Cloud Type: Undulatus Asperatus
Features: Dark, ominous, wavy clouds present after thunderstorms
When they form: After a period of stormy weather where atmospheric turbulence is present
Making them official: The UK's Cloud Appreciation Society is working to make undulatus asperatus the first new cloud type added to the United Nations' International Cloud Atlas in more than 50 years.
Chance of spotting in a year: AverageShare this on Facebook?