1. The term mackerel sky is also common to Altocumulus (and cirrocumulus) clouds that display a pattern resembling fish scales.

2. Altocumulus From the Latin altum, ‘height’ and cumulus, ‘heap’, the name of a genus of clouds composed largely of water droplets and consisting of grey-white sheets, or banded layers and rolls, which may also be broken up into cells.Sometimes it has a banded appearance, occasionally giving a mackerel-sky effect; this is probably associated with strong vertical wind shear in middle