Altostratus Clouds (Middle Cloud Group)
Picture by Carlye Calvin
Picture by Peggy LeMone
Picture by Stefan Bauer
Altostratus clouds usually cover the whole sky and have a gray or blue-gray appearance.
The sun or moon may shine through an altostratus cloud, but will appear watery or fuzzy.
An altostratus cloud usually forms ahead of storms with continuous rain or snow.