Arcus

English: An arcus cloud is a low, horizontal cloud formation associated with the leading edge of thunderstorm outflow, or occasionally with a cold front even in the absence of thunderstorms. Roll clouds and shelf clouds are the two types of arcus clouds, slight variations in their generation and look being the difference.
From the Shelf cloud gallery
English: A shelf cloud is one type of arcus cloud.

</noinclude>

From the Roll cloud gallery
English: A roll cloud is one type of arcus cloud.
Last modified on 9 December 2008, at 07:26