altocumulus (Ac)

White and/or gray patches, sheets, or lalyers of clouds generally with shading composed of rounded masses or rolls, which are sometimes partially fibrous or diffuse and which may or may not be merged. Altocumulus clouds exist in the mid level of the sky between 2 to 6 kilometers above the ground (in meteorology, the prefix alto is used with other cloud types to describe other mid-level clouds as well). They are one of four genera that are hybrids of cumulus clouds. [See also cumulus.]