You are here
16 fascinating cloud formations
Clouds can be divided into three main categories based upon the Latin root words, which refer to the process of formation and physical structure of the clouds. The first is Cirrus, which are clouds in the high altitude range and occur mostly in the form of filaments. The other two are Stratus, which are mostly sheet-like in structure, and Cumulus, which appear heaped, rolled, and/or rippled. Stratus and Cumulus occur in the high, middle, and low levels of the troposphere.
Stratus clouds are uniform grayish clouds that often cover the entire sky. They resemble fog that does not reach the ground. Usually no precipitation falls from stratus clouds, but sometimes they may drizzle. Puffy stratocumulus clouds like these indicate changing conditions. This is especially true if they turn dark and form nimbostratus clouds.
Blanketing stratus formations foretell of fair weather unless they turn dark and clumpy, forming into nimbostratus clouds. Stratus clouds can reach down to the ground, creating fog.
Altocumulus clouds are middle level clouds that are made of water droplets and appear as gray, puffy masses, sometimes rolled out in parallel waves or bands. The appearance of these clouds on a warm, humid summer morning often means thunderstorms may occur by late afternoon.
Altostratus clouds are gray or blue-gray middle level clouds composed of ice crystals and water droplets. These clouds usually cover the entire sky. In the thinner areas of the cloud, the sun may be dimly visible as a round disk. Altostratus clouds often form ahead of storms that will produce continuous precipitation.
Cirrus clouds are thin, wispy clouds blown by high winds into long streamers. They are considered "high clouds" forming above (20,000 ft). Cirrus clouds usually move across the sky from west to east. They generally mean fair to pleasant weather.
Cirrocumulus formations are marked by clouds clumping together in rows or rolls. A sky with cirrocumulus clouds is sometimes referred to as a "mackerel sky." Rain is likely if such clouds form in a fast-moving pattern. Note the altostratus layer above the horizon indicating a change in weather.
Cirrostratus clouds are thin, sheet-like high clouds that often cover the entire sky. They are so thin that the sun and moon can be seen through them.
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 m (330 ft) above the ground. The top of the cloud has rounded towers.
When the top of the cumulus clouds resembles the head of a cauliflower, it is called cumulus congestus or towering cumulus. These clouds grow upward, and they can develop into a giant cumulonimbus, which is a thunderstorm cloud.
Cumulus clouds, by themselves, forecast a pleasant afternoon and a quiet night. But when they gather into the monstrous cumulonimbus clouds, as can happen on hot summer days, then expect severe weather.
Halos form when light from the sun or moon is refracted by ice crystals through high-level clouds like cirrostratus clouds.
Lenticular cloud formations, which can take the form of saucers or smooth elongated pillows, are a form of mountain wave clouds that are formed downwind from an obstacle, often a mountain, in the path of a strong air current.
Mammatus clouds are pouch-like formations protruding from the underside of cumulonimbus clouds. They are formed by downdrafts in which the air is cooler than the surrounding air. Though often observed near severe thunderstorms, mammatus do not produce severe weather themselves.
Wave clouds form downwind from an obstacle in the path of a strong air current such as a mountain range. Mountain wave clouds can often be seen along the lee side of the range.
A supercharged form of cumulonimbus clouds, a supercell thunderstorm can produce hail, rain, strong winds and substantial downbursts. This image shows a supercell thunderstorm with a rotating updraft indicated by the striations.
Virga are streaks of water droplets or ice particles that evaporate before reaching the ground. When sighted in or near a thunderstorm, virga indicate the risk of a downdraft of rain-cooled air that may take the form of a microburst, which can be extremely dangerous for aircraft.
Do you know your clouds? Here are 16 fascinating formations, sponsored by Honda.