Low Middle and High Level Clouds
Content
Low-level Clouds Low clouds are of mostly composed of water droplets since their bases generally lie below 6,500 feet (2,000 meters! "owever, when temperatures are cold enough, these clouds may also contain ice particles and snow Nimbostratus Clouds
dark, low-level clouds with precipitation Nimbostratus are dark, low-level low-level clouds accompanied accompanied by light to moderately moderately falling precipitation. Low clouds clouds are primarily composed composed of water droplets since their their bases generally lie below 6,500 feet !,000 meters". #owever, when temperatures are cold enough, these clouds may also contain ice particles and snow.
Mid-Level Clouds #he bases of mid-level mid-level clouds clouds typically appear appear between between 6,500 to 20,000 feet (2,000 to 6,000 meters! $ecause of their lower altitudes, they are composed primarily of water drople droplets, ts, however, they can also be composed of ice crystals when temperatures are cold enough! Altocumulus Clouds
parallel bands or rounded rounded masses
%ltocumulus may appear as parallel bands (top photograph or rounded masses (bottom photograph! #ypically a portion of an altocumulus cloud is shaded, a characteristic which ma&es them distinguishable from the high-level cirrocumulus! %ltocumulus clouds usually form by convection convection in in an unstable layer aloft, which may result from the gradual gradual lifting of air in advance of a cold front! front! #he
presence of altocumulus clouds on a warm and humid summer morning is commonly followed by thunderstorms later in the day!
High-Level Clouds "igh-level clouds form above 20,000 feet (6,000 meters and since the temperatures are so cold at such high elevations, these clouds are primarily composed of ice crystals! "igh-level clouds are typically thin and white in appearance, but can appear in a magni'cent array of colors when the sun is low on the horion! Cirrus Clouds
thin and wispy $he most common form of high-level clouds are thin and often wispy cirrus clouds. $ypically found at heights greater than !0,000 feet 6,000 meters", cirrus clouds are composed of ice crystals that originate from the free%ing of supercooled water droplets. &irrus generally occur in fair weather and point in the direction of air movement at their elevation.
0ase usually between 4,5(( and 1(,((( ft oer 0ritish 2sles$
Low clouds -#%. 0ase usually below 4,5(( ft oer 0ritish 2sles$
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3ltostratus
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Nimbostratus
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6tratocumulus
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6tratus
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#umulus
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#umulonimbus
dark, low-level clouds with precipitation Nimbostratus are dark, low-level low-level clouds accompanied accompanied by light to moderately moderately falling precipitation. Low clouds clouds are primarily composed composed of water droplets since their their bases generally lie below 6,500 feet !,000 meters". #owever, when temperatures are cold enough, these clouds may also contain ice particles and snow.
Mid-Level Clouds #he bases of mid-level mid-level clouds clouds typically appear appear between between 6,500 to 20,000 feet (2,000 to 6,000 meters! $ecause of their lower altitudes, they are composed primarily of water drople droplets, ts, however, they can also be composed of ice crystals when temperatures are cold enough! Altocumulus Clouds
parallel bands or rounded rounded masses
%ltocumulus may appear as parallel bands (top photograph or rounded masses (bottom photograph! #ypically a portion of an altocumulus cloud is shaded, a characteristic which ma&es them distinguishable from the high-level cirrocumulus! %ltocumulus clouds usually form by convection convection in in an unstable layer aloft, which may result from the gradual gradual lifting of air in advance of a cold front! front! #he
presence of altocumulus clouds on a warm and humid summer morning is commonly followed by thunderstorms later in the day!
High-Level Clouds "igh-level clouds form above 20,000 feet (6,000 meters and since the temperatures are so cold at such high elevations, these clouds are primarily composed of ice crystals! "igh-level clouds are typically thin and white in appearance, but can appear in a magni'cent array of colors when the sun is low on the horion! Cirrus Clouds
thin and wispy $he most common form of high-level clouds are thin and often wispy cirrus clouds. $ypically found at heights greater than !0,000 feet 6,000 meters", cirrus clouds are composed of ice crystals that originate from the free%ing of supercooled water droplets. &irrus generally occur in fair weather and point in the direction of air movement at their elevation.
0ase usually between 4,5(( and 1(,((( ft oer 0ritish 2sles$
Low clouds -#%. 0ase usually below 4,5(( ft oer 0ritish 2sles$
•
3ltostratus
•
Nimbostratus
•
6tratocumulus
•
6tratus
•
#umulus
•
#umulonimbus
