Cirrus uncinus is a species of

cirrus cloud Cirrus ( cloud classification symbol: Ci) is a genus of high cloud made of ice crystals. Cirrus clouds typically appear delicate and wispy with white strands. In the Earth's atmosphere, cirrus are usually formed when warm, dry air rises, causing ...

. The name ''cirrus uncinus'' is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for "curly hooks". Commonly called "mare's tail", this

cloud species Cloud species are a set of fourteen terms used to describe the shape and structure of clouds. Each one has its name abbreviated to a three letter term. References See also

* List of cloud types Cloud types pl:Chmura#Klasyfikacja ch ...

is very thin and generally sparse in the

sky The sky is an unobstructed view upward from the planetary surface, surface of the Earth. It includes the atmosphere of Earth, atmosphere and outer space. It may also be considered a place between the ground and outer space, thus distinct from ...

. The clouds occur at high

altitude Altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum (geodesy), datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometr ...

s, at a temperature of about . They are generally seen when a

warm Warm, WARM, or Warmth may refer to: * A somewhat high temperature; heat * Kindness Music Albums * ''Warm'' (Herb Alpert album), 1969 * ''Warm'' (Jeff Tweedy album), 2018 * ''Warm'' (Johnny Mathis album), 1958, and the title song * ''Warm'' (T ...

occluded front In meteorology, an occluded front is a type of weather front formed during cyclogenesis. The classical and usual view of an occluded front is that it starts when a cold front overtakes a warm front near a cyclone, such that the warm air is sepa ...

is approaching. They are very high in the

troposphere The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...

and generally mean that

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

, usually

rain Rain is a form of precipitation where water drop (liquid), droplets that have condensation, condensed from Water vapor#In Earth's atmosphere, atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is res ...

, is approaching. File:Cirrus clouds 011.jpg, Cirrus uncinus clouds over

Salinas Victoria Salinas Victoria, is a municipality and town located in the center of the state of Nuevo León, Mexico. It shares borders with 11 municipalities including, to the north Villaldama and Sabinas Hidalgo; to the south Escobedo and Apodaca; to the ...

Nuevo León Nuevo León, officially the Free and Sovereign State of Nuevo León, is a Administrative divisions of Mexico, state in northeastern Mexico. The state borders the Mexican states of Tamaulipas, Coahuila, Zacatecas, and San Luis Potosí, San Luis ...

, Mexico File:Cirrus uncinus clouds in the morning sky.jpg, Cirrus uncinus clouds in the morning sky over Nandli,

Himachal Pradesh Himachal Pradesh (; Sanskrit: ''himācāl prādes;'' "Snow-laden Mountain Province") is a States and union territories of India, state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen Indian Himalayan ...

, India

References

External links

International Cloud Atlas – Cirrus uncinus
{{Cloud types Cirrus