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Altocumulus
Altocumulus () is a middle-altitude cloud genus that belongs mainly to the physical category, characterized by globular masses or rolls in layers or patchesthe individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus. However, if the layers become tufted in appearance due to increased airmass instability, then the altocumulus clouds become more purely ''cumuliform'' in structure. Like other cumuliform and stratocumuliform clouds, altocumulus signifies convection. A sheet of partially conjoined altocumulus perlucidus is sometimes found preceding a weakening warm front, where the altostratus is starting to fragment, resulting in patches of altocumulus perlucidus between the areas of altostratus. Altocumulus is also commonly found between the warm and cold fronts in a depression, although this is often hidden by lower clouds. Towering altocumulus, known as altocumulus castellanus, frequently signals the development of thun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Cloud Types
The list of cloud types groups all genera as ''high'' (cirro-, cirrus), ''middle'' (alto-), ''multi-level'' (nimbo-, cumulo-, cumulus), and ''low'' (strato-, stratus). These groupings are determined by the altitude level or levels in the troposphere at which each of the various cloud types is normally found. Small Cumulus cloud, cumulus are commonly grouped with the low clouds because they do not show significant vertical extent. Of the multi-level genus-types, those with the greatest convective activity are often grouped separately as ''towering vertical''. The genus types all have Latin names. The genera are also grouped into five physical forms. These are, in approximate ascending order of instability or convective activity: ''stratiform'' sheets; ''cirriform'' wisps and patches; ''stratocumuliform'' patches, rolls, and ripples; ''cumuliform'' heaps, and ''cumulonimbiform'' towers that often have complex structures. Most genera are divided into ''species'' with Latin names, some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altocumulus Floccus
Altocumulus () is a middle-altitude cloud genus that belongs mainly to the physical category, characterized by globular masses or rolls in layers or patchesthe individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus. However, if the layers become tufted in appearance due to increased airmass instability, then the altocumulus clouds become more purely ''cumuliform'' in structure. Like other cumuliform and stratocumuliform clouds, altocumulus signifies convection. A sheet of partially conjoined altocumulus perlucidus is sometimes found preceding a weakening warm front, where the altostratus is starting to fragment, resulting in patches of altocumulus perlucidus between the areas of altostratus. Altocumulus is also commonly found between the warm and cold fronts in a depression, although this is often hidden by lower clouds. Towering altocumulus, known as altocumulus castellanus, frequently signals the development of thu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratocumulus
A stratocumulus cloud, occasionally called a cumulostratus, belongs to a genus-type of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumulus, and the whole being at a lower height, usually below . Weak convective currents create shallow cloud layers (see also: sea of clouds) because of drier, stable air above preventing continued vertical development. Historically, in English, this type of cloud has been referred to as a twain cloud for being a combination of two types of clouds. Description Stratocumulus clouds are rounded clumps or patches of white to dark gray clouds that normally form in groups. The individual cloud elements, which cover more than 5 degrees of arc each, can connect with each other and are sometimes arranged in a regular pattern. Occurrence Vast areas of subtropical and polar oceans are covered with massive sheets of stratocumulus. These may organize into distinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrocumulus
Cirrocumulus is one of the three main genus types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus. They usually occur at an altitude of , however they can occur as low as in the arctic and weather reporting standards such as the Canadian MANOBS suggests heights of in summer and in winter. Like lower-altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Unlike other high-altitude tropospheric clouds like cirrus and cirrostratus, cirrocumulus includes a small amount of liquid water droplets, although these are in a supercooled Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid below its freezing point without it becoming a solid. Per the established international definition, supercooling means ''‘cooling a substance be ... state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled water drops in the cloud to rapidly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altocumulus Stratiformis
Altocumulus stratiformis is the most common species of the Altocumulus Altocumulus () is a middle-altitude cloud genus that belongs mainly to the physical category, characterized by globular masses or rolls in layers or patchesthe individual elements being larger and darker than those of cirrocumulus and smaller t ... genus of clouds. They tend to form broad layers of individual, cell-like clumps, often separated from each other, though they sometimes can coagulate into a larger individual cloud. They often have a vertical extent of less than 500 m. Due to their formation dynamics, they are commonly associated with the imminent arrival of precipitation. Formation The presence of stratiformis clouds in the mid-levels of the atmosphere is indicative of some instability at that level; atmospheric pressure falls, often associated with nearby systems of low pressure, can depress the altitude of stratiformis into the lower atmosphere, often evolving into Nimbostratus clouds, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mackerel Sky
A mackerel sky is a term for clouds made up of rows of cirrocumulus or altocumulus clouds displaying an undulating, rippling pattern similar in appearance to fish scales; this is caused by high altitude atmospheric waves. Cirrocumulus appears almost exclusively with cirrus some way ahead of a warm front and is a reliable forecaster that the weather is about to change. When these high clouds progressively invade the sky and the barometric pressure begins to fall, precipitation associated with the disturbance is likely about 6 to 12 hours away. A thickening and lowering of cirrocumulus into middle-étage altostratus or altocumulus is a good sign that the warm front or low front has moved closer and it may start raining within less than six hours. The old rhymes "Mackerel sky, not twenty-four hours dry" and " Mares' tails and mackerel scales make lofty ships to carry low sails" both refer to this long-recognized phenomenon. Other phrases in weather lore take mackerel skies as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lenticular Cloud
Lenticular clouds (, ) are stationary clouds that form mostly in the troposphere, typically in parallel alignment to the wind direction. They are often comparable in appearance to a lens or saucer. polar stratospheric cloud, Nacreous clouds that form in the lower stratosphere sometimes have lenticular shapes. There are three main types of lenticular clouds: altocumulus standing lenticular (ACSL), stratocumulus lenticularis, stratocumulus standing lenticular (SCSL), and cirrocumulus lenticularis, cirrocumulus standing lenticular (CCSL), varying in altitude above the ground. Formation and appearance As air travels along the surface of the Earth, obstructions are often encountered, including natural features, such as mountains or hills, and artificial structures, such as buildings and other constructions, which disrupt the flow of air into "eddies", or areas of turbulence. When moist, stable air flows over a larger eddy, such as those caused by mountains, a series of large-scal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mackerel Sky
A mackerel sky is a term for clouds made up of rows of cirrocumulus or altocumulus clouds displaying an undulating, rippling pattern similar in appearance to fish scales; this is caused by high altitude atmospheric waves. Cirrocumulus appears almost exclusively with cirrus some way ahead of a warm front and is a reliable forecaster that the weather is about to change. When these high clouds progressively invade the sky and the barometric pressure begins to fall, precipitation associated with the disturbance is likely about 6 to 12 hours away. A thickening and lowering of cirrocumulus into middle-étage altostratus or altocumulus is a good sign that the warm front or low front has moved closer and it may start raining within less than six hours. The old rhymes "Mackerel sky, not twenty-four hours dry" and " Mares' tails and mackerel scales make lofty ships to carry low sails" both refer to this long-recognized phenomenon. Other phrases in weather lore take mackerel skies as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altocumulus Castellanus
In meteorology, Altocumulus castellanus or Altocumulus castellatus (ACCAS) is a cloud type named for its tower-like projections that billow upwards from the base of the cloud. The base of the cloud can form as low as 2,000 metres (6,500 feet), or as high as 6,000 metres (20,000 feet). They are very similar to cumulus congestus clouds, but at a higher level and with the cloud heaps joined at the base. Castellanus clouds are evidence of mid-atmospheric instability and a high mid-altitude lapse rate. They may be a harbinger of heavy showers and thunderstorms and, if surface-based convection can connect to the mid-tropospheric unstable layer, continued development of Castellanus clouds can produce cumulonimbus clouds. Altocumulus castellanus clouds are typically accompanied by moderate turbulence as well as potential icing conditions In aeronautics, icing is the atmospheric icing, formation of water ice on an aircraft. Icing has resulted in numerous aviation accidents and incide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virga
A virga, also called a dry storm, is an observable streak or shaft of precipitation that evaporates or sublimates before reaching the ground. A shaft of precipitation that does not evaporate before reaching the ground is known in meteorology as a precipitation shaft. At high altitudes, precipitation falls mainly as ice crystals before melting and finally evaporating. That is often due to compressional heating, because air pressure increases closer to the ground. Virga is very common in deserts and temperate climates. In North America, it is commonly seen in the Western United States and the Canadian Prairies. It is also very common in the Middle East, Australia, and North Africa. Virgae can cause varying weather effects because as rain is changed from liquid to vapor form it removes significant amounts of heat from the air due to water's high heat of vaporization. Precipitation falling into these cooling downdrafts may eventually reach the ground. In some instances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
