Altostratus

An Altostratus is a cloud belonging to a class characterized by a generally uniform gray sheet or layer, lighter in color than nimbostratus and darker than cirrostratus. These clouds are of medium altitude, about 8000 to 20,000 ft (2400-6100 m).

External Links

• National Science Digital Library - Altostratus (http://www.nsdl.arm.gov/Library/glossary.shtml#Altostratus)