ALTOSTRATUS (AS)

High, sheet-like (layered) clouds which are found at an average height of about 3,000 meters (10,000 feet) or 1,700 to 6,000 meters (6,000 to 20,000 feet). They appear fibrous, striated, or lightly striped. The clouds are composed of water droplets and/or ice crystals (unlike the higher cirrostratus which are primarily made up of ice crystals). [See also stratus.]