Clouds
Clouds are made from condensed water vapour that has evaporated. The water vapour rises to heights of 6000m and condenses into clouds. The vapour continues to condense and becomes heavier, making the clouds drop. Eventually the vapour condenses into water droplets and becomes too heavy for the cloud to hold it so it releases it as rain, snow or hail, precipitation. There are ten main types of clouds ranging from 0-6000m in altitude. The ten types can be divided into four groups; Cirrus, Alto, Stratus and Cumulus. Cumulus clouds are the lowest clouds and Cirrus clouds are the highest. Alto is slightly higher than Stratus.
Cirrus
There are three types of Cirrus clouds; Cirrus, Cirrocumulus and Cirrostratus, all of which are made entirely of earth crystals. Cirrus clouds are thin, wispy clouds that are usually white or slightly grey. The wisps are formed when the clouds start to drop and are caught in winds which stretch out the cloud. Cirrus clouds are often an indication of strong ground-level winds. Cirrocumulus clouds often form before cold fronts while Cirrostratus form before warm fronts. Cirrostratus clouds aren’t thick enough to completely obscure a view of the sun or moon but they can make them seem like they are glowing or have a halo. A halo can indicate incoming rain.
Alto
Altocumulus and Altostratus clouds form around 2000 to 3000m high. Both types of clouds can be white. Altocumulus can also be grey, whereas Altostratus can be slightly blue. Altocumulus forms rolls or lines, waves or rounded masses and often forms at night. Altostratus clouds are often thick enough to obscure the sun or moon. Cirrostratus often appears before Altostratus and, as the Cirrostratus drops, it merges with the Altostratus.
Stratus
Stratus and Stratocumulus clouds occur all year round, all around the world, although Stratus clouds are more common around coastal areas and mountains during winter months. Stratus clouds create a sheet that can cover the sky. It can be transparent or thick enough to cover the sun or moon. Stratocumulus clouds can be nearly any shape; patches, sheets, layers, rolls or rounded masses. They are formed when a sheet of warm air is met by slightly cooler, rising air. Stratocumulus can take several days to clear or can clear in a few hours.
Cumulus
There are two types of Cumulus clouds, Cumulus and Cumulonimbus. Cumulus clouds can form below 2000m and can stretch up to 20m high and 10m wide. They are often very bright because they reflect large amounts of sunlight. Cumulonimbus form everywhere except in Antarctica. They can extend vertically to 6000m or more. Cumulonimbus clouds produce severe weather storms like torrential rain and snow, thunderstorms, hailstorms and tornadoes.
Nimbostratus
Nimbostratus clouds are dense clouds that look like a blanket of grey with no particular shape. They are low lying clouds that are produced up to 2000m high. Nimbostratus often produces steady rain or snow. The cloud temperatures can reach below -20 degrees Celsius.
Cirrus
There are three types of Cirrus clouds; Cirrus, Cirrocumulus and Cirrostratus, all of which are made entirely of earth crystals. Cirrus clouds are thin, wispy clouds that are usually white or slightly grey. The wisps are formed when the clouds start to drop and are caught in winds which stretch out the cloud. Cirrus clouds are often an indication of strong ground-level winds. Cirrocumulus clouds often form before cold fronts while Cirrostratus form before warm fronts. Cirrostratus clouds aren’t thick enough to completely obscure a view of the sun or moon but they can make them seem like they are glowing or have a halo. A halo can indicate incoming rain.
Alto
Altocumulus and Altostratus clouds form around 2000 to 3000m high. Both types of clouds can be white. Altocumulus can also be grey, whereas Altostratus can be slightly blue. Altocumulus forms rolls or lines, waves or rounded masses and often forms at night. Altostratus clouds are often thick enough to obscure the sun or moon. Cirrostratus often appears before Altostratus and, as the Cirrostratus drops, it merges with the Altostratus.
Stratus
Stratus and Stratocumulus clouds occur all year round, all around the world, although Stratus clouds are more common around coastal areas and mountains during winter months. Stratus clouds create a sheet that can cover the sky. It can be transparent or thick enough to cover the sun or moon. Stratocumulus clouds can be nearly any shape; patches, sheets, layers, rolls or rounded masses. They are formed when a sheet of warm air is met by slightly cooler, rising air. Stratocumulus can take several days to clear or can clear in a few hours.
Cumulus
There are two types of Cumulus clouds, Cumulus and Cumulonimbus. Cumulus clouds can form below 2000m and can stretch up to 20m high and 10m wide. They are often very bright because they reflect large amounts of sunlight. Cumulonimbus form everywhere except in Antarctica. They can extend vertically to 6000m or more. Cumulonimbus clouds produce severe weather storms like torrential rain and snow, thunderstorms, hailstorms and tornadoes.
Nimbostratus
Nimbostratus clouds are dense clouds that look like a blanket of grey with no particular shape. They are low lying clouds that are produced up to 2000m high. Nimbostratus often produces steady rain or snow. The cloud temperatures can reach below -20 degrees Celsius.