What You Need to Know:
Name(s): Cirrocumulus Undulatus, Mackerel Sky
Common Altitudes of Formation: 5000-14000m (16,500-45,000ft)
Signals: Cirrocumulus usually indicates fair weather. If it is sighted after rain, it is a sign hat the weather will improve.
Meaning of the Name: Deriving from latin: diversified as with waves
Elaborated, More Comprehensive Information
The wavy, undulating appearance of cirrocumulus undulatus is the result of wind shear ( a difference in wind speed or direction over a relatively short distance in the atmosphere). The shape of each cloudlet may be round or long, but are usually thin. Unlike the stratiformis species, this cirrocumulus tends to occupy only a small patch or layer of sky.
Cirrocumulus undulatus usually forms following strong winds which create the undulations, though because the cloud patch is surrounded by two different air masses the patch remains intact. The cloud is very distinct making it easy to identify.
Cirrocumulus is mostly spotted during winter. Though they do not signal any precipitation, they usually come with a colder temperature, and if spotted in the western part of the sky, signals the next day’s bad weather.