I’m torn between angry stingray and USS Enterprise entering Warp-speed. We don’t have clouds like that here, (at least that I ever saw).

@odd I don't see the stringray, but I definitely get the sense of motion, which is common with this form. These clouds appear where the wind forms standing waves. Much like when you get a standing wave in water flowing over a rock, these winds have persistent shapes over mountain peaks. If the wind carries moisture, it will condense at the point where the pressure change is right. That's my current understanding, anyway. No doubt a meteorologist would have corrections.

Then there might be such clouds in the west-facing mountains of Jotunheimen National park and/or in the steepest mountains of Northern Norway.

@odd Yes.