Cirrus uncinus cloud

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Cirrus uncinus cloud
Abbreviation	Ci
Genus	Cirrus (curl of hair)
Species	uncinus (hooked)
Altitude	Above 7000 m (Above 23,000 ft)
Classification	Family A (High-level)
Appearance	curly, hooked
Precipitation Cloud?	No

Cirrus uncinus is a type of cirrus cloud. Its name is derived from Latin, meaning curly hooks. Also known as mares' tails, these clouds are generally sparse in the sky, and very thin.

The clouds occur at very high altitudes, at a temperature of about minus 40-50 degrees Celsius. They are generally seen when a warm or occluded front is approaching. They are very high in the troposphere, and generally mean that precipitation, usually rain, is approaching.

v • d • e Clouds
High Clouds (Family A):	Cirrus (Ci) • Cirrus uncinus • Cirrus Kelvin-Helmholtz colombia • Cirrostratus (Cs) • Cirrocumulus (Cc) • Pileus • Contrail
Middle Clouds (Family B):	Altostratus (As) • Altostratus undulatus • Altocumulus (Ac) • Altocumulus undulatus • Altocumulus mackerel sky • Altocumulus castellanus cloud • Altocumulus lenticularis
Low Clouds (Family C):	Stratus (St) • Nimbostratus (Ns) • Cumulus humilis (Cu) • Cumulus mediocris (Cu) • Stratocumulus (Sc)
Vertical Clouds (Family D):	Cumulonimbus (Cb) • Cumulonimbus incus • Cumulonimbus calvus • Cumulonimbus with mammatus • Cumulus congestus • Pyrocumulus  • Pyrocumulonimbus