Cirrocumulus

Cirrocumulus is a genus of high-altitude clouds composed of ice crystals, forming in the upper troposphere at altitudes roughly 5 to 12 kilometers (about 16,000 to 40,000 feet). They appear as small, white, rounded puffs or as patches arranged in long, often regular bands. When many tiny elements occur in a row, the sky can resemble a “mackerel sky.” Cirrocumulus are thinner and more delicate than lower clouds, with weak contrast against the blue sky.

Formation and structure: Cirrocumulus forms where moist air near the tropopause rises and cools, causing ice crystals to develop. The pattern and texture reflect conditions in the upper troposphere, including stability and wind shear. They may present in several patterns, including layered or wavy arrangements, and often occur alongside other high clouds such as cirrus or cirrostratus.

Meteorological significance: The presence of cirrocumulus often indicates moisture at high levels and can be associated with approaching weather systems, particularly when accompanied by other cirriform clouds. They rarely produce precipitation that reaches the ground; if any precipitation occurs, it is typically virga. For aviators, cirrocumulus can signal strong upper-level winds and potential turbulence due to wind shear.

Relationship to other clouds: Cirrocumulus are part of the high-cloud family that includes cirrus and cirrostratus. They differ from cirrus by their puffier, more cumulus-like appearance and from cirrostratus by not forming as a thin veil. They are most commonly seen in regions with active upper-level dynamics, such as near jet streams.