Clouds are formed from condensed water vapor or ice crystals in the Earth’s atmosphere. They come in various shapes, sizes, and altitudes, and their classification is based on their appearance and characteristics. The main types of clouds recognized by the International Cloud Atlas are as follows:
- Cirrus Clouds: Cirrus clouds are high-altitude clouds that are thin, wispy, and composed mostly of ice crystals. They have a fibrous or feathery appearance and are often white. Cirrus clouds are commonly associated with fair weather but can indicate an approaching change in weather.
- Cumulus Clouds: Cumulus clouds are puffy, white clouds with a distinct cotton-like appearance. They are typically seen at mid-level altitudes but can extend into the high or low levels. Cumulus clouds are often associated with fair weather but can grow into larger cumulonimbus clouds, which bring thunderstorms.
- Stratus Clouds: Stratus clouds are low-level clouds that appear as a uniform layer covering the sky. They are often gray or white and have a smooth, flat appearance. Stratus clouds are usually associated with overcast conditions and can bring light drizzle or steady rain.
- Nimbostratus Clouds: Nimbostratus clouds are thick, dark, and featureless clouds that extend across the sky. They are associated with continuous precipitation, such as rain or snow, and often bring overcast and gloomy weather.
- Stratocumulus Clouds: Stratocumulus clouds are low-level clouds with a layered or wavy appearance. They are often gray or white and cover parts of the sky. Stratocumulus clouds are typically not associated with precipitation but can develop into more significant cloud formations.
- Altocumulus Clouds: Altocumulus clouds are mid-level clouds that appear as rounded masses or patches. They are white or gray in color and can have a bumpy or wavy texture. Altocumulus clouds often form in groups and are usually associated with fair weather conditions.
- Altostratus Clouds: Altostratus clouds are mid-level clouds that cover the sky with a uniform gray or bluish-gray sheet. They are thicker than altocumulus clouds and can often block out the Sun. Altostratus clouds can bring steady precipitation, such as rain or snow.
- Cumulonimbus Clouds: Cumulonimbus clouds are large, towering clouds that extend through various altitudes, from low to high levels. They are associated with thunderstorms and can reach great heights. Cumulonimbus clouds often have a distinct anvil-shaped top and can produce heavy rain, lightning, thunder, and even hail.
These are some of the main cloud types, but there are also variations and combinations of cloud formations. Clouds are an essential part of weather patterns and can provide valuable information about current and impending atmospheric conditions.