Opacus Cloud Variety: Opaque, Masks The Sun

Description & Characteristics. The ‘opacus’ cloud variety can be found amongst four cloud types: altocumulus, altostratus, stratus, and stratocumulus. Translated from latin, meaning darkened, the four types of opacus clouds are respectively abbreviated as ‘Ac op’, ‘As op’, ‘St op’, and ‘Sc op’. Of the nine cloud varieties, this is arguably the easiest to identify. Plain and simple, opacus cloud formations are dark clouds where you cannot see the sun.

It’s important to note that the opacus cloud variety is the opposite of the translucidus cloud variety. If you can see the sun shining through the cloud or make out the sun’s position in one of these four cloud types, classify the cloud as translucidus. If not, the mark it as opacus. Even though clouds can have more than one variety applied to it, a cloud cannot be classified as opacus and translucidus simultaneously..

As a cloudspotter, the opacus variety is one of the more popular varieties in altostratus and stratus clouds. It’s also important to note that more often than not, you’ll find the opacus cloud variety in altocumulus and stratocumulus clouds when they’re of the stratiformis cloud species.