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Enhanced Fujita Ratings Debate Thread

Grand Poo Bah said:
Yellow is sill plate, green is bolt, red is joist.

Code for bolts is every 36 inches, joists is every 16 inches. These joists look like they're about 12 inches (could be wrong though) which tells me this was a sturdy structure.

The goal with rating homes is to look for a continuous load path from the roof to the ground. If the roof comes off easy the walls will come down just as easy, if the walls are poorly secured it's the same thing. If the house is properly secured from top to bottom it's much harder for the structure to fail because it basically has to be ripped off the ground in one piece.

When you see cracked subfloor and joists it tells you the walls were well secured to the floor at the very least.

@buckeye05 and @Sawmaster know more than me about the topic though.
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So sill plate distancing works similar to bolt distancing.

I'm assuming this is because that means the walls tore off part of the subfloor due to anchoring strength? I saw the chipped and blown-out part of the rim(?) joists and that initially made me think the wood was just horribly-connected or possible termites, but re-looking your explanation makes more sense.

Might have a few more general questions when I get back home.
 
SouthFLwx said:
Another case of being overly conservative and nitpicking every aspect of structural damage. While I do think it could be lowered to low-end EF4 based off contextual damage and the degree of damage to the home, I don't think it's necessary to lower the rating by a whole category.
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Agreed. Low-end EF4 would for sure be acceptable. However, this normalization of swept frame homes being EF3 damage has gotta end. Everything Nick described is why the tornado is an EF4 instead of EF5. Not EF3.

I presume the reason it received the 190 mph rating is because of the numerous structural engineers the NWS had examine it who determined 190 mph+ winds were required to sweep it. Going against them is ridiculous. It's a bit of a self burn too because it showcases the complete lack of objective reasoning that has plagued several NWS offices for so long.

Welcome to modern damage surveying, where the precedent is made up and the wind speeds don't matter.

1765849022875.gif
 
Grand Poo Bah said:
Agreed. Low-end EF4 would for sure be acceptable. However, this normalization of swept frame homes being EF3 damage has gotta end. Everything Nick described is why the tornado is an EF4 instead of EF5. Not EF3.

I presume the reason it received the 190 mph rating is because of the numerous structural engineers the NWS had examine it who determined 190 mph+ winds were required to sweep it. Going against them is ridiculous. It's a bit of a self burn too because it showcases the complete lack of objective reasoning that has plagued several NWS offices for so long.

Welcome to modern damage surveying, where the precedent is made up and the wind speeds don't matter.

View attachment 49226
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Its clear the home failed at the straight nailed connections. The tree damage rated EF4 behind the home was clearly enhanced due to debris from the “190” home. In my personal opinion, this tornado could go both ways, whether its EF3 160 or EF4 170. Its just up to personal discretion. Theres nothing wrong with Nick’s rating, and I wouldn’t doubt that most other offices would go with a lower windspeed for that home. It’s clear NWS Paducah has been a little bullish this year, which isn’t a bad thing, it’s just their method of rating, and some people disagree with it (perfectly acceptable). Also, subjectivity will never go away in the EF scale. It may be reduced slightly with the upcoming revised version, however in the end the rating is down to the personal opinions of the surveyors within the NWS office rating a tornado.
 
Grand Poo Bah said:
Agreed. Low-end EF4 would for sure be acceptable. However, this normalization of swept frame homes being EF3 damage has gotta end. Everything Nick described is why the tornado is an EF4 instead of EF5. Not EF3.

I presume the reason it received the 190 mph rating is because of the numerous structural engineers the NWS had examine it who determined 190 mph+ winds were required to sweep it. Going against them is ridiculous. It's a bit of a self burn too because it showcases the complete lack of objective reasoning that has plagued several NWS offices for so long.

Welcome to modern damage surveying, where the precedent is made up and the wind speeds don't matter.

View attachment 49226
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It doesn't help his case that he replied to a reply under his twitter post with a gif of “why are you booing me, I'm right.”

He has alot of good takes, but going so low on this one against a panel of expert who reviewed it and all came to a unanimous conclusion of EF4 at the very least is, bold to say the least.

I agree Marion shouldn't be 190mph. But 170mph is just fine. Don’t need to go EF3.
 
Eli_Ruth57 said:
Its clear the home failed at the straight nailed connections. The tree damage rated EF4 behind the home was clearly enhanced due to debris from the “190” home. In my personal opinion, this tornado could go both ways, whether its EF3 160 or EF4 170. Its just up to personal discretion. Theres nothing wrong with Nick’s rating, and I wouldn’t doubt that most other offices would go with a lower windspeed for that home. It’s clear NWS Paducah has been a little bullish this year, which isn’t a bad thing, it’s just their method of rating, and some people disagree with it (perfectly acceptable). Also, subjectivity will never go away in the EF scale. It may be reduced slightly with the upcoming revised version, however in the end the rating is down to the personal opinions of the surveyors within the NWS office rating a tornado.
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*Also to note, Nick is a human too, and some people here seem to be a little rude towards him (not specifically the person I am replying to). Remember, we are here to discuss the ratings of a tornado, and the final windspeed attached is not nearly as important as the lives impacted and the overall destruction caused by a tornado.
 
tornado examiner said:
It doesn't help his case that he replied to a reply under his twitter post with a gif of “why are you booing me, I'm right.”

He has alot of good takes, but going so low on this one against a panel of expert who reviewed it and all came to a unanimous conclusion of EF4 at the very least is, bold to say the least.

I agree Marion shouldn't be 190mph. But 170mph is just fine. Don’t need to go EF3.
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This was a clear joke, hes being satirical here
 
Eli_Ruth57 said:
Its clear the home failed at the straight nailed connections. The tree damage rated EF4 behind the home was clearly enhanced due to debris from the “190” home. In my personal opinion, this tornado could go both ways, whether its EF3 160 or EF4 170. Its just up to personal discretion. Theres nothing wrong with Nick’s rating, and I wouldn’t doubt that most other offices would go with a lower windspeed for that home. It’s clear NWS Paducah has been a little bullish this year, which isn’t a bad thing, it’s just their method of rating, and some people disagree with it (perfectly acceptable). Also, subjectivity will never go away in the EF scale. It may be reduced slightly with the upcoming revised version, however in the end the rating is down to the personal opinions of the surveyors within the NWS office rating a tornado.
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They were straight nailed as well as toe nailed. There is nothing weak about this construction practice. It is standard and up to code. The EF scale was written with this code in mind.

There's multiple issues with giving Marion an EF3 rating.

1. It goes against the engineers who were actually there and assessed it. How would Nick or anyone else know the home's strength better than them? It's completely unsubstantiated.

2. It reinforces bad precedent that should have never been set in the first place, and has been repeatedly proven as incorrect (in terms of wind speeds).

3. It goes outside of the bounds of the scale. The lower bound for DOD 10 is 165 mph (the EF4 threshold). The EF scale was written with code in mind, so homes that obey code should recieve the proper rating. The expected wind value for DOD 10 on a home like this is 200 mph. It's ok to use context to go below that, but EF3 is just a plain misrepresentation of the tornadoes actual strength.

4. Violent damage deserves a violent rating. Accurate records are important. The rating a tornado gets is a representation of its human impact. Tornadoes affect real people, and change lives. Downplaying those tornadoes historically is a diservice to the people who experienced them. Imagine losing everything and being gaslit that the tornado actually wasn't as bad as it seemed, it's just your house that was bad. Luckily most people don't see it this way, but there are multiple instances of surveyors offending victims with incorrect and/or dismissive assessments.
 
I'd actually go with EF-4 180 for Marion. Definetely not a weaker home but idk about 190 MPH strong. 160 MPH is way too low (Straight nail+toe nail isn't weak by any means. Infact it's stronger than many think) but 190 MPH is a bit high aswell.

Of course, contextual damage would factor in, but there was windrowing and solid tree damage. Mid-end EF-4 is fine, no more, no less.
 
Grand Poo Bah said:
View attachment 49136
Also looking up the December 2021 outbreak again and it looks like the NWS is actually saying the Mayfield tornado had the longest track in history? When did that happen? I thought officially the Tri-state tornado was still (controversially) longer.
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Tri-state is definitely longer and has a near confirmed 174 mile path. Not sure its controversial to say its stronger either. On the same page they also have this which is interesting. 1765893324554.png
 
Grand Poo Bah said:
1. It goes against the engineers who were actually there and assessed it. How would Nick or anyone else know the home's strength better than them? It's completely unsubstantiated.
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Isn't that what this thread mainly does? Nick is simply giving his opinion, something we do here all the time. I do agree that the contextuals are extremely lacking, and that the tree damage behind the home could've easily been caused by debris-loading. There's nothing inherently wrong with nitpicking homes - we are trying to get an accurate windspeed, after all.
 
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HAwkmoon said:
Tri-state is definitely longer and has a near confirmed 174 mile path. Not sure its controversial to say its stronger either. On the same page they also have this which is interesting. View attachment 49228
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It's not controversial at all to say Tri-state was stronger. Most people would agree, including me.

Central Ohio Wx said:
Isn't that what this thread mainly does? Nick is simply giving his opinion, something we do here all the time. I do agree that the contextuals are extremely lacking, and that the tree damage behind the home could've easily been caused by debris-loading. There's nothing inherently wrong with nitpicking homes - we are trying to get an accurate windspeed, after all.
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Great point and you're completely right. I should've specified I meant *independent* engineers because there's multiple engineers behind the EF ecale who I disagree with all the time, and that's mainly because imo they've repeatedly displayed some clear bad faith practices. The indepent nature of the (multiple) engineers in the Marion survey does eliminate a lot of potential bias, though.

I'm not a fan at all of the nitpicking of homes and I think I've been pretty consistent with that viewpoint. Nick's a very bright kid and I enjoy his posts. This one seemed like a bit of a troll and engagement bait to me, but it also serves as a great opportunity to discuss some of these prominent issues, so it's welcome.
 
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