Cirrus clouds (Cirrus, Ci) have a thickness from hundreds of meters to several kilometers. They consist of ice crystals in the form of needles, columns, plates. The luminaries shine through them. There are different types of cirrus clouds: filamentous, claw-shaped, tower-shaped, dense, flocculent, entangled, radial, ridge-shaped, double .

Cirrocumulus clouds (Cirrocumulus, Cc) characterized by a small width - 200–400 m. The structure of the clouds is lumpy. They are transparent. There are wavy, cumulus with turrets, and flocculus varieties of cirrocumulus clouds.

Cirrostratus clouds (Cirrostratus, Cs) They look like a white or bluish translucent veil. Their thickness ranges from 100 m to several kilometers.

Altocumulus (Ac) They look like white, sometimes grayish waves, consisting of plates or flakes separated by gaps in the blue sky, but they can also merge into a continuous cover. The thickness of the layer of altocumulus clouds is about 200–700 m. Rain and snow fall from them.

Altostratus clouds (Altostratus, As) form a continuous gray or bluish “carpet” in the sky with the lower boundary usually at an altitude of 3–5 km. The thickness of the cloud layers is 1–2 km.

High-layered translucent (Altostratus translucidus, As trans)

Stratocumulus clouds (Nimbostratus, Ns) - these are gray clouds consisting of large ridges, waves, plates, separated by gaps or merging into a continuous gray wavy cover. Consist mainly of drops. The thickness of the layer is from 200 to 800 m. Precipitation, as a rule, does not fall. Stratocumulus clouds can be wavy, cumuliform, dissecting, or vesicular.

Stratus clouds (Stratus, St) They are a uniform gray or gray-yellow cover. There are different types: foggy, wavy and broken. Under the veil of stratus clouds, broken-nimbus clouds are often observed.

Nimbostratus the clouds look like a solid gray veil, covering the entire sky in the form of ridges and shafts. They consist of water droplets, rarely mixed with snowflakes. The lower base of the clouds can fall below 100 m, and the upper one can extend above 5 km. This type of cloud produces heavy precipitation.

Cumulus clouds (Cumulus, Cu) They are divided into cumulus, medium cumulus and powerful cumulus. Thickness is 1-2 km, sometimes 3-5 km. The upper parts of cumulus clouds look like domes or towers with rounded outlines.

Cumulonimbus (Cb)- very powerful cloud accumulations; they are “bald” and “hairy”, with a thunderous arched shaft in front.

Unusually shaped clouds

Rarely found, most often in the tropics. Their appearance is associated with the formation of tropical cyclones.

is also a very rare occurrence.

Stratus(St) – stratus clouds are clouds that, in contrast to convective clouds (cumulus, Cumulus (Cu)), develop horizontally rather than vertically. They form in the lower troposphere and can be dark gray or light gray in color. In the absence of clouds of other tiers above the St layer, the Moon and the Sun can be visible through St, and the contours of the disks of the luminaries can have clear boundaries (large sunspots can even be seen on the Sun). St includes fog, so stratus clouds can form close to the ground. St usually does not produce precipitation (unless there are other types of clouds that produce precipitation), but can cause drizzle. Precipitation may be associated with nimbostratus clouds (Nimbostratus, Ns). The higher forms of stratus clouds are Altostratus and Cirrostratus. Stratus nebulosus- This is a uniform layer of stratus clouds without clearly distinguishable elements and compactions. They are the most common form of St. Stratus fractus– Ragged low clouds, carried by the wind, usually against a background of nimbostratus clouds (Ns). They are a sign of bad weather. Clusters of such clouds are called “pannus”.

Stratocumulus (Stratocumulus, Sc)

Average bottom border height: 0.6 - 1.5 km. Thickness: from 0.2 to 0.8 km. Cloud microstructure: Mostly drip, sometimes mixed, extremely rarely crystalline. The droplet radius is 5 µm. Crystals are in the form of thin plates or needles. Water content - 0.2 - 0.5 g/m3. Optical phenomena, transparency: The sun and moon can only be seen through the thin edges of the clouds, and crowns are occasionally visible. Precipitation: As a rule, they do not fall out. Light, short-lived precipitation may fall from stratocumulus clouds that are not translucent. Location Features: Often arranged in regular parallel rows or waves. Description and distinctive features: They form large and rather low-lying waves, ridges, blocks of grayish or gray color, usually located in regular rows. Sometimes there are gaps of blue sky between them - these are translucent stratocumulus clouds - Stratocumulus translucidus (Sc trans). In other cases, they form a continuous dark gray cover consisting of swells or large blocks - dense stratocumulus clouds - Stratocumulus opacus (Sc op). Nimbostratus clouds consist predominantly of small droplets of water, supercooled in winter. Translucent stratocumulus clouds never produce precipitation and are not a sign of deteriorating weather. On the contrary, they often form in good, stable and calm weather, in which case their formation indicates high air humidity. Dense stratocumulus clouds are very often observed in inclement weather when they accompany more powerful clouds ( nimbostratus or cumulonimbus ), giving precipitation. Stratocumulus clouds are formed as a result of the occurrence of wave movements in inversion layers located below 2 km, spreading cumulus clouds in the layer under inversions below 2 km, as well as in the evening due to weakening convection. Stratocumulus clouds formed from cumulus are called stratocumulus formed from cumulus - Stratocumulus cumulogenitus (Sc cug). Differ from altocumulus smaller height, larger sizes of individual blocks and plates and greater density. From layered And nimbostratus Clouds are distinguished by a more distinct lower boundary and a clear wavy structure, and they also differ from nimbostratus by the absence of prolonged precipitation.

Stratocumulus (Stratocumulus, Sc)

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Description and distinctive features: They form large and rather low-lying waves, ridges, blocks of grayish or gray color, usually located in regular rows. Sometimes there are gaps of blue sky between them - these are translucent stratocumulus clouds - Stratocumulus translucidus (Sc trans). In other cases, they form a continuous dark gray cover consisting of swells or large blocks - dense stratocumulus clouds - Stratocumulus opacus (Sc op).
Nimbostratus clouds consist predominantly of small droplets of water, supercooled in winter. Translucent stratocumulus clouds never produce precipitation and are not a sign of deteriorating weather. On the contrary, they often form in good, stable and calm weather, in which case their formation indicates high air humidity. Dense stratocumulus clouds are very often observed in inclement weather, when they accompany more powerful clouds (nimbostratus or cumulonimbus) producing precipitation.
Stratocumulus clouds are formed as a result of the occurrence of wave movements in inversion layers located below 2 km, the spreading of cumulus clouds in the layer under inversions below 2 km, and also in the evening due to weakening convection. Stratocumulus clouds formed from cumulus are called stratocumulus formed from cumulus - Stratocumulus cumulogenitus (Sc cug).
They differ from altocumulus by their smaller height, larger sizes of individual blocks and plates, and greater density. They differ from stratus and nimbostratus clouds by a more distinct lower boundary and clear wavy structure, and they also differ from nimbostratus by the absence of prolonged precipitation.

Additional Information

Stratocumulus(stratocumulus, Sc) appear on the sky as cumulus-shaped cells, stretched vertically and with no significant vertical development. Typically, Sc cloud elements form wavy and/or cellular ridges with dark central parts and lighter (thinner) edges of the cloud elements through which the Sun and Moon can show through. The merging of Sc cloud elements results in the formation of an uneven gray cloud cover.
Sc is quite easy to confuse with altocumulus (Ac) clouds, similar in shape to Sc, but located at a higher altitude (in the middle troposphere). Considering that Sc is closer to us than Ac, distinctive feature differences in the apparent size of cloud elements may serve to separate them. If individual cloud elements of the observed clouds have an apparent extent of more than 5°, then it is Sc, and if less than 5°, then it is Ac. This angular size corresponds to the three middle fingers of an adult at arm's length. However, if you take off on an airplane, then Ac becomes indistinguishable from Sc for you. Precipitation given by Sc is observed rarely, and is short-lived and weak (for example, rare snowflakes may fall - “white flies” - which, due to their insignificance, may go unnoticed by the observer or be observed in a small area). Most often, only dip bands can be observed under Sc. The most common Sc species are Stratocumulus floccus, Stratocumulus castellanus and Stratocumulus stratiformis.

Stratocumulus floccus appear as a layer of closely grouped flat cellular cloud elements. At the same time, higher clouds or clear skies may be visible through the gaps between cloud elements.

cloud elements Stratocumulus castellanus look like

Nimbostratus

Nimbostratus clouds are dark gray, in the form of a continuous layer. During precipitation, it appears homogeneous; in the intervals between precipitation, some heterogeneity and even some undulation of the layer is noticeable. They differ from stratus clouds in their darker and bluish color, heterogeneity of structure and the presence of overlying sediments.

Stratocumulus

Gray clouds consisting of large ridges, waves, plates, separated by gaps or merging into a continuous gray wavy cover. They consist mainly of water droplets. The sun and moon can only shine through the thin edges of the clouds. Precipitation, as a rule, does not fall. Light, short-lived precipitation may fall from non-translucent stratocumulus clouds.

Layered

Stratus clouds form a homogeneous layer, similar to fog. They usually cover the entire sky, but can sometimes appear as broken cloud masses. The base of these clouds can drop very low; sometimes they merge with ground fog. Sometimes precipitation falls from these clouds, most often in the form of snow grains or drizzle.

Stratus fog clouds

Stratus clouds

Nimbostratus clouds and strong air currents

This article lists and describes all types of clouds.

Cloud types

Upper clouds are formed in temperate latitudes above 5 km, in polar latitudes above 3 km, in tropical latitudes above 6 km. The temperature at this altitude is quite low, so they consist mainly of ice crystals. The upper level clouds are usually thin and white. The most common forms of upper clouds are cirrus and cirrostratus, which can usually be seen in good weather.

Mid-level clouds usually located at an altitude of 2-7 km in temperate latitudes, 2-4 km in polar latitudes and 2-8 km in tropical latitudes. They consist mainly of small particles of water, but at low temperatures they can also contain ice crystals. The most common types of mid-level clouds are altocumulus (altocumulus), altostratus (altostratus). They may have shadowed parts, which distinguishes them from cirrocumulus clouds. This type of cloud usually occurs as a result of air convection, as well as the gradual rise of air ahead of a cold front.

Low clouds They are located at altitudes below 2 km, where the temperature is quite high, so they consist mainly of water droplets. Only in the cold season. When the surface temperature is low, they contain particles of ice (hail) or snow. The most common types of low clouds are nimbostratus and stratocumulus - dark low clouds accompanied by moderate precipitation.

Fig1. Main types of clouds: Cirrus, Ci, Cirrocumulus, Cc, Cirrostratus, Cs, Altocumulus, Ac, Altostratus, As, Altostratus translucidus , As trans) , Stratostratus (Nimbostratus, Ns), Stratus (Stratus, St), Stratocumulus (Stratocumulus, Sc), Cumulus (Cumulus, Cu), Cumulonimbus (Cb)

Pinnate (Cirrus, Ci)

They consist of individual feather-like elements in the form of thin white threads or white (or mostly white) tufts and elongated ridges. They have a fibrous structure and/or a silky sheen. They are observed in the upper troposphere; in mid-latitudes their bases most often lie at altitudes of 6-8 km, in tropical latitudes from 6 to 18 km, in polar latitudes from 3 to 8 km). Visibility inside the cloud is 150-500 m. Constructed from ice crystals large enough to have a noticeable fall speed; therefore, they have a significant vertical extent (from hundreds of meters to several kilometers). However, wind shear and differences in crystal size cause the filaments of cirrus clouds to become skewed and twisted. These clouds are characteristic of the leading edge of a cloud system of a warm front or an occlusion front associated with upslip. They often also develop in anticyclonic conditions and are sometimes parts or remnants of ice caps (anvils) of cumulonimbus clouds.

There are different types: filiform(Cirrus fibratus, Ci fibr.), claw-shaped(Cirrus uncinus, Ci unc.), tower-shaped(Cirrus castellanus, Ci cast.), dense(Cirrus spissatus, Ci spiss.), flaky(Cirrus floccus, Ci fl.) and varieties: confused(Cirrus intortus, Ci int.), radial(Cirrus radiatus, Ci rad.), ridge-shaped(Cirrus vertebratus, Ci vert.), double(Cirrus duplicatus, Ci dupl.).

Sometimes this type of cloud, along with the described clouds, also includes cirrostratus And cirrocumulus clouds.

Cirrocumulus (Cc)

They are often called "lamb". Very high small spherical clouds, elongated in lines. They look like the backs of mackerels or ripples on the coastal sand. The height of the lower boundary is 6-8 km, the vertical length is up to 1 km, visibility inside is 5509-10000 m. They are a sign of an increase in temperature. Often observed together with cirrus or cirrostratus clouds. They are often the precursors of a storm. With these clouds, the so-called “iridization” is the rainbow coloring of the edges of the clouds.

Cirrostratus, Cs)

Halo formed on cirrus clouds

Sail-like clouds of the upper tier, consisting of ice crystals. They look like a homogeneous, whitish veil. The height of the lower edge is 6-8 km, the vertical extent ranges from several hundred meters to several kilometers (2-6 or more), visibility inside the cloud is 50-200 m. Cirrostratus clouds are relatively transparent, so the sun or moon can be clearly visible through them. These upper-level clouds usually form when large layers of air rise upward due to multi-level convergence.

Cirrostratus clouds are characterized by the fact that they often produce halo phenomena around the sun or moon. Halos are the result of the refraction of light by the ice crystals that make up the cloud. Cirrostratus clouds, however, tend to thicken when a warm front approaches, which means increased ice crystal formation. As a result, the halo gradually disappears and the sun (or moon) becomes less visible.

Altocumulus, Ac

Formation of altocumulus clouds.

Altocumulus (Ac) - typical cloudiness for the warm season. Gray, white, or bluish clouds in the form of waves and ridges, consisting of flakes and plates separated by gaps. The height of the lower boundary is 2-6 km, the vertical length is up to several hundred meters, visibility inside the cloud is 50-80 m. They are usually located above places facing the sun. Sometimes they reach the stage of powerful cumulus clouds. Altocumulus clouds usually occur as a result of rising warm air masses, as well as the arrival of a cold front that pushes warm air upward. Therefore, the presence of altocumulus clouds on a warm and humid summer morning foreshadows the imminent appearance of thunderclouds or a change in weather.

High-stratified (Altostratus, As)

Altostratus clouds

They look like a uniform or faintly wavy veil of gray or bluish color; the sun and moon usually shine through, but faintly. The height of the lower boundary is 3-5 km, the vertical extent is 1-4 km, visibility in the clouds is 25-40 m. These clouds consist of ice crystals, supercooled water droplets and snowflakes. Altostratus clouds may bring heavy rain or snow.

High-layered translucent (Altostratus translucidus, As trans)

Altostratus clouds at sunset

Altostratus translucent clouds. The wavy structure of the cloud is noticeable, the solar circle of the sun is quite visible. Quite visible shadows can sometimes appear on the ground. The stripes are clearly visible. A veil of clouds, as a rule, gradually covers the entire sky. The height of the base is within 3-5 km, the thickness of the As trans cloud layer is on average about 1 km, occasionally up to 2 km. Precipitation falls, but in low and middle latitudes in summer it rarely reaches the ground.

Nimbostratus (Nimbostratus, Ns)

Nimbostratus clouds and strong air currents.

Layered (Stratus, St)

Stratus clouds.

Stratus clouds form a homogeneous layer, similar to fog, but located at an altitude of hundreds or even tens of meters. They usually cover the entire sky, but can sometimes appear as broken cloud masses. The base of these clouds can drop very low; sometimes they merge with ground fog. Their thickness is small - tens and hundreds of meters.

Stratocumulus (Sc)

Gray clouds consisting of large ridges, waves, plates, separated by gaps or merging into a continuous gray wavy cover. They consist mainly of water droplets. The thickness of the layer is from 200 to 800 m. The sun and moon can only shine through the thin edges of the clouds. Precipitation, as a rule, does not fall. Light, short-lived precipitation may fall from non-translucent stratocumulus clouds.

Cumulus clouds (Cumulus, Cu)

Cumulus clouds. View from above.

Cumulus clouds are dense, bright white clouds during the day with significant vertical development (up to 5 km or more). The upper parts of cumulus clouds look like domes or towers with rounded outlines. Typically, cumulus clouds arise as convection clouds in cold air masses.

Cumulonimbus (Cb)

Cumulonimbus clouds (Cumulonimbus capillatus incus)

Cumulonimbus - powerful and dense clouds with strong vertical development (up to a height of 14 km), producing heavy rainfall with powerful hail and thunderstorm phenomena. Cumulonimbus clouds/clouds develop from powerful cumulus clouds. They can form a line called a squall line. The lower levels of cumulonimbus clouds are composed primarily of water droplets, while at higher levels, where temperatures are well below 0°C, ice crystals predominate.