Castellanus

Definition

A cloud species in which small turrets rise from a common base, giving the cloud a crenellated, castle-like appearance. It occurs in cirrocumulus, altocumulus and stratocumulus.

Field note

Castellanus is the single most important instability signature at middle levels. Altocumulus castellanus in mid-morning is a recognised precursor to afternoon thunderstorm development.

Related terms

• Altocumulus · Altocumulus
• Floccus · floccus
• Congestus · congestus