What is Going On Here?

[Roshan Bliss]

This single (cirrus?) cloud evolved over the course of a sunset from this choppy wave formation into super curly swirls or waves, and I’d never seen anything like it. The long waves seemed to be created by flows of air that were moving in different directions. Does anyone know what phenomenon might explain this super interesting cloud?

[Hans Stocker]

Oh, wow, what an amazing cloud you spotted, Roshan. Thanks for sharing here. There is at the left in the first image clearly undulatus, which makes the cloud altocumulus. The curly ones are also altocumulus since they miss the striations of cirrus.  Maybe the curly part and the more plane and flat part are different clouds seen as one but at a different altitude.  This explains nothing about what’s happening but the lat image shows clearly fluctus or KH. They are caused by shearing winds at the level where they show up. The undulatus is also caused by shearing winds perpendicular to the pattern. It might be the same wind that causes the two phenomena at different altitudes in different clouds but both altocumulus. I must admit this is a bit speculative and I look forward to any other opinion. Anyway very nice.

Hans

[Amy Hamill]

I find this case of KH to be really unique because the KH is twisting veils of cloud with wind-shear, fluctus can really be sneaky, disguised among a sea of cumulus, to huddled up in a contrail. This is why KH is one of my favourite clouds, after Asperitas clouds. (Which I hope to see some day!)

[Roshan Bliss]

Thanks Hans! Your theory that this is actually two clouds stacked on top of each other that look like one because of the viewing angle would make a lot of sense – at least, in my understanding.

[Author]

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