CIRROCUMULUS
A cirriform cloud with vertical development, appearing as a thin sheet of small white puffs which give it a rippled effect. It often creates a "mackerel sky", since the ripples may look like fish scales. Sometimes it is confused with altocumulus, however, it has smaller individual masses and does not cast a shadow on other elements. It is also the least common cloud type, often forming from cirrus or cirrostratus, with which it is associated in the sky.
Thin white patches, sheets, or layers of cloud with no shading seen at high altitudes (greater than 6 kilometers above the ground) and composed of small elements in the form of grains or ripples, merged or separated, more or less regularly arranged. Cirrocumulus clouds are one of four genera that are hybrids of cumulus clouds. [See also cumulus.]
