Everyday skies · genus
Altocumulus
Islands in the middle sky
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Full credit
Own work
Displayed at reduced resolution. See the original file for full licensing information.
Swipe or scroll sideways to explore the photographs. Photos may include other cloud types; names and credits come from their source records.
Spot it
Mid-level cloudlets, often with shaded sides, arranged in patches or rows.
How it forms
Moisture, uplift and atmospheric waves shape a middle-level layer.
Read the sky
Patterns provide clues about air movement, not a reliable forecast by themselves.
Where to look
Look in middle-level moist layers over many landscapes.
Little sky facts
Reveal fact 1
Cloudlets may be separate or joined together.
Reveal fact 2
Grey shading helps distinguish many examples from cirrocumulus.
Reveal fact 3
Some patches form orderly rows.
Reveal fact 4
Lens-shaped examples belong to the lenticularis species.
Try this
Turn a row of cloudlets into a tiny archipelago.
Draw your own cloud ↗Read a little deeper
Met Office · formation and weather
Conditions described here are places to look, not a global frequency ranking. Use local weather forecasts and warnings for decisions. Never look directly at the Sun.