Clouds Formation

Middle clouds tend to form at 6,500 ft (2,000 m) but may form at heights up to 13,000 ft (4,000 m), 23,000 ft (7,000 m) or 25,000 ft (8,000 m) depending on the region. Generally the warmer the climate, the higher the cloud base. Family B usually comprises one cumuliform and one stratiform-category genus.
Family B includes:
- Genus Altocumulus (Ac): A cloud layer of limited convection usually in the form of irregular patches or rounded masses in groups, lines, or waves. High altocumulus may resemble cirrocumulus but is usually thicker and composed of water droplets so that the bases show at least some light grey shading. Opaque altocumulus associated with a weak frontal or low pressure disturbance can produce very light intermittent precipitation.
+ Species Altocumulus stratiformis (Ac str): Sheets or relatively flat patches of altocumulus.