I’m referring to houses with masonry walls that aren’t reinforced with metal or extra concrete, which can lead to exterior wall failure at wind speeds as low as EF1.
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Shakespeare 2016
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At the very most you maybe could have squeezed a low-end EF4 rating out of it but if the building was of poor construction then EF3 would be the right call.
Shakespeare 2016
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Ok, but are cookie cutter homes much easier to sweep away vs large well-built well-anchored brick homes?
Shakespeare 2016
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Ok, So basically poor attachment to the walls using cheaper construction or something like that.
joshoctober16
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a other bothersome issue is ... there is no official way to classify a tornado except for the EF scale ... and the EF scale has so much issues and contradictions (wind speed is almost all the time stronger then what its officially rated, and too strict, use contextual to downgrade but not upgrade) it isn't helping the EF scale has pretty much become a FIND any reason to rate it low and NOT most likely (average/mean).
Currently the real measured Average/Mean is the black solid line , and the EF scale predicted winds are the Dash line , top left gray background color is over rated zone and bottom right gray background color is under rated zone.
there are zero over rated tornadoes and more then half are under rated.
strange point to note is that it seems 166 MPH is where EF2 damage is on average made.
then again these are for tornadoes that had some radar scans at 10-15 meters and most are 15 meters.
Currently the real measured Average/Mean is the black solid line , and the EF scale predicted winds are the Dash line , top left gray background color is over rated zone and bottom right gray background color is under rated zone.
there are zero over rated tornadoes and more then half are under rated.
strange point to note is that it seems 166 MPH is where EF2 damage is on average made.
then again these are for tornadoes that had some radar scans at 10-15 meters and most are 15 meters.
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Really great point! This summarizes the issue really nicely. It's too bad Josh Wurman won't even own up to that study now. I definitely see where @ColdFront was coming from with his point earlier, but couldn't Wurman have avoided trashing surveyors without saying "tornadoes just haven't hit the right structures"? Say anything but that!
WIL9287
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This is literally textbook EF-3 damage. It was either a stick-built home on an unanchored CMU foundation or even a double-wide trailer on an unanchored CMU block. It is not very hard for a tornado with a strong vertical lift to just pick up the structure and toss it aside. I can find many other examples of this exact damage being rated as EF-2 to low-end EF-3 from various tornadoes just within the past 4 or 5 years, but given the previous responses, that is just a futile effort. But anyway, here are just a few that I thought of off the top of my head and grabbed. I'm sure if I sit down and spend the time to go through the DAT I can find countless more examples, but these are the few that I could think of just off the top of my head.What about this?
Survey notes say "CMU house swept away". All I see is a giant swath of nubbed and debarked trees. Can't find any lumber though.
This first image is from Bertie County, NC. August 4, 2020. Rated EF-3 145 mph. Stick-built homes lofted off their CMU foundations and destroyed, resulting in two fatalities and about a dozen injuries.
Image two: May 3, 2021, Callalo, VA. The home on unanchored CMU blocks was demolished. Rated EF-2, 115 mph.
Photo 3: April 30, 2024 Westmoreland, Kansas. Two frail homes on CMU foundations were swept away, rated EF-3 142 mph. Here's the comment from the surveyor on the DAT: "Two small single family homes were both completely destroyed in this area with debris swept away toward the northeast. Cinder block foundation with weak connections of subfloor structure to foundation noted so keeping DOD as low as possible due to quality issues. Bottom line, damage in this area is consistent with high-end EF2, and this area would suggest possible low-end EF3 type damage with winds of 135-140 mph."
Guy is a weirdo and sent me some kind of treatise over DM on why he’s right and everyone is wrong.
WIL9287
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As someone who lives in Appalachia, I see houses like the one you have in your third point every single day. It doesn't take much to shift these off their foundations, and once they shift, it doesn't take much more to either loft it completely or sweep it away. Several homes like this in my area were damaged pretty significantly by 100 mph straight-line winds on March 16 of this year, and one was unroofed by a 90 mph EF-1. Even using the F-Scale, it would be hard to rate the total destruction of this home higher than F3. I have surveyed tornadoes with the NWS before and have even performed surveys for them when they weren't able to actually able to get out and do it. So I have real-world experience when it comes to these types of homes being damaged, and I feel like I'm at least a tad bit qualified to be able to point out the way these homes hold up in tornadoes, lol.I don't appreciate the tone in the first part of your post, but I'm just gonna ignore that completely and jump right into explaining this:
1. Where did you read the wording "Anchored and reinforced CMU home"? I checked the DAT myself and that note literally does not exist for the structure in question (unless you read it somewhere other than the DAT). Still, know how I know this was a wood-framed house? It has anchor bolts. Walls made from CMU's are not attached to foundations using anchor bolts. See this example of a true CMU-framed structure (this is the Oak Grove restaurant from Hackleburg - the photo is post-cleanup, but it gets my point across):
Another CMU-framed structure from the 1998 Kissimmee tornado (all the wood you see is mostly roofing material btw):
2. Read the actual description for that DI (it's in Earlington for those who wish to view it) and it says "Not bolted down well. CMU foundation." So, it was a poorly anchored (wood-frame) home sitting on a block foundation. Pretty self-explanatory...
3. Again, the survey notes do not say "CMU house swept clean". Before I got the chance to finish writing this post, @WIL9287 gave a very good explanation of this DI. Still, if you needed more proof this home was not made of concrete, here it is before the tornado:
View attachment 37559
4. Can't find the "before" photo of the Bremen home atm, but I believe it's posted somewhere on the December 2021 thread. It was a wood-framed home with solar panels on the roof. Also, the sill plating is a dead giveaway of the wood framing.
To double down on the point I made in my reply to the original post, something I forgot to mention in regard to the Mayfield home in question, trees were snapped and nubbed in high-end EF-2/EF-3 fashion, and little to no debarking was present. So, even using context, there's not really enough to support a violent rating for the home in question, and trying to use it as proof that Mayfield was an EF-5 just becomes preposterous.
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Mayfield absolutely was of EF5 intensity at some point throughout its life, but nothing it hit warranted the rating. Unfortunately (or fortunately, depending on how you look at it) it’s just the way it is. I used to be of the opinion that Mayfield should have been rated EF5 but seeing all of this imagery thoroughly debunked has made me realize that my old ideas were outdated.
I wonder, if there’s a way you can crudely calculate the “chance” that the Mayfield tornado genuinely didn’t reach EF5 intensity at any point in its life, through its entire 165 mile path, with nothing but statistical analysis… I’m willing to bet that the chance is very, very low, whatever the number may be.
EDIT: It’s also worth mentioning that Ethan Moriarty from June First (a mechanical engineer) believed that the home rated 190 MPH EF4 in Bremen was absolutely capable of being rated EF5 - he stated something along the lines of “not seeing why you couldn’t go EF5 here” iirc.
I wonder, if there’s a way you can crudely calculate the “chance” that the Mayfield tornado genuinely didn’t reach EF5 intensity at any point in its life, through its entire 165 mile path, with nothing but statistical analysis… I’m willing to bet that the chance is very, very low, whatever the number may be.
EDIT: It’s also worth mentioning that Ethan Moriarty from June First (a mechanical engineer) believed that the home rated 190 MPH EF4 in Bremen was absolutely capable of being rated EF5 - he stated something along the lines of “not seeing why you couldn’t go EF5 here” iirc.
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WIL9287
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I 100% agree with you. Was it an EF-5? Without a doubt. But did it produce clear-cut EF-5 damage? Well, I have yet to see any damage that sticks out to me as obvious EF-5 damage. I'm not saying it didn't happen, but I have yet to see the damage that makes me go, "Oh, that is 100% EF-5 damage." Mayfield isn't a case like Vilonia or Matador, where the ratings are obviously way too low. And when you use the ratings in the way they've been applied post-2014, EF-5 is extinct at this point; hell, even an EF-4 rating is nearly extinct. It's to the point now that I see an EF-4 rating for an obviously violent tornado and think, "Well, at least they went EF-4," even if it's 170 mph for something that is clearly stronger than a 170 mph EF-4.
Hopefully, the updated EF-scale will fix this issue of making an EF-5 rating unattainable and perhaps will give leeway to go back and allow upgrades to these borderline cases, such as Mayfield. But I feel like that's just wishful thinking on my part.
jiharris0220
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The damage in Bremen specifically to that weirdly constructed home would’ve gotten an F5 rating without question had it occurred before 1980. The contextual damage is easily ef5 as well and despite the odd construction of the home it pulverized the debris in smithville like fashion. The undebarked trees come into question but Rochelle didn’t do any debarking either despite causing plenty of EF5 worthy DIs as well.
And I’m gonna bring up Rolling Fork here, specifically this quote.
"So, what gave it the 195 mark? And, the best answer to that is what didn't give it the 200 mark...The Green Apple Florist, essentially a single family home that was modified to built to be a floral shop and it is slabbed to the ground and swept clean. Why not F5? Why not EF5? And two things really stuck out to us from the consensus on why not EF5. One was this building, even though it was extremely, extremely destroyed, I mean on its own, taken out of context, I think most people would agree this would be representative of an EF5 tornado; the damage to that building...If there had even been two of these side-by-side that had suffered the same fate, then maybe we could have had more confidence on that, but we didn't...But it was, to that point that we were very very close and this is probably about as close as you'll get across that threshold, without making it...A question we get a whole lot is like how can you be so sure that it was a five miles per hour from F5, but not quite there? And the answer to that is we aren't. What the EF-scale is, is a damage scale...Is it possible that it had winds that were stronger? Certainly."
— Logan Poole, National Weather Service in Jackson, Mississippi[29]
Based of this, Rolling Fork was the closest we got to a tornado being rated Ef5, and it was denied of that rating because a nearby building next to the flower shop wasn’t destroyed to the same degree, which is utterly stupid.
NWS Jackson did a splendid job with this survey. Unfortunately, they dropped the ball massively here.
Maybe I have dementia but where does it say in the EF scale that a structure near an EF5 DI has to also be an Ef5 DI?
That’s nothing short of mental gymnastics, on the same level shown in Vilonia. If a structure shows sufficient evidence to be an EF5 DI, then you rate the tornado EF5.
Honestly this goes to show how exceedingly impossible an EF5 rating has become. This is why I don’t take the EF scale seriously anymore, and anyone who does is simply not going to have pigmentation in their hair past 40.
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Why haven’t I ever seen this quote before? This is crazy - I thought the floral shop was simply a well-rated instance of HE EF4 damage. Looks like Rolling Fork can now go into the bin of “should’ve been EF5” just based on this quote alone. For Christ’s sake, we know that tornadoes have extremely complex and sharp damage gradients due to subvortices, and yet we base EF5 damage off of a neighboring house that may not have felt the same subvortex? Just absurd.
Rolling Fork absolutely had “the look” albeit, quite baseline for EF5 standards. My opinion has definitely shifted tonight.
jiharris0220
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I just found this quote a couple a days ago on wiki, and I was gobsmacked.
I completely agreed with the rating rolling fork got and that NWS Jackson went above and beyond. (Which they absolutely did) and admittedly, other than the flower shop, there’s practically nothing that says rolling fork was an Ef5.
But recently learning about the flower shop being an genuine EF5 DI, rolling fork should’ve gotten that rating.
Rolling Fork's rating is fine. The floral shop still had debris left on the slab and, technically speaking, a small part of the building was left standing.
The fact it was even considered a potential EF5 DI just goes to show how above and beyond NWS Jackson went with their survey of this tornado. Unlike other WFO's, they take damage surveying and rating tornadoes accurately very seriously.
I can understand why that quote is a bit a head-scratcher, but I think they were literally just trying to say that seeing another equally swept home would have increased confidence for a potential EF5 rating in the case of that particular DI, considering it was technically not swept completely away - and that if there was another well-constructed building equally swept, it would have also been rated EF5.
If there was ever a tornado that accurately fits the bill of the quote "EF5 winds, EF4 damage" Rolling Fork is pretty much it. Same exact thing for the 2021 Czech tornado. One DI in Mikulčice was considered for an IF5 rating but the tornado was ultimately rated high-end IF4 - which is totally fine imo.
Both Rolling Fork and the 2021 Czech tornado were nearly identical in intensity imo and both straddle the line between a 4 and a 5. If they had been given EF5 and IF5, that would have been fine too.
edit: To add, if the flower shop in Rolling Fork had been swept completely clean, then I would consider it an EF5 DI without question.
The fact it was even considered a potential EF5 DI just goes to show how above and beyond NWS Jackson went with their survey of this tornado. Unlike other WFO's, they take damage surveying and rating tornadoes accurately very seriously.
I can understand why that quote is a bit a head-scratcher, but I think they were literally just trying to say that seeing another equally swept home would have increased confidence for a potential EF5 rating in the case of that particular DI, considering it was technically not swept completely away - and that if there was another well-constructed building equally swept, it would have also been rated EF5.
If there was ever a tornado that accurately fits the bill of the quote "EF5 winds, EF4 damage" Rolling Fork is pretty much it. Same exact thing for the 2021 Czech tornado. One DI in Mikulčice was considered for an IF5 rating but the tornado was ultimately rated high-end IF4 - which is totally fine imo.
Both Rolling Fork and the 2021 Czech tornado were nearly identical in intensity imo and both straddle the line between a 4 and a 5. If they had been given EF5 and IF5, that would have been fine too.
edit: To add, if the flower shop in Rolling Fork had been swept completely clean, then I would consider it an EF5 DI without question.
This makes me think of the (I believe) the Perryville Missouri EF4. I’ll have to find the original source, but I had read one surveyor said they put the EF5 rating up to a vote amongst the group of surveyors. And of course the 4s won out, but I thought that was something odd to admit
Yeah backing @TH2002 on this one. Survey logic aside, high-end EF4 isn’t an egregious call by any stretch of the imagination. Just a reminder, this is the structure in question:
It’s a very similar situation to the recent Diaz, AR tornado, where a well-built structure was mostly, but not entirely slabbed, resulting in a high-end EF4 rating. In fact, there’s a pretty deep debris pile on top of the left port of the foundation. If we were looking at a totally clean sweep, then we’d have a problem.
It’s a very similar situation to the recent Diaz, AR tornado, where a well-built structure was mostly, but not entirely slabbed, resulting in a high-end EF4 rating. In fact, there’s a pretty deep debris pile on top of the left port of the foundation. If we were looking at a totally clean sweep, then we’d have a problem.
jiharris0220
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I would agree with this, but Poole said it himself and that most people, (I can only assume he’s talking about other surveyors) that the damage was representative of an EF5.
Sure the slab wasn’t swept clean, but many conventional DIs were rated EF5 without a clean slab.
It was an absolutely splendid survey, but the main point is that if an EF5 DI is present, then the tornado should be rated as such, plain and simple.
The EF scale is a damage scale, it has nothing to do with “confidence” in whether other buildings nearby should warrant the rating.
That’s quite interesting. I’ve always felt the 180 MPH estimate for that one was a little on the low side. IDK if EF5 would be appropriate for Perryville given the lack of extreme contextual damage, but I think high-end EF4 would have been a better call.
Yeah it surprised me because I had never even thought Perryville was a candidate for a 5. I will have to go find the source. I want to say it was an email response from a NWS employee to someone on Twitter that had emailed about the lack of EF5s.