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locomusic01

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Those brown patches in the grass; is that scouring or just partially plowed-grass? Also, the descriptions of this thing blasting trees down to stumps and severe ground scouring reminds me of some of the accounts in Missouri and Illinois of the Tri-State tornado, and of course, just like that tornado, it's also hard to find photographs of F4-F5 damage with this tornado.
They're just ruts from a tractor - you can see one of its rear wheels off to the right. I've found lots of reports of severe crop damage but nothing conclusive re: ground scouring. Apparently some of the yards in the Tottenham area (near the home I posted a while back that was blown away except for a toilet) were "torn up" but that's kinda ambiguous.

This area here made me wonder a bit, but it's hard to tell for sure what it shows:

8EoG0lJ.jpg


EI3Tp9B.jpg


That's basically the path the center of the tornado took, and probably about the same width as the core, but it's hard to imagine it being that extreme. Especially given the 55-60 mph forward speed and the relative lack of debris sources upstream (a few houses were demolished but they're pretty sparse). On the other hand, a guy who lived in the area said that he didn't remember there being anything like that before the tornado but he couldn't say for sure. I dunno.
 

buckeye05

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Some of the most intense vehicle damage I could find from Tuscaloosa 2011 (with some scouring?)
View attachment 10532
That looks like legit scouring to me, albeit not the most severe I’ve seen. Tuscaloosa/Birmingham didn’t produce much ground scouring as far as I know. The worst that I saw was in a grassy area right next to Alberta Elementary In Tuscaloosa, which was almost totally leveled. There’s an aerial photo in Tim Marshall’s survey that shows the swath of scouring by the school quite clearly.
 

TH2002

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That looks like legit scouring to me, albeit not the most severe I’ve seen. Tuscaloosa/Birmingham didn’t produce much ground scouring as far as I know. The worst that I saw was in a grassy area right next to Alberta Elementary In Tuscaloosa, which was almost totally leveled. There’s an aerial photo in Tim Marshall’s survey that shows the swath of scouring by the school quite clearly.
If you are talking about this photo there does appear to be some scouring:
tuscaloosa-ef5-tornado-damage.png

On another note, at first glance one could assume the school qualified for an EF5 rating but I believe Tim Marshall went with EF4 due to subpar construction.

As far as violent tornadoes are concerned Tuscaloosa's strongest points were the wind rowing, debarking and heavy objects being tossed while its weakest points were the lack of very intense scouring and vehicle damage. Don't get me wrong, the vehicle damage is pretty bad but I have failed to find any photos of vehicles totally mangled beyond recognition.
 
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That looks like legit scouring to me, albeit not the most severe I’ve seen. Tuscaloosa/Birmingham didn’t produce much ground scouring as far as I know. The worst that I saw was in a grassy area right next to Alberta Elementary In Tuscaloosa, which was almost totally leveled. There’s an aerial photo in Tim Marshall’s survey that shows the swath of scouring by the school quite clearly.
I don't always agree with Tim Marshall on everything either. Westminster 2006 was his worst survey ever and how he could make a mistake that big! It makes me wonder if someone else could have happened and the desire to get rid of the F-SCALE to prove that it doesn't work by lowballing tornadoes. I also agree more with the windspeeds for the F-SCALE.
 

TH2002

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Photos of the home swept away on Holt Peterson Road in Tuscaloosa. In the ground level photos some cleanup has taken place, but the aerial photo proves it was swept away by the tornado and not bulldozers.
Tuscaloosa-EF5-damage-home.JPG
Tuscaloosa-damage-holt-peterson.JPG
Tuscaloosa-damage-holt-peterson2.JPG
Tuscaloosa-damage-holt-peterson3.JPG
Not going to make any assumptions on what it should or shouldn't have been rated though because I don't want this thread to devolve into an "EF4 vs EF5" argument for Tuscaloosa again.
 

buckeye05

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I don't always agree with Tim Marshall on everything either. Westminster 2006 was his worst survey ever and how he could make a mistake that big! It makes me wonder if someone else could have happened and the desire to get rid of the F-SCALE to prove that it doesn't work by lowballing tornadoes. I also agree more with the windspeeds for the F-SCALE.
Yeah any way you slice it, Westminster was inexcusable. I think Westminster was a “we’ve overcorrected and need to fix this” moment. While the EF scale isn’t perfect, it’s generally better than the post La Plata dark ages of tornado ratings.
 
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Yeah any way you slice it, Westminster was inexcusable. I think Westminster was a “we’ve overcorrected and need to fix this” moment. While the EF scale isn’t perfect, it’s generally better than the post La Plata dark ages of tornado ratings.
I just wonder about the winds because Hurricane Andrew had wind gusts of over 200 mph at times and I have never seen anything that matches the power of an F5 or EF5 tornado!
 
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I’m slowly coming around to the idea of EF5 being more appropriate for Tuscaloosa/Birmingham tbh. From what I’ve heard, TornadoTalk dug up some info that has me more on board with the idea. I’ll leave it at that.
I'll have to subscribe to TornadoTalk at some point, from back in this thread it does seem like Tuscaloosa MAY have caused EF5 damage to some remote countryside houses or other buildings in the areas between Tuscaloosa and Birmingham, where it likely hit peak intensity, but the remote nature and rugged terrain of that vast area prevented damage surveyors from being able to fully access these spots, or made them easy to miss.
 

locomusic01

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I just wonder about the winds because Hurricane Andrew had wind gusts of over 200 mph at times and I have never seen anything that matches the power of an F5 or EF5 tornado!
Even when the wind speeds are broadly similar, the dynamics are quite different. Tornadic winds have a very intense vertical component and tend to involve more extreme accelerations, which produces greater dynamic wind loads and pressure fluctuations. And obviously debris is a major factor as well - large missiles cause a lot of damage, but the huge volumes of smaller debris inside violent tornadoes can also massively increase their destructive potential. For the most part, you don't really get that in hurricanes. Hurricane-prone areas also have stronger building codes, so you'd expect the structures they impact to be more wind-resistant overall.

All that being said, there's really no doubt we're underestimating the strength of tornadoes in general. We just don't yet have a way to reliably correct for that. All the EF-scale can really tell us is the approximate wind speed at which a structure failed, which is pretty unlikely to be the maximum intensity of the tornado itself.
 
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Even when the wind speeds are broadly similar, the dynamics are quite different. Tornadic winds have a very intense vertical component and tend to involve more extreme accelerations, which produces greater dynamic wind loads and pressure fluctuations. And obviously debris is a major factor as well - large missiles cause a lot of damage, but the huge volumes of smaller debris inside violent tornadoes can also massively increase their destructive potential. For the most part, you don't really get that in hurricanes. Hurricane-prone areas also have stronger building codes, so you'd expect the structures they impact to be more wind-resistant overall.

All that being said, there's really no doubt we're underestimating the strength of tornadoes in general. We just don't yet have a way to reliably correct for that. All the EF-scale can really tell us is the approximate wind speed at which a structure failed, which is pretty unlikely to be the maximum intensity of the tornado itself.
I think a better compromise would be for a windspeed for EF5 would be somewhere between the EF-SCALE windspeed and the F-SCALE windspeed for an F5. So roughly 230 to 235 mph.
 

pohnpei

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Even when the wind speeds are broadly similar, the dynamics are quite different. Tornadic winds have a very intense vertical component and tend to involve more extreme accelerations, which produces greater dynamic wind loads and pressure fluctuations. And obviously debris is a major factor as well - large missiles cause a lot of damage, but the huge volumes of smaller debris inside violent tornadoes can also massively increase their destructive potential. For the most part, you don't really get that in hurricanes. Hurricane-prone areas also have stronger building codes, so you'd expect the structures they impact to be more wind-resistant overall.

All that being said, there's really no doubt we're underestimating the strength of tornadoes in general. We just don't yet have a way to reliably correct for that. All the EF-scale can really tell us is the approximate wind speed at which a structure failed, which is pretty unlikely to be the maximum intensity of the tornado itself.
I think the extremity of tornadic winds can be perfectly reflected in our discussion about duration. One can always argue 10 second or 2-3 minutes makes a huge difference in tornado damage and It played a major role in Jarrell's ultimate unimagiable damage or smithville made all these destruction under 5 or 10s which was incredible. Such discussion means almost nothing in hurricane's wind damage. And it's hard to see the difference between 10 mins hurricane winds and 10 hours hurricane winds in terms of destruction.
 

MNTornadoGuy

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A report on the Hodonin tornado was just released and it revealed some interesting cases of damage. https://www.chmi.cz/files/portal/docs/tiskove_zpravy/2021/Souhrnna_zprava_tornado_24.6.2021.pdf
1DC6B050-43C7-4DB6-B44F-A5CB1A916ABA.pngShipping container that was thrown an unknown distance and mangled.
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unknown.png

Car that was tossed into a field and had its engine block torn out and thrown several hundred yards.
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unknown.png

Reinforced concrete ceiling slabs were torn out and thrown tens of yards into a field at these farm buildings. A load-bearing reinforced concrete structure was also severely damaged here.
 

MNTornadoGuy

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A report on the Hodonin tornado was just released and it revealed some interesting cases of damage. https://www.chmi.cz/files/portal/docs/tiskove_zpravy/2021/Souhrnna_zprava_tornado_24.6.2021.pdf
View attachment 10563Shipping container that was thrown an unknown distance and mangled.
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unknown.png

Car that was tossed into a field and had its engine block torn out and thrown several hundred yards.
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unknown.png

Reinforced concrete ceiling slabs were torn out and thrown tens of yards into a field at these farm buildings. A load-bearing reinforced concrete structure was also severely damaged here.
I believe that Hodonin is likely one of the most violent tornadoes of the year with only those Inner Mongolian tornadoes also being contenders for the most violent tornado of the year so far.
 

MNTornadoGuy

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Also speaking of the Inner Mongolian tornadoes, have they been rated yet or has any new information come out about them. Same for those China tornadoes from the July outbreak.
 
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