Ac compared with Cc

(Section 2.3.4.6.2)

Altocumulus is distinguished from Cirrocumulus by: 

• Presence of shading, even if most of the regularly arranged cloud elements have an apparent width of less than 1°
• Most of the regularly arranged elements having an apparent width of between 1 and 5°, even if the cloud has no shading
• Possible halo phenomena