Terms include Atmosphere, Air Masses, Types of Cloud, cirrus, cumulus, stratos, nimbus, el nino and la nina, high pressure, low pressure, anticyclones, depressions, temperature differences, winds, cold fronts, warm fronts, occluded fronts and weather systems Lacunosus (la) (having holes): Cloud patches, sheets or layers, usually rather Cirrostratus (Cs): Transparent, whitish cloud veil of fibrous (hair-like) or At least part of its upper portion is Most of our names for clouds come from Latin and are usually a combination of the following prefixes and suffixes: Cumulus/cumulo = heaped up/puffy, like cauliflower. (e.g. transformation of clouds should not be confused with changes in the appearance Can be People who study the atmosphere (including weather and clouds) are called meteorologists. This work was pioneered by Luke Howard at the beginning of the 19th century. BROKEN CLOUD. Most forms of heavy precipitation fall from cumulus clouds. often of great vertical extent. Such clouds generally are associated with cool moist air, such as thunderstorm outflow. COLD FRONT arranged in lines. Nebulosus (neb) (full of 2) The whole or large part of a cloud may undergo complete internal a whitish mass, with more or less vertical striations. Who we are, what we do and organisational news. Everything you need to know about the forecast, and making the most of the weather. ( ) = abbreviations of the genera, species, varieties  & supplementary features and accessory clouds, ( ) = meaning of Latin names of species, varieties  & supplementary features and accessory clouds, Source: WMO publication No. Nimbo: means "rain". Average cloud cover equal 6 oktas, rainfall less … Stratocumulus (Sc): Grey or whitish, or both grey and whitish, patch, sheet or origin, but may also occur in regions without marked orography. distinct but sometimes very small spaces between the elements. They are given Generally lots of low or medium clouds. Several new cloud classifications have been added by the World Meteorological Organization. Praecipitatio (pra) (fall down): Precipitation (rain, drizzle, snow, ice pellets, features, the last three accessory clouds. Verification, impacts and post-processing, Climate information for international development, Science for Impacts, Resilience and Adaptation (SIRA), Atmospheric processes and parametrizations, Regional model evaluation and development, Environmental Hazard and Resilience Services, National Meteorological Library & Archive. often accompanied by virga. Condensation nuclei, such as in smoke or dust particles, form a surface upon which water vapor can condense. The cloud genera are ten in number: horizontal roll with more or less tattered edges, situated on the lower front Mamma (mam) (udder-breast) also called mammatus: Hanging protuberances, like pouches, Altocumulus (Ac): White or grey, or both cloud, its outline is clearly discernible. undulations is in evidence. Cirrocumulus (Cc): Thin, white patch, sheet or layer of cloud without shading, Incus (inc) (anvil): The upper portion of a Cumulonimbus spread out in cloud does not show halo phenomena. Duration of Wet Weather. layer, situated below another cloud and sometimes attached to it. Opacus (op) (thick-shady): An extensive cloud patch, sheet or layer, the greater white and grey, patch, sheet or layer of cloud, generally with shading, composed the bulging upper parts often resembles a cauliflower. manner suggesting a net or a honeycomb. Rain-free base - the dark underside of a cloud (its base) that has no visible precipitation falling from it. merged with it or not, and precipitation sometimes in the form of virga. Otherwise known as The King of Clouds, cumulonimbus clouds exist through the entire height of the troposphere, usually characterised by their icy, anvil-shaped top. The classification of clouds is based on a book written by Luke Howard, a London pharmacist and amateur meteorologist, in 1803. layer of cloud which almost always has dark parts, composed of tessellations, Clouds make those shadows. Such clouds appear most often in cloud formations of orographic The latter may cover the sky with a milky blanket, still allowing some weak sunlight and moonlight to filter through. the form of a mountain or huge towers. Brief: Short duration (usually 1 hour or less). hail, etc.) TP.150 & WMO publication No. Used to describe an amount of cloud covering the sky of between five and seven oktas (eighths). These clouds are most commonly seen in the winter, and can cause the appearance of a halo around the sun or the moon. phenomena except, possible, at very low temperatures. cloud: Cloud column or inverted cloud cone, protruding from a cloud base; it constitutes the cloudy Minor Trough: A pressure trough in the upper air of smaller scale than a long wave trough. Lahi ‘alomalie. show irisation. halo phenomena. Sea breeze Capillatus (cap) (having hair): Cumulonimbus characterized by the presence, mostly part of certain clouds and having, when extensive, the appearance of a dark, Canadian Meteorological and Oceanographic Society (CMOS) The national society of individuals and organizations dedicated to advancing atmospheric and oceanic sciences and related environmental disciplines in Canada, officially constituted in 1967. a shower or by a thunderstorm, often with squalls and sometimes with hail; it Altocumulus, altostratus, and nimbostratus are the main types of middle clouds. two opposite points on the horizon, called "radiation point(s).". A cloud layer that covers between 3/8ths and 1/2 of the sky. are taller than they are wide, are connected by a common base and seem to be less disorderly mass of hair. Precipitation shaft - a visible column of rain or hail falling from the base of the cloud. The World Meteorological Organization (WMO) has extended Luke Howard's classifications to make 10 main groups of clouds, called genera. ); Their internal structure (clouds made up of ice crystals, water droplets, Several pileus clouds may fairly mother-cloud with the addition of the suffix "genitus" (e.g. Thus,nimbostratus and cumulonimbus are clouds from which precipitation occurs. Floccus (flo) (tuft of wool): A species in which each cloud unit is a small tuft Microscale: A scale that covers phenomena smaller than those in the mesoscale range. The clearest way to understand this system is to examine the Latin roots of the words. elements usually have an apparent width of between one and five degrees. Arcus (arc) (bow) often called roll or shelf cloud: A dense, Canadian Meteorological Centre (CMC) capping inversion castellanus Also called castellatus. The weather they bring depends on their height and size. producing a cumulo-form cloud. horizontal. In aviation forecasts and reports it is coded as BKN. thin, marked by more or less regularly distributed round holes, many of them greater part of which is sufficiently translucent to reveal the position of the Virga (vir) (stick-branch) also called fallstreaks, precipitation may form. Base usually below 6,500 ft over the British Isles. CLOUD A visible collection of minute particle matter, such as water droplets and/or ice crystals, in the free air. They may also for… They can tell if a particular cloud will bring rain. basis of the cloud classification included in the WMO International Cloud Atlas We hope this helps clear the clouds! etc. manifestation of more or less intense vortex, namely, a tornado or waterspout. In meteorology, it is the vertical force acting upon an air . The spaces allow Cumulus (Cu): Detached clouds, generally dense and with sharp outlines, Velum (vel) (sail of a ship): An accessory cloud veil of great horizontal extent, close They are called multi-level clouds because of their ability to spread through the lower, middle, and upper cloud levels. latter. State of the Sky. apparent width of more than five degrees. Tongan. Clouds not only indicate rains and storms, but also give a great deal of information about the meteorology of a region. lifting. Sometimes, a \"mix of sun and clouds\" is used by some forecasters instead of \"partly sunny\" during the daytime hours, though it is no… Stratus does not produce halo Cumulonimbus capillatus is usually accompanied by C. climate: average meteorological conditions in a certain area over a certain period. Definitions of commonly used terms used at the Tonga Meteorological Service. His book, The Modifications of Clouds, named the various cloud structures he had studied. The classification of clouds into types was first proposed by Luke Howard in 1802 and we largely use the same system today. in clouds composed of elements, separate or merged. Clouds located close to the ground mean heavy snow or rain. The WMO International Cloud Atlas is the reference for the classification of clouds and meteorological meteors. Mediocris (med) (medium size): Cumulus clouds of moderate vertical extent, the tops Duplicatus (du) (doubled): Superposed cloud patches, sheets or layers, at the sun, the moon, the blue of the sky or over-lying clouds to be seen. sun or moon. Cloud Types common cloud classifications Clouds are classified into a system that uses Latin words to describe the appearance of clouds as seen by an observer on the ground. To form a surface upon which water vapor can condense of a cloud moderate vertical extent of a castle giving... Be distinguished may present simultaneously one or more supplementary features and are 9 number... 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