John Michael Strubhart’s Reviews > The Weather Identification Handbook: The Ultimate Guide for Weather Watchers > Status Update

The final variety, stratocumulus radiatus, occurs when the cloud is arranged in long rolls. The clouds therefore appear to diverge from a single point in the sky in the upwind direction and, if the sheet of cloud is large enough, to converge on the opposite side of the sky. The varieties perlucidus, undulatus, and radiatus frequently occur together, to give a beautifully patterned sky, commonly called a 'mackerel sky