These systems may produce a considerable amount of cirrus cloud as the anvil spreads out. Mid Level Clouds — Base is usually between 6,ft and 20,ft with some exceptions. Mid level clouds typically form at temperatures between 0 and —40C depending on altitude and season, so may consist of warm or supercooled droplets and ice particles. Cloud base ranges between 10, and 20,ft. Thicker forms of these clouds often produce continuous light precipitation and hide the sun or moon, though thinner forms show the sun or moon with a ground glass appearance.
This type of cloud typically occurs between 6, and 20,ft and is generally broken in appearance, though can occasionally produce precipitation and be thick enough to hide the sun or moon. Cloud base ranges from the surface to 10,ft. These clouds always hide the sun or moon, and normally produce continuous precipitation which is often moderate to heavy. Base is typically between 20, and 40,ft in the UK, and may be considerably higher in the tropics.
Cirrus clouds do not produce precipitation which reaches the ground, though streaks of particles known as fall streaks are often observed below these clouds. Various halos and other optical effects may be produced by cirrus cloud.
In some cases these clouds are also thick enough to hide the sun. Cirrus clouds typically form at temperatures below C and consist entirely of ice particles. A thin high level layer cloud, which often produce halos and through which the outline of the sun is generally visible. These clouds are often the first visible indication of an approaching weather front, and may progressively thicken to altostratus and then nimbostratus with lowering of cloud base as the front approaches.
Typically found in a similar altitude range to cirrus, these clouds do not produce precipitation and are usually more broken in appearance than cirrus, with the position of the sun or moon being visible.
Formed as air is forced to rise over elevated terrain, cloud base is dependant on prevailing conditions, but is similar in range to that of other low level clouds. Clouds of vertical development fair-weather cumulus, cumulus-congestus, cumulonimbus cannot be classified as high, middle or low because they typically occupy more than one of the above three altitude markers.
For example, the base of a tall cumulonimbus cloud often forms below 6, feet and then builds upward to an altitude far above 20, feet. High clouds can either be "plain" cirrus, or we can add the prefix " cirro " to a suffix that describes their appearance cirrostratus for high-altitude, layered clouds; cirrocumulus for high-altitude, "heap" clouds.
Middle clouds carry the prefix " alto " and also a suffix that describes their appearance altostratus for mid-level, layered clouds; altocumulus for mid-level, "heap" clouds. Clouds of vertical development always include the word "cumulus" or the prefix " cumulo ," but can have various suffixes or other descriptive modifiers like "fair-weather cumulus". The names of low clouds have more variation. Low clouds can be referred to as plain "stratus" if they're smooth and layered or "stratocumulus" if they have both layered and heap-like characteristics, for example.
The cirrocumulus type with smaller puffs still is found about 4 to 5 miles up. Cirrus clouds occur at an altitude of 4 miles or more, where the temperature is always below freezing; hence, these clouds are always filled with ice crystals. Characteristics of world weather and climate.
Cloud Types. Clouds are the visible collections of water droplets or ice particles in the atmosphere. These nuclei are everywhere in the atmosphere. They attract water vapor and as they ascend the vapor condenses to form liquid water or ice, which results in the formation of tiny globules called cloud droplets.
Much smaller than raindrops, cloud droplets are extremely light and amass while they float , mixing with air to form the fluffy formations we see suspended in the sky. Clouds generally form within the troposphere, or the layer of atmosphere closest to the earth. As they rise and fall, they may appear in infinite variations. To create some order scientists have established three broad categories into which most clouds can be grouped. Below that is the home of mid-level clouds, which generally occur between 6, and 25, feet.
Within each of these three tiers, scientists further organize clouds into ten broad categories based on the general shapes the clouds take. High clouds are classified as either cirrus, cirrostratus, or cirrocumulus. Cirrus clouds are made of ice crystals and appear thin, white, and wispy. Cirrostratus clouds are whitish and transparent and tend to blanket the whole sky, sometimes creating a halo effect around the sun or moon.
Cirrocumulus clouds are also white and can be sheet-like and rippled. Mid-level clouds are usually gray and are identified as either altocumulus, altostratus, or nimbostratus. Altocumulus clouds are full of liquid water but generally do not produce rain. They are patchy and often appear as ripples or rows. Altostratus clouds cover the sky but are darker than cirrostratus clouds and may give the sun or moon a fuzzy appearance. Altostratus clouds may portend a storm.
Nimbostratus clouds are thick and dark and can produce both rain and snow.
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