Explanatory remarks

(Section 2.3.4.8)

During the initial stages of its formation, Altocumulus is frequently a fairly smooth cloud of moderate horizontal extent. This cloud then subdivides into more or less regularly arranged small elements, in the form of laminae or tessellations.

Altocumulus in the shape of a lens or almond often forms in clear air as a result of local orographic lifting of a layer of moist air.

Altocumulus frequently occurs at different levels in the same sky and is, in many instances, associated with Altostratus. In this case, the air is often hazy immediately below the sheets or layers of Altocumulus or between the elements constituting them.