Altostratus clouds
They are a type of mid-level cloud that form in the atmosphere between about 2,000 and 7,000 meters (6,500–23,000 feet) above the ground.
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Key Varieties of Altostratus Clouds
- Altostratus duplicatus
A rare form consisting of two or more, sometimes merged, layers of altostratus at slightly different levels.
- Altostratus opacus
A thick, dense variety that completely obscures the sun or moon.
- Altostratus radiatus
Features large, parallel bands or rolls that appear to radiate towards the horizon.
- Altostratus opacus
A thick, dense variety that completely obscures the sun or moon.
- Altostratus translucidus (As tr)
A thin variety that allows the sun or moon to be seen dimly, often described as a “ground glass” or “watery” appearance.
- Altostratus undulatus (As un)
These exhibit a wavy, rippling, or undulating pattern, sometimes called billow clouds.
- Altostratus translucidus: A thin variety that allows the sun or moon to be seen dimly, often described as a “ground glass” or “watery” appearance.
- Altostratus radiatus: Features large, parallel bands or rolls that appear to radiate towards the horizon.
What’s This Cloud +5
Associated Features and Observations
- Altostratus mamma (Mammatus): Features hanging, pouch-like, or “udder-like” structures on the underside of the cloud layer.
- Virga: Rain or snow that evaporates before reaching the ground, often appearing as streaks hanging below the cloud base.
- Praecipitatio: Occurs when rain or snow reaches the ground.
- Coronas/Iridescence: Diffraction of light through the cloud can cause bright rings (coronas) or colors (iridescence) around the sun or moon.