I suppose these are not really 'strange clouds' but I think it's pretty cool.

When wind of the right speed flows around a non-streamlined object, vortex shedding occurs leaving an oscillating flow in the object's wake. The von Karman vortex street is a repeating pattern of that oscillating flow.

Meteorologically, these vortex streets seem to form best from islands in the ocean. There's nothing around but open sky and, since the air is all moving in the same general direction, these 'streets' and can be 400 km (260 mi) long with the low pressure vorticies being usually 20-40 km (12-25 mi) in diameter.

Apparently these are very rare to see from underneath and are best seen from space.

Alejandro Selkirk Island- Sept. 15, 1999. See the link for the original, gorgeous, hi-def image.
Alejandro Selkirk Island- Sept. 15, 1999(rs).jpg

Cape Verde Islands- Apr. 26, 2004.
Cape Verde Islands- Apr. 26, 2004(rs).jpg

Cape Verde Islands- Jan. 5, 2005. Phrygian caps! Or Greek Meander?
Cape Verde Islands- Jan. 5, 2005(rs).jpg

Aleutian I in the Aleutian Islands- May 23, 2007
Aleutian I in the Aleutian Islands- May 23, 2007(rs).jpg

Jan Mayen Island- Apr. 4, 2012. This island is home the the worlds most northern volcano, Beerenberg.
Jan Mayen Island- Apr. 4, 2012(rs).jpg

Heard Island- Nov. 2, 2015
Heard Island- Nov. 2, 2015(rs).jpg

This phenomenon can also be destructive.
If the bluff structure is not mounted rigidly and the frequency of vortex shedding matches the resonance frequency of the structure, then the structure can begin to resonate, vibrating with harmonic oscillations driven by the energy of the flow.

Weatherwatch: vortex 'streets' that can flatten power stations

Oct. 31, 2017

Kármán found that air flowing around an obstacle broke away into distinct whirlwinds. At a particular wind speed, the forces involved produce resonance, causing wires to sing in the wind, or towers to wobble.

Ferrybridge power station damage

Two of the three 350ft cooling towers at Ferrybridge, Yorkshire, which were brought down by a Kármán vortex street on 1 November 1965. Photograph: Keystone/Getty Images

A powerful Kármán vortex street occurred at Ferrybridge power station in West Yorkshire, on 1 November 1965. Eight cooling towers, each over a hundred metres tall, had been built only three years previously, but 80mph gusts had a catastrophic effect. The four towers on the windward side stood firm, but those behind were buffeted by vortices from those upwind. At 10.30am one tower collapsed, followed by two others over the next hour. Fire damaged the remaining five towers. Fortunately, nobody was hurt.
I saw something similar yesterday afternoon but much more smaller and if I look at this picture it might be that I only saw the "foot" of the "mushroom" - I dont know how to describe it better -- - I did take a picture but my camera is so bad one cannot see anything . . . But I am glad that there are more pictures. 😇 :-D :-D

Another photo from another perspective. Trujillo Alto, Puerto Rico 🇵🇷
(Oct 16, 2023) 📸 Jory
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