Horseshoe vortex 'unraveling'
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Hi, all. New to the site, due to an encounter with a horseshoe vortex last Friday. Did not know what I was seeing. From sighting, perhaps 30 seconds were spent driving to a small clearing and parking. I then walked while powering the camera, checking settings and locking down infinity focus manually. It took 15 or 20 seconds for me to feel ready to shoot. I looked up, saw the object, centered it, and pressed the release, having overlooked the self-timer. To the estimates above, add two seconds. Waiting for the exposure to happen, or soon thereafter, I realized that I had walked to a terrible location, power lines and their pole fairly dominating my wide frame. The first exposure is timestamped 5:10:14 pm.
Waffling (such a nit-wit!) between “got it” (I was on my way somewhere) and, seeing that the phenomenon was persisting, another shot with more open sky and me more ready, I spent another 38 seconds before a second exposure. A Crop from that later image is shown below. Feeling I had a good image, I went back to my vehicle, thinking the vantage from the ridge top would be best. But I hadn’t started driving before looking back, maybe a minute after the second picture, to see the vortex disintegrated, and I regret not photographing the rubble.
I vaguely remember, eons ago, seeing a curious tiny distant ‘arch’ of clouds, either in the sky or in a photo I was editing, I can’t be sure. But what happened last Friday was my first close encounter, without any doubt.
Would love to discuss the theory of these events, if members might indulge someone considering it for the first time. The details of the image suggest to me that a horseshoe is, in simplest terms, a vortex within a vortex. Is this so? Other aspects of the image imply additional complexities, but uncertain in some instances whether I’m seeing facts or image artifacts, I would very much appreciation reading what others know about the phenomenon and see in this fortuitous image:
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Congrats epshulz! The HV is amazing to witness. I’ve seen a few. But..what makes them.. is invisible according to the latest..Imagine a roller of air..horizontal..a column of air rolling along horizontally. The ” cloud” that we call a horizontal vortex,,is created at the top of the rolling air column and eventually the ends of it drop forming the downward arms creating the Horseshoe appearance, or upside down U. The column of horizontal air may last awhile or not. I’ve seen vortexes that last a 5 minutes and some that lasted 30 to 45 seconds.
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Thank you, Michael. No one in my extended family of many experienced nature observers had seen one. And what you say about it being made by something invisible fits the evidence of the photo, since the object becomes progressively transparent, from a fairly dense core to a nearly “invisible” nimbus, but the movement, and its ensuing structure, extend beyond what is whitened with mists, no doubt.
For this very reason, my first photograph of the HV (thanks for the acronym!) I had rejected on first inspection as blurry, not appreciating how, rather than a blurry shot of a distinct object, it might be a clear image of a quasi-invisible object. Because its quasi-transparent structures are, understandably, scarcely separable from the background, the extreme contrast needed to bring them into relief causes nearby shades in the sky gradient to break apart, an ill that seems less unpleasant in a monochrome rendering.
Most noticeably, seen 38 seconds earlier, the thickened part of the upper branch was much more tightly wound–practically a cylinder–in comparison with its unfurled state in the later picture posted above.
Also of note, from near the center of the image extending upward are two smaller, darker ‘arms’ that appear to come together at the tips, like two wires twisted together (the general shape also suggests the little ribbons worn to endorse various causes). The arm curving in front has visible undulations of its outer edge, resembling the “Michelin Man” outline visible in other parts of this image, and more so in the image previously posted. I mention this as it suggests that the small arm is itself a vortex, one of a pair of vortices spawned from the HV proper. If these features of the image correspond with actual structures correctly identified, I wonder if vortices spawned in pairs, pairs that seem bent on joining at the tips, if of sufficient energy and duration to actually join into one arching structure… Seeing things that aren’t there, perhaps.
I only noticed this HV in its final moments, and wish I had known not to take my eyes and lens off of it. And Michael, with utmost appreciation for the knowledge and experience you shared, indulge my curiosity: in your multiple sightings, did you see one bend from horizontal to horseshoe?
Thanks again for your reply. Here, then, is the same HV in monochrome and 38 seconds earlier.
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Eric, I can’t say I’ve seen a HV from the very beginning. I have seen one or two evolve from slightly bent to full arms to wobbly ribbon of flapping then to gone, dissipated back from which it came. But most have been full horseshoe by the time I recognize them.I’ve kept an eye for them especially when there is fast moving layers of cloud. I’ve noticed HV tend to occur on the edges of active clouds as in contorted or undulating etc. Its like looking for pileus. One learns when conditions are right and where to look for just a smudge signalling the beginning. And yes..I’ve learned don’t take the camera away until its over. The Gallery would make it seem HV are common until you look at the dates of the Pictures. There are cloudspotters who have never seen one.
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Well heck!…This afternoon I noticed the clouds where A) low cumulus B) coming down from the north north east rather than from the normal west. C) Winds at cloud level , 3kft to 5ft+, appeared rather strong, bending cloud tops over in wave form..D) one area of the sky just north and east of me, appeared rather turbulent. So ..i kept my eyes open. With a little patience, maybe 30 minutes of lawn and gardening, there it was. A large one, well a close one, a classic horseshoe in the sky just about center of the earlier turbulent area.How strange I thought as I took a pic or two, just posting about these at CAS. It lasted for over 2 minutes. I didn’t see it evaporate due to a lower cloud swept under it hiding its demise from me. Once again when weather comes from a rare direction expect a rare spotting!
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Thank you, Keelin. It was a beauty. The conversationally easy cliche would be to add, and so fleeting! But while it was happening, it seemed quit long-lasting. Maybe my first expectation was for it to vanish before I could focus my eyes.
Exploring the site, I’ve already come across many wonderful photos of yours, and Michael’s, and look forward to seeing more!
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Quite so, Hans, and Michael’s splendid demonstration gives me hope that with an understanding of the phenomenon and greater awareness of local conditions, we can improve our luck. If relying on luck to see another HV takes me another 60 years, I’m afraid I will have lost interest. But kidding aside, I’d like to know your opinion: assuming I understand and can follow Michael’s advice and cloud watch mindfully, do you put my odds of seeing another HV down with those of winning the lottery?
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Haha, in my opinion you don’t have to live another 60 years to have a second close encounter with a horseshoe vortex, Eric.
At the moment I started cloudspotting some 4 years ago it seemed a sheer impossible thing to observe, but now I count two experiences. When one don’t know about the existence one will not observe it, but when one is looking for something, one will find it more often …. and certainly with the helpful description of circumstances Michael gave.
A striking example of what I also estimated as really rare was a circumzenithal arc (CZA). When you don’t know about the existence of this phenomenon you won’t look op at the zenith where it might be. As soon as I knew about the circumstances of this and other arcs you will look up and observe them more then you might expect. I don’t count anymore the times I saw a CZA. I guess to see it about 5 to 10 times a year. The same applies to Kelvin Helmholtz, etc.
To end with I think that the HV is mainly so rare because it is so short lived. To see it develop must be luck. To see it disintegrate after having its characteristic shape is “easier” to observe I suppose. Of all the cloud features this must be the most rare, but nevertheless occurring enough to let it catch by a keen observer. So good luck with the lottery. Your odds are pretty good.
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Not to contradict Hans … I too did not think I would see a horseshoe vortex and then I saw two on two consecutive days after about a year of cloud spotting. But they were remote and rather simple.
What you got there, EP, is a beauty. Not saying it’s unlikley to see another like it but …
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