View source for Cirrus uncinus cloud

{{Short description|Type of cloud}}
{{use dmy dates|date=May 2025}}
{{Infobox cloud
|name=Cirrus uncinus
|image location=Cirrus clouds2.jpg
|image name=Cirrus uncinus cloud
|abbreviation=Ci unc
|genus=Cirrus ("curl")
|species=uncinus ("hook")
|variety=
|altitude_m=above 7,000
|altitude_ft=23,000
|level = high
|appearance=curly, hooked
|precipitation=No, but may indicate precipitation approach.
}}

'''Cirrus uncinus''' is a species of [[cirrus cloud]]. The name ''cirrus uncinus'' is [[Latin]] for "curly hooks". Commonly called "'''mare's tail'''", this [[cloud species]] is very thin and generally sparse in the [[sky]].<ref>{{cite web |url=https://cloudatlas.wmo.int/species-cirrus-uncinus-ci-unc.html |title=Cirrus uncinus (Ci unc) |publisher=[[World Meteorological Organization]] |website=[[International Cloud Atlas]] |language=en |access-date=2019-06-25}}</ref>

The clouds occur at high [[altitude]]s, at a temperature of about {{cvt|-50|to|-40|C|F}}. They are generally seen when a [[warm front|warm]] or [[occluded front]] is approaching. They are very high in the [[troposphere]] and generally mean that [[precipitation (meteorology)|precipitation]], usually [[rain]], is approaching.<ref>{{cite web |url=https://whatsthiscloud.com/cloud-species/uncinus |title=Learn About Cirrus Uncinus Clouds: Curved, Comma-shaped |publisher=whatsthiscloud.com |language=en-US |access-date=2019-06-25}}</ref>

<gallery>
File:Cirrus clouds 011.jpg|Cirrus uncinus clouds over [[Salinas Victoria]], [[Nuevo León]], Mexico
File:Cirrus uncinus clouds in the morning sky.jpg|Cirrus uncinus clouds in the morning sky over Nandli, [[Himachal Pradesh]], India
</gallery>

==See also==
*[[List of cloud types]]

==References==

<references />

==External links==
*[http://nephology.eu/cirrus/cirrus-uncinus International Cloud Atlas – Cirrus uncinus] {{Webarchive|url=https://web.archive.org/web/20221110195531/http://nephology.eu/cirrus/cirrus-uncinus |date=2022-11-10 }}

{{Cirrus cloud types}}
{{Cloud types}}

[[Category:Cirrus]]