Lacunosus

Definition

A cloud variety in which the layer has regular round holes, often with fringed edges, giving a honeycomb or net-like appearance. It occurs in cirrocumulus and altocumulus, and more rarely in stratocumulus.

Field note

Lacunosus is a transitional form: the holes mean the layer is being broken up by localised descent or by mixing. It is often short-lived, and it is worth photographing the moment you see it because it may be gone in 15 minutes.

Related terms

• Altocumulus · Altocumulus
• Cirrocumulus · Cirrocumulus
• Perlucidus · perlucidus