Storm architecture · species
Altocumulus castellanus
Tiny castles in the air
Full credit
Janne Naukkarinen
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Full credit
Own work
Displayed at reduced resolution. See the original file for full licensing information.
Full credit
Own work
Displayed at reduced resolution. See the original file for full licensing information.
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
Small turrets rising from a shared middle-level base.
How it forms
Instability within a moist layer lets cloud elements grow upward.
Read the sky
Turrets can suggest instability aloft; storms are not guaranteed.
Where to look
Look in middle-level cloud layers with elevated instability.
Little sky facts
Reveal fact 1
Castellanus describes turret-like tops.
Reveal fact 2
The turrets share a common base.
Reveal fact 3
They are easier to recognize from the side.
Reveal fact 4
The species name can apply to several cloud genera.
Try this
Draw the castle battlements along a shared base.
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.