Lenticular clouds - rare a natural phenomenon, which is formed on the crests of air waves or between two layers of air. characteristic feature of these clouds is that they do not move, no matter how strong the wind is.

lenticular clouds

A stream of air passing over earth's surface, flows around obstacles, and thus air waves are formed. Clouds usually hang on the lee side of mountain ranges, behind ridges and individual peaks at a height of two to fifteen kilometers.

Asperatus
wavy-hilly, also asperatus, (asperatus) is a rare type of cloud that has an unusual and awesome appearance

In wave flows, a continuous process of water vapor condensation occurs when the dew point height is reached and evaporation occurs when the air moves downward. Therefore, lenticular clouds do not change their position in space, but stand in the sky as if glued.

Hole Punch Cloud (nasal cavity, also known as fallstreak)

The appearance of lenticular clouds indicates that there are strong horizontal air currents in the atmosphere, forming waves over mountain obstacles, that the air contains a sufficiently high moisture content. This is usually associated with the approach atmospheric front or with vigorous transport of air from remote areas.

Roll Clouds - "Morning Gloria" (Roll Clouds)

Since 1953, meteorologists have been talking about a new type of cloud that has emerged. These clouds look like either a stormy sea or the surface of the earth. They are dark, bizarrely “dented”. Curling “horns” protrude from them. The view is frightening, ominous. Pictures of such clouds come from all over the world.

“Judging by the color, the structures contain a lot of moisture,” says Professor Paul Hardaker, chief executive of the British Royal Meteorological Society. “It takes a lot of energy and heat to form clouds like this.” Some associate the appearance of the Asperatus clouds with the alleged apocalyptic events of 2012.

A cap cloud is a small, rapidly changing shape, horizontal, highly stratified cloud. Usually found above cumulus and cumulonimbus clouds. May form above an ash or fire cloud during a volcanic eruption

Noctilucent Clouds - Rare atmospheric phenomenon. Similar clouds are visible in deep twilight. These are the highest clouds in the Earth's atmosphere; formed in the mesosphere at an altitude of about 85 km, and are visible only when illuminated by the sun from behind the horizon, while the lower layers of the atmosphere are in the earth's shadow; during the day they are not visible. At the same time, their optical density is so negligible that stars often peep through them.

Lenticular (lenticular) clouds

These unusual clouds are like the “gateway to heaven”, an amazing and strange hole in the sky. The most common hypothesis states that the holes in the clouds are caused by falling ice crystals. Ice crystals can form over high clouds or in the exhaust gases of an overflying aircraft. If the air has the right temperature and humidity, the falling crystals will absorb water from the air and grow. For this to happen, the water must be so cold that it only needs a suitable surface to freeze. The loss of moisture from the air increases the rate of evaporation of water droplets in the cloud, and they disperse, forming a hole. The heavier ice crystals continue to fall and form thin, clumpy, cloud-like deposits that are visible inside and below the hole. Water and ice in these precipitations evaporate before reaching the ground.

Altocumulus (Altocumulus)

They are rare, mainly in tropical latitudes and are associated with the formation of tropical cyclones. Cells usually have a size of about half a kilometer, most often sharply defined, but sometimes with blurry edges. Their color is usually gray-blue, like the main cloud, but due to direct sunlight or illumination from other clouds, they may appear golden or reddish. In meteorology, “vymyaobraznye” clouds are called Mammatus (or Mammatocumulus), that is, they are one of the varieties of cumulus (Cumulus) clouds that have a cellular structure and, as a rule, are located under the “parent” cluster of powerful cumulus or cumulonimbus clouds.

Vymyaobraznye clouds in the Himalayas

At a low height of the Sun above the horizon (for example, at sunset), mammatus can acquire a gray-blue, gray-pink, golden and even reddish color. Mammatus are always associated with lightning storms and therefore with cumulonimbus clouds. these clouds can be separated from the thunderstorm source at a distance of up to several tens of kilometers. Mammatus remain in the sky from several minutes to several hours, gradually disappearing along with the fading thunderstorm. The duration of the existence of Mammatus depends on the size of the droplets (or ice crystals) circulating within the cloud ensemble, since what more sizes drops or ice crystals, the more energy must be spent on their evaporation. Consisting of small drops or ice crystals, mammatus are visible in the sky for only a few minutes and quickly disappear.

wavy clouds

There are also wavy clouds - clouds in the formation of which wave processes in the atmosphere participate, as opposed to stratus-shaped clouds associated with upward sliding, and cumulus-shaped clouds associated with convection (a type of heat transfer)

stratus clouds- monotonous pale low clouds that can be observed in cloudy weather

There are also iridescent clouds - a relatively rare occurrence. These clouds can be painted in all colors of the spectrum. They consist of small water droplets of almost the same size. Rainbow clouds appear when the Sun occupies a certain position in the sky and is almost completely hidden behind denser clouds. As a result of almost coherent diffraction of sunlight on thin clouds, they are colored in different colors because the rays of light different lengths waves are deflected differently. Therefore, light of different wavelengths comes to the observer from several different directions. It often happens that clouds, initially painted in iridescent colors, become too dense and inhomogeneous, and also move away from the Sun at a great distance.

rainbow clouds

There is a squall gate - which is formed under conditions high humidity due to the interaction of air flows of different temperatures

squall gate

Rolling or roll clouds. They usually form during thunderstorms and ahead of an advancing cold front. They look like dark cloud streaks, or ledges like "shelves" under the "canopy" storm clouds. The lower edges are torn, sometimes as if boiling. Under them, there is almost always a squally increase in wind, right behind such a shaft is usually a wall of rain. Nothing good can be expected from them. And in the deserts, such ramparts bring dust storms.

Pyrocumulus clouds or pyrocumulus - or, literally, fiery clouds

Pyrocumulus clouds or pyrocumulus. Literally translated as "fire clouds" - convective (cumulus or cumulonimbus) clouds caused by fire or volcanic activity. These clouds got their name from the fact that the fire creates convective updrafts, which, as they rise when they reach the level of condensation, lead to the formation of clouds - first cumulus, and under favorable conditions - cumulonimbus. In this case, thunderstorms are possible; lightning strikes from this cloud then cause new fires. It is not uncommon for rainfall from a cloud to contain the fire below the cloud, or even to extinguish it.

Pyrocumuluses can be seen wherever large, long-lasting fires occur: for example, in California, the French Riviera, in southeastern Australia. Pyrocumulus clouds have a high percentage of positive cloud-to-ground lightning, unlike "normal" cumulus clouds.

Pyrocumulus clouds or pyrocumulus - or, literally, "fire clouds"

During forest fires in Russia in late July-early August 2010, according to data from the NASA satellites "Terra" (spectrometer MISR) and "Aqua", pyrocumuluses were recorded in the stratosphere - their tops reached a height of 12 km, which, according to NASA employees, indicates a high intensity fires.

Pearlescent clouds. They are located at an altitude of about 15 - 25 km in the stratosphere and troposphere

Pearlescent clouds. Clouds that form in the sky at high altitudes (about 20-30 km) and apparently consist of ice crystals or supercooled water droplets. These are thin, translucent clouds. They are observed relatively rarely, usually at latitudes of 55-60 °, immediately after sunset or before sunrise. In the daytime, against the background of bright diffused light, they become invisible.

Clouds due to the instability of the Kelvin-Helmholtz (Cirrus Kelvin-Helmholtz)
Anvil Clouds Fallstreak Hole

Now, after reading this article, you yourself will be able to determine what “this is a cloud”. Try it!

What are clouds? These are the smallest drops of water or ice crystals suspended in the atmosphere and visible in the sky from the surface of the earth. Clouds are also a well-known lyrical image that is associated with peace and serenity.

Clouds are everywhere, in any part of our planet. But in nature there are also rare species clouds that few people were lucky enough to see.

Great overview of the rarest types of clouds.

Thunder collar

It's beautiful weather phenomenon called storm collar- rare long clouds that usually form ahead of advancing cold fronts.

How do clouds of this type form? rising warm wet air cools below the dew point and condenses to form a cloud. If such a process occurs along the entire length along an elongated air front, then a thunderstorm collar can form.

Air currents in a thunderstorm collar can circulate around its horizontal axis, but a tornado cannot form from such a cloud.

lenticular cloud

Lenticular (lenticular) clouds is a rather rare natural phenomenon. They form on the crests of air waves or between two layers of air.

An amazing feature of these clouds is that they do not move and stand in the sky, as if glued, no matter how strong the wind is. They look like UFOs hovering in the air.

Clouds usually hang on the lee side of mountain ranges, behind ridges and individual peaks at a height of 2 to 15 kilometers.

The appearance of lenticular clouds indicates that the air has a sufficiently high moisture content. This is usually associated with the approach of a weather front.

Noctilucent (night glowing) clouds

Noctilucent clouds are the highest cloud formations appearing at altitudes of 75-95 km. The time of discovery of this type of clouds is considered to be the year 1885.

Another name for clouds - night luminous clouds - most accurately corresponds to them appearance. During the day, even against the background of a clear sky, these clouds are not visible, because they are very thin: stars are perfectly visible through them.

Noctilucent clouds can only be seen in summer months: in the Northern Hemisphere in June-July, in the Southern Hemisphere at the end of December and in January.

On the night after the Tunguska disaster on June 30, 1908, noctilucent clouds were observed everywhere in Western Europe and Russia, becoming a source of optical anomalies.

Fallstreak effect in cirrocumulus clouds

This rare effect can be observed in cirrocumulus clouds- a large circular gap, which is called the Fallstreak.

Such "holes" in the clouds are formed when the water temperature in them is below zero, but it has not yet frozen. When some of the water in the cloud starts to freeze, it sometimes settles on the ground, forming large "holes".

Due to its rarity, this natural phenomenon is often mistaken for a UFO.

Vymoid clouds

These clouds (Mammatus clouds) have an unusual cellular shape. They are rare and mainly in tropical latitudes, because. they are associated with the formation of tropical cyclones.

Cloud cells usually have a size of about 0.5 km, and are most often well distinguishable, although they sometimes have blurred edges.

The clouds are a blue-gray color, like the main cloud, however, due to the sun's rays, they may appear golden or reddish.

wavy clouds

Looking at the appearance of these clouds, it becomes clear why they are called wavy.

Rainbow in the cloud

This rather rare natural phenomenon is associated with the appearance of colors in the cloud, similar to those observed in the oil film in puddles. It is most commonly found in altocumulus, cirrocumulus and lenticular (see above) clouds.

When sunlight hits small water drops or ice crystals of different sizes in a cloud, the refraction of the light causes a gamut of colors called iridescence.

protruding clouds

Shelf clouds make a strong impression. They are usually seen before a thunderstorm, although they can also precede a front of relatively cold air.

protruding clouds looks like a storm collar(see above), but differ from them, as they are always associated with a large cloud system hidden at the top.

fiery clouds

Fire clouds or pyrocumulus (Pyrocumulus cloud, fire cloud) are formed during intense heating of air near the surface of the earth.

This type of cloud can occur during forest fires, volcanic eruption, atomic explosion.

Indeed, they are very similar to a cloud of dust after an explosion:

ray clouds

Ray clouds were discovered in the 1960s. Their name (actinoform) comes from the Greek word for "ray" and refers to their radial structure. Their sizes can reach up to 300 kilometers in diameter, so they can only be seen from a satellite.

Currently, scientists cannot give an exact explanation of how this rare type of cloud is formed.

Polar stratospheric clouds

Polar stratospheric clouds or mother-of-pearl clouds form at altitudes of 15 to 25 km in cold regions of the stratosphere (temperatures below -80C).

This type of cloud appears very rarely. Perhaps, in the entire history of atmospheric physics, polar stratospheric clouds have been observed only about 100 times. The thing is that in the stratosphere the concentration of water vapor is several thousand times less than in the lower part of the atmosphere (troposphere).

cloud hat

These are small, rapidly changing horizontal, altostratus clouds that are usually found above cumulus and cumulonimbus clouds. A cap cloud can form over an ash or fire cloud (see above) during a volcanic eruption.

morning glory

These are strange, long horizontal clouds that look like rotating pipes: up to 1,000 km in length, from 1 to 2 km in height. They are only 100 to 200 meters above the ground and can move at speeds up to 60 km/h.

This rare type of clouds can be seen all over the world, but only in the spring over the city of Burktown in Queensland (Australia) can they be observed more or less constantly and predictably. The formation of Morning Glory is often accompanied by sudden gusty winds.

Rough waves (Undulatus asperatus)

Only in 2009 was it proposed to single out this unusual weather phenomenon in separate view clouds - Undulatus asperatus. The last time new cloud formations were entered into the International Cloud Atlas was already in 1951!

A rough translation of the name of a new type of clouds is "rough waves".

In appearance, these are the most sinister and devilish clouds. They look like a seething sea, a dark, intricately “rumpled” surface.

Some even link the appearance of Undulatus asperatus clouds to the alleged apocalyptic events of 2012.

Tubular or vymeform clouds - clouds, the base of which has a specific cellular or marsupial shape. They are rare, mainly in tropical latitudes, and are associated with the formation of tropical cyclones.

Cells usually have a size of about half a kilometer, most often sharply defined, but sometimes with blurry edges. Their color is usually gray-blue, like the main cloud, but due to direct sunlight or illumination from other clouds, they may appear golden or reddish.

Tubular clouds look either like sections of pipes, or like many suspended balls, the hue of which varies from white to blue-gray. The color depends on the thickness of the cloud. However, under special conditions (moist air above and dry below), cloud pockets begin to form in the atmosphere, filled with large water droplets or even ice crystals, which, under their weight, literally fall into fresh air. This behavior of clouds is associated with the turbulent movement of air masses. And the turbulent movement of air indicates the proximity of a powerful thunderstorm front.
In meteorology, “vymyaobraznye” clouds are called Mammatus (or Mammatocumulus), that is, they are one of the varieties of cumulus (Cumulus) clouds that have a cellular structure and, as a rule, are located under the “parent” cluster of powerful cumulus or cumulonimbus clouds.

Clouds are a manifestation of the Rayleigh-Taylor instability - a spontaneous increase in pressure, density and velocity perturbations in gaseous and liquid media with an inhomogeneous density, located in a gravitational field (Rayleigh, 1900) or moving with acceleration (Taylor, 1950).

Heaven has been a source of human admiration since time immemorial. Clouds are what, in one form or another, everyone on earth has seen. They come in a variety of sizes, shapes, and colors, and their various formations have been studied by meteorologists for centuries. Below is a selection of 15 mesmerizing and incredible cloud formations. Enjoy!

(Total 20 photos)

Post sponsor: OOO : Create entity simple - enough to navigate in terms and concepts. Find answers to all your questions in the section with general information about legal entities.

1. Lenticular (lenticular) clouds

Lenticular (lenticular) clouds is a term for a rather rare natural phenomenon. Lenticular clouds form on the crests of air waves or between two layers of air. A characteristic feature of these clouds is that they do not move, no matter how strong the wind is. The flow of air rushing over the earth's surface flows around obstacles, and thus air waves are formed. Clouds usually hang on the lee side of mountain ranges, behind ridges and individual peaks at a height of two to fifteen kilometers.

2. In wave flows, a continuous process of water vapor condensation occurs when the dew point height is reached and evaporation occurs during the downward movement of air. Therefore, lenticular clouds do not change their position in space, but stand in the sky as if glued.

The appearance of lenticular clouds indicates that there are strong horizontal air currents in the atmosphere, forming waves over mountainous obstacles, that the air contains a sufficiently high moisture content. This is usually associated with the approach of an atmospheric front or with an energetic transfer of air from remote areas.

3. Clouds of Asperatus

Since 1953, meteorologists have been talking about a new type of cloud that has emerged. These clouds look like either a stormy sea or the surface of the earth. They are dark, bizarrely "dented". Curling "horns" protrude from them. The view is frightening, ominous. Pictures of such clouds come from all over the world.

4. "Judging by the color, the structures contain a lot of moisture," says Professor Paul Hardaker, chief executive of the British Royal Meteorological Society. "It takes a lot of energy and heat to form such clouds." Some associate the appearance of the Asperatus clouds with the alleged apocalyptic events of 2012.

5. Noctilucent (night, mesospheric) clouds

Noctilucent clouds are a rare atmospheric phenomenon. Similar clouds are visible in deep twilight. These are the highest clouds in the Earth's atmosphere; formed in the mesosphere at an altitude of about 85 km, and are visible only when illuminated by the sun from behind the horizon, while the lower layers of the atmosphere are in the earth's shadow; during the day they are not visible. At the same time, their optical density is so negligible that stars often peep through them.

6. Clouds with a hole or a hole-punch cloud

These unusual clouds are like "gates to heaven", an amazing and strange hole in the sky. The most common hypothesis states that the holes in the clouds are caused by falling ice crystals. Ice crystals can form in higher clouds or in the exhaust gases of an overflying aircraft. If the air has the right temperature and humidity, the falling crystals will absorb water from the air and grow. For this to happen, the water must be so cold that it only needs a suitable surface to freeze. The loss of moisture from the air increases the rate of evaporation of water droplets in the cloud, and they disperse, forming a hole. The heavier ice crystals continue to fall and form thin, clumpy, cloud-like deposits that are visible inside and below the hole. Water and ice in these precipitations evaporate before reaching the ground.

7. Vymyaobraznye or tubular clouds

They are rare, mainly in tropical latitudes and are associated with the formation of tropical cyclones. Cells usually have a size of about half a kilometer, most often sharply defined, but sometimes with blurry edges. Their color is usually gray-blue, like the main cloud, but due to direct sunlight or illumination from other clouds, they may appear golden or reddish. In meteorology, “vymyaobraznye” clouds are called Mammatus (or Mammatocumulus), that is, they are one of the varieties of cumulus (Cumulus) clouds that have a cellular structure and, as a rule, are located under the “parent” cluster of powerful cumulus or cumulonimbus clouds.

8. of the elements. However, at a low height of the Sun above the horizon (for example, at sunset), mammatus can acquire a gray-blue, gray-pink, golden and even reddish color. Mammatus are always associated with lightning storms and therefore with cumulonimbus clouds.

At the same time, these clouds can be separated from the thunderstorm source at a distance of up to several tens of kilometers. Mammatus remain in the sky from several minutes to several hours, gradually disappearing along with the fading thunderstorm. The duration of the existence of Mammatus depends on the size of the droplets (or ice crystals) circulating within the cloud ensemble, since the larger the size of the droplets or ice crystals, the more energy must be spent on their evaporation. Consisting of small drops or ice crystals, mammatus are visible in the sky for only a few minutes and quickly disappear.

9. Wavy clouds

10. These are clouds in the formation of which the wave processes in the atmosphere participate, as opposed to stratus clouds associated with upward sliding, and cumuliform clouds associated with convection.

11. Rainbow cloud

So-called rainbow clouds are a relatively rare occurrence. These clouds can be painted in all colors of the spectrum. They consist of small water droplets of almost the same size. Rainbow clouds appear when the Sun occupies a certain position in the sky and is almost completely hidden behind denser clouds. As a result of almost coherent diffraction of sunlight on thin clouds, they are colored in different colors, since light rays of different wavelengths are deflected differently. Therefore, light of different wavelengths comes to the observer from several different directions. It often happens that clouds, initially painted in iridescent colors, become too dense and inhomogeneous, and also move away from the Sun at a great distance.

12. Squall Gate

It is formed in conditions of high humidity as a result of the interaction of air flows of different temperatures.

See also on the video: Shkvalovy gate in St. Petersburg.

13. Rolling or roll clouds

They usually form during thunderstorms and ahead of an advancing cold front. They look like dark cloud bands, or ledges like "shelves" under the "canopy" of thunderclouds. The lower edges are torn, sometimes as if boiling. Under them, there is almost always a squally increase in wind, right behind such a shaft is usually a wall of rain. Don't expect anything good from them. In the deserts, such ramparts bring dust storms.

15. Pyrocumulus clouds or pyrocumulus

Literally, "fire clouds" are convective (cumulus or cumulonimbus) clouds caused by fire or volcanic activity. These clouds got their name from the fact that the fire creates convective updrafts, which, as they rise when they reach the level of condensation, lead to the formation of clouds - first cumulus, and under favorable conditions - cumulonimbus. In this case, thunderstorms are possible; lightning strikes from this cloud then cause new fires. It is not uncommon for rainfall from a cloud to contain the fire below the cloud, or even to extinguish it.

Pyrocumuluses can be seen wherever large, long-lasting fires occur: for example, in California, the French Riviera, in southeastern Australia. Pyrocumulus clouds have a high percentage of positive cloud-to-ground lightning, unlike "normal" cumulus clouds.

Clouds that form in the sky at high altitudes (about 20-30 km) and apparently consist of ice crystals or supercooled water droplets. These are thin, translucent clouds. They are observed relatively rarely, usually at latitudes of 55-60 °, immediately after sunset or before sunrise. In the daytime, against the background of bright diffused light, they become invisible.

19. Cloud hat

Photo: NASA

Since ancient times, people have viewed the heavens as something mysterious and mysterious, not amenable to logical explanation. It was the place of the gods and an intermediate stage on the way to another world. Cloud phenomena are associated with astronomical, divine or celestial concepts. People can see in them the silhouettes of animals, people, symbolic signs of nature, deities and much more.

Probably, there is no person on earth who, at least once in his life, did not lie on the grass, mentally hugging bright sky and admiring the passing clouds. Such happy moments tend to happen more often in childhood. How older man, the more worries he has, and the less he pays attention to the beauty that surrounds him.

Time passes, the sky remains as boundless, beautiful and unique as the clouds that rush at speed into an unknown distance. Or slowly float over our heads, acquiring strange and bizarre forms. In this article, we will look at the most unusual clouds that exist in nature.

Amazing natural phenomenon

Cloud masses are never the same, they are invariably diverse and always worthy of human attention, because they are incredibly beautiful and amazing in their essence.

Clouds are divided into different categories, have interesting names, features of their appearance. They have been the subject of discussion and study of meteorologists from all over the world for many centuries. But we, ordinary people, as a rule, do not notice them at all behind a layer of problems in life cycle. We invite you to admire the heavenly creations, which are simply breathtaking. In science, they are called cloud formations. Nature has created a huge number of their species with different forms, sizes and colors. In addition, there are some specimens that are extremely rare, and may even be observed once in the entire history of the world.

Thunder collar

Silvery

The second name is luminous, very unusual clouds in the sky. This is one of the most tall formations, which are observed at an altitude of 80-95 kilometers. The view was discovered in 1885. Their second name - "glowing clouds", corresponds to their appearance.

During the day they are invisible, as they are very thin, but stars can be seen through them. You can watch this beauty in summer time in the Northern Hemisphere, in winter - in the Southern.

Fallstreak effect

Occurs in cirrocumulus clouds - a very rare occurrence, manifests itself in an annular gap. These holes are created when the temperature of the water in them drops below zero, but it has not yet frozen. When a certain part of the water in the cloud freezes, it settles on the ground and thus forms holes.

vymeiformes

Consist of unusual cellular forms. You can meet them extremely rarely and mainly in tropical latitudes, since they influence the formation of tropical cyclones. These clouds are blue-gray, like everything else, however, when the sun's rays hit them, they can be golden or red.

wavy clouds

Looking at the photo unusual clouds, you can immediately understand why they are called wavy. Something like the water in the ocean, which went ripples.

protruding clouds

The unusual shape of such formations is very impressive. As a rule, they occur before a thunderstorm, although they can be precursors of cold air. They are a bit like storm collars, but their difference is that the protruding clouds are connected by a huge cloud mass that is hidden from above.

Fiery unusual clouds

The second name is "pyrocumulus". They are created during the powerful heating of air on the surface of the earth. This type occurs as a result of forest fires, volcanic eruptions or atomic explosions. In appearance, they resemble clouds of dust after explosions.

Radiation

They were opened in 1960. The name comes from the Greek "beam" and is associated with an effective structure. The size reaches 300 km in diameter, so you can contemplate them from a satellite. To date, scientists cannot give a definitive answer on how these clouds form.

Polar stratospheric clouds

The second name is "mother-of-pearl". They form at an altitude of 15 to 25 km in the cold parts of the stratosphere (temperatures are usually below -80 degrees). This species occurs relatively rarely. For all the time, such formations were noted only 100 times, no more. And the thing is that in the stratosphere the accumulation of water vapor is thousands of times less than in the troposphere.

cloud hat

Changes the configuration very quickly. In appearance, altostratus clouds are usually located above the cumulonimbus clouds. They can also be created from ash or a fiery cloud texture, such as during a volcanic eruption.

morning glory

Unusual clouds, long and horizontal. Something like rotating pipes. They can reach up to 1000 km in length, from 1 to 2 km in height. They are located only 150-200 meters above the ground and move at speeds up to 60 km/h.

This type of clouds can be seen everywhere, but only in spring time in the state of Queensland (in Australia) they are in a more or less stable position. Morning Gloria is formed very often due to sudden heavy winds.

Rough waves

In 2009, they were identified as a special type of cloud called Undulatus asperatus. The last time significant cloud phenomena were included in the International Atlas was in 1951. They resemble ominous and demonic clouds, similar to the seething waters of the sea with a dark rumpled surface. Many at one time associated these clouds with the supposedly approaching apocalyptic events in 2012.