Ballycastle

[Steveo74]

Need help! Was in Ballycastle and noticed this before storm clouds rolled in.









Any advice would be much appreciated 

[Paul]

Wow! There's obvious Iridescence there which is what the colour is, but as to the circular formation, we'll have to wait for Martin to get here:-)

[Steveo74]

Thanks Paul! Yes WOW indeed, I just pointed the camera and took 3 shots before it was gone. Never seen anything like it before, all taken at Ballycastle.

[John9929]

Afraid I can't help either Steve, never seen anything like that before, but what a catch, well done!

[Steveo74]

Thanks John!

[martinastro]

Wow indeed!. Those are impressive Steven, good job you had the camera close to hand to capture those. As for what they are...I simply don't know!. The white mid level cloud is a type of altocumulus, the dark lower cloud is either cumulus or broken stratocumulus, I suspect the curved formation could be some sort of accessory cloud under the cumulus perhaps drawn into a curve by a local area of vorticity or convergence zone but I'm blindly guessing. 

Bit of a tricky one. Brian, any ideas?.

Nice catch anyway!

Here's a couple of convective maps for today. Both these show broad areas of vorticity over N. Ireland today so this might have caused that effect.

[Steveo74]

Thanks Martin,
                    Would love to know what I captured, Looks weird!!

[brianb]

I suspect the curved formation could be some sort of accessory cloud under the cumulus perhaps drawn into a curve by a local area of vorticity or convergence zone but I'm blindly guessing.

Bit of a tricky one. Brian, any ideas?.

Not really, the only phenomena I've seen like that are shock waves ... you didn't hear a bang, did you? (Maybe up to a minute later)

The association with the position of the Sun appears to be "accidental" but it's possible that the effect would have been invisible if it occurred somewhere else in the sky i.e. it needed the Sun to be close by to make the "wall" visible.

It looks as though the effect is either disrupting the higher thin broken layer or is a seperate thin layer underneath it as the structure of the altocumulus (?) layer is fuzzed out in the vicinity. The presence of the iridescence suggests that the water droplets in the cloud are very uniform in size, which would suggest that the cloud is just forming. That, I think, is a clue to one possible cause - suppose a rising warm dry air bubble bursts through a thin layer of air which is saturated vapour without droplets, forcing it to rise & cooling it enough to start condensing, whilst the bubble of warm air passes through (and eventually makes its own cumulus head). But this is theoretical, as I say I've never seen it like this - the dimensions look about right for a typical weak thermal, though. What usually happens is that the warm air bubble is more humid than the surrounding air (because it's come from a warmer level, and has picked up more moisture) so it saturates & starts to condense rather than the air it drags up with it.

Really I don't know.

[Steveo74]

Hi Brian,
            No! didn't hear a bang but thanks all for your comments.