Cirrostratus (Cs)


Personal Photo

Level: 23,000 ft. and up

Composition: Ice

Typical Conditions: Fair weather, but frequently a prelude to the approach of a storm system, especially if they cover the entire sky.

Appearance: Very thin "sheet" of ice crystals in the upper-levels. Sometimes visible as a faint, translucent white layer, but if they are thin enough, the only visual indication of their presence may be a halo around the sun or moon.