Cirrus Clouds

Cirrus Clouds are one of the three basic cloud forms. The other two are cumulus and stratus. They are thin, wispy clouds composed of ice crystals and often appear as veil patches or strands. In the mid-latitudes, cloud bases are usually found between 20,000 to 30,000 feet. Cirrus clouds are the highest clouds that form in the sky, except for the anvils of cumulonimbus clouds.
Concept Mapping Toolkit
Insitute for Human and Machine Cognition
The University of West Florida