M3 Clouds: Semi-transparent Altocumulus (Ac)
Altocumulus, the greater part of which is semi-transparent; the various elements of the cloud change only slowly and are all at a single level.
Additional Views:
Notes: The next seven cloud classifications deal with altocumulus clouds and its occurrences in various layers, opacities and combinations.
This altocumulus is a single level, the greater part of which is sufficiently transparent to reveal the position of the sun and moon. The clouds do not progressively invade the sky, and the individual elements change very little. These thin altocumulus clouds usually produce a corona.
