Enhanced Fujita Ratings Debate Thread

[jiharris0220]

vilonia fits right in with the 4/27 EF5's when looking at photos of the tornado, or damage photos. Easily the most egregious snub of an EF5 rating, up there with Goldsby and Chickasha 2011.

Agreed, out of every single potential F5/EF5 tornado in history I’ve never quite seen a case where a tornado does blindingly blatant, on the wall ef5 damage just to be slapped with an ef4 rating based off of nothing but the premise “oh well those completely debarked trees next to this obvious ef5 DI are still standing”.

Many tornadoes rightfully deserve to be rated ef5, but what they all have in common is you can make a reasonable argument as to why they should stay as ef4, even Chickasaw and Goldsby despite being egregious, you can at least see the reasoning why they went with ef4 and the surveyors themselves said they were likely ef5s. But Vilonia? No person who has a reasonable rational of thinking will look at the damage in question and think “yea, these surveyors were in their right minds” in any capacity.

One can only hope that someday a reanalysis will come and right this wrong.

 

[jiharris0220]

That's a fair assumption. I have Vilonia and Mayfield comfortably above the rest.

View attachment 52264
^^
Some utterly insane tornado damage here. It contains every single thing indicative of an extremely violent tornado. Debris granulation, windrowing, Tree debarking and knubbing, ground scouring, and probably more

I'd even go as far as to say that Vilonia and Mayfield (Specifically around Bremen) were on par Smithville at their peak. Mayfield less so than Vilonia but they are comparable to Smithville nonetheless.

One thing that I do when determining if a tornado was en ef5 in a particular area is identify two simple things, degree of granulation and sweeping. The mayfield tornado beyond all reasonable doubt attained ef5 intensity here.

There’s hardly any debris left in this area where it went through, the sparse amount of debris that did get left behind was granulated to the point that not a single piece larger than a two-by-four was left. The concrete cinder block foundation of the oddly built two-story house on the far right was granulated in Smithville like fashion. This tornado did a very rare feat where if you looked at the damage first glance, you wouldn’t even be impressed or shocked at first because there’s nothing to indicate that anything was even there in the first place.

Despite it all, not really possible to make an argument to legitimately change the Mayfield tornado to an ef5 with the current scale in this specific spot because the construction of the homes here definitely would’ve failed in lower wind speeds.

 

[Ozonelayer]

One thing that I do when determining if a tornado was en ef5 in a particular area is identify two simple things, degree of granulation and sweeping. The mayfield tornado beyond all reasonable doubt attained ef5 intensity here.

There’s hardly any debris left in this area where it went through, the sparse amount of debris that did get left behind was granulated to the point that not a single piece larger than a two-by-four was left.

The concrete cinder block foundation of the oddly built two-story house on the far right was granulated in Smithville like fashion. Despite it all, not really possible to make an argument to legitimately change the Mayfield tornado to an ef5 with the current scale in this specific spot because the construction of the homes here definitely would’ve failed in lower wind speeds.

Yeah this area is more so contextual EF-5. The homes here probably could be rated 170-180 MPH at most. The real EF-5 DI's from this tornado is the 190 MPH Home and the large heritage church in downtown Mayfield. Multi-Tree goes up to 210 on the new scale so The Land Between The Lakes and some areas in Bremen would be rated that as per the very description of the DI.

 

[TH2002]

I'm not even gonna touch the Vilonia debate today, cause quite frankly, I'm already pissed off at unrelated life things. Still, I will reiterate that my stance is unchanged: it was 100% an EF5 and 100% robbed of its rating.

Not to mention Vilonia is the "original" underrated tornado everybody still loses their s**t over before Matador came along in 2023.

 

[Lake Martin EF4]

Who wants to show Nick some instances of obvious EF5 at Vilonia? Be nice. I like him. Respond on Twitter if you can

I wonder what nick Kraz would say on vilonia. Probably the same nonsense he’s said everywhere else. “The only 190mph home should be downgraded because contextual discrepancies conclusion 170mph EF4.” Ugh I really dislike nitpicky people.

He's not ALL conservative. He has stated he believes Vilonia was an EF5, actually upgraded Goldsby to 240 EF5 in his analysis of that tornado, and made a post that basically states that Rolling Fork would be rated EF5 on the new EF scale (at the Dollar General).

That said his Chickasha and Rochelle surveys can go kick rocks. No, that house with the moved sidewalk was NOT EF3 in ANY way shape or form.

@tornado examiner Nevermind I take it all back you were right all along

Even worse is the way the convo unfolded makes me think that that one horrendously constructed EF4 neighborhood that LZK used as a misdirect in their survey helped him decide on EF4 *GROAN*

 

[tornado examiner]

@tornado examiner Nevermind I take it all back you were right all along

Even worse is the way the convo unfolded makes me think that that one horrendously constructed EF4 neighborhood that LZK used as a misdirect in their survey helped him decide on EF4 *GROAN*

Well well well…how the turns have tabled.

It’s funny. He really seems to be bi-polar with his takes. Some really great. Others really misguided.
He does great work though regardless. His personal surveys are high in effort and locally informed.
So I’ve taken a difference stance on his takes, lightening up on them because often times my own personal takes are just as hit or miss.
(Most of the time a miss as judging by my history here in retrospect) r.i.p

 

[buckeye05]

Hi, my "work" done on the Vilonia home was legitimately just a random discord message I sent one day after looking at the house for like thirty minutes. It was never intended to be taken as law, and I never asked anyone to use this random message I typed up in about thirty minutes in a full on debate, especially without asking me. This is still a continuation of a problem I mentioned when I joined the forum. It's a recurring problem where people take screenshots of my messages or just copy-and-paste my point without asking me or understanding what it means. I can assure you, it's just as frustrating for me when I see people getting mad at my "work" when people just copy and paste my message from some time ago and get all defensive about it when the argument is actually challenged (as any anonymous online user's work should be). To clear up my view on the Vilonia home on Wicker Street, by the standards provided in Marshall's survey of Moore, this single residence does not qualify as an EF5 DI by Marshall et al. (2014). Does this mean another expert in the field may disagree? Of course they can. My point in the single message I sent (which was not written with intent to be copied and pasted on forums) was that according to the methodology set by the most recent survey explicitly defining EF5 damage to a slab-on-grade residence, this single damage indicator could not qualify. Does this mean no other site in the tornado's path could get rated EF5? No, and I did not say this. This is again another problem with people regurgitating my work is that my initial point can be skewed and taken out of context. Is the tornado itself an EF5? Absolutely, I don't think anyone disagrees. The tornado was objectively into EF5 intensity for a solid portion of its path in Vilonia.

Regarding my Rochelle study, I researched this tornado for a year. No, I did not spend this entire time on just the single residence. I surveyed all EF4 DIs, some more in-depth than others. The reason I could not provide an in-depth analysis on each home in this forum is because I'm a college student. I have things to do. I don't have the time to show everything I've ever done on a forum. Does this mean I didn't complete the analysis? No. The residence you are thinking of in Rochelle suffers from essentially the same problems as other residences in the neighborhood. This isn't directly related to whoever constructed the residence, but rather these types of homes as a whole. I will provide a short summary for why that home qualifies as EF4. The residence at 4807 S Richard Rd, Rochelle, IL 61068 is on a poured concrete wall foundation. The major failure here was the connection between the floor joists and sill plates. This is evident by nearly every single sill plate remaining on the foundation, which infers the wind load never reached the anchor bolts. No bent bolts were evident at this residence, because the anchor bolts never had a chance to bend. The house was swept away before the anchor bolts were exposed to the forces necessary to bend the bolts. The home did not have any major failure modes with its exterior design, but interior connections near the foundation were subpar. Of note, earlier photos of this home (before major cleanup) showed a vehicle on or near the foundation opposite of the garage. By this definition, the home meets an EF4 qualification. If you are doubting why I am a valid source on this topic (which is a valid question to ask): I am a Civil Engineering undergraduate, all of my research was presented to and approved by Ethan Moriarty, degreed Mechanical Engineer, and challenged by other highly knowledgeable individuals in the field who agreed with my conclusions. Unfortunately, this home has the least amount of angles I could find out of the entire Rochelle track of EF4 DIs. While you could argue the lack of documentation could still infer a possibility of EF5, the current angles of the residence suggest EF4. I can also annotate this aerial photograph later if I have the time.
View attachment 52261

For anyone wondering, I have made significant progress with my research on cycloidal marks and my paper is progressing very well. Hopefully I have the chance to release some of my work later this year for you guys to read if you are interested.

Ok I’ll concede on Rochelle and my claim that you only went into depth on one house there. Rochelle is a borderline case, and with the Richard Road house actually analyzed, that’s fair. As soon as that house was addressed I was willing to put that specific case to rest.

But with Vilonia, what you’re saying proves my point precisely. You’re just using the Moore standard as an iron clad basis for a completely separate tornado and survey, when the Moore survey and the people directly involved with it explicitly state that the criteria used there is NOT a catch all standard for EF5 damage that is to be used in every future survey. When you are dealing with the type of extreme contextual damage you see in Vilonia, you need to seriously consider taking take a step back and think about whether the degree of scrutiny you are applying is appropriate if the goal is to find a way to ascertain a rating that is appropriate given the circumstances and overall intensity of the damage. In terms of this type of damage intensity, I have seen it only a handful of times in my lifetime of looking at tornado damage, and it’s very clear to me what caliber of tornado we are looking at here, and it seems that you can agree with that. So the question becomes, is levying the rating on deep scrutiny of things like roof shape, presence of porch overhang, and relatively small scale details related to the bolts and plates actually a good decision to make if the goal is accurate documentation of the true intensity of the event? Also, if those specific features were different (different house shape/stonger evidence of the bolts really putting up a fight), are you actually going to try to tell me that the overall scene at Wicker Street would have been dramatically different in terms of the DOD, as in maybe we wouldn’t have had a totally slabbed home at that location? The answer to both of those questions is absolutely not.

You yourself say the tornado was likely an EF5 event, so you should be asking yourself, when dealing with an event of that caliber, plus the historic significance of the first possible F5/EF5 event in Arkansas history, is it a good idea for you to not give any real thought to the degree of scrutiny you are applying here and whether the outcome of this scrutiny will lead to a positive outcome? If the goal is to accurately document a remarkably intense and historic tornado event, what you are doing is actually harmful in that context, and I don’t know if you are able to see that or not.

Yes you can scrutinize that house into oblivion, and you can also ignore non DI contextual evidence that is consistent with an extremely violent tornado. But just because you can, does that really mean that you SHOULD? That is the question you need to be asking yourself, especially since this kind of thing sets the tone for future surveys. My biggest concern is accurate ratings and proper documentation of tornado events, and the kind of mindset and approach you bring to the table here in this specific instance is inherently destructive to that objective.

It again boils down to the simple adage of just because you can, doesn’t mean that you should. You are technically correct, but are completely off the rails in terms of reasonability and ability to fairly modulate scrutiny given the circumstances. Also when you have influence, you need to look at whether you are using that influence in a manner that is conducive to progress, or conducive to further problems in this field of study.

 

[buckeye05]

Oh and one more thing, from what I remember, one of the reasons that specific criteria for EF5 house damage was used in Moore was to account for the chaos of an urban/suburban debris field. Given the density of housing in Moore, it was very difficult to trace debris patterns from individual homes and identify specific instances of collateral damage. The emphasis on a specified degree of sill plate removal and bolt bending to define EF5 was to identify specific homes that without a shadow of a doubt put up a lot of fight as they were ripped from their foundations, rather than being blasted apart by debris from nearby homes. Vilonia occurred in an area of lower housing density, so the Moore EF5 criteria isn’t the best definition to use given that difference. Do I acknowledge that more sill plate removal and bolt bending would yield higher confidence regardless of housing density? Sure. But when you are dealing with a tornado that produced contextual damage that is flirting with Bridge Creek, it’s not an absolute necessity. A person could hypothetically create a photographic diagram of each and every contextual indicator associated with extremely high-end tornado events while exclusively using photos from Vilonia. That to me paints a very clear picture and should carry more weight than some lingering questions about house shape and bolts/plates.

 

[TH2002]

oh i forgot to say that ... a 1957 tornado got upgraded to IF5
View attachment 52178

they are really giving away the 5 rating to a lot of tornadoes lately , however most high end EF4 seem to likely warrant a 5 rating then some of the new IF5

@Tokai.Ryu Here's the ESWD confirmation you wanted. Happy now?

On a side note - did they combine this with the Robecca Pavese tornado, since all evidence suggests they were the same tornado?

Replying before this gets buried further...

Looked it up, and it's true! Here's the link, although the ESWD database doesn't reflect the update yet.

They are still listed as separate tornadoes. Unless there's something the ESWD's researchers saw that I haven't, why they didn't combine the tracks is beyond me. One of the cited sources in the event entry even says word for word "La zona devastata dalla tromba d'aria si stende lungo una stricia di 15 chilometri, fra Valle Scuro Passo e Robecco Pavese" (translation: The area devastated by the tornado stretches 15 kilometers from Vallescuropasso to Robecco Pavese). Both La Stampa and l'Unità state a continuous path between Pavese and Scuropasso.

However, I did at least confirm that the listed death toll of six is correct. I can't remember how the confusion between six and seven arose, but their death toll is correct, not mine.

 

[Ivanthetornadoenthusiast]

Replying before this gets buried further...

Looked it up, and it's true! Here's the link, although the ESWD database doesn't reflect the update yet.

They are still listed as separate tornadoes. Unless there's something the ESWD's researchers saw that I haven't, why they didn't combine the tracks is beyond me. One of the cited sources in the event entry even says word for word "La zona devastata dalla tromba d'aria si stende lungo una stricia di 15 chilometri, fra Valle Scuro Passo e Robecco Pavese" (translation: The area devastated by the tornado stretches 15 kilometers from Vallescuropasso to Robecco Pavese). Both La Stampa and l'Unità state a continuous path between Pavese and Scuropasso.

However, I did at least confirm that the listed death toll of six is correct. I can't remember how the confusion between six and seven arose, but their death toll is correct, not mine.

I wonder if there's damage photos from the Broni area that apparently received a direct hit while the tornado was roping out

 

[TH2002]

I wonder if there's damage photos from the Broni area that apparently received a direct hit while the tornado was roping out

I saw a newspaper report of injured people being taken to Broni, but no evidence of said town being hit by the tornado.

Valle Scuropasso is directly south of Broni, which is probably where the report comes from.

 

[Ivanthetornadoenthusiast]

I saw a newspaper report of injured people being taken to Broni, but no evidence of said town being hit by the tornado.

Valle Scuropasso is directly south of Broni, which is probably where the report comes from.

Do you still have any damage photos from the Robecco Pavese-Vallescuropasso tornado?

 

[A Guy]

I've got good news and bad news.

The good news is a brand new study on cycloidal debris swaths just dropped! Was published one week ago today. They observed Mayfield 2021, Clarkesville 2023, Washington 2013, Rochelle-Fairdale 2015, and Dodge City 2016.

The study is behind a paywall, but I signed up for a 30 day free trial of deepdyve.com to get access.

The Viability of Cycloidal Debris Swaths as a Tornado Wind Speed Estimation Method​

The bad news is the results of the study aligned almost perfectly with the assigned EF ratings and maximum wind speeds of those tornadoes.

Mayfield
View attachment 52238

Clarkesville
View attachment 52239

Washington, Rochelle-Fairdale, Dodge City
View attachment 52240

After a streak of recent studies have found the EF scale underestimates wind speeds, we now have at least one on the board that supports those wind speeds. Using Fujita's own methods, no less!

I'm a tad surprised at them only getting 190-205 for Washington. I looked at them some years ago and got around 220 using pretty much the same method, I think someone else got even higher.

One thing I pointed out in my posts from last year explaining the method from Fujita's original paper is that we don't know how representative a speed obtained from a surface feature is for winds at the standard 10 metre reference height, as frictional effects may be important on the centimetre scales at hand.

 

[Saltical Wx]

I'm a tad surprised at them only getting 190-205 for Washington. I looked at them some years ago and got around 220 using pretty much the same method, I think someone else got even higher.

One thing I pointed out in my posts from last year explaining the method from Fujita's original paper is that we don't know how representative a speed obtained from a surface feature is for winds at the standard 10 metre reference height, as frictional effects may be important on the centimetre scales at hand.

There are a few things that come into play with cycloid analysis. The specific forward speed used for calculations and the manually traced cycloids in Fujita's methodology can present some variations in the final calculated tangential velocity. The numbers you saw were in an earlier version of the study, the published journal last week is the polished version of the calculations. Essentially meaning it was the tracing or forward speed that were tweaked and polished over the past couple years.

Regarding how cycloid analysis is determining wind velocities, it is essentially the lowest altitude (reliable) method of actually determining a wind speed. While the EF scale estimates a wind gust at 10m AGL (which is an altitude higher than the average house in the United States), cycloid analysis is calculating an exact tangential velocity at the lowest level (although unknown where specifically it is). It's not necessarily calculating tangential velocities at 1 cm, 1 mm, or anything like that. It's likely in the lowest few meters of the tornado, which is where nearly all damage occurs. So if anything, cycloid analysis is calculating wind speeds of a more impactful altitude than what the EF scale is estimating. It's possible tangential velocities may increase with altitude slightly, but I believe there have been also been studies that have found winds get stronger closer to the ground as a result of some sort of interaction, but I'm not sure on that one. Although important to note, cycloid analysis is strictly determining the tangential velocity and does not include the radial or axial velocities of a tornado. The EF scale estimates a wind gust of the horizontal component which includes both the tangential and radial velocities. The difference between strictly the tangential velocity and the total horizontal velocity depends on the swirl ratio, which can be somewhat reasonably estimated.

 

[Saltical Wx]

Also, this analysis is a good frame of reference to compare my formulas and methodology to Fujita's formula and methodology. See my full post on Washington's cycloidal marks here. My cycloid analysis of the Washington tornado, and the one conducted recently by Roegner et al. (2026) conducted cycloid analysis on the same cycloidal marks directly outside Washington. My analysis calculated tangential velocities of 89±3 m/s directly outside town, which falls in line with Roegner et al. (2026) which found 88.5±3.5 m/s at the same location. My analysis used a forward speed of 23.5 m/s while Roegner et al. (2026) used a forward speed of 24 m/s, a 1 mph difference in forward speed. The slight differences in our numbers stem from our different methodology, specifically how we measure cycloidal marks (not the calculation part). The plus or minus is to include the range of error for the forward speed of the tornado.

 

[tornado examiner]

I’m not gonna engage with them but now we have people calling Rochelle an “improperly rated low end EF4”

Newnan and caviness would like a word.

 

[Grand Poo Bah]

Also, this analysis is a good frame of reference to compare my formulas and methodology to Fujita's formula and methodology. See my full post on Washington's cycloidal marks here. My cycloid analysis of the Washington tornado, and the one conducted recently by Roegner et al. (2026) conducted cycloid analysis on the same cycloidal marks directly outside Washington. My analysis calculated tangential velocities of 89±3 m/s directly outside town, which falls in line with Roegner et al. (2026) which found 88.5±3.5 m/s at the same location. My analysis used a forward speed of 23.5 m/s while Roegner et al. (2026) used a forward speed of 24 m/s, a 1 mph difference in forward speed. The slight differences in our numbers stem from our different methodology, specifically how we measure cycloidal marks (not the calculation part). The plus or minus is to include the range of error for the forward speed of the tornado.
View attachment 52308

What are the highest wind speeds you've ever calculated from cycloidal marks?

 

[Saltical Wx]

What are the highest wind speeds you've ever calculated from cycloidal marks?

The highest wind speeds I've calculated from cycloidal marks is actually from the Robinson, Illinois EF3 from three years ago today on March 31st, 2023. The cycloidal mark at 38.96855471337801, -87.78138646421091 clocked in at a tangential velocity of 233±10 mph. One major factor that contributed to this high windspeed is the fact the tornado was moving at ~71-72 mph at this location, helping boost the tangential winds of the tornado.

 

[ColdFront]

The highest wind speeds I've calculated from cycloidal marks is actually from the Robinson, Illinois EF3 from three years ago today on March 31st, 2023. The cycloidal mark at 38.96855471337801, -87.78138646421091 clocked in at a tangential velocity of 233±10 mph. One major factor that contributed to this high windspeed is the fact the tornado was moving at ~71-72 mph at this location, helping boost the tangential winds of the tornado.

Thanks for being so open to hopping on here and answering questions, and so gracefully I might, considering some of the past interactions/history on here.

I’m assuming this calculation is sort of the original example of people taking your findings out of context.

 

[Saltical Wx]

Thanks for being so open to hopping on here and answering questions, and so gracefully I might, considering some of the past interactions/history on here.

I’m assuming this calculation is sort of the original example of people taking your findings out of context.

Thank you! I enjoy talking about these sort of things so I'm glad you guys are as well. And yes, this calculation was a source for people taking my work out of context and not being able to back up the methodology.

Good news though, I have made a significant amount of progress on my paper and presentations. Hopefully sometime in the next few months I can get a paper out somewhere for people to read. It will include essentially everything I have learned about cycloids over the past year and a half of research on them and will hopefully be able to answer every possible question on cycloidal marks.