Topic summary
Altocumulus
Extracted from the Wikipedia article Altocumulus cloud.
Altocumulus generally forms at about 2,000–6,100 m (6,600–20,000 ft) above ground level, a similar level to altostratus formations, and satellite photography reveals that the two types of cloud can create formations that can stretch for thousands of square miles. Extensive altocumulus formations, particularly if they take the form of undulatus, are often referred to as altocumulus mackerel sky.