Over Pewaukee, Wisconsin, US

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CLOUD COLLECTING POINTS

Arcus is the roll running along the front of the base of the Cumulonimbus storm cloud.

Full classification:

Over Pewaukee, Wisconsin, US
© Nancy Wolck
Other examples of arcus:
Over Genoa, Italy

Cumulonimbus capillatus arcus

 Over Grand Teton National Park, Wyoming, US

Cumulonimbus capillatus arcus

Website © Gavin Pretor-Pinney and The Cloud Appreciation Society, 2009.
If you think we have got a classification wrong, please tell us about it.