“Solid” Altocumulus stratiformis occurring in a sheet or layer with merged elements

(Section 2.5.2.4.2)

This type of Altocumulus is usually less than 500 m (1 650 ft) thick. Occasionally it occurs in two or more thin sheets or patches, and then it has a dark appearance suggesting a considerably greater depth. The total thickness from the base of the lowest to the top of the highest layer is usually less than 2 000 m (6500 ft).

Below the cloud. Viewed from below, this cloud appears as a sheet or layer, entirely grey or sometimes white and grey, and with varying opacity. When observed from nearby, the elements appear large and dark, and look exactly like Stratocumulus.

Within the cloud. This cloud is composed of small water droplets, sometimes accompanied by ice crystals. Variations in visibility are fairly distinct, particularly at night when the aircraft lights are on. There may be considerable icing. Turbulence is usually weak, but may be moderate.

Above the cloud. Viewed from above, this cloud usually appears continuous except for crevices that mark the thinner borders of the elements. The upper surface may be smooth and undulated or may have a fleecy appearance. Glory, fog bow and subsun (undersun) may be observed, sometimes simultaneously.