Stratiformis Cloud Species: Horizontal, Layer-Like

Definition: Layered cumuliform clouds that are capable of covering the sky

Description & Characteristics. The ‘stratiformis’ cloud species can be found amongst three cloud types: cirrocumulus, altocumulus, and stratocumulus. Translated from latin, meaning layer form, the three types of stratiformis clouds are respectively abbreviated as ‘Cc str’, ‘Ac str’, and ‘Sc str’. If one of these three cloud types extend across the sky’s entirety, they’re usually classified as stratiformis. The term ‘mackerel sky’ is a term commonly used to describe altocumulus stratiformis and cirrocumulus stratiformis clouds.

Get to know the stratiformis cloud species for several reasons. First, the stratiformis species is especially common in both stratocumulus and altocumulus clouds. In comparison, it’s not as common to witness cirrocumulus stratiformis clouds, but certainly not unusual.

Secondly, the stratiformis cloud species makes it possible for a handful of cloud varieties to appear. The cloud varieties lacunosus (perforated, round frayed holes), undulatus (wavelike, undulating), and duplicatus (multilayered) will a lot times be accompanied by the stratiformis species in all three cloud types. The cloud varieties opacus (opaque) and translucidus (transparent) exist in altocumulus stratiformis and stratocumulus stratiformis clouds and help describe the cloud’s density. Finally, the cloud variety perlucidus (transparent by small gaps) helps further describe both stratocumulus and altocumulus clouds. If you classify a cloud to be of the perlucidus variety, it’s almost always of the stratiformis species.

Finally, the stratiformis cloud species allows for several cloud features to appear more frequently or exist. Fallstreak holes (cavum cloud feature), which can occur in cirrocumulus, altocumulus, and stratocumulus cloud types, are almost always seen in stratiformis cloud formations. The cloud feature asperitas (chaotic, wavy underneath) often will occur in altocumulus stratiformis and stratocumulus stratiformis clouds. Finally, mammatus clouds (mamma cloud feature) and virga (evaporating rain strips) can usually be picked out in the stratiformis cloud species.

Stratiformis Cloud Types


The stratiformis cloud species is associated with the following three cloud types: cirrocumulus, altocumulus, and stratocumulus.

High-altitude cloudlets

Mid-altitude cloud heaps

Low, puffy layer