Storm architecture · feature
Mammatus clouds
Pockets underneath the sky
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English Wikipedia, original upload 7 March 2005 by Brian0918 From NOAA Photo Library and NSSL: [1]
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Displayed at reduced resolution. See the original file for full licensing information.
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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
Rounded pouches hanging from the underside of a cloud.
How it forms
Localized descending regions create a pocketed underside; processes vary.
Read the sky
Often photographed under storm anvils; pouches alone do not diagnose a tornado.
Where to look
Look beneath cloud layers, especially near the edges of thunderstorm anvils.
Little sky facts
Reveal fact 1
The formal feature name is mamma.
Reveal fact 2
The pouches project downward.
Reveal fact 3
They are a feature of a parent cloud, not a separate genus.
Reveal fact 4
They can occur on more than one cloud genus.
Try this
Draw the shadows between the pouches.
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.