We talked about cirrus, it's time to move on to the description of cumulus and stratus clouds. As already mentioned, not all clouds are important in weather forecasting in yachting. Cirrus are long-range indicators, and imply a change in conditions soon. Cumulus clouds typically imply an unstable mass of air - warmer air rises and mixes with colder air. These clouds can develop into cumulonimbus or thunderstorms. Large cumulus clouds are the most important type clouds for weather forecasting in yachting, because they can lead to "shift" of the wind, sudden squalls and require the utmost respect.
Altocumulus Altocumulus (Ac)
Cloud description: Altocumulus (Ac) high cumulus - typical warm season cloud cover. It is located, as a rule, above the slopes facing the sun. Sometimes they reach the stage of powerful cumulus clouds.
Lenticular high cumulus - Altocumulus lenticularis (Aс lent)
Description of clouds: lenticular altocumulus clouds - Altocumulus lenticularis (Ac lent) - separate rather dense clouds of lenticular or cigar-shaped shape with smooth outlines and a wavy border. Formed at an altitude of 2-6 km. Precipitation can fall in the form of individual drops or snowflakes. Unlike cirrocumulus clouds, they can have shaded parts, which, as a rule, consist of water droplets.
They arise due to wave motions of air at high-lying boundaries of inversions, in particular, in front of cold fronts or fronts of occlusions.
Translucent high cumulus clouds - Altocumulus translucidus (Ac trans)
Description of clouds: translucent altocumulus clouds - Altocumulus translucidus (Ac trans) usually consist of sharply delimited elements (waves, plates), characterized by non-uniform density Dense areas gray color alternate with thin, more illuminated parts of the transparent white color. In thin parts through cumulus clouds can shine through heavenly bodies or blue sky. Formed at an altitude of 2-6 km. Precipitation can fall in the form of individual drops or snowflakes.
Ac trans usually occurs as a result of the rise of warm air masses, as well as the onset of a cold front, which displaces warm air upwards. Therefore, the presence of Ac trans on a warm and humid summer morning often portends the imminent appearance of storm clouds or a change in the weather.
Opaque highly stratified clouds - Altostratus opacus (As op)
Description of clouds: opaque highly stratified clouds - Altostratus opacus (As op) are a uniform cover of gray color, often of variable density, which is noted by the degree of their illumination (clouds are darker in places, lighter in places). Through these stratus clouds, the sun and moon do not shine through, but their location can be determined by a blurry bright spot on the clouds. They form at a height of 3-5 km in the form of a veil of light gray or bluish color, in which stripes or fibers can be distinguished. They almost always replace cirrostratus clouds.
Most often, they occur in the process of lowering and compacting a cirrostratus cloud. They consist of small water droplets, but the top of these stratus clouds can reach the upper tier and consist of ice crystals. In this case, ice crystals, falling into the main mass of the stratus cloud, act as condensation nuclei and cause precipitation. But in the middle and southern latitudes, precipitation, as a rule, does not reach the ground due to evaporation. In winter, these layered the clouds are coming snow.
As op, cover large spaces, as their bases decrease, they become denser, small dark shreds appear under them.
Flaky high cumulus - Altocumulus floccus (Ac fl)
Description of clouds: flaky high cumulus clouds - Altocumulus floccus (Ac fl) - are white flakes of cumulus clouds, broken at the edges, relatively quickly changing their shape. They are formed at a height of 2-6 km due to the convective movement of air in a layer above 2 km. Precipitation can fall in the form of individual drops or snowflakes. Unlike cirrocumulus clouds, they can have shaded parts, which, as a rule, consist of water droplets.
Altocumulus clouds usually form as a result of the rise of warm air masses, as well as the onset of a cold front, which displaces warm air upwards. Therefore, the presence of altocumulus clouds on a warm and humid summer morning often portends the imminent appearance of thunderclouds or a change in the weather.
Translucent highly stratus clouds - Altostratus translucidus (As trans)
Description of clouds: translucent highly stratus clouds - Altostratus translucidus (As trans). The wavy structure of the stratus cloud is noticeable, the solar circle of the sun is quite distinguishable. Quite distinguishable shadows can sometimes appear on the ground. Stripes are clearly visible. A veil of stratus clouds, as a rule, gradually covers the entire sky. The height of the base is within 3-5 km, the thickness of the Ac trans stratus clouds is on average about 1 km, occasionally up to 2 km. Precipitation falls, but in the southern and middle latitudes it rarely reaches the ground in summer.
Orographic highly stratus and nimbostratus - Altostratus and Nimbostratus (As and Ns)
Description of clouds: orographic highly stratus clouds and nimbostratus - Altostratus and Nimbostratus (As and Ns) form on the windward slopes of mountain ranges. If a powerful stream of moist air flows onto the mountains, then the formation of clouds occurs mainly on their windward slopes. Clouds initially take the form of highly stratified clouds, and then grow upward to high altitudes. The range of visibility in stratus clouds, horizontal and oblique, changes rapidly.
Daytime stratocumulus clouds - Stratocumulus diurnalis (Sc diur)
Description of clouds: daytime stratocumulus clouds - Stratocumulus diurnalis (Sc diur) are formed from cumulus clouds during their spreading. Spreading occurs not in the middle, but in lower tier(below the inversion boundary, located rather low). In the initial stage of formation, their relationship with Cu is clearly visible, individual peaks of which protrude from the Sc layer. It is conditionally assumed that the apparent size of the elements of stratocumulus clouds exceeds ten times the diameter of the sun. Stratocumulus clouds form due to wave motions in inversion layers located below 2 km on the earth's surface.
Spreading evening stratocumulus clouds - Stratocumulus vesperalis (Sc vesp)
Description of clouds: spreading evening stratocumulus clouds - Stratocumulus vesperalis (Sc vesp) occur in the evening with the usual spreading of cumulus clouds due to the weakening of ascending air movements (convection). They look like flat elongated ridges of stratocumulus clouds, formed when the tops of cumulus clouds settle and their bases spread. They consist of drops, at negative temperatures - from supercooled drops or from a mixture of them with crystals and snowflakes.
Translucent stratocumulus clouds - Stratocumulus translucidus (Sc trans)
Description of clouds: translucent stratocumulus clouds - Stratocumulus translucidus (Sc trans) gray clouds consisting of large ridges (waves) of plates or blocks separated by gaps. In between, you can see an upper layer of translucent stratocumulus clouds or a blue sky. The height of the base is within 0.5, -1.5 km. The layer thickness is from 200 to 800 meters. They consist of drops, at negative temperatures from supercooled drops or from a mixture of them with crystals and snowflakes. Most of the time there is no precipitation.
Flat cumulus Cumulus humulus (Cu hum)
Description of clouds: flat cumulus Cumulus humulus (Cu hum) - scattered across the sky, rather dense cumulus clouds with clear horizontal bases, little developed vertically. They are observed mainly in the warm season. They usually appear in the morning, reach their maximum development around noon, and spread out in the evening, turning into stratocumulus evening clouds. Occasionally observed in temperate latitudes in winter. The presence of flat cumulus clouds Cu hum indicates good weather and are called "good weather clouds"
Hazy stratus clouds - Stratus nebulosus (St neb)
Description of clouds: misty stratus clouds - Stratus nebulosus (St neb). A completely uniform layer of gray or yellowish color, similar to fog raised above the surface of the earth. Usually hazy stratus clouds cover the entire sky. The height of the base is within 0.1 to 0.7 km, but sometimes clouds merge with ground fog. Sometimes drizzle or small snow grains (fine snow) can fall from the clouds, which significantly impairs visibility. They are formed, as a rule, due to the cooling of relatively warm air as it moves over a cold underlying surface, or during the radiation cooling of the lower layer of air during the night or several days in a row.
Broken rain - Fractonimbus (Frnb)
Description of clouds: broken rain - Fractonimbus (Frnb) dark gray clouds, sometimes with a yellowish or bluish tint. During precipitation, the layer of clouds seems to be homogeneous; in the interval between precipitation, its heterogeneity and even its undulations are noticeable. Clouds cover the entire sky without gaps. The height of the base is from 0.1 km to 1 km. The thickness of the base varies between 2-3 km, but sometimes reaches 5 km. The sun and moon do not shine through Frnb, and even approximately it is impossible to mark their location. Precipitation falls as patchy rain or snow, sometimes intermittently.
The main process of formation of Frnb is air cooling during its upward movement along an inclined frontal surface near the front.
Fog
Fog. A collection of condensation products (droplets or crystals, or both) suspended in the air just above the ground. It occurs due to the movement of the air mass to a colder bedding surface.
Dense stratocumulus clouds - Stratocumulus opacus (Sc op)
Description of clouds: dense stratocumulus clouds - Stratocumulus opacus (Sc op) is a layer of dark gray clouds, consisting of merging blocks or plates. Dense stratocumulus clouds persist as long as their lower surface is sufficiently distinct and one can distinguish shafts, ridges or individual plates on it. When the elements of the clouds merge completely, and the layer becomes homogeneous, then the clouds pass into stratified rain Ns or stratified. Stratocumulus clouds (Sc op) form in most cases inside homogeneous air masses. The height of the base is within 0.5-1.5 km. The layer thickness is from 0.2 to 0.8 km. Through (Sc op) the sky is not translucent, with this form of cloudiness it is impossible to determine the location of the sun or moon. Precipitation may fall as rain or occasional snow.
Wavy stratus clouds - Stratus undulatus (St und)
Description of clouds: wavy stratus clouds - Stratus undulatus (St und), a gray or yellowish-gray layer of stratus clouds, uniform in structure, on the lower surface of which weakly pronounced waves can be distinguished. These waves, due to their great length and low location are sometimes noticeable only in the form of a regular alternation of darker and lighter places. The height of the base is usually within 0.2-0.7 km. The sun and moon do not shine through the clouds. Wavy stratus clouds are made up of droplets low temperatures- supercooled.
From the clouds, drizzle or small snow grains may fall, which significantly impair visibility. They are formed mainly inside a homogeneous air mass. Wavy stratus clouds are formed mainly due to cooling of relatively warm air as it moves over a cold underlying surface or due to radiative cooling of the lower air layer during the night or several days in a row. One of the reasons for the formation of wavy stratus clouds can be the transfer of water vapor by turbulent upward motions into the subinversion layer and the condensation of excess steam in the upper part of the layer. Diffusion of water vapor into the subinversion layer from above their warm air mass is also possible if it is more humid than the lower air layer. Great importance for formation has the presence of a temperature inversion layer located at a small height above the earth's surface.
Powerful cumulus clouds - Cumulus congestus (Cu cong)
Description of clouds: powerful cumulus clouds - Cumulus congestus (Cu cong) highly developed vertical clouds. Some of them are partially torn, shaggy, in the form of towers tilted to the side. The thickness is 1.5 - 2 times the base of the cumulus cloud. The top of the cumulus cloud is dazzling white, swirling, the base is darkened. In the central part, powerful cumulus clouds completely cover the sun, while the edges are translucent, and crowns often form. Precipitation usually does not fall. They are formed mainly as a result of powerful ascending air currents caused by uneven heating of the underlying surface. Cu cong's development summer time leads to the development of cumulonimbus clouds and torrential rainfall.
Medium cumulus - Cumuluc mediocris (Cum med)
Description of clouds: medium cumulus clouds - Cumuluc mediocris (Cum med), having the appearance of isolated cloud masses, white heaps with a gray flat base and white tops, resembling cauliflower. The vertical dimensions of medium cumulus clouds are commensurate with the horizontal ones. The height of the base in temperate latitudes is usually from 0.8 to 1.5 km. However, it can fluctuate significantly, depending on the values relative humidity at the surface of the earth. Vertical extent from hundreds of meters to several kilometers. They are usually formed due to thermal convection or frontal rise. They are intermediate between Cu hum and Cu cong. Precipitation from medium cumulus usually does not fall. In temperate latitudes, individual drops of rain can fall from Cu med, or very short rare rain (sometimes during the fall of rain drops on the ground, the clouds from which they fell, the precipitation is already dissipated. Such rain is called “rain from a clear sky”
Cumulonimbus Cumulonimbus (Cb)
Cloud Description: Cumulonimbus Cumulonimbus (Cb), white clouds with dark, sometimes bluish bases, rising as huge cloud tops. Often observed in the form of individual clouds, but there may be clusters of them. The whole sky is not closed, there may be gaps between individual clouds. The height of the base varies from 0.4 to 1.0 km, the vertical extent is usually up to 3-4 km, but can develop up to the tropopause. Precipitation always has a stormy shower character: in summer it falls in the form of large-drop rain or hail, in spring and autumn in the form of ice or snow pellets, and in winter in the form of heavy snow, partly wet. Often at Cb there is a thunderstorm. Clouds usually form as a result of the development of powerful cumulus Cu cong. Falling precipitation bands are usually observed under the clouds, and in individual cases Rainbow.
This concludes the description of the clouds. I hope this information will help you navigate in a huge amount. various kinds clouds and increase the accuracy of your weather forecasts at sea. Which will ultimately make your yachting safer and more comfortable.
By international classification distinguish 10 main types of clouds of different tiers.
> UPPER CLOUDS(h>6km) 
Spindrift clouds(Cirrus, Ci) - these are separate clouds of a fibrous structure and a whitish hue. Sometimes they have a very regular structure in the form of parallel filaments or stripes, sometimes, on the contrary, their fibers are tangled and scattered across the sky in separate spots. Cirrus clouds are transparent because they are made up of tiny ice crystals. Often the appearance of such clouds portends a change in the weather. From satellites, cirrus clouds are sometimes difficult to distinguish.
cirrocumulus clouds(Cirrocumulus, Cc) - a layer of clouds, thin and translucent, like cirrus, but consisting of individual flakes or small balls, and sometimes, as it were, of parallel waves. These clouds usually form, figuratively speaking, a "cumulus" sky. Often they appear together with cirrus clouds. They are visible before storms.
Cirrostratus clouds(Cirrostratus, Cs) - a thin, translucent whitish or milky cover, through which the disk of the Sun or Moon is clearly visible. This cover can be homogeneous, like a layer of fog, or fibrous. On cirrostratus clouds, a characteristic optical phenomenon is observed - a halo (bright circles around the Moon or the Sun, a false Sun, etc.). Like cirrus, cirrostratus clouds often indicate the approach of inclement weather.
> MIDDLE CLOUDS(h=2-6 km)
They differ from similar cloud forms of the lower layer by their high height, lower density, and higher probability of the presence of an ice phase. 
Altocumulus clouds(Altocumulus, Ac) - a layer of white or gray clouds, consisting of ridges or separate "blocks", between which the sky is usually translucent. The ridges and "clumps" that form the "feathery" sky are relatively thin and arranged in regular rows or in a checkerboard pattern, less often in disorder. Cirrus skies are usually a sign of pretty bad weather.
Altostratus clouds(Altostratus, As) - a thin, less often dense veil of a grayish or bluish hue, in some places heterogeneous or even fibrous in the form of white or gray patches all over the sky. The sun or the moon shines through it in the form of bright spots, sometimes quite weak. These clouds are a sure sign of light rain.
> LOWER CLOUDS(h According to many scientists, nimbostratus clouds are assigned to the lower tier illogically, since only their bases are located in this tier, and the tops reach a height of several kilometers (cloud levels of the middle tier). These heights are more characteristic of clouds of vertical development, and therefore, some scientists refer them to clouds of the middle tier.
Stratocumulus clouds(Stratocumulus, Sc) - a cloud layer consisting of ridges, shafts or their individual elements, large and dense, gray in color. There are almost always darker areas.
The word "cumulus" (from the Latin "heap", "heap") denotes a stinginess, a heap of clouds. These clouds rarely bring rain, only sometimes they turn into nimbostratus, from which rain or snow falls.
stratus clouds(Stratus, St) - a rather homogeneous layer of low gray clouds devoid of the correct structure, very similar to fog that has risen to the ground for a hundred meters. Layered clouds cover large spaces, look like torn patches. In winter, these clouds are often held all day, precipitation on the ground usually does not fall from them, sometimes there is a drizzle. In summer, they quickly dissipate, after which fine weather sets in.
Nimbostratus clouds(Nimbostratus, Ns, Frnb) are dark gray clouds, sometimes threatening. Often low dark fragments of broken rain clouds appear below their layer - typical harbingers of rain or snowfall.
> VERTICAL EVOLUTION CLOUD
Cumulus clouds (Cumulus, Cu)- dense, sharply defined, with a flat, relatively dark base and a domed white, as if swirling, top, reminiscent of a cauliflower. They begin as small white shards, but soon a horizontal base forms and the cloud begins to rise imperceptibly. With low humidity and a weak vertical ascent of air masses, cumulus clouds portend clear weather. Otherwise, they accumulate during the day and can cause a thunderstorm.
Cumulonimbus (Cumulonimbus, Cb)- powerful cloud masses with strong vertical development (up to a height of 14 kilometers), giving heavy showers with thunderstorms. Develop from cumulus clouds, differing from them top made up of ice crystals. These clouds are associated with squally winds, heavy precipitation, thunderstorms, and hail. The lifetime of these clouds is short - up to four hours. The base of the clouds has a dark color, and the white top goes far up. In the warm season, the peak can reach the tropopause, and in cold season when convection is suppressed, the clouds are flatter. Usually clouds do not form a continuous cover. As a cold front passes, cumulonimbus clouds can form a swell. The sun does not shine through cumulonimbus clouds. Cumulonimbus clouds form when the air mass is unstable, when there is an active upward movement of air. These clouds also often form on a cold front when cold air hits a warm surface.
Each genus of clouds, in turn, is divided into types according to the features of the shape and internal structure, for example, fibratus (fibrous), uncinus (claw-like), spissatus (dense), castellanus (tower-shaped), floccus (flaky), stratiformis (layered-different ), nebulosus (foggy), lenticularis (lenticular), fractus (torn), humulus (flat), mediocris (medium), congestus (powerful), calvus (bald), capillatus (hairy). Types of clouds, further, have varieties, for example, vertebratus (ridge-like), undulatus (wavy), translucidus (translucent), opacus (non-translucent), etc. Further, additional features of clouds are distinguished, such as incus (anvil), mamma (mammoth) , vigra (falling stripes), tuba (trunk), etc. And, finally, evolutionary features are noted that indicate the origin of clouds, for example, Cirrocumulogenitus, Altostratogenitus, etc.
When observing clouds, it is important to determine by eye the degree of sky coverage on a scale of ten. Clear sky - 0 points. Clearly, there are no clouds in the sky. If it is covered with clouds no more than 3 points warm the firmament, it is slightly cloudy. Cloudy with a clearing of 4 points. This means that clouds cover half of the firmament, but at times their number decreases to "clear". When the sky is half closed, cloudiness is 5 points. If they say "sky with gaps", they mean that the cloudiness is not less than 5, but not more than 9 points. Overcast - the sky is completely covered with clouds of a single blue gap. Cloudiness 10 points.
From the surface of the Earth, it seems that all the clouds are at about the same height. However, there can be huge distances between them, equal to several kilometers. But what are the highest and lowest of them? This post has all the necessary information to become a cloud expert!
10. Layered clouds (average height - 300-450 m)
Wikipedia info: Stratus clouds are low-level clouds characterized by horizontal layering with a uniform layer, as opposed to cumuliform clouds, which are formed by ascending warm currents.
More specifically, the term "stratus" is used to describe low-level flat, hazy clouds that range in color from dark gray to almost white.
9. Cumulus clouds (average height - 450-2000 m)
Wikipedia info: "Cumulus" in Latin means "heap, heap". Cumulus clouds are often described as "fat", "cotton-like", or "fluffy" in their appearance and have a flat bottom border.
As low clouds, they are usually less than 1000 meters high unless they are a more vertical form of cumulus. Cumulus clouds can appear on their own, in lines, or in clusters.
8. Stratocumulus clouds (average height - 450-2000 m)
Wikipedia Info: Stratocumulus belongs to a type of cloud characterized by large dark, rounded masses, usually in clusters, lines or waves, the individual elements of which are larger than altocumulus clouds, forming at a lower altitude, usually below 2400 meters .
Weak convective air currents create shallow cloud layers due to the drier, still air above them, preventing further vertical development.
7. Cumulonimbus clouds (average height - 450-2000 m)
Wikipedia Info: Cumulonimbus clouds are dense, towering vertical clouds associated with thunderstorms and atmospheric instability, formed from water vapor carried by powerful updrafts.
Cumulonimbus clouds can form alone, in clusters, or as a swell with a squall along a cold front. These clouds are capable of producing lightning and other dangerous severe weather such as a tornado.
6. Nimbostratus clouds (average height - 900-3000 m)
Wikipedia info: Nimbostratus clouds usually generate precipitation over a vast area. They have a diffuse base, usually located somewhere near the surface at the lower levels and at an altitude of about 3000 meters at the middle levels.
Although nimbostratus clouds are usually dark in color at the base, they are often illuminated from within when viewed from the Earth's surface.
5. Altostratus clouds (average height - 2000-7000 m)
Wikipedia Info: Altostratus clouds are a type of mid-layer clouds belonging to the layer-like physical category, which is characterized by a generally uniform layer that varies in color from gray to bluish-green.
They are lighter than nimbostratus and darker than high cirrostratus. The Sun can be seen through thin altostratus clouds, but thicker clouds can have a denser, opaque structure.
4. Altocumulus clouds (average height - 2000-7000 m)
Wikipedia info: Altocumulus is a type of mid-tier cloud that belongs predominantly to the stratocumulus physical category, characterized by spherical masses or ridges in layers or sheets, the individual elements of which are larger and darker than cirrocumulus clouds, and smaller. than stratocumulus clouds.
However, if the layers become flocculent due to increased air mass instability, then altocumulus clouds become more cumulus in structure.
3. Cirrus clouds (average height - 5000-13.500 m)
Wikipedia info: Cirrus clouds are a type of atmospheric cloud, usually characterized by thin, filamentous filaments.
The filaments of the cloud sometimes form into tufts of a characteristic shape known collectively as mare's tails. Cirrus clouds are usually white or light gray in color.
2. Cirrostratus clouds ( average level- 5000-13.500 m)
Wikipedia info: Cirrostratus clouds are a type of thin, whitish stratus clouds made up of ice crystals. They are difficult to detect and are capable of halo formation when they take the form of a thin cirrostratus mist cloud.
1. Cirrocumulus clouds (average height - 5000-13.500 m)
Wikipedia info: Cirrocumulus is one of the three main varieties of upper tropospheric clouds (the other two are cirrus and cirrostratus). Like lower cumulus clouds, cirrocumulus clouds signify convection.
Unlike other tall cirrus and cirrostratus, cirrocumulus are composed of a small amount of transparent water droplets, although they are in a supercooled state.
You don't need a supercomputer to predict how the weather overhead will change in the next few hours. By watching the sky and having some knowledge of cloud formation, it is possible to predict whether it will rain.
Modern weather forecasts are based on complex computer simulations. These simulations use physical equations that describe the atmosphere, including the movement of air, solar heat forming clouds and rain. The gradual improvement of forecasts over time means that today's five-day forecasts are as accurate as three-day forecasts were 20 years ago.
But you don't need a supercomputer to predict how the weather overhead will change in the next few hours - such signs are known in different cultures for many thousands of years. By watching the sky and having some knowledge of cloud formation, it is possible to predict whether it will rain.
What's more, a little understanding of the physics of cloud formation highlights the complexity of the atmosphere and sheds light on why predicting weather beyond a few days is such a challenge.
Here are six types of clouds you can see and how they can help you understand the weather.
1) Cumulus clouds
Clouds form when air cools down to its dew point, the temperature at which the air can no longer handle the water vapor it contains. At this temperature, water vapor condenses and forms droplets of liquid water, which we see as a cloud. For this to happen, the air must be forced to rise in the atmosphere, or moist air must come into contact with a cold surface.
On a sunny day, the rays warm the ground, which warms the air directly above it. The heated air rises due to convection and forms cumulus clouds. These "good weather" clouds are like cotton wool. If you look at a sky filled with cumulus clouds, you can see that they have a flat bottom, located at the same level for all the clouds. At this altitude, air rising from ground level cools down to the dew point. It usually does not rain from cumulus clouds, which means that the weather will be good.
2) Cumulonimbus clouds
Small cumulus clouds do not rain, but if they increase and grow in height, this is a sign that soon there will be heavy rain. This often happens in the summer when morning cumulus clouds turn into cumulonimbus during the day.
Close to the ground, the cumulonimbus clouds are well-defined, but with height they begin to become more smoky at the edges. Such a transition indicates that the cloud no longer consists of water drops, but of ice crystals. When gusts of wind blow water droplets out of the cloud, they quickly evaporate in a drier environment, which is why water clouds have very sharply defined edges. Ice crystals blown out of the cloud do not evaporate as quickly, making the edges of the cloud look more hazy.
Cumulonimbus clouds often have a flat top. Air convection occurs inside such a cloud, and it gradually cools until it reaches a temperature ambient atmosphere. At this point, he loses buoyancy and can no longer rise higher. Instead, it spreads laterally, forming the characteristic shape of an anvil.
3) Cirrus clouds
Cirrus clouds form in very high layers of the atmosphere. They are smoky because they are made entirely of ice crystals falling through the atmosphere. If cirrus clouds carry winds moving from different speeds, they acquire a characteristic curved shape. And only at very high altitudes or at high latitudes do cirrus clouds produce rain that reaches the ground.
But if you notice cirrus clouds are starting to cover large area sky, become lower and thicker, this is a sure sign of the approach of a warm front. V warm front warm and cold air masses. Lighter warm air rises above the cold, which leads to the formation of clouds. The lowering of the clouds indicates the approach of the front, and that it will rain in the next 12 hours.
4) Layered clouds
A stratus cloud is a low-lying, continuous sheet of cloud that covers the sky. Stratus clouds are formed by slowly rising air or light winds covering moist air. cold earth or the surface of the sea. The stratus clouds are thin, therefore, despite the gloomy picture, it is unlikely to rain from them, at most a slight drizzle. Stratus clouds are identical to fog, so if you've ever walked on highlands on a foggy day, you were inside a cloud.
5) Lenticular clouds
The last two types of clouds will not help you predict the weather, but they will give you a glimpse of the extremely complex movements of the atmosphere. Smooth and lenticular lenticular clouds form when air is blown up and over a mountain range.
Having crossed the mountain, the air descends to its previous level. At this time, it warms up and the cloud evaporates. But it can slip further, as a result of which the air rises again and forms another lenticular cloud. This can lead to the appearance of a chain of clouds extending far beyond the boundaries of the mountain range. The interaction of wind with mountains and other surface features is one of the many details that must be taken into account in computer simulations to obtain accurate predictions weather.
6) Kelvin - Helmholtz
And finally, my favourites. Kelvin-Helmholtz clouds resemble a breaking ocean wave. When air masses at different heights move horizontally at different speeds, their state becomes unstable. The boundary between the air masses begins to ripple and form large waves.
Such clouds are quite rare - I personally saw them the only time over Jutland, western Denmark - because we can observe this process in the atmosphere only if in the lower air mass there is a cloud. Then it can outline breaking waves and detect intricate movements going on above our heads that are not normally visible. published
If you have any questions on this topic, ask them to specialists and readers of our project.
Sometimes they cover the firmament in the form of a continuous veil, sometimes they appear in the form of isolated cloud masses, sometimes very powerfully developing in height, sometimes they have a relatively delicate structure, sometimes in the form of stripes or feathers of a fibrous structure, sometimes in the form of white small lambs, or scales, etc. The density of clouds largely depends on their height. The thickest and most powerful clouds usually float at a low altitude - below two kilometers. The higher the clouds float, the thinner and more transparent their structure becomes. All the clouds that we observe in the sky usually float in a layer from the surface to a height of 10-12 kilometers.
Our idea of the weather is usually closely connected with the picture of the firmament, that is, with the forms and number of clouds observed in the sky.
Lower clouds
Fog
When the process of condensation of water vapor occurs in the most lower layers, the resulting cloud is located near the surface of the earth. It directly surrounds us and appears to us in the form of fog. In general, any cloud, if you are inside it, for example, on a mountain or when flying in an airplane, appears to the observer in the form of fog.
stratus clouds
Everyone knows the picture of clouds in gloomy gray weather, when the sky is covered with a continuous, completely uniform gray cloud cover, relatively low above the ground. It gives the impression of a raised fog. usually does not shine through this veil at all. Sometimes a light drizzle falls out of it in the form of fine water dust, while in winter sometimes the smallest rare snowflakes. These are the so-called stratus clouds ( international name Stratus or abbreviated St). Essentially, these clouds represent fog raised above the surface of the earth. They usually swim not high - sometimes at a height of a hundred or several hundred meters, usually not more than a kilometer.
In some cases, stratus clouds are torn into separate pieces with ragged edges. Then they are called stratus clouds (the international name is Fracto-Stratus or FrSt for short).
Nimbostratus clouds
Consider another picture of the sky. Bad weather. It's raining, but not one that breaks out quickly in the form of a downpour, and quickly passes, but rain (snow in winter), which, as they say, “charged for a long time” and over a large area (it is called a heavy rain). It may happen that there is no rain yet, but the very sight of the clouds makes one expect it soon. The clouds have the appearance of a low dark gray layer, almost uniform, so that only in some places this layer seems darker, in other places a little lighter. These typical inclement weather clouds are called nimbostratus or colloquially rain clouds (the international name is Nimbo-Stratus or NbSt for short).
Stratocumulus clouds
Stratocumulus clouds (international name Strato-Cumulus, abbr. StCu) should not be confused with the latter form of clouds, which appear as stretching dark cloud shafts or spherical masses, giving the sky a wavy appearance. Usually the cover of stratocumulus clouds is not continuous, but with gaps between individual shafts. These clouds are usually not accompanied by precipitation. They are most often found in winter time year, although they occur in the summer. In their form, they are, as it were, transitional from the stratus clouds described above to cumulus clouds, on which we will dwell.
Cumulus clouds
Let us now consider the form of clouds, common to good summer day. In the morning the sky is completely clear; but at about 8-10 o'clock light, white clouds begin to appear in the sky in some places. They grow rapidly both to the sides and, mainly, upwards. Their base is almost horizontal, while the tops have a dome-like appearance with separate, usually sharply defined bulges at the top. Illuminated by the sun, they appear to the observer of dazzling whiteness. If they are between the observer and the sun, they appear dark in the middle part.
These clouds grow during the day, but by the evening they usually begin to melt and gradually disappear. They are called cumulus (international name Cumulus, abbreviated Cu).
Thunderclouds
Sometimes clouds, which initially look like cumulus clouds, grow so intensely that they reach huge size(often up to several kilometers), take the form of mountains or huge towers. The very top of the cloud often begins to take on a fibrous structure instead of the shape of bulges, and sometimes it looks like an anvil. Such clouds usually bring with them thunderstorms, downpours and hail, and in winter heavy snowfalls. They are called cumulonimbus clouds (international name Cumulo-Nimbus, abbreviated CuNb); when they are accompanied by thunderstorms, they are colloquially referred to as thunderstorms.
The five forms of clouds considered by us - stratus, nimbostratus, stratocumulus, cumulus and cumulonimbus are called "lower clouds". They float relatively low above the ground, so that their base is no higher than 2000 meters. For stratus clouds, the limiting level of the lower base is approximately two times less (usually they float no higher than 1000 meters). The clouds of the lower tier differ from other forms of clouds (middle and upper tiers) described below in their density and power, visibly obscuring the sun. In addition, floating at a relatively low altitude, they often create a well-known difficulty in flying. Flight in cumulonimbus clouds is further hampered by the fact that these clouds are often accompanied by whirlwinds and generally restless air movements.
Middle clouds
Let us now turn to the consideration of higher clouds, to the so-called "middle tier" clouds.
Altostratus clouds
A continuous cloud cover of the sky in the form of a grayish or bluish veil can also be located significantly above 1000 meters, i.e., above the limit level at which ordinary stratus clouds float. This veil is usually so transparent that it makes it possible to distinguish the sun or moon as a more or less blurred spot. Such cloud cover is called altostratus clouds (international name Alto-Stratus, abbreviated as AlSt). Altostratus clouds, becoming denser, can gradually turn into nimbostratus clouds, which have a darker color, completely covering the sun or moon. Overcast rain or snow sometimes falls from the layer of altostratus clouds.
Altocumulus clouds
These clouds have an international name - Aito-Cumuius, abbreviated as A-Cu. In appearance, they correspond to the cumulus clouds of the lower tier, although they differ from them in a much lower power, more delicate structure, and swim much higher. To the observer, altocumulus clouds appear as white caps, sometimes as small flakes of snow, or small rounded flakes of cotton wool, often approaching a spherical shape, with fairly distinct edges, or as flakes. Their thickness is so insignificant that they almost do not obscure the sun, due to which they appear uniformly white in the sky without shadows. These lambs, flakes or scales are usually arranged in connected groups or rows on the palate. Sometimes they appear as parallel bands or waves, which seem (due to "perspective") to converge at the horizon. Altocumulus clouds also belong to the clouds of the so-called "middle" tier. They usually swim at an altitude between 2000 and 6000 meters.
Upper clouds
The highest cloud forms or upper clouds include three forms: cirrocumulus, cirrostratus, and cirrus.
cirrocumulus clouds
These clouds have the international name Cirro-Cumulus, abbreviated as CiCu. In transitional forms, they sometimes resemble in miniature high cumulus clouds, with which they can be confused. To the observer, cirrocumulus clouds appear as very small white flakes or miniature snowballs arranged in regular groups or rows, or as ripples in the sand. They sometimes form from the cirrostratus or cirrus clouds described below, and have a fibrous structure. They are of such a delicate structure that on their lower side they do not give a completely shadow.
Cirrostratus clouds
Similar to stratus clouds in the lower tier and high stratus in the middle, in the upper tier there is also a cloud form in the form of a continuous homogeneous veil, the so-called cirrostratus clouds (international name Cirro-Stratus or abbreviated CiSt). These clouds cover the sky with a solid whitish veil, completely washed out and giving the sky a whitish tint. Through this veil the sun can be seen so clearly that the edges of their discs are perfectly distinct and not blurred. A characteristic feature of cirrostratus clouds is the appearance of circles in the sky near the sun or moon.
Spindrift clouds
Sometimes very delicate individual clouds of a fibrous or filamentous structure are observed in the sky at high altitude. They come in the most varied forms, either in the form of feathers or ponytails, or in the form of thin flakes of cotton wool with a fibrous structure, or in the form of threads or light, transparent strokes of white paint on a blue sky. Sometimes individual clouds are scattered randomly across the sky, sometimes they are bizarrely entangled with each other or arranged in the form of parallel stripes crossing the entire sky or part of it, and, due to perspective, such stripes seem to converge with each other. Such clouds are called cirrus (the international name is Cirrus or Ci for short).
Cirrus clouds are the highest of the upper clouds.
In general, the clouds of the upper tier are usually located at levels above 6,000 meters.
In our latitudes, the upper boundary of the layer of air where the highest "cirrus" clouds form extends to about 11-12 kilometers. Rarely, they are seen slightly higher.
The highest clouds
The layer of the atmosphere from the earth's surface to a height of about 11 kilometers (in our latitudes) called the "troposphere" is characterized by the fact that it decreases with increasing altitude. In the overlying layer, called the "stratosphere", the drop in temperature with height stops. Thus, all clouds observed in the sky float in the troposphere. In the higher layers of the atmosphere, clouds of the usual type are not observed at all.
noctilucent clouds
However, in rare cases, sometimes at enormous heights, faintly luminous, so-called "silvery clouds" appear, the origin of which is still largely mysterious. They are observed in the sky after sunset, when its rays continue obliquely to illuminate the upper layers of the atmosphere in which these clouds float, which is why they seem to glow on dark background sky after sunset.
These clouds were discovered in 1885 shortly after the huge eruption of the Krakatoa volcano (between the islands of Java and Sumatra) in 1883. They floated at an exceptionally high altitude: about 70-80 kilometers. Some scientists have suggested that these clouds are the products of a volcanic eruption thrown to a great height, consisting mainly of ice crystals formed from water vapor thrown out during the eruption. reflecting Sun rays, they seem to us luminous. However, in the last century (starting from 1926), noctilucent clouds began to be observed again in the sky, but already at a much lower height, namely about 28 kilometers.
Observations of the appearance of noctilucent clouds are important in the sense that they may help to resolve the still mysterious question of the causes of their origin.
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