Significant Tornado Events

[Sawmaster]

There seems to be a much lower density of debris strewn about in those darker areas. In the lighter-colored areas much of the debris is light colored, Looking at less-affected areas I see very similar darkening. So this could just indicate debris patterns and not scouring, or it could be a combination of the two. Now I'll be looking at similar situations to see where the light and dark sections are and what they seem to indicate. Whatever prevails in that will likely be the same in Xenia.

 

[A Guy]

I recently had the... misfortune to stumble upon tornado-related sub-Reddits. Now aside from the general awful quality of discourse (dOn'T quEstIOn oFficIAl rAtiNgs) there seems to be a running theme of threads on what the Tri-State tornado may have looked like, or even people posting their own illustrations, some of which are... interesting.

Now most posters here have already come to the conclusion that it probably looked like a large, low based wedge tornado. Some time last year I read the excellent MWR paper on the Rossville, Kansas tornado family from 1960. This included an interesting passage:

"A number of people have been interviewed who saw the tornado in its formative or early stages; most of them had some difficulty in recognizing it as a tornado. That is, it either did not resemble tornadoes that they had seen previously or it did not correspond to their conception of what a tornado should look like. Most described it as a rather shapeless and poorly defined very dark mass hanging down out of the clouds. Others described it as a black mass resembling a huge cone or ball bulging down from the clouds which, after it carne to earth, seemed to resemble a truncated cone with its apex cut off at the ground and the lower portion obscured by the dust scarf which developed shortly after it hit the ground. Later it seemed to take on the appearance of a connection between the ground and the clouds such as a large pillar or column with its outlines greatly obscured by dust or cloud fragments."

Although perhaps not at the same lifecycle stage, I was strongly reminded of descriptions of the Tri-State tornado, and of course pictures it show a very wide dusty wedge. Particularly pertinent was the fact that people had trouble recognising it as a tornado because it wasn't a taller, narrower funnel. In 1925 not many people would've had photographs at hand, and fewer still a picture of a low, wide one like the 1913 Omaha tornado.

If we look at descriptions of the Tri-state tornado itself, there are many but W.O. Blanchard chose the following:

"The observer, F. M. Hewitt, of Carbondale, occupied a vantage point at DeSota [sic], directly in the path of the storm, which he first noticed when about three fourths of a mile to the southwest. He described the sky above the tornado as a seething boiling mass of clouds whose color changed con- stantly. From the upper portion, there came a roaring noise as of many trains. So definite seemed the source of the noise that it called for his remark to his two companions that the sound all seemed to "come from this upper part." Below this agitated, baggy-shaped mass of cloud, there was a tapering dark cloud mass reaching earthward. Lighter clouds flanked this dark mass upon either side. He estimated the width of the dark pendent portion as one fourth mile where it touched the earth."

Now I can't account for the roar not appearing to come directly from the tornado, but otherwise I think there's nothing exotic going on. From the photogrammetry I have seen, your regular wedge seems to be in the region of 250-300 metres across at the base - that's the condensation funnel - while 400 is getting on the wide side. Considering the width of heavy destruction, Hewitt might even have underestimated. The paper also cites state meteorologist Clarence Root, who advanced the theory of 'an inverted truncated cone' based on descriptions of the Mattoon and Lorain tornadoes, the latter in which the crew of a boat 'saw a very black cloud estimated at one-half mile wide at the water and much wider at the top".

Hewitt's description of a 'baggy shaped mass of cloud' from which the 'tapering mass' (i.e. the tornado itself) emanated makes me think it may actually have had a reasonably prominent wall cloud or mesocyclone base at that point. I have often seen people talk about it probably being rain wrapped etc. hence the odd descriptions and very long tracked rain wrapped tornadoes do happen (e.g Yazoo City). But from most descriptions I have read, it seems to me that most people saw the tornado itself, it just didn't meet their expectations as to what one should look like. After all, there's no particular reason to think that tornadoes then were any different from tornadoes now.

 

[CheeselandSkies]

"The observer, F. M. Hewitt, of Carbondale, occupied a vantage point at DeSota [sic], directly in the path of the storm, which he first noticed when about three fourths of a mile to the southwest. He described the sky above the tornado as a seething boiling mass of clouds whose color changed con- stantly. From the upper portion, there came a roaring noise as of many trains. So definite seemed the source of the noise that it called for his remark to his two companions that the sound all seemed to "come from this upper part." Below this agitated, baggy-shaped mass of cloud, there was a tapering dark cloud mass reaching earthward. Lighter clouds flanked this dark mass upon either side. He estimated the width of the dark pendent portion as one fourth mile where it touched the earth."

Now I can't account for the roar not appearing to come directly from the tornado, but otherwise I think there's nothing exotic going on.

Now that is interesting. As the Stoughton, WI tornado (rated high-end F3) of August 18, 2005 was approaching my neighborhood I could hear a sound that seemed to be emanating from the supercell updraft tower while the tornado was some distance away. It wasn't a roar per se, but a deep, rhythmic "ka-thump, ka-thump." I have since observed a similar sound with a couple of tornadic supercells while on chases. I didn't hear it with the Keota tornado (the only other time I've been in close proximity to a supercell producing an E/F3+ tornado); but it was difficult to hear anything else above the stiff inflow and ambient gradient winds.

 

[Casuarina Head]

There seems to be a much lower density of debris strewn about in those darker areas. In the lighter-colored areas much of the debris is light colored, Looking at less-affected areas I see very similar darkening. So this could just indicate debris patterns and not scouring, or it could be a combination of the two. Now I'll be looking at similar situations to see where the light and dark sections are and what they seem to indicate. Whatever prevails in that will likely be the same in Xenia.

@Sawmaster You do bring up an invaluable point: that debris-marks are very often mistaken for genuine scouring. In many cases debris rather than wind alone causes so-called “scouring,” or rather isolated holes or gouges in the earth (I believe this happened near Cayce, Kentucky, during the Mayfield EF4, for instance). More experienced observers like @buckeye05 can attest to this, and are a good check on more trigger-happy analysers. In this case, however, the Xenia tornado had largely encountered farmland before hitting the slabbed homes (in 1974 areas to the immediate southwest had not yet been developed, if I recall correctly). In fact the very first homes that it impacted in Xenia were rated F5 and were clustered around the “scoured” areas in the image above. The isoline analysis by Dr. Fujita, published in Chapter 3 (“Tornadoes: the Outbreak of 3–4 April 1974”) of Edwin Kessler’s The Tornado in Human Affairs (Norman: University of Oklahoma Press, 1983, p. 65), also shows this well.

 

[slenker]

@Sawmaster You do bring up an invaluable point: that debris-marks are very often mistaken for genuine scouring. In many cases debris rather than wind alone causes so-called “scouring,” or rather isolated holes or gouges in the earth (I believe this happened near Cayce, Kentucky, during the Mayfield EF4, for instance). More experienced observers like @buckeye05 can attest to this, and are a good check on more trigger-happy analysers. In this case, however, the Xenia tornado had largely encountered farmland before hitting the slabbed homes (in 1974 areas to the immediate southwest had not yet been developed, if I recall correctly). In fact the very first homes that it impacted in Xenia were rated F5 and were clustered around the “scoured” areas in the image above. The isoline analysis by Dr. Fujita, published in Chapter 3 (“Tornadoes: the Outbreak of 3–4 April 1974”) of Edwin Kessler’s The Tornado in Human Affairs (Norman: University of Oklahoma Press, 1983, p. 65), also shows this well.

I haven’t heard of that (debris mistaken for scouring) before but it makes so much more sense. While Mayfield did do some genuine scouring of the ground in that area, I was always very confused as to why there were random deep trenches in some spots that looked very out of place. I thought it would have had something more to do with subvortices hitting an extreme intensity maxima at that instant or something along those lines, but large debris impacting the ground and “trenching” it is a lot more of a realistic outcome.

 

[Western_KS_Wx]

This doesn’t relate to the current discussion whatsoever, but I found some interesting photos from the 2013 El Reno tornado detailing some pretty gnarly vehicle damage that occurred east of Highway 81. If anyone wondered what would happen if a vehicle was caught in a subvortex and subject to 300mph winds, this is a prime example:

This was once a truck that originated from a home east of Highway 81. According to the owner who took this photo, the frame of his truck pictured above landed over a mile away, and other fragments of the vehicle including the license plate were scattered over a 3 mile radius. Curiously, the home it came from only sustained EF1 damage.



This was all that could be recovered of a separate vehicle from the same area. Although few vehicles were subject to the most violent winds of the tornado, the ones that did encounter these winds were quite literally pulverized to bits.




These are all from where the TWISTEX vehicle was recovered and along I-40 where fatalities occurred in these vehicles.

 

[Sawmaster]

On-site inspection can determine which is scouring and which is from debris-impact trenching very well, but we're missing that perspective from this part of Xenia and with many of the other storms which occurred long ago. Thus we need to be cautious trying to infer which is which from distant photographs that do not show enough detail as we keep an open mind to all the possibilities.

 

[Western_KS_Wx]

But from most descriptions I have read, it seems to me that most people saw the tornado itself, it just didn't meet their expectations as to what one should look like. After all, there's no particular reason to think that tornadoes then were any different from tornadoes now.

This part right here. Back then people really only had depictions of what a tornado looked like based off what people told them, and unless you lived in some heavily tornado prone area you probably didn’t have a singular clue what the hell a tornado looked like.

I’d like to imagine they were told of picturesque cone tornadoes that were highly visible, so it’s no wonder they didn’t know what they were looking at when a giant low-hanging wedge obscured by rain was barreling toward them at 60-70mph. That’s also probably why in some older accounts of tornadoes people literally thought they were being under attack by god or some higher power.

If the Tuscaloosa tornado occurred in that age and people witnessed it at the stage it was in as it impacted Birmingham where essentially the whole mesocyclone dropped to the ground and it looked like a giant black wall, you likely would’ve heard some biblical descriptions.

 

[HAwkmoon]

This doesn’t relate to the current discussion whatsoever, but I found some interesting photos from the 2013 El Reno tornado detailing some pretty gnarly vehicle damage that occurred east of Highway 81. If anyone wondered what would happen if a vehicle was caught in a subvortex and subject to 300mph winds, this is a prime example:
View attachment 28401
This was once a truck that originated from a home east of Highway 81. According to the owner who took this photo, the frame of his truck pictured above landed over a mile away, and other fragments of the vehicle including the license plate were scattered over a 3 mile radius. Curiously, the home it came from only sustained EF1 damage.

View attachment 28402
View attachment 28403
This was all that could be recovered of a separate vehicle from the same area. Although few vehicles were subject to the most violent winds of the tornado, the ones that did encounter these winds were quite literally pulverized to bits.

View attachment 28404
View attachment 28405View attachment 28406View attachment 28407View attachment 28408
View attachment 28409
These are all from where the TWISTEX vehicle was recovered and along I-40 where fatalities occurred in these vehicles

Amazing finds. Henderson's truck is a new one and that vehicle at the top is some pretty severe mangling.

 

[Casuarina Head]

I haven’t heard of that (debris mistaken for scouring) before but it makes so much more sense. While Mayfield did do some genuine scouring of the ground in that area, I was always very confused as to why there were random deep trenches in some spots that looked very out of place. I thought it would have had something more to do with subvortices hitting an extreme intensity maxima at that instant or something along those lines, but large debris impacting the ground and “trenching” it is a lot more of a realistic outcome.

@slenker The thing is, discerning between localised debris- and vortex-marks requires considerable context. Besides proximity to varying types of debris (structural, vegetative, etc.), another determinant is soil-type, along with season. @buckeye05 made a good point about soil and its influence on scouring some time ago, as well as the fact that genuine scouring removes surface-based vegetation (I admit that I am guilty of stretching the definition of scouring before, as well as of confusing debris-marks with scouring, so I must take this into account—while not making judgments based on incomplete data derived from inconclusive imagery). Interestingly, both the Cayce and Philadelphia tornadoes, according to soil-maps, scoured somewhat similar soils in open fields. Both southwestern KY and northeastern MS are dominated by Coastal Plain-type soils, which are typically well weathered, low in nutrients, and sandy or clayey. However, Philadelphia, if I recall correctly, affected pasture, whereas Cayce impacted cropland, and this makes a difference. This is why Philadelphia’s case, regardless of debris, is much more imposing than Case’s.

 

[Western_KS_Wx]

Amazing finds. Henderson's truck is a new one and that vehicle at the top is some pretty severe mangling.

There were some claims from homeowners in the area saying they never recovered their vehicles, and that some of the cars landed ‘a couple miles away’, how much validity there is to that I’m not sure but I wouldn’t be surprised given just how violent those subvortices were.

Vegetation damage along the whole track even under the spots with the highest DOW velocities was really not that impressive, but given the fact that subvortices were also moving 160-180mph and had a fraction of a second to do any sort of damage it makes sense. Also wonder if the ground speed and very concentrated area of extreme winds played a factor in the severity of the vehicle damage. I’d imagine any vehicle or object that became airborne and encountered the incredibly high wind velocities in those vortices just flat out disintegrated. But yeah the vehicle damage from the tornado was seriously violent in some instances, well on par with past EF4-5 tornadoes.

 

[locomusic01]

@locomusic01 Re: Xenia: note these dark splotches near the slabbed foundations. (Incidentally, several of the slabs fall within the F5 isoline contour plotted by Dr. Fujita for Xenia [see Kessler 1983, p. 65], bounded roughly by Gayhart, Commonwealth, and Roxbury Drives.) The contrast between the adjacent lawns and these splotches is as striking as the difference in structural damage. So there are, in my view, grounds to believe that these splotches represent genuine and rather intense scouring. I wouldn’t put it on the same level as that of other (urban) events, e.g., Moore 2013, but the similarity in pattern is rather evident. Some of those lawns near the slabs literally appear to have been reduced to mud and/or nearly bare soil in Xenia’s case. I really wish there were a closer view of those slabs.

I think a lot of that is probably tracks from vehicles and/or heavy machinery. You can see something similar here just north of that area, especially between Gayhart & Wyoming:

Here's another view of the original area:

Seems notable that that particular area is totally cleared of debris, and it appears a bunch of cars have been moved there (I doubt so many were collected in that specific area by the tornado itself). I'm sure I've got ground-level photos from somewhere around that area; I'll look later and see what I can find.

 

[locomusic01]

@Sawmaster You do bring up an invaluable point: that debris-marks are very often mistaken for genuine scouring. In many cases debris rather than wind alone causes so-called “scouring,” or rather isolated holes or gouges in the earth (I believe this happened near Cayce, Kentucky, during the Mayfield EF4, for instance). More experienced observers like @buckeye05 can attest to this, and are a good check on more trigger-happy analysers. In this case, however, the Xenia tornado had largely encountered farmland before hitting the slabbed homes (in 1974 areas to the immediate southwest had not yet been developed, if I recall correctly). In fact the very first homes that it impacted in Xenia were rated F5 and were clustered around the “scoured” areas in the image above. The isoline analysis by Dr. Fujita, published in Chapter 3 (“Tornadoes: the Outbreak of 3–4 April 1974”) of Edwin Kessler’s The Tornado in Human Affairs (Norman: University of Oklahoma Press, 1983, p. 65), also shows this well.

It didn't encounter a whole lot prior to entering Windsor Park, but it did destroy a number of houses and farms SW of the city. The damage was actually pretty impressive at some of them, although definitely nothing like Windsor Park/Arrowhead.

 

[locomusic01]

Okay, last one lol. I just skimmed through some of the aerial photos quick and noticed one from before the cleanup occurred (or before much cleanup, anyway) - it's in black & white, but there doesn't seem to be any evident scouring/dark splotches in that area. In fact, the only darker patch (corner of Hook Rd & Commonwealth Dr) is where it looks like heavy machinery has been through because you can see the tracks across the foundation on the corner lot:

 

[Casuarina Head]

@locomusic01 Now that I think about it and look more closely, I think that there really isn’t much, if any, hard evidence of genuine scouring (vegetative removal) in Xenia, or even much soil removal. I do see that some lawns look greyish-brownish in a different fashion (i.e., at the intersection of Texas and Nebraska Drives, on either side), but if not vehicles, that could be due to other factors besides scouring. Is there a way to tell whether that shows genuine scouring of at least some grass? I would like to learn how to better question myself about details on aerials so that I know how to avoid making errors that lead to erroneous assumptions.

 

[locomusic01]

@locomusic01 Now that I think about it and look more closely, I think that there really isn’t much, if any, hard evidence of genuine scouring (vegetative removal) in Xenia, or even much soil removal. I do see that some lawns look greyish-brownish in a different fashion (i.e., at the intersection of Texas and Nebraska Drives, on either side), but if not vehicles, that could be due to other factors besides scouring. Is there a way to tell whether that shows genuine scouring of at least some grass? I would like to learn how to better question myself about details on aerials so that I know how to avoid making errors that lead to erroneous assumptions.

It's really hard to accurately identify scouring from aerials alone (except in some really obvious cases, of course). Even ground-level photos can be pretty ambiguous. There are just so many reasons the ground might look discolored/disturbed (actual scouring, debris impacts, vehicle/equipment tracks, dead grass or soil that was already bare for whatever reason, dirt deposited on top of the grass, grass flattened to the ground but not scoured, etc). You can be more confident if there are accounts confirming that scouring occurred in a particular place, although it's not always mentioned even when it does occur.

In this specific case, I've noticed that a lot of the aerials in that series of photos have that kind of look. Not entirely sure why, but I'm skeptical that it's actually scouring. You can also see it in places here around the Hamlet Dr & Marshall Dr area in a neighborhood in northeast Xenia (the name of which escapes me at the moment):

Any discoloration/apparent scouring is a lot less noticeable in other views, like this one (same area but looking more E instead of S):

If you look closely, you can also see a few areas in Wilberforce from the first photo series that seem to show vaguely scouring-like discolorations, but I don't think that's what they are in reality:

 

[slenker]

Regarding the Mayfield tornado, I do believe true scouring occurred still, it just was not to an incredible degree like in certain EF5 or F5 events of the past. It may have also been harder to identify the “true” level of scouring due to the conditions of the soil and the time of year it occurred in. However, it definitely wasn’t anywhere close to tornadoes like Moore 2013 or Philadelphia in terms of ground damage.

Also, on a side note, I don’t particularly understand why some people view Moore as a lower end of the EF5 threshold, as that tornado did some absolutely ridiculous ground scouring. I would genuinely put it above Joplin in terms of intensity - the damage at Orr family farm and Celestial acres was comparable to the worst of the worst, imo.

 

[locomusic01]

Regarding the Mayfield tornado, I do believe true scouring occurred still, it just was not to an incredible degree like in certain EF5 or F5 events of the past. It may have also been harder to identify the “true” level of scouring due to the conditions of the soil and the time of year it occurred in. However, it definitely wasn’t anywhere close to tornadoes like Moore 2013 or Philadelphia in terms of ground damage.

Also, on a side note, I don’t particularly understand why some people view Moore as a lower end of the EF5 threshold, as that tornado did some absolutely ridiculous ground scouring. I would genuinely put it above Joplin in terms of intensity - the damage at Orr family farm and Celestial acres was comparable to the worst of the worst, imo.

Moore is pretty much on the same level as Bridge Creek, or very nearly so. Aside from obvious context clues, I think you'd have a hard time telling them apart if you mixed their photos together. It's honestly pretty eerie.

 

[Maxis_s]

Regarding the Mayfield tornado, I do believe true scouring occurred still, it just was not to an incredible degree like in certain EF5 or F5 events of the past. It may have also been harder to identify the “true” level of scouring due to the conditions of the soil and the time of year it occurred in. However, it definitely wasn’t anywhere close to tornadoes like Moore 2013 or Philadelphia in terms of ground damage.

Also, on a side note, I don’t particularly understand why some people view Moore as a lower end of the EF5 threshold, as that tornado did some absolutely ridiculous ground scouring. I would genuinely put it above Joplin in terms of intensity - the damage at Orr family farm and Celestial acres was comparable to the worst of the worst, imo.

I haven't seen those photos of ground scouring or extreme damage myself, could you share them or link me to an existing post of those images?

 

[slenker]

I haven't seen those photos of ground scouring or extreme damage myself, could you share them or link me to an existing post of those images?

This Reddit post has imagery from the celestial acres area. Extreme vehicle mangling and insane ground scouring is evident here. I’d say it’s at least on par with Joplin, but I’d wager it’s more intense than that.