altostratus

meteorology

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June 18, 2026

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Altostratus clouds are a mid-altitude layer of gray cloud, darker than cirrostratus. They form a fairly uniform layer in the middle troposphere. The name "altostratus" comes from Latin "altus" meaning "high" and "stratus" meaning "layer". These clouds are part of the stratiform cloud type, which forms as saturated air is mechanically forced upward. Altostratus clouds are typically darker than cirrostratus and can cover a large area of the sky. They are classified as middle clouds, found at mean heights between 2 to 7 km (1 to 4 miles).1234

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atmosphere
Cloud formation within the troposphere
…stratiform clouds are known as altostratus. In the upper troposphere, the terms cirrostratus and cirrus are used. The cirrus cloud type refers to thin, often wispy, cirrostratus clouds. Stratiform clouds that both extend through a large fraction of the troposphere and precipitate are called nimbostratus.
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…stratiform clouds are known as altostratus. In the upper troposphere, the terms cirrostratus and cirrus are used. The cirrus cloud type refers to thin, often wispy, cirrostratus clouds. Stratiform clouds that both extend through a large fraction of the troposphere and precipitate are called nimbostratus.
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