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This is a photograph of altocumulus clouds.
Click on image for full size
Courtesy of UCAR Digital Image Library

Altocumulus

Altocumulus clouds are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups and are about 1 km thick.

Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm's length to look at the cloud.

If you see altocumulus clouds on a warm humid morning, then expect thunderstorms by late afternoon.


Last modified September 25, 2007 by Becca Hatheway.

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