Asperitas (formerly referred to as Undulatus Asperitas) is a distinctive, but relatively rare cloud formation that takes the appearance of
rippling waves. These wave-like structures form on the underside of the cloud to makes it look like a rough sea surface when viewed from below.the way in which asperitas clouds form is somewhat a
mystery, yet there is much debate and confusion over how the wave-like clouds come into existence. It is hypothesised that their appearance is associated with the aftermath of convective
thunderstorms, though they have also been sighted in relatively calm environments.
What is clear however is that atmospheric conditions must be unstable to form a wavy cloud base like that seen with asperitas.