@SweptSlab5
Here is Lyza’s paper on the 200 MPH debacle and more generally, his takedown of the EF scale at large.
Here is Lyza’s paper on the 200 MPH debacle and more generally, his takedown of the EF scale at large.
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joshoctober16
Member
tornado examiner
Member
The bigger issue here is them using the wrong DOD.
Like, by a country mile.
I’ve heard mixed things about whether or not there’s direct evidence showing that the duplex in Bowling Green was actually hit by that storage building and the equipment inside it. Another user here made a pretty compelling case for it being questionable, and I believe it centered around aerial imagery showing how the location and trajectory of the shed and its contents isn’t as direct and clear cut as the survey makes it seem. Basically, I recall the crux of it was that the imagery showed that the two structures weren’t particularly close together and don’t exactly line up with one another. Now I can’t say for certain as to whether the collateral damage argument there is actually debunked or not, as it’s still very possible that the survey team found conclusive evidence of collateral damage. But I will say the EF2 rating at that location has always seemed a bit low to me.
Edit: Taking a look at the photo above, there is clearly a large metal equipment trailer resting upside down behind the foundation of the duplex (to the right of the white utility vehicle). This would suggest that the duplex was at least hit by this trailer.
Edit: Taking a look at the photo above, there is clearly a large metal equipment trailer resting upside down behind the foundation of the duplex (to the right of the white utility vehicle). This would suggest that the duplex was at least hit by this trailer.
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Tokai.Ryu
Member
Theres a few examples of debris loading that ISN'T just lofted objects against another, that mainly being parkersburg's concrete wall, as far as I remember, it was hit by a huge sum of debris. Unless you don't count that as debris loading and instead debris impacting.
There are two valid scenarios in which debris loading/impacts can exacerbate damage and thus lower ratings:
1) A big, heavy object slamming into the structure.
2.) A concentrated absolute blizzard of numerous smaller objects from disintegrating nearby structures that clearly and conclusively played a role in the destruction of a specific building.
It’s basically like comparing a slug round versus a shotgun shell, but both can play a role in exacerbating destruction. My big issue is when scenario 2 is cited with zero specificity or conclusive evidence that such a thing actually occurred. An example would be the Wicker Street home in Vilonia. The official reasoning is that the house was downwind of downtown Vilonia, but that’s vague and just not conclusive at all. As far as I know, there was no specific building ever cited as being the source of any debris, and there was no actual evidence of any specific foreign heavy building material being found on the property of the Wicker Street home. Now if they were able to say “Large rafters and many pieces of heavy masonry from this specific building were found resting on the slab and in the debris field of the Wicker Street home, conclusively proving debris loading as a significant factor in the destruction”, it would be a valid point. But that’s not what happened, and instead the rationale was vague and ambiguous in nature. That is the kind of thing I take issue with.
Now with Parkersburg, I do recall the infamous basement wall photo. There was indeed a significant accumulation of debris there against that wall, but it’s all lightweight stuff (vegetation, plywood, drywall, etc). Given the relatively light nature of the material that accumulated there, the fact that it was a poured concrete wall with reinforcements, and the fact that the accumulated debris isn’t traceable to any specific nearby structure, makes it dubious to claim that it played a significant role in the failure of that concrete wall. The house was fairly isolated, and we are likely seeing an accumulation of general transient debris, rather than a concentrated “shotgun” effect from a specific nearby structure. In addition, the construction at these golf course homes was described by the survey team as being well above the standard of what was needed for EF5 criteria. Also some of them, including that one, were so thoroughly obliterated that they had no discernible debris scatter path extending away from the foundations. It was about as thorough of a wipeout as you’ll ever see, and there was grass scouring and extreme debris granulation too. All in all, while there was evidence of debris accumulation against that basement wall, that’s about all we can say conclusively, and there is nothing there that genuinely calls the EF5 rating into question.
But to answer your question, yes the “concentrated blizzard of debris” phenomenon is absolutely debris loading. Yes it can have a valid impact on a rating, but only when the destruction of the building in question is conclusively tied to a concentrated blast of debris from another nearby obliterated building. It’s a total nothing-burger when there’s no specificity to it, and the reasoning comes down to something vague like “the tornado was impacting a populated area and there was a lot of debris flying around”. I mean…yeah duh? That’s what happens when any significant tornado hits a population center. If that was something that was actually factored into ratings, we’d only see higher-end ratings in rural areas and all direct town strikes would become ineligible for EF5. It’s simply not a valid or relevant point to bring up when it’s presented in a non-specific manner.
Sorry this got so long winded.
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I just looked at the Parkersburg basement wall photo for the first time in a while. Yeah, there’s actually less debris accumulation than I remember, and a good amount of it honestly appears to be mud and scoured grass. The claim that it was “hit by a huge sum of debris” does not appear to be an accurate statement at all. Pretty much any EF5 rated home ends up getting pummeled by debris, and there’s nothing to suggest that this particular home got it any worse than others. Honestly, it probably received a milder debris pummeling than any of the EF5 homes from Moore 2013. Also, the assertion that this debris accumulation is directly connected to the failure of the basement wall is far from conclusive, especially after taking a closer look. There’s just no real compelling evidence to suggest that.
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SweptSlab5
Member
Parkersburg was arguably one of the most violent tornadoes ever, especially with the homes in the golf course subdivision being essentially evaporated.
speedbump305
Member
Parkersburg is firmly in my top 10 most violent tornadoes ever recorded. The golf course damage was as extreme as it gets and was well above and beyond at EF5 intensity there. I mean, one home literally had no traceable debris left! Can’t say that happens too often.
Lake Martin EF4
Member
It's on my Top 10 as well, tied with Greensburg which has its own assortment of incredible feats.
speedbump305
Member
What’s your top 10 looking like right now?
Lake Martin EF4
Member
#1 Piedmont
#2 Tri-State
#3 Jarrell
#4 Bridge Creek
#5 Bakersfield Valley / Stratton
#6 Smithville
#7 Matador
#8 Greensburg / Parkersburg
#9 New Richmond / Moore
#10 Catania
SweptSlab5
Member
What did Catalina do that was extreme? I haven’t heard much on that tornado and would put San Justo higher.
1. Smithville
2.jarrel
3. Tri state
4.bakersfield valley
5.bridge creek
6. Parkersburg
7. Leedy
8. Brandenburg
9. San justo
10. New Richmond
Lake Martin EF4
Member
It took what was, by all accounts, an extremely well built house and literally reduced it to a pile of rubble, and not a particularly large pile either. There was also apparently some extreme contextual damage. I've seen it referred to as "Woldegk if all the legends about it were true".
Tokai.Ryu
Member
Oh not just one home! It annihilated multiple extremely thick homes, with the villa being the most well built, and actually the most well built structure to ever be hit by a tornado! That is if you exclude orthodox indicators like CC117.
I have sent feats of Catania here, but I could send them again. Here.
The structure was purely a two story villa that had 1.3 meter thick walls, very heavy timber joists, with floors having strong connections and were made of tile roofs, and this structure specifically was heavily damaged, despite it having inconceivable levels of construction, with its walls overturned onto the streets in compact masses of several cubic meters in volume.
Various descriptions by Damiano Macaluso's Survey (approved by numerous academics, and even by ESWD and ESSL, link is: https://www.uni-met.it/trombedaria/documents/1884_Macaluso.pdf )
- A garden between Civali and Borgo had the topsoil removed revealing a volcanic lava layer below.
- Multiple stone and/or brick homes with walls up to 1 meter thick partially and/or entirely destroyed, with their marble slabs being displaced as well, all of which had very heavy timber joists, with floors having strong connections and were made of tile roofs, these homes were two story.
- A two story villa with inconceivable levels of construction and had walls greater than 1 meter was completely leveled, with its walls overturned onto the streets in compact masses of several cubic meters in volume.
- Laid brick roads scoured or lifted away.
- Orange, Lemon and Olive trees snapped at the base or twisted, some lofted extreme distances.
SweptSlab5
Member
Wow! That sounds extremely violent! No wonder it was upgraded to If5.
Not to open a whole new can of worms, but what is your guys’s opinion on the fairly recent Jim LaDue presentation on current day EF scale application? It was posted on this forum not too long ago.
The thing that I’ve been having a hard time wrapping my brain around is the part where he essentially describes some of the bare subfloor EF4 homes in Elkhorn as being rated too low, and he provides a scenario for EF5 ratings at bare subfloor homes. The scenario is either extensive toe-nailing of the wall studs, OR extensive sheathing (that green stuff you see on homes under construction) that overlaps with the side of the floor platform. What’s mind boggling to me is how this essentially provides a scenario for an EF5 house rating in which anchor bolts are not visible and seemingly not directly in play. It has me thinking, would this be applicable to a boltless slab foundation home too?
If extensive sheathing or toe-nailing alone is enough to make a home an EF5 candidate, it would lower the bar for EF5 house damage significantly, but I just can’t see that being put into practice. I’m unsure as to whether this is something that is currently becoming widely accepted, or if it’s just something that Jim LaDue is proposing but hasn’t “caught on” yet?
The idea of an EF5 house rating without any kind of visible bolting has been making my head spin, and I’d love to hear from others about the viability of this concept (paging @Saltical Wx)
The thing that I’ve been having a hard time wrapping my brain around is the part where he essentially describes some of the bare subfloor EF4 homes in Elkhorn as being rated too low, and he provides a scenario for EF5 ratings at bare subfloor homes. The scenario is either extensive toe-nailing of the wall studs, OR extensive sheathing (that green stuff you see on homes under construction) that overlaps with the side of the floor platform. What’s mind boggling to me is how this essentially provides a scenario for an EF5 house rating in which anchor bolts are not visible and seemingly not directly in play. It has me thinking, would this be applicable to a boltless slab foundation home too?
If extensive sheathing or toe-nailing alone is enough to make a home an EF5 candidate, it would lower the bar for EF5 house damage significantly, but I just can’t see that being put into practice. I’m unsure as to whether this is something that is currently becoming widely accepted, or if it’s just something that Jim LaDue is proposing but hasn’t “caught on” yet?
The idea of an EF5 house rating without any kind of visible bolting has been making my head spin, and I’d love to hear from others about the viability of this concept (paging @Saltical Wx)
slenker
Member
I’m not too sure about it myself. I feel like this being put into practice would make achieving an EF5 rating too easy, honestly. But I don’t know enough about the way such construction compares to anchor bolted UB homes, specifically with wind resistance. If a guy like LaDue is saying this and is in support of it when it comes to applying a high end rating, I can’t really say I would ultimately disagree with it either.
My question is does Marion 2025 apply to the descriptions listed by LaDue?
That’s the thing. Between Elkhorn and Marion, we’ve seen an uptick in violent ratings assigned to bare subfloor homes, which makes me think something is going on behind the scenes. But high-end EF4 and especially EF5 feels hard to accept without anchor bolts directly anchoring the walls.
Like you said, it feels like it would make achieving an EF5 rating too easy, and I just can’t see it becoming a widely accepted practice. I was excited when I first watched the presentation, but I’ve become more skeptical after thinking it over for a while,
Is there something I’m missing here?
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Grand Poo Bah
Member
I personally don't care how easy or hard EF5 is to achieve as long as we're getting the wind speeds right. I think the real reason it seems like bare subfloors would make EF5s too easy is because we've been seeing a dramatic uptrend in violent tornadoes.
We used to average 1-2 F5s per year even when subfloors were being rated as such. If we surveyed this year like we did in the 90s there would've easily been 6 F5s this year. Which is pretty wild when you consider what it means.
We used to average 1-2 F5s per year even when subfloors were being rated as such. If we surveyed this year like we did in the 90s there would've easily been 6 F5s this year. Which is pretty wild when you consider what it means.