The Most Unusual Tornado Sound I've Ever Heard

[Mike Smith]

Scott Peake has an amazing capture of a drill bit tornado and the damaging sound it makes when it loses contact with the ground.

https://twitter.com/i/web/status/1425631314259156995

It sounds like the SFX used in The Adventures of Superman when George Reeves landed.

Any thoughts?

 

[JamesCaruso]

That is really amazing, I’ve never heard anything like that. I haven’t *seen* anything like that either - the quick, narrow and bright white appearance of that suction vortex right when you hear the sound and it lifts. One could almost mistake it for a lightning strike.

You can’t hear it as well in the portion where Scott shows it in slo-mo, and it doesn’t look quite as impressive either. The beginning and ending of the video in real-time speed are better.

 

[Jeff Duda]

Our own Billy Faletti also captured this from the other direction and slightly further away, but you can definitely still hear it. Others replying to him claim to have heard it as well, so there seems to be consensus on this:

https://twitter.com/i/web/status/1425812342747639812

 

[Ethan Schisler]

I don't shoot much video, but I was nearby as well and could hear it quite loudly too. Struck me as unusual for what appeared to be a lower end tornado to hear such an audible roar.

 

[Jeff Duda]

I suspect there was a rapid and high-magnitude pressure change in the vicinity of the dying vortex that essentially created a sonic boom.

Could have potentially been on the order of a few tens of millibars, which could have produced instantaneous pressure gradient forces similar to those produced by the sound wave created by a lightning strike rapidly heating the air in the channel.

Mathematically, I'm thinking of PGF ~ 1e1 mb / 1e0 m = 1000 Pa / 1 m = 1e4 kg/(m^2*s^2). Synoptic scale pressure gradients are more like 1e1 mb / 1e6 m = 1e-5 kg/(m^2*s^2), so...9 orders of magnitude lower! When applying the inverse of air density to get an acceleration (rho ~ 1 kg / m^3 at low elevations), you're still looking at instantaneous accelerations of 10000 m/s^2! That'll get you some sound waves fo' sho.

 

[Andy Wehrle]

As usual, I managed to miss this tornado by being lazy. I had already driven north after the early storms (Monroe County) and aborted the attempt noting that (a) the terrain was awful up there and (b) any tornado would dissipate before I could reach it. I looped back through the equally horrible terrain of Sauk County and along the Wisconsin River, and passed through Barneveld before sitting in Mt. Horeb watching the storms on radar. The consensus seemed to be that slightly too strong capping/slightly weaker instabililty than forecast was preventing storms from taking off as expected, and although I noted what appeared to be some subtle rotation on radar about 15-20 minutes before the tornado warning went out, I expected it would soon dissipate and didn't want to get suckered back out further from home when I was less than half an hour from there. I work 3AM-noon which means that while I can chase during the afternoon/evenings, I am usually very tired. This also influenced my decision to start for home after seeing the first tornado near Clare/Kirland, IL on Monday after storms appeared to be becoming HP, not expecting another supercell to follow almost the exact same path 40 minutes later and produce the Esmond/Sycamore tornadoes.

 

[Greg McLaughlin]

Gabe Garfield posted a link to this research paper on Twitter:

https://t.co/QDVL3KoVgy?amp=1

This paper seems to suggest precisely what occurred with the Mineral Point, WI tornado. Amazing stuff. I am sure like many of you, I have observed vortex breakdown on several occasions and have video documentation. I have never seen/heard anything like what the above videos show.

 

[JamesCaruso]

I did not read in detail the paper @Greg McLaughlin posted (and won’t pretend I would even be able to comprehend it), but for me it raises the question, was the sound in the Mineral Point video an actual sonic boom caused by transonic wind speeds, or simply a ”suction” noise, kind of like the sound my central vacuum system makes, when I pull the hose out of the wall and it automatically shuts off? Maybe technically a sonic boom in either case, bit a different mechanism?

 

[Andy Wehrle]

I did not read in detail the paper @Greg McLaughlin posted (and won’t pretend I would even be able to comprehend it), but for me it raises the question, was the sound in the Mineral Point video an actual sonic boom caused by transonic wind speeds, or simply a ”suction” noise, kind of like the sound my central vacuum system makes, when I pull the hose out of the wall and it automatically shuts off? Maybe technically a sonic boom in either case, bit a different mechanism?

 

[Boris Konon]

I suspect there was a rapid and high-magnitude pressure change in the vicinity of the dying vortex that essentially created a sonic boom.

Could have potentially been on the order of a few tens of millibars, which could have produced instantaneous pressure gradient forces similar to those produced by the sound wave created by a lightning strike rapidly heating the air in the channel.

Mathematically, I'm thinking of PGF ~ 1e1 mb / 1e0 m = 1000 Pa / 1 m = 1e4 kg/(m^2*s^2). Synoptic scale pressure gradients are more like 1e1 mb / 1e6 m = 1e-5 kg/(m^2*s^2), so...9 orders of magnitude lower! When applying the inverse of air density to get an acceleration (rho ~ 1 kg / m^3 at low elevations), you're still looking at instantaneous accelerations of 10000 m/s^2! That'll get you some sound waves fo' sho.

Would this vortex breakdown noise be akin to when one opens a sealed jar, and you get that "whoosh" noise?

 

[Jeff Duda]

I honestly don't know, Boris, but it seems plausible.

 

[Dan Rupnow]

I can also attest to hearing the "whoosh-boom" of this tornado in person. Very interesting in Scott's video to see the tree nearest the vortex react in rhythm with the sound. Some major pressure changes occurring for sure! My question is what would cause such a sudden and complete vortex breakdown such as this? I don't think I've ever seen a tornado "vaporize" so quickly!

 

[Jeff Duda]

I can also attest to hearing the "whoosh-boom" of this tornado in person. Very interesting in Scott's video to see the tree nearest the vortex react in rhythm with the sound. Some major pressure changes occurring for sure! My question is what would cause such a sudden and complete vortex breakdown such as this? I don't think I've ever seen a tornado "vaporize" so quickly!

That's a great observation that I hadn't noticed before! Now I'm curious what the corn in that area looks like after the fact - is there 360-degree convergence on a spot or does it retain the more spiral shape typical of tornadic wind flows?

 

[Dean Baron]

It looks like the tornado instantaneously strengthens for that half second or so and then vanishes. Would such a quick strengthening cause a pressure gradient big enough to actually be heard? The tornado actually looks pretty violent when it's "vaporizing." It would be really interesting to know what the winds were during that short period. Wish I had access to the HD video and could look at it frame by frame.

 

[Jeff Wright]

Vortex breakdown perhaps…the low was filled and it is muffled (not quite) thunder.

A true thunderclap sounds like clapping or a gunshot..then the rumbling.

Now I have wondered…if a poor soul was somehow tied down to something…could a suction spot tear flesh…can a horizontal vortex reach into a structure almost like a tentacle. These things seem more and more Lovecraftian…

I wonder if HPL was influenced by Tri-State…mid March of 1925 was the time of Call of Cthulhu…

 

[Tom Mitchell]

While I cannot say I have experience with hearing this from a weather event, this sounds exactly like the vortices that occur with the passing of airliners. I often go to a beach which is directly under the approach path about 4000 ft from the runway threshold. Here is a video, not mine, but you can hear the crack of the vortices:

wingtip vortices sound