Cirrostratus clouds are thin, high-altitude clouds that form at heights above 20,000 feet (6,000 meters) in the atmosphere. These clouds are composed of ice crystals, and they often cover the sky in a thin, transparent, or semi-transparent layer. Cirrostratus clouds are usually wispy and diffuse, creating a veil-like effect across the sky. While they don’t bring precipitation themselves, they can indicate that a weather system, such as a warm front, is approaching. One of the most distinctive features of cirrostratus clouds is that they can create optical phenomena like halos, which form when the ice crystals in the clouds refract sunlight.
