Key facts
- Abbreviation
- Cs
- Genus
- Cirrus ("curl") and, - stratus ("layered")
- Species
- Fibratus Nebulosus
- Variety
- Duplicatus Undulatus
- Altitude
- 6,000–13,000 m, (20,000–43,000 ft)
- Classification
- Family A (High-level)
- Appearance
- Thin, transparent, high-altitude layer capable of producing a halo
- Precipitation
- No, but usually signal the approach of a warm front that may bring rain within 24 hours
via Wikipedia infobox
Article
Cirrostratus (/ˌsɪroʊˈstrætəs, -ˈstreɪtəs/) is a high-altitude, very thin, and generally uniform stratiform genus-type of cloud. It is composed of ice crystals, which are particles of frozen water. Cirrostratus is difficult to see and can produce halos. These optical effects are caused when the cloud takes the form of thin cirrostratus nebulosus.
The cloud has a fibrous texture with no halos if it is thicker cirrostratus fibratus. On the approach of a frontal system, the cirrostratus often begins as nebulous and turns to fibratus. If the cirrostratus begins as fragmented of clouds in the sky it often means the front is weak. Cirrostratus usually lies above 5.5 km (3.4 mi; 18,000 ft). Its presence indicates a large amount of moisture in the upper troposphere.