Altostratus clouds are part of the middle cloud group.
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Courtesy of Keith G. Diem. Used by permission.

Middle Clouds

The middle cloud group consists of Altostratus and Altocumulus clouds. The prefix alto- means 'middle.' Middle clouds consist of ice crystals and water droplets. The base of a middle cloud above the surface can be anywhere from 2000-8000m in the tropics to 2000-4000m in the polar regions.

Last modified September 25, 2007 by Becca Hatheway.

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