Mackeral Sky maybe?

[Mike G]

I'm not sure if this is a Mackeral Sky?

Nikon Z6 + Nikkor 24-70mm @ 1/2000 f4 ISO100.

 

[theoldsmithy]

It looks like one, with a bit of lower level cirrus at right angles to it.

 

[drd1135]

Holy . . . !!!

 

[Matero]

I'm not sure if this is a Mackeral Sky?

View attachment 213353
Nikon Z6 + Nikkor 24-70mm @ 1/2000 f4 ISO100.

I would say not exactly Mackeral, which is formed of cirrocumulus or altocumulus clouds. This looks like cirrus as Martin already pointed. But very interesting formation of high level clouds. Imaging what's happening on that level, wind etc.