The Basics
By Studio Pangu / Published 2023
Clouds are one of nature's most consistently visible wonders and can also tell us a lot about what is going on up in the atmosphere. This serves as an introduction to some of the most common clouds and their properties, most of which exist in specific atmospheric conditions eg. high, medium and low altitudes, whilst the Cumulonimbus cloud be found in multiple conditions.
High Altitude
Cirrus
Cirrus clouds are short, detached, hair-like clouds found at high altitudes. These delicate clouds are wispy, with a silky sheen, or look like tufts of hair. They often form in advance of a warm front, where the air masses meet at high levels, indicating a change in the weather is on the way.
Cirrus
Cirrus clouds are short, detached, hair-like clouds found at high altitudes. These delicate clouds are wispy, with a silky sheen, or look like tufts of hair. They often form in advance of a warm front, where the air masses meet at high levels, indicating a change in the weather is on the way.
Cirrostratus
Cirrostratus are transparent high clouds, which cover large areas of the sky. They sometimes produce white or coloured rings, spots or arcs of light around the Sun or Moon, that are known as halo phenomena. If cirrostratus nebulosus exists in the sky it is likely that an incoming warm front will bring persistent rain within a day. If cirrostratus fibratus is spotted, stratus may proceed it, bringing only light drizzle.
Cirrocumulus
Cirrocumulus clouds are made up of lots of small white clouds called cloudlets, which are usually grouped together at high levels. Composed almost entirely from ice crystals, the little cloudlets are regularly spaced, often arranged as ripples in the sky. Precipitation from cirrocumulus clouds never reaches the surface, meaning that these clouds are usually associated with fair weather. However, their appearance can often prelude stormy weather.
Cirrostratus are transparent high clouds, which cover large areas of the sky. They sometimes produce white or coloured rings, spots or arcs of light around the Sun or Moon, that are known as halo phenomena. If cirrostratus nebulosus exists in the sky it is likely that an incoming warm front will bring persistent rain within a day. If cirrostratus fibratus is spotted, stratus may proceed it, bringing only light drizzle.
Cirrocumulus
Cirrocumulus clouds are made up of lots of small white clouds called cloudlets, which are usually grouped together at high levels. Composed almost entirely from ice crystals, the little cloudlets are regularly spaced, often arranged as ripples in the sky. Precipitation from cirrocumulus clouds never reaches the surface, meaning that these clouds are usually associated with fair weather. However, their appearance can often prelude stormy weather.
Mid Altitude
Nimbostratus
Nimbostratus clouds are dark, grey, featureless layers of cloud, thick enough to block out the Sun. Producing persistent rain, these clouds are often associated with frontal systems provided by mid-latitude cyclones. These mid-level clouds are often accompanied by continuous moderate rain or snow and appear to cover most of the sky. Nimbostratus will often bring precipitation which may last for several hours until the associated front passes over.
Altocumulus
Altocumulus clouds are small mid-level layers or patches of clouds, called cloudlets, which most commonly exist in the shape of rounded clumps. There are many varieties of altocumulus, however, meaning they can appear in a range of shapes. Altocumulus are made up of a mix of ice and water, giving them a slightly more ethereal appearance than the big and fluffy lower level cumulus. Mostly found in settled weather, altocumulus clouds are usually composed of droplets, but may also contain ice crystals. Precipitation from these clouds is rare, but even if rain does fall it doesn't reach the ground.
Altostratus
Altostratus are large mid-level sheets of thin cloud. Usually composed of a mixture of water droplets and ice crystals, they are thin enough in parts to allow you to see the Sun weakly through the cloud. They are often spread over a very large area and are typically featureless. These clouds often form ahead of a warm or occluded front. As the front passes, the altostratus layer deepens and bulks out to become nimbostratus, which produces rain or snow. As a result, sighting it can usually indicate a change in the weather is on the way.
Nimbostratus clouds are dark, grey, featureless layers of cloud, thick enough to block out the Sun. Producing persistent rain, these clouds are often associated with frontal systems provided by mid-latitude cyclones. These mid-level clouds are often accompanied by continuous moderate rain or snow and appear to cover most of the sky. Nimbostratus will often bring precipitation which may last for several hours until the associated front passes over.
Altocumulus
Altocumulus clouds are small mid-level layers or patches of clouds, called cloudlets, which most commonly exist in the shape of rounded clumps. There are many varieties of altocumulus, however, meaning they can appear in a range of shapes. Altocumulus are made up of a mix of ice and water, giving them a slightly more ethereal appearance than the big and fluffy lower level cumulus. Mostly found in settled weather, altocumulus clouds are usually composed of droplets, but may also contain ice crystals. Precipitation from these clouds is rare, but even if rain does fall it doesn't reach the ground.
Altostratus
Altostratus are large mid-level sheets of thin cloud. Usually composed of a mixture of water droplets and ice crystals, they are thin enough in parts to allow you to see the Sun weakly through the cloud. They are often spread over a very large area and are typically featureless. These clouds often form ahead of a warm or occluded front. As the front passes, the altostratus layer deepens and bulks out to become nimbostratus, which produces rain or snow. As a result, sighting it can usually indicate a change in the weather is on the way.
Low Altitude
Stratocumulus
Stratocumulus clouds are low-level clumps or patches of cloud varying in colour from bright white to dark grey. They are the most common clouds on earth recognised by their well-defined bases, with some parts often darker than others. They usually have gaps between them, but they can also be joined together. These clouds can be present in all types of weather conditions, from dry settled weather to more rainy conditions, but they themselves are often not the culprit. Stratocumulus clouds are often mistaken for rain clouds when in reality, it is quite rare to get anything more than the lightest drizzle from them, if anything at all.
Stratus
Stratus clouds are low-level layers with a fairly uniform grey or white colour. Often the scene of dull, overcast days in its 'nebulosus' form, they can persist for long periods of time. They are the lowest-lying cloud type and sometimes appear at the surface in the form of mist or fog. Stratus is usually accompanied by little to no rainfall but if it is thick enough, it can produce light drizzle. This drizzle can also fall in the form of light snow if cold enough.
Cumulus
Cumulus clouds are detached, individual, cauliflower-shaped clouds usually spotted in fair weather conditions. The tops of these clouds are mostly brilliant white tufts when lit by the Sun, although their base is usually relatively dark. Mostly, cumulus indicates fair weather, often popping up on bright sunny days. Though if conditions allow, cumulus can grow into towering cumulus congestus or cumulonimbus clouds, which can produce showers.
Cumulonimbus - High, Mid + Low
Cumulonimbus clouds are menacing looking multi-level clouds, extending high into the sky in towers or plumes. More commonly known as thunderclouds, cumulonimbus is the only cloud type that can produce hail, thunder and lightning. The base of the cloud is often flat, with a very dark wall-like feature hanging underneath, and may only lie a few hundred feet above the Earth's surface. Cumulonimbus clouds are associated with extreme weather such as heavy torrential downpours, hail storms, lightning and even tornadoes.
Cumulonimbus clouds are menacing looking multi-level clouds, extending high into the sky in towers or plumes. More commonly known as thunderclouds, cumulonimbus is the only cloud type that can produce hail, thunder and lightning. The base of the cloud is often flat, with a very dark wall-like feature hanging underneath, and may only lie a few hundred feet above the Earth's surface. Cumulonimbus clouds are associated with extreme weather such as heavy torrential downpours, hail storms, lightning and even tornadoes.