No Vilonia's in central Arkansas, which is in the Dixie Alley shade (at least according to this map). Really what happened was most likely a deliberately bad or sabotaged survey to underrate it to to EF4 because of insurance premiums or the like.
I think the insurance premiums theory gets thrown around a lot without much scrutiny or deeper analysis. It seems to be something that people hear and then just regurgitate without totally understanding what it entails (which I don't myself, not gonna lie).
Nullifies what argument exactly? Not being snarky I’m just trying to figure out what you’re referring to. Robinson is indeed quoted in an interview as making that statement about how high single-family homes should be rated.
This whole discussion is what makes me hope that Grazulis rates Vilonia EF5 whenever his new book comes out (no clue when that will be). If he does so it will likely set things back on track or help clarify confusions/inconsistencies with ratings.
I kinda was actually trying to make a bad joke, but this conversation is interesting.
Is JR also the likely the reason Chickasha & Goldsby, OK were given EF4 instead of EF5 ratings?
These two tornadoes being rated EF4 does confuse me... the office surveying them (Norman) surveyed and assigned EF5 ratings to another tornado that very day and the Moore tornado 2 years later, as well as originally assigning an EF5 rating for El Reno 2013 for DOW alone (not 100% on that but I think I saw that somewhere), so it's not like it was an office which avoided higher ratings or didn't believe in homes being rated EF5 and so on and so on. Contextual damage on those tornadoes does strongly suggest EF5 to me, but maybe there was a very valid reason that they couldn't be rated EF5. I dont really know too much on those particular tornadoes damage surveys, maybe other people have some ideas?
I forgot if it was Tim Marshall, someone else involved with the Chickasha survey or a general statement from Norman but I remember reading somewhere where they pretty much admitted "well based on context we would rate it EF5, but because of the homes it hit we can't rate it EF5." Basically dependence on needing an EXTREMELY solid EF5 candidate home to compliment the contextual damage. Personally I disagree with this approach, and if anything I think it should be the other way around, but I digress. Though I do wonder about the one home that had "missing nuts and washers" if they may have actually been stripped off by the tornado itself rather than missing beforehand.
To me these tornadoes were undoubtedly EF5s, and I agree on many of your points. The fact that 2011 had two days with basically 2+ EF5 tornadoes is pretty exceptional.
This is the biggest discrepancy that nobody seems to have an answer for. If context can be used to downgrade, it should be user to upgrade too. It doesn’t take a statistics expert to figure out that only allowing a certain factor to lower ratings is going to result in skewed results with a bias towards lower estimates. Why does nobody want to address this?
Exactly. If we are getting this Scale Upgrade this is what I would like to see it address.
While I'm at it; what was the reasoning for Chapman 2016 being rated EF4 instead of EF5? I understand it encountered very little man-made structures until it was near the end of its path but if anything the fact it managed to completely sweep away a farmstead and mangle every single vehicle it encountered beyond recognition in its last few miles is even more proof it was EF5. Of course, I wasn't on the survey, so what do I know?
Not even a fence. A fencePOST. That sole fencepost led to EF4.
It hit rural areas and no more than a few structures. The surveyors flat out admitted that if it had hit Chapman directly, it'd be a 5, no questions asked.
One idea I have always thought could work is a list of established contextual “violent tornado indicators”, each with their own severity scale and corresponding wind speeds (ie partial ground scouring allows for +10 MPH, severe ground scouring allows for +15 MPH and so on). There could be others VTI’s per se such as different types of debris patterns, with corresponding example photos for reference. Obviously I’m no wind engineering expert and it’s likely more complex than that, but I do think it’d be a good start.
Yeah when Tornado Talk interviewed NWS Topeka about Chapman, they did say that, but I don’t fully understand their logic. What Chapman did to that farmstead and railroad tracks seems like enough basis for EF5 as is. I mean hell, it ripped the house from its bolts so violently part of the concrete foundation broke off.
More or less the same reason that Chickasha got rated EF4; it boiled down to the homes. The one brick farmhouse was "not swept completely clean", and the other house that NWS Topeka didn't survey but Tim Marshall looked at was downgraded based on "a lack of wall stud connections" (which seems kind of vague if you ask me, does that mean the studs were nailed rather than plate tied or were they barely connected in any way at all?). It seems like they didn't consider the mangled vehicles and farm equipment when deciding on a rating, or at least not enough to go higher than the upper end of EF4.
I hope stuff like ground/topsoil scouring, low-lying vegetation being stripped, grass being matted to the ground and tree debarking/denuding are also added to the DI category and implemented consistently. I'm really hoping that things don't get even stricter and the EF5 rating is done away with completely.
