Altostratus (As)

Type: Medium-level cloud

Height of cloud base: 8,000-17,000 ft

Cloud Colour: Greyish or bluish.

Cloud shape: A sheet of uniform appearance totally or partly covering the sky.

Other cloud features: Sometimes thin enough to reveal the sun or moon vaguely, as through ground glass. Objects on the ground do not cast shadows. May give generally light rain or snow, occasionally ice pellets, if the cloud base is no higher than about 10,000 ft.