Aaron Rider
Member
It was a low end F5I was going to say, I don’t think it was overrated at all; the 190 was justified by both structural and surrounding contextual damage.
EF5? Whatever, I'm not doing that whole argument
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It was a low end F5I was going to say, I don’t think it was overrated at all; the 190 was justified by both structural and surrounding contextual damage.
Yea, not saying it was an EF5, that’s a bit of a stretch. Definitely high-end damage, though.It was a low end F5
EF5? Whatever, I'm not doing that whole argument
I mean, at the residence in question, it slabbed the house, apparently wind rowed or "scattered" debris, and stubbed trees. I think at at least that property structural damage + context were EF4. Going by the report, anyway. And the house was built well.In terms of contextual damage when it comes to Marion, one can’t deny that it doesn’t signal a high end EF4 at all.
I do agree with EF4, I just don’t believe the contextual damage pointed to damage around 190 MPH.I mean, at the residence in question, it slabbed the house, apparently wind rowed or "scattered" debris, and stubbed trees. I think at at least that property structural damage + context were EF4. Going by the report, anyway. And the house was built well.
I haven't seen very many pictures, though, of this tornado in general.
I mean, at the residence in question, it slabbed the house, apparently wind rowed or "scattered" debris, and stubbed trees. I think at at least that property structural damage + context were EF4. Going by the report, anyway. And the house was built well.
I haven't seen very many pictures, though, of this tornado in general.
Here's a picture I stole from Aaron Rigsby's video. The house that got the ef4 is in the top left, while the tree damage in center was also rated ef4.I mean, at the residence in question, it slabbed the house, apparently wind rowed or "scattered" debris, and stubbed trees. I think at at least that property structural damage + context were EF4. Going by the report, anyway. And the house was built well.
I haven't seen very many pictures, though, of this tornado in general.
Exactly. This is one of the rare cases where a tornado may have been overestimated. The home in Marion, Illinois sat either on pier and beam foundation or poured concrete wall foundation (likely the latter), where the sill plates were likely properly anchored to the perimeter foundation walls. The elevated floor system consisted of floor joists toe-nailed into the sill plates (evidenced by nails being ripped out of the subflooring, as well as wall bottom plates removed), with wall bottom plates straight-nailed into either the header or floor joists depending on their position on the floor system.I do agree with EF4, I just don’t believe the contextual damage pointed to damage around 190 MPH.
Glad to have you back on here.Exactly. This is one of the rare cases where a tornado may have been overestimated. The home in Marion, Illinois sat either on pier and beam foundation or poured concrete wall foundation (likely the latter), where the sill plates were likely properly anchored to the perimeter foundation walls. The elevated floor system consisted of floor joists toe-nailed into the sill plates (evidenced by nails being ripped out of the subflooring, as well as wall bottom plates removed), with wall bottom plates straight-nailed into either the header or floor joists depending on their position on the floor system.
Although the home was swept from the floor system, that system itself remained intact and in place. The main issue with the survey was the degree of damage (DoD) applied. According to engineer and meteorologist Tim Marshall, homes swept from crawlspace or CMU foundations should be assigned a DoD-9, not a DoD-10. DoD-10 is typically reserved for slab-on-grade homes only. If we apply DoD-9 in this case, considering the construction and nearby tree damage, estimated winds around 170 mph are more appropriate.
A great comparison is the EF4 tornado in Fifty-Six, Arkansas on March 14th. A similar home built on a crawlspace was swept from its elevated floor system and properly rated as DoD-9, EF4 with 170 mph winds. For further reference, images 1 and 2 are from Marion, Illinois and images 3 and 4 are from Fifty-Six, Arkansas.
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Yeah, I'll say that as a forum how we acted definitely wasn't our proudest moment, and we promise it'll be better this time round.Glad to have you back on here.
Hopefully a more welcoming experience for you this time around.
Exactly. This is one of the rare cases where a tornado may have been overestimated. The home in Marion, Illinois sat either on pier and beam foundation or poured concrete wall foundation (likely the latter), where the sill plates were likely properly anchored to the perimeter foundation walls. The elevated floor system consisted of floor joists toe-nailed into the sill plates (evidenced by nails being ripped out of the subflooring, as well as wall bottom plates removed), with wall bottom plates straight-nailed into either the header or floor joists depending on their position on the floor system.
Although the home was swept from the floor system, that system itself remained intact and in place. The main issue with the survey was the degree of damage (DoD) applied. According to engineer and meteorologist Tim Marshall, homes swept from crawlspace or CMU foundations should be assigned a DoD-9, not a DoD-10. DoD-10 is typically reserved for slab-on-grade homes only. If we apply DoD-9 in this case, considering the construction and nearby tree damage, estimated winds around 170 mph are more appropriate.
A great comparison is the EF4 tornado in Fifty-Six, Arkansas on March 14th. A similar home built on a crawlspace was swept from its elevated floor system and properly rated as DoD-9, EF4 with 170 mph winds. For further reference, images 1 and 2 are from Marion, Illinois and images 3 and 4 are from Fifty-Six, Arkansas.
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From my POV, the house was toe-nailed, which is explicitly laid out by even Tim himself to be EXP resistance. If I'm being honest, that should mean ef4-200, but I guess I see the downgrade to 190?Exceptional that you're back. What rating would you have given Marion? Haven’t seen too much contextual or really any DI that indicates that it was a 190 MPH tornado. Violent? Certainly? Almost exceptionally violent? Maybe not the case. Would you have been more content with like a 170-175 rating?
From my POV, the house was toe-nailed, which is explicitly laid out by even Tim himself to be EXP resistance. If I'm being honest that should mean ef4-200, but I guess I see the downgrade to 190?
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EF4 (170 mph) is better applicable, DoD-9 should’ve been used rather than 10. Or EF4 (180 mph) if applying the WFR DI in the revised EF scale.Exceptional that you're back. What rating would you have given Marion? Haven’t seen too much contextual or really any DI that indicates that it was a 190 MPH tornado. Violent? Certainly. Almost exceptionally violent? Maybe not the case. Would you have been more content with like a 170-175 rating? The home that got the 190 rating is usually a home that would range from 170-180 depending on which office is more liberal.
Do you have a source on that Tim Marshall crawlspace rule? IMO it seems pretty stupid but I wonder if he has something to back it upEF4 (170 mph) is better applicable, DoD-9 should’ve been used rather than 10.
Even though the home is swept away and of typical construction, given it’s built on an elevated floor system, the max DoD that can be applied is 9 for homes swept off it. It has a weaker connection since the studs aren’t directly nailed to the sill plates, they’re nailed to the wall bottom plate that sits on the floor joist system. DoD-9 should’ve been applied instead, winds around 170 mph.From my POV, the house was toe-nailed, which is explicitly laid out by even Tim himself to be EXP resistance. If I'm being honest, that should mean ef4-200, but I guess I see the downgrade to 190?
Also, it seems from the description of the damage point that the windspeed was given more based of the trees behind it: "The extreme tree stubbing combined with the typical construction methods of the home support an estimated peak wind speed rating of 190 mph."
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He actually emailed Tim Marshall. It's a direct response. Also let's keep it chill and not go slinging insults.Do you have a source on that Tim Marshall crawlspace rule? IMO it seems pretty stupid but I wonder if he has something to back it up