by its first name. The second and third names add to the cloud description and may be used if you choose.
Low Clouds
Clouds in the Low Cloud family: cumulus, stratocumulus, and stratus and cumulonimbus.
(Cumulonimbus is in the low family IF its base is below 6,500 feet.)
Below 6,500 feet
(2000 meters)
Cumulus
Cumulus means ‘heaped.’ Cumulus range in size from tiny puffy clouds to towering clouds with many bulding pillow shaped formations. The bases of cumulus are below 6,500 feet but the tops of tall cumulus may be higher than 20,000 feet. The smallest cumulus is the fair weather cumulus known as cumulus humilus. It is a very humble looking cloud. Cumulus in low levels are called cumulus, in the mid-levels they are called altocumulus and in the high levels are cirrocumulus. The largest are cumulus congestus which can have tops above 20,000 feet.
Rain does not fall from cumulus but large cumulus, such as cumulus congestus may produce small rain or snow streaks that do not reach the ground. Cumulus approaching the size of a small cumulonimbus may produce rain or snow.
The grand daddy of all cumulus is the cumulonimbus - the thunderstorm. Cumulonimbus is a special case of cumulus and it has its own cloud category. It can be a low or middle cloud depending on which level the base is located. See clouds of great vertical extent.
small cumulus forming
A humble cumulus cloud (Cumulus humilus)
cumulus
Cumulus
Cumulus
Cumulus
Cumulus
Cumulus in the foreground with altocumulus above in background
Cumulus mediocris (medium size cumulus)
Cumulus mediocris (mediocre)
Cumulus Mediocris (medium size)
Cumulus mediocris (medium size)
Cumulus mediocris (medium size)
Cumulus mediocris (medium size)
Cumulus congestus (larger than mediocris)
Cumulus in the foreground. Notice the altocumulus in the background (upper left)
Developing Cumulus
Cumulus congestus (lower center) - (The dark clouds in the foreground are actually streaks of falling snow)
Ice crystals aloft (in streaks) with the tops of cumulus below (bottom of photo)
Cumulus congestus
Cumulus under a layer of middle clouds above
Cumulus congestus
Cumulus floccus (like tufts of wool)
Cumulus mediocris and cumulus congestus (across bottom) with cumulo congestus bases ( center and top)
Dissipating cumulus as the sun sets
Stratocumulus
Stratocumulus look like stratus and cumulus. The clouds are rounded in the vertical but appear in broad flat sheets or patches with elements of puffy or rounded cloud or waves. Stratocumulus is not found in the middle or high levels. Rain or snow does not fall from stratocumulus.
Cumulus and stratocumulus
Stratocumulus
Stratocumulus
Stratocumulus and cumulus
Stratocumulus
Stratocumulus with fractus
Stratus
Stratus are flat layered clouds. They are usually a dull gray but may appear white if the Sun is shining on them. True stratus do not produce rain or snow although it is possible to get drizzle from low stratus. Stratus in the middle levels are called altostratus and in the high levels are called cirrostratus.
Stratus