Sc op

Statocumulus opacus 
variety of Statocumulus

Dense Statocumulus, composed of a continuous or nearly continuous sheet or layer of large dark rolls or rounded masses, most of which are sufficiently opaque to mask the sun or moon. The base of Statocumulus opacus is sometimes even. And its apparent subdivision into merged elements results from the irregularity of its upper surface. More often. However, the under surface is uneven, and the elements stand out in true relief.