Clouds Flashcards
Cirrostratus
Origin: from Cirrus (Latin: curl, tuft, fringe) + Stratum (Latin: a covering)
Altitude: High (>7000 m)
Discription: Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky.
Compositon: Ice Crystals
Sunlight: Produces an halo around the sun or moon.
Weather Indications: Usually come 12 to 24 hours before a rain or snowstorm
Possible Confusion: A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus. The halo is the width of your hand held at arm’s length.
Cirrus
Origin: from Latin: curl, tuft, fringe
Altitude: High (>7000 m)
Discription: Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance.
Compositon: always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals.
Sunlight: As a rule when these clouds cross the sun’s disk they hardly diminish its brightness. Before sunrise and after sunset, cirrus is often colored bright yellow or red. These clouds are lit up long before other clouds and fade out much later.
Weather Indications: Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way.
Altocumulus
Origin: from Altus (Latin: high) + Cumulus (Latin: mass, pile)
Altitude: Middle (7000m>2000 m)
Discription: One part of cloud darker than another. White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse. Altocumulus clouds usually form in groups and are about one kilometer thick. Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm’s length.
Compositon: Chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present.
Sunlight: When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.
Weather Indications: If in the morning, often thunderstorms by late afternoon as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus.
Possibel Confusion: Similar to cirrocumulus, but individual segments are larger and darker.
Cumulus
Origin: Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal; They are puffy white or light gray clouds that look like floating cotton balls; They are generally about one kilometer wide which is about the size of your fist or larger when you hold up your hand at arm’s length to look at the cloud.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications:“Fair weather clouds”; Over land cumulus develops on days of clear skies, and is due diurnal convection; it appears in the morning, grows, and then more or less dissolves again toward evening. Watch for rain showers when the cloud’s tops look like cauliflower heads.
Cirrocumulus “Mackeral Sky”
Origin: from Cirrus (Latin: curl, tuft, fringe) + Cumulus (Latin: mass, pile)
Altitude: High (>7000 m)
Discription: Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. They are the same size or smaller than the width of your littlest finger when you hold up your hand at arm’s length.
Compositon: Ice Crystals
Weather Indications: Cirrocumulus are common in winter and indicate fair, but cold, weather.
Stratus
Origin: from Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Uniform grayish, Covers entire sky; A generally gray cloud layer with a uniform base, often when a layer of Stratus breaks up and dissipates blue sky is seen; Stratus clouds can look like a fog that doesn’t reach the ground.
Composition: Primarily of water droplets
Sunlight: When the sun is visible through this cloud, its outline is clearly discernible.
Weather Indications: Sometimes light mist or drizzle
Altocumulus
Origin: from Altus (Latin: high) + Cumulus (Latin: mass, pile)
Altitude: Middle (7000m>2000 m)
Discription: One part of cloud darker than another. White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse. Altocumulus clouds usually form in groups and are about one kilometer thick. Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm’s length.
Compositon: Chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present.
Sunlight: When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.
Weather Indications: If in the morning, often thunderstorms by late afternoon as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus.
Possibel Confusion: Similar to cirrocumulus, but individual segments are larger and darker.
Cirrocumulus “Mackeral Sky”
Origin: from Cirrus (Latin: curl, tuft, fringe) + Cumulus (Latin: mass, pile)
Altitude: High (>7000 m)
Discription: Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. They are the same size or smaller than the width of your littlest finger when you hold up your hand at arm’s length.
Compositon: Ice Crystals
Weather Indications: Cirrocumulus are common in winter and indicate fair, but cold, weather.
Cumulonimbus
Origin: Cumulus (Latin: mass, pile) + Nimbus (Latin: rainstorm)
Altitude: Low (<2000 m) building up vertically
Description: A heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed by wind, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume. Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base.
Composition: Water droplets at base to ice at top
Sunlight: Cannot see sun if covered
Weather Indications: Produce heavy precipitation, which sometimes is in the form of virga, Lighting and thunder. Cumulonimbus clouds also produce hail and tornadoes. In winter, snow.
Stratocumulus
Origin: from Stratum (Latin: covering) + Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Low, Lumpy; Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm’s length). Sometimes they line up in rows and other times they spread out.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Only light rain (usually drizzle) falls from stratocumulus clouds.
Possible Confusion: To distinguish between a stratocumulus and an altocumulus cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.
Nimbostratus
Origin: from Nimbus (Latin: rainstorm) + Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Dark Gray, have ragged bases and sit low in the sky.
Composition: Primarily of water droplets
Sunlight: Cannot see sun
Weather Indications: The continuous rain cloud. Precipitation light to moderate; long duration
Possible Confusion: The sun (or moon) is not visible through nimbostratus clouds, which distinguishes them from mid-level altostratus clouds.
Altostratus
Origin: from Altus (Latin: high) + Stratum (Latin: covering)
Altitude: Middle (7000m>2000 m)
Description: Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky.
Composition: Altostratus may be composed of ice crystals. In some ice crystal altostratus, very thin, rapidly disappearing horizontal sheets of water droplets appear at random. The sizes of the ice crystals in the cloud tended to increase as altitude decreased. However, close to the bottom of the cloud, the particles decreased in size again.
Sunlight:“water sun”; They are thin enough to regularly reveal the sun as if seen through ground glass.
Weather Indications: Light snow or rain possible, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.
Cumulus Congestus
Origin: Cumulus (Latin: mass, pile), Congestus (accumulating)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts resembling a cauliflower; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal;
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Often first sign of thunderstorms
Altocumulus
Origin: from Altus (Latin: high) + Cumulus (Latin: mass, pile)
Altitude: Middle (7000m>2000 m)
Discription: One part of cloud darker than another. White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse. Altocumulus clouds usually form in groups and are about one kilometer thick. Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm’s length.
Compositon: Chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present.
Sunlight: When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.
Weather Indications: If in the morning, often thunderstorms by late afternoon as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus.
Possibel Confusion: Similar to cirrocumulus, but individual segments are larger and darker.
Stratus
Origin: from Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Uniform grayish, Covers entire sky; A generally gray cloud layer with a uniform base, often when a layer of Stratus breaks up and dissipates blue sky is seen; Stratus clouds can look like a fog that doesn’t reach the ground.
Composition: Primarily of water droplets
Sunlight: When the sun is visible through this cloud, its outline is clearly discernible.
Weather Indications: Sometimes light mist or drizzle
Stratus
Origin: from Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Uniform grayish, Covers entire sky; A generally gray cloud layer with a uniform base, often when a layer of Stratus breaks up and dissipates blue sky is seen; Stratus clouds can look like a fog that doesn’t reach the ground.
Composition: Primarily of water droplets
Sunlight: When the sun is visible through this cloud, its outline is clearly discernible.
Weather Indications: Sometimes light mist or drizzle
Nimbostratus
Origin: from Nimbus (Latin: rainstorm) + Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Dark Gray, have ragged bases and sit low in the sky.
Composition: Primarily of water droplets
Sunlight: Cannot see sun
Weather Indications: The continuous rain cloud. Precipitation light to moderate; long duration
Possible Confusion: The sun (or moon) is not visible through nimbostratus clouds, which distinguishes them from mid-level altostratus clouds.
Stratocumulus
Origin: from Stratum (Latin: covering) + Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Low, Lumpy; Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm’s length). Sometimes they line up in rows and other times they spread out.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Only light rain (usually drizzle) falls from stratocumulus clouds.
Possible Confusion: To distinguish between a stratocumulus and an altocumulus cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.
Nimbostratus
Origin: from Nimbus (Latin: rainstorm) + Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Dark Gray, have ragged bases and sit low in the sky.
Composition: Primarily of water droplets
Sunlight: Cannot see sun
Weather Indications: The continuous rain cloud. Precipitation light to moderate; long duration
Possible Confusion: The sun (or moon) is not visible through nimbostratus clouds, which distinguishes them from mid-level altostratus clouds.
Cirrocumulus “Mackeral Sky”
Origin: from Cirrus (Latin: curl, tuft, fringe) + Cumulus (Latin: mass, pile)
Altitude: High (>7000 m)
Discription: Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. They are the same size or smaller than the width of your littlest finger when you hold up your hand at arm’s length.
Compositon: Ice Crystals
Weather Indications: Cirrocumulus are common in winter and indicate fair, but cold, weather.
Altostratus
Origin: from Altus (Latin: high) + Stratum (Latin: covering)
Altitude: Middle (7000m>2000 m)
Description: Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky.
Composition: Altostratus may be composed of ice crystals. In some ice crystal altostratus, very thin, rapidly disappearing horizontal sheets of water droplets appear at random. The sizes of the ice crystals in the cloud tended to increase as altitude decreased. However, close to the bottom of the cloud, the particles decreased in size again.
Sunlight:“water sun”; They are thin enough to regularly reveal the sun as if seen through ground glass.
Weather Indications: Light snow or rain possible, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.
Stratocumulus
Origin: from Stratum (Latin: covering) + Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Low, Lumpy; Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm’s length). Sometimes they line up in rows and other times they spread out.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Only light rain (usually drizzle) falls from stratocumulus clouds.
Possible Confusion: To distinguish between a stratocumulus and an altocumulus cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.
Cirrocumulus “Mackeral Sky”
Origin: from Cirrus (Latin: curl, tuft, fringe) + Cumulus (Latin: mass, pile)
Altitude: High (>7000 m)
Discription: Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. They are the same size or smaller than the width of your littlest finger when you hold up your hand at arm’s length.
Compositon: Ice Crystals
Weather Indications: Cirrocumulus are common in winter and indicate fair, but cold, weather.
Altostratus
Origin: from Altus (Latin: high) + Stratum (Latin: covering)
Altitude: Middle (7000m>2000 m)
Description: Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky.
Composition: Altostratus may be composed of ice crystals. In some ice crystal altostratus, very thin, rapidly disappearing horizontal sheets of water droplets appear at random. The sizes of the ice crystals in the cloud tended to increase as altitude decreased. However, close to the bottom of the cloud, the particles decreased in size again.
Sunlight:“water sun”; They are thin enough to regularly reveal the sun as if seen through ground glass.
Weather Indications: Light snow or rain possible, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.
Stratocumulus
Origin: from Stratum (Latin: covering) + Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Low, Lumpy; Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm’s length). Sometimes they line up in rows and other times they spread out.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Only light rain (usually drizzle) falls from stratocumulus clouds.
Possible Confusion: To distinguish between a stratocumulus and an altocumulus cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.
Cirrostratus
Origin: from Cirrus (Latin: curl, tuft, fringe) + Stratum (Latin: a covering)
Altitude: High (>7000 m)
Discription: Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky.
Compositon: Ice Crystals
Sunlight: Produces an halo around the sun or moon.
Weather Indications: Usually come 12 to 24 hours before a rain or snowstorm
Possible Confusion: A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus. The halo is the width of your hand held at arm’s length.
Cumulonimbus
Origin: Cumulus (Latin: mass, pile) + Nimbus (Latin: rainstorm)
Altitude: Low (<2000 m) building up vertically
Description: A heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed by wind, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume. Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base.
Composition: Water droplets at base to ice at top
Sunlight: Cannot see sun if covered
Weather Indications: Produce heavy precipitation, which sometimes is in the form of virga, Lighting and thunder. Cumulonimbus clouds also produce hail and tornadoes. In winter, snow.
Altostratus
Origin: from Altus (Latin: high) + Stratum (Latin: covering)
Altitude: Middle (7000m>2000 m)
Description: Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky.
Composition: Altostratus may be composed of ice crystals. In some ice crystal altostratus, very thin, rapidly disappearing horizontal sheets of water droplets appear at random. The sizes of the ice crystals in the cloud tended to increase as altitude decreased. However, close to the bottom of the cloud, the particles decreased in size again.
Sunlight:“water sun”; They are thin enough to regularly reveal the sun as if seen through ground glass.
Weather Indications: Light snow or rain possible, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.
Altocumulus
Origin: from Altus (Latin: high) + Cumulus (Latin: mass, pile)
Altitude: Middle (7000m>2000 m)
Discription: One part of cloud darker than another. White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse. Altocumulus clouds usually form in groups and are about one kilometer thick. Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm’s length.
Compositon: Chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present.
Sunlight: When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.
Weather Indications: If in the morning, often thunderstorms by late afternoon as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus.
Possibel Confusion: Similar to cirrocumulus, but individual segments are larger and darker.
Cirrostratus
Origin: from Cirrus (Latin: curl, tuft, fringe) + Stratum (Latin: a covering)
Altitude: High (>7000 m)
Discription: Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky.
Compositon: Ice Crystals
Sunlight: Produces an halo around the sun or moon.
Weather Indications: Usually come 12 to 24 hours before a rain or snowstorm
Possible Confusion: A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus. The halo is the width of your hand held at arm’s length.
Cumulus
Origin: Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal; They are puffy white or light gray clouds that look like floating cotton balls; They are generally about one kilometer wide which is about the size of your fist or larger when you hold up your hand at arm’s length to look at the cloud.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications:“Fair weather clouds”; Over land cumulus develops on days of clear skies, and is due diurnal convection; it appears in the morning, grows, and then more or less dissolves again toward evening. Watch for rain showers when the cloud’s tops look like cauliflower heads.
Cumulus
Origin: Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal; They are puffy white or light gray clouds that look like floating cotton balls; They are generally about one kilometer wide which is about the size of your fist or larger when you hold up your hand at arm’s length to look at the cloud.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications:“Fair weather clouds”; Over land cumulus develops on days of clear skies, and is due diurnal convection; it appears in the morning, grows, and then more or less dissolves again toward evening. Watch for rain showers when the cloud’s tops look like cauliflower heads.
Cumulus Congestus
Origin: Cumulus (Latin: mass, pile), Congestus (accumulating)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts resembling a cauliflower; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal;
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Often first sign of thunderstorms
Cumulonimbus
Origin: Cumulus (Latin: mass, pile) + Nimbus (Latin: rainstorm)
Altitude: Low (<2000 m) building up vertically
Description: A heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed by wind, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume. Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base.
Composition: Water droplets at base to ice at top
Sunlight: Cannot see sun if covered
Weather Indications: Produce heavy precipitation, which sometimes is in the form of virga, Lighting and thunder. Cumulonimbus clouds also produce hail and tornadoes. In winter, snow.
Cumulus Congestus
Origin: Cumulus (Latin: mass, pile), Congestus (accumulating)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts resembling a cauliflower; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal;
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Often first sign of thunderstorms
Stratus
Origin: from Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Uniform grayish, Covers entire sky; A generally gray cloud layer with a uniform base, often when a layer of Stratus breaks up and dissipates blue sky is seen; Stratus clouds can look like a fog that doesn’t reach the ground.
Composition: Primarily of water droplets
Sunlight: When the sun is visible through this cloud, its outline is clearly discernible.
Weather Indications: Sometimes light mist or drizzle
Cumulus
Origin: Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal; They are puffy white or light gray clouds that look like floating cotton balls; They are generally about one kilometer wide which is about the size of your fist or larger when you hold up your hand at arm’s length to look at the cloud.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications:“Fair weather clouds”; Over land cumulus develops on days of clear skies, and is due diurnal convection; it appears in the morning, grows, and then more or less dissolves again toward evening. Watch for rain showers when the cloud’s tops look like cauliflower heads.
Cirrus
Origin: from Latin: curl, tuft, fringe
Altitude: High (>7000 m)
Discription: Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance.
Compositon: always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals.
Sunlight: As a rule when these clouds cross the sun’s disk they hardly diminish its brightness. Before sunrise and after sunset, cirrus is often colored bright yellow or red. These clouds are lit up long before other clouds and fade out much later.
Weather Indications: Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way.
Stratocumulus
Origin: from Stratum (Latin: covering) + Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Low, Lumpy; Gray or whitish patch, sheet, or layered clouds which almost always have dark tessellations (honeycomb appearance), rounded masses or rolls. Except for virga they are non-fibrous and may or may not be merged. They also have regularly arranged small elements with an apparent width of more than five degrees (three fingers - at arm’s length). Sometimes they line up in rows and other times they spread out.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Only light rain (usually drizzle) falls from stratocumulus clouds.
Possible Confusion: To distinguish between a stratocumulus and an altocumulus cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.
Cumulus
Origin: Cumulus (Latin: mass, pile)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts often resembling a cauliflower.; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal; They are puffy white or light gray clouds that look like floating cotton balls; They are generally about one kilometer wide which is about the size of your fist or larger when you hold up your hand at arm’s length to look at the cloud.
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications:“Fair weather clouds”; Over land cumulus develops on days of clear skies, and is due diurnal convection; it appears in the morning, grows, and then more or less dissolves again toward evening. Watch for rain showers when the cloud’s tops look like cauliflower heads.
Cumulus Congestus
Origin: Cumulus (Latin: mass, pile), Congestus (accumulating)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts resembling a cauliflower; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal;
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Often first sign of thunderstorms
Stratus
Origin: from Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Uniform grayish, Covers entire sky; A generally gray cloud layer with a uniform base, often when a layer of Stratus breaks up and dissipates blue sky is seen; Stratus clouds can look like a fog that doesn’t reach the ground.
Composition: Primarily of water droplets
Sunlight: When the sun is visible through this cloud, its outline is clearly discernible.
Weather Indications: Sometimes light mist or drizzle
Cirrocumulus “Mackeral Sky”
Origin: from Cirrus (Latin: curl, tuft, fringe) + Cumulus (Latin: mass, pile)
Altitude: High (>7000 m)
Discription: Thin, white patch, sheet, or layered of clouds without shading. They are composed of very small elements in the form of more or less regularly arranged grains or ripples. They are the same size or smaller than the width of your littlest finger when you hold up your hand at arm’s length.
Compositon: Ice Crystals
Weather Indications: Cirrocumulus are common in winter and indicate fair, but cold, weather.
Cumulonimbus
Origin: Cumulus (Latin: mass, pile) + Nimbus (Latin: rainstorm)
Altitude: Low (<2000 m) building up vertically
Description: A heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed by wind, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume. Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base.
Composition: Water droplets at base to ice at top
Sunlight: Cannot see sun if covered
Weather Indications: Produce heavy precipitation, which sometimes is in the form of virga, Lighting and thunder. Cumulonimbus clouds also produce hail and tornadoes. In winter, snow.
Cirrus
Origin: from Latin: curl, tuft, fringe
Altitude: High (>7000 m)
Discription: Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance.
Compositon: always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals.
Sunlight: As a rule when these clouds cross the sun’s disk they hardly diminish its brightness. Before sunrise and after sunset, cirrus is often colored bright yellow or red. These clouds are lit up long before other clouds and fade out much later.
Weather Indications: Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way.
Altostratus
Origin: from Altus (Latin: high) + Stratum (Latin: covering)
Altitude: Middle (7000m>2000 m)
Description: Gray or bluish cloud sheets or layers of striated or fibrous clouds that totally or partially covers the sky.
Composition: Altostratus may be composed of ice crystals. In some ice crystal altostratus, very thin, rapidly disappearing horizontal sheets of water droplets appear at random. The sizes of the ice crystals in the cloud tended to increase as altitude decreased. However, close to the bottom of the cloud, the particles decreased in size again.
Sunlight:“water sun”; They are thin enough to regularly reveal the sun as if seen through ground glass.
Weather Indications: Light snow or rain possible, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.
Cirrus
Origin: from Latin: curl, tuft, fringe
Altitude: High (>7000 m)
Discription: Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance.
Compositon: always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals.
Sunlight: As a rule when these clouds cross the sun’s disk they hardly diminish its brightness. Before sunrise and after sunset, cirrus is often colored bright yellow or red. These clouds are lit up long before other clouds and fade out much later.
Weather Indications: Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way.
Nimbostratus
Origin: from Nimbus (Latin: rainstorm) + Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Dark Gray, have ragged bases and sit low in the sky.
Composition: Primarly of water droplets
Sunlight: Cannot see sun
Weather Indications: The continuous rain cloud. Percipitation light to moderate; long duration
Possible Confusion: The sun (or moon) is not visible through nimbostratus clouds, which distinguishes them from mid-level altostratus clouds.
Cirrostratus
Origin: from Cirrus (Latin: curl, tuft, fringe) + Stratum (Latin: a covering)
Altitude: High (>7000 m)
Discription: Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky.
Compositon: Ice Crystals
Sunlight: Produces an halo around the sun or moon.
Weather Indications: Usually come 12 to 24 hours before a rain or snowstorm
Possible Confusion: A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus. The halo is the width of your hand held at arm’s length.
Nimbostratus
Origin: from Nimbus (Latin: rainstorm) + Stratum (Latin: covering)
Altitude: Low (<2000 m)
Description: Dark Gray, have ragged bases and sit low in the sky.
Composition: Primarily of water droplets
Sunlight: Cannot see sun
Weather Indications: The continuous rain cloud. Precipitation light to moderate; long duration
Possible Confusion: The sun (or moon) is not visible through nimbostratus clouds, which distinguishes them from mid-level altostratus clouds.
Altocumulus
Origin: from Altus (Latin: high) + Cumulus (Latin: mass, pile)
Altitude: Middle (7000m>2000 m)
Discription: One part of cloud darker than another. White and/or gray patch, sheet or layered clouds, generally composed of laminae (plates), rounded masses or rolls. They may be partly fibrous or diffuse. Altocumulus clouds usually form in groups and are about one kilometer thick. Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm’s length.
Compositon: Chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present.
Sunlight: When the edge or a thin semitransparent patch of altocumulus passes in front of the sun or moon a corona appears. This colored ring has red on the outside and blue inside and occurs within a few degrees of the sun or moon.
Weather Indications: If in the morning, often thunderstorms by late afternoon as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus.
Possibel Confusion: Similar to cirrocumulus, but individual segments are larger and darker.
Cumulus Congestus
Origin: Cumulus (Latin: mass, pile), Congestus (accumulating)
Altitude: Low (<2000 m)
Description: Detached, generally dense clouds and with sharp outlines that develop vertically in the form of rising mounds, domes or towers with bulging upper parts resembling a cauliflower; The sunlit parts of these clouds are mostly brilliant white while their bases are relatively dark and horizontal;
Composition: Primarily of water droplets
Sunlight: Cannot see sun if covered
Weather Indications: Often first sign of thunderstorms
Cumulonimbus
Origin: Cumulus (Latin: mass, pile) + Nimbus (Latin: rainstorm)
Altitude: Low (<2000 m) building up vertically
Description: A heavy and dense cloud in the form of a mountain or huge tower. The upper portion is usually smoothed by wind, fibrous or striated and nearly always flattened in the shape of an anvil or vast plume. Under the base of this cloud which is often very dark, there are often low ragged clouds that may or may not merge with the base.
Composition: Water droplets at base to ice at top
Sunlight: Cannot see sun if covered
Weather Indications: Produce heavy precipitation, which sometimes is in the form of virga, Lighting and thunder. Cumulonimbus clouds also produce hail and tornadoes. In winter, snow.
Cirrostratus
Origin: from Cirrus (Latin: curl, tuft, fringe) + Stratum (Latin: a covering)
Altitude: High (>7000 m)
Discription: Transparent, whitish veil clouds with a fibrous (hair-like) or smooth appearance. A sheet of cirrostratus which is very extensive, nearly always ends by covering the whole sky.
Compositon: Ice Crystals
Sunlight: Produces an halo around the sun or moon.
Weather Indications: Usually come 12 to 24 hours before a rain or snowstorm
Possible Confusion: A milky veil of fog (or thin Stratus) is distinguished from a veil of Cirrostratus of a similar appearance by the halo phenomena which the sun or the moon nearly always produces in a layer of cirrostratus. The halo is the width of your hand held at arm’s length.
Cirrus
Origin: from Latin: curl, tuft, fringe
Altitude: High (>7000 m)
Discription: Detached clouds in the form of white, delicate filaments, mostly white patches or narrow bands. They may have a fibrous (hair-like) and/or silky sheen appearance.
Compositon: always composed of ice crystals, and their transparent character depends upon the degree of separation of the crystals.
Sunlight: As a rule when these clouds cross the sun’s disk they hardly diminish its brightness. Before sunrise and after sunset, cirrus is often colored bright yellow or red. These clouds are lit up long before other clouds and fade out much later.
Weather Indications: Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way.
