Altostratus

This is a photograph of altostratus clouds. Click on image for full size version (42K JPG) Cloud photos copyright 2000-2001 by Keith G. Diem. Used by permission.

Altostratus clouds belong to the Middle Cloud group. An altostratus cloud usually covers the whole sky. The cloud looks gray or blue-gray. The sun or moon may shine through an altostratus cloud, but will look like a watery or fuzzy blob.

An altostratus cloud usually forms ahead of storms that have a lot of rain or snow. Sometimes, rain will fall from an altostratus cloud. If the rain hits the ground, then the cloud is called a nimbostratus cloud.