cirrostratuspilvet

Cirrostratuspilvet is a term used to denote the cirrostratus cloud in a form that emphasizes its veiled, sheetlike appearance. It belongs to the high-level, stratiform family of clouds and is characterized by a thin, extensive veil that can cover large portions or the entirety of the sky. The cloud is composed mainly of ice crystals and typically forms at very high altitudes, roughly 5,000 to 13,000 meters (16,000 to 43,000 feet).

The visual attributes of cirrostratuspilvet range from smooth, uniform milky sheets to more fibrous or layered textures. Common subtypes include cirrostratus fibratus (fibrous or streaked), cirrostratus nebulosus (smooth and featureless), and cirrostratus duplicatus (two distinct layers). A hallmark of cirrostratuspilvet is its ability to produce halos around the sun or moon, most notably the 22-degree halo, resulting from the optical effects of light refracting through the ice crystals. Shadows from the sun are rarely visible through this cloud.

Meteorologically, cirrostratuspilvet often signals the approach of a warm front and can precede precipitation by 12 to 24 hours, typically with the development of thicker mid-level clouds such as altostratus. Its presence indicates moist, rising air at high altitude and can be an early indicator of changing weather conditions.

Cirrostratuspilvet is observed in various climates and seasons, though it is more common in transitional periods when air masses interact. In observational cloud classification, cirrostratus is distinguished from cirrus by its uniform veil and halo-inducing properties rather than the discrete, wispy fibers of cirrus.