Enhanced Fujita Ratings Debate Thread

[buckeye05]

I would agree with this, but Poole said it himself and that most people, (I can only assume he’s talking about other surveyors) that the damage was representative of an EF5.

Sure the slab wasn’t swept clean, but many conventional DIs were rated EF5 without a clean slab.

It was an absolutely splendid survey, but the main point is that if an EF5 DI is present, then the tornado should be rated as such, plain and simple.

The EF scale is a damage scale, it has nothing to do with “confidence” in whether other buildings nearby should warrant the rating.

I’m just not really comfortable with EF5 without it genuinely meeting the “slab swept clean” description, or alternatively, something remarkable like slab buckling/dislodgement as seen at the restaurant in Mount Hope, AL back in 2011.

Generally, non-clean slabs with EF5 ratings occur as a result of debris from neighboring structures being taken into account. This was the case at a few of the EF5 homes in Moore 2013.

 

[TH2002]

I would agree with this, but Poole said it himself and that most people, (I can only assume he’s talking about other surveyors) that the damage was representative of an EF5.

Sure the slab wasn’t swept clean, but many conventional DIs were rated EF5 without a clean slab.

It was an absolutely splendid survey, but the main point is that if an EF5 DI is present, then the tornado should be rated as such, plain and simple.

The EF scale is a damage scale, it has nothing to do with “confidence” in whether other buildings nearby should warrant the rating.

Him saying "most people would agree this would be representative of an EF5 tornado" is a bit of Poole's own subjective opinion. It's just a fancy way of him saying "this structure was an EF5 candidate". The fact that an EF5 rating was considered for that DI doesn't automatically mean it should have received that rating.

The EF scale is a damage scale, and the damage to that building was that it was leveled but not completely slabbed.

 

[jiharris0220]

I’m just not really comfortable with EF5 without it genuinely meeting the “slab swept clean” description, or alternatively, something remarkable like slab buckling/dislodgement as seen at the restaurant in Mount Hope, AL back in 2011.

Generally, non-clean slabs with EF5 ratings occur as a result of debris from neighboring structures being taken into account. This was the case at a few of the EF5 homes in Moore 2013.

It’s hard to tell how much of that debris on the slab of the Flower shop is its own or from that structure near by, which according to Poole’s own words is what lowered confidence in an Ef5 rating.

Which again, that just should not be a factor going into tornado ratings. Perhaps I’m just not aware of some sort of unspoken rule regarding that.

 

[slenker]

Him saying "most people would agree this would be representative of an EF5 tornado" is a bit of Poole's own subjective opinion. It's just a fancy way of him saying "this structure was an EF5 candidate". The fact that an EF5 rating was considered for that DI doesn't automatically mean it should have received that rating.

The EF scale is a damage scale, and the damage to that building was that it was leveled but not completely slabbed.

I do dislike the way it was phrased in the quote then. It is absolutely my bad for jumping to such a conclusion so quickly, but I still feel like it was a very strange quote. It also kinda highlights the fact that since the scale is so subjective it leads to a significant amount of inconsistencies between surveys of differing WFOs. I’m sure if Rolling Fork happened elsewhere there would be at least 1 WFO that rates it an EF5 somewhere. Not to say it would be valid, but the fact that it’s interpreted so differently between different offices is a major flaw with the scale, without question.

 

[jiharris0220]

Him saying "most people would agree this would be representative of an EF5 tornado" is a bit of Poole's own subjective opinion. It's just a fancy way of him saying "this structure was an EF5 candidate". The fact that an EF5 rating was considered for that DI doesn't automatically mean it should have received that rating.

The EF scale is a damage scale, and the damage to that building was that it was leveled but not completely slabbed.

I don’t know about that.

Honestly I think he should’ve phrased this differently, because it’s open to interpretation.

He could’ve said this out of his own subjective opinion or from genuine conversations with many surveyors.

And I’m not sure I agree that if a structure is an ef5 candidate that it still doesn’t mean it’s an ef5 DI. The “EF5 candidate” thing since its introduction along with the 201mph designation as a whole isn’t exactly what you would call a “beneficial contribution” to the EF scale.

As it pretty much lets surveyors say, “well it was an Ef5 but no”.

It’s better to just say it’s high end ef4 damage in the first place to not cause confusion.

 

[ColdFront]

Yeah it surprised me because I had never even thought Perryville was a candidate for a 5. I will have to go find the source. I want to say it was an email response from a NWS employee to someone on Twitter that had emailed about the lack of EF5s.

@buckeye05

So - I found where this was from. A user had posted this last May in this thread. The background is some Weenie on Twitter emailed NWS Paducah, Jackson, and Des Moines on some kind of EF5 Rant/Question. Chris Noles from Paducah was kind enough to answer him back and here are the emails posted below.

When he talks about Perryville, it seems to me like he voted for it to be a 5.

 

[jiharris0220]

So - I found where this was from. A user had posted this last May in this thread. The background is some Weenie on Twitter emailed NWS Paducah, Jackson, and Des Moines on some kind of EF5 Rant/Question. Chris Noles from Paducah was kind enough to answer him back and here are the emails posted below.




View attachment 37601
View attachment 37602

I’ve seen this reply, and it’s a very well thought out answer.

Specifically the part where he shares his opinion regarding the path length of the Mayfield tornado. It is an interesting thought, and an argument could be made that not enough effort was not put in making sure the tornado actually lifted when it was occluding/cycling. (Although there wasn’t any visible damage within the interval between the two paths)

I can also tell reading this specific part that he was a bit frustrated with the OP’s comment and the lack of care or concern about the lives affected by these tornadoes regardless of what they’re rated.

 

[slenker]

I understand the sentiment of “who cares about EF5 if these people were affected drastically” because it’s 100% true. At the end of the day, it does not matter what the ultimate rating is in terms of lives lost and damage done.

However, it does play an important scientific role in terms of post-analysis of the storms. I feel like we should be striving to be as consistent and as accurate as possible in these tornado ratings, and not rely on a dogmatic and inconsistent scale, completely open to subjective interpretation that repeatedly underrates the intensity of tornadoes. This is clearly shown in data that the EF scale is not an accurate representation of a tornado’s intensity, and it’s still entirely valid to critique a tornado’s rating if it didn’t receive the valid one as well. Vilonia, Chickasha, Goldsby and Rochelle were without a doubt in my mind EF5s and should have absolutely been rated as such, and the fact that tornado ratings don’t matter when it comes to the monetary and lively impact they have shouldn’t free said ratings from criticism.

It’s still a very well thought out post and I do believe that a lot of it holds credence.

 

[TH2002]

Wasn't sure where to post this comment, but the recent earthquake in Myanmar got me thinking...

The common misconception that tornadoes are the only disaster that are rated based on the damage they leave behind is not true.

Earthquakes are rated using two scales - the more commonly known Richter scale that measures an earthquake by its magnitude, and then there's the Mercalli scale that ranks the earthquake based on its actual intensity.

Much like the F and EF scales, it is based on damage surveys. Take the 1992 Landers earthquake, which was given a maximum Mercalli intensity rating of IX (Violent) based on the destruction of a well-built wood-framed home, and the Big Bear earthquake that followed a few hours later was given a rating of VIII (Severe) based on the destruction of unreinforced masonry structures. Like how non-structural contextual damage is taken into consideration (by reasonable WFO's, anyhow) when rating tornadoes, non-structural damage including soil liquefaction and surface ruptures is taken into account when assigning a Mercalli rating as well.

More information and damage photos from the Landers and Big Bear earthquakes here...

Anyhow, not related to the current discussion, but thought that was an interesting tidbit.

 

[UK_EF4]

Wasn't sure where to post this comment, but the recent earthquake in Myanmar got me thinking...

The common misconception that tornadoes are the only disaster that are rated based on the damage they leave behind is not true.

Earthquakes are rated using two scales - the more commonly known Richter scale that measures an earthquake by its magnitude, and then there's the Mercalli scale that ranks the earthquake based on its actual intensity.

Much like the F and EF scales, it is based on damage surveys. Take the 1992 Landers earthquake, which was given a maximum Mercalli intensity rating of IX (Violent) based on the destruction of a well-built wood-framed home, and the Big Bear earthquake that followed a few hours later was given a rating of VIII (Severe) based on the destruction of unreinforced masonry structures. Like how non-structural contextual damage is taken into consideration (by reasonable WFO's, anyhow) when rating tornadoes, non-structural damage including soil liquefaction and surface ruptures is taken into account when assigning a Mercalli rating as well.

More information and damage photos from the Landers and Big Bear earthquakes here...

Anyhow, not related to the current discussion, but thought that was an interesting tidbit.

Wow, that is very interesting - I had previously thought they assigned the intensity based on the speed of measured ground motion, but clearly the tornado rating system is not unique in that regard! Thanks for sharing.

 

[TH2002]

Back to tornadoes - I've done quite a bit of digging on the 6/20/2011 Outbreak, and I honestly have to say the surveys of the intense tornadoes from that outbreak were pretty poor.

Let me give the rundown:
Hill City, KS EF3 - this shape-shifting tornado threw heavy farm implements 3/4 of a mile. Unfortunately I could not find any photos of this damage, but it was confirmed by the NWS. This storm also produced two satellite tornadoes, both rated EF1.

Almena, KS EF3 - I've brought this one up as a potentially underrated event before, but here's a brief summary for those who may have not heard of it. It leveled a poorly constructed home, partially debarked trees, scoured farmland and threw and mangled farm implements much like the Hill City tornado.

Another possibility is that maybe the NWS made a mistake and attributed this damage to the Hill City tornado? That wouldn't explain why the Storm Data entries specifically mention damage to heavy farm equipment for both tornadoes though. I've done some research and the photos of the farm equipment posted above were taken north of KS-383 on the Norton-Phillips county line, most definitely putting them on the Almena path.

Osceola, NE EF3 - heavily scoured farm fields and threw vehicles and farm implements long distances, including a combine that was tossed 100 yards and a tractor that was mangled beyond recognition. Low-end EF3? Not a chance.

Bradshaw, NE EF2 - threw a combine an unspecified distance and left it pretty badly mangled:

 

[TH2002]

On June 28, 2018, one of the most underrated tornadoes in history touched down on the Montana-South Dakota border south of Camp Crook. Tracking slowly northeastward, it struck Doug Davis' farm 200 yards east of the MT-SD border with almost unimaginable intensity. Davis' 10,000 pound 1974 Case 1070 tractor was flung a mile and a half AGAINST the forward motion of the tornado, with the remaining pieces being scattered another mile and a half. This is, in my opinion, far and down the worst damage to heavy farm equipment from a tornado that has ever been documented. In addition to the tractor, several vehicles were lofted and never recovered, pronounced ground scouring occurred, trees were debarked and a farm outbuilding was obliterated, with its foundation "extracted from the ground and broken apart".

Despite all of this, NWS Rapid City gave this tornado the ridiculous rating of LOW-END EF3. Not even high-end EF3 like Matador! 2018 went into the record books as the only year post-1950 that (officially) no violent tornadoes touched down in the US, when we all know damn well that simply isn't true.

A Case 1070 similar to Davis' beloved tractor, as it would have appeared before the tornado...

And this is the largest piece that remained of it, found a mile and a half away from Davis' ranch across the state line in Montana. Other pieces from the tractor were recovered from as far as three miles away.

Other images of impressive contextual damage including scouring, debarking and the outbuilding that had its foundation sucked up:

This is one of the rare cases where, although there wasn't any genuine EF5 damage to homes or other well-built structures, the context paints a pretty clear picture imo. Grazulis rated this tornado a high-end EF4 in SigTor2022, which I can accept - but honestly, this is a case like Rainsville where the contextual damage tells the story more than anything else.

 

[eep]

On June 28, 2018, one of the most underrated tornadoes in history touched down on the Montana-South Dakota border south of Camp Crook. Tracking slowly northeastward, it struck Doug Davis' farm 200 yards east of the MT-SD border with almost unimaginable intensity. Davis' 10,000 pound 1974 Case 1070 tractor was flung a mile and a half AGAINST the forward motion of the tornado, with the remaining pieces being scattered another mile and a half. This is, in my opinion, far and down the worst damage to heavy farm equipment from a tornado that has ever been documented. In addition to the tractor, several vehicles were lofted and never recovered, pronounced ground scouring occurred, trees were debarked and a farm outbuilding was obliterated, with its foundation "extracted from the ground and broken apart".

Despite all of this, NWS Rapid City gave this tornado the ridiculous rating of LOW-END EF3. Not even high-end EF3 like Matador! 2018 went into the record books as the only year post-1950 that (officially) no violent tornadoes touched down in the US, when we all know damn well that simply isn't true.

A Case 1070 similar to Davis' beloved tractor, as it would have appeared before the tornado...

And this is the largest piece that remained of it, found a mile and a half away from Davis' ranch across the state line in Montana. Other pieces from the tractor were recovered from as far as three miles away.

Other images of impressive contextual damage including scouring, debarking and the outbuilding that had its foundation sucked up:

This is one of the rare cases where, although there wasn't any genuine EF5 damage to homes or other well-built structures, the context paints a pretty clear picture imo. Grazulis rated this tornado a high-end EF4 in SigTor2022, which I can accept - but honestly, this is a case like Rainsville where the contextual damage tells the story more than anything else.

This has always felt like a classic instance of the Fujita scale failing to interpret rural damage indicators.

 

[NewFoundWeatherNerd]

On June 28, 2018, one of the most underrated tornadoes in history touched down on the Montana-South Dakota border south of Camp Crook. Tracking slowly northeastward, it struck Doug Davis' farm 200 yards east of the MT-SD border with almost unimaginable intensity. Davis' 10,000 pound 1974 Case 1070 tractor was flung a mile and a half AGAINST the forward motion of the tornado, with the remaining pieces being scattered another mile and a half. This is, in my opinion, far and down the worst damage to heavy farm equipment from a tornado that has ever been documented. In addition to the tractor, several vehicles were lofted and never recovered, pronounced ground scouring occurred, trees were debarked and a farm outbuilding was obliterated, with its foundation "extracted from the ground and broken apart".

Despite all of this, NWS Rapid City gave this tornado the ridiculous rating of LOW-END EF3. Not even high-end EF3 like Matador! 2018 went into the record books as the only year post-1950 that (officially) no violent tornadoes touched down in the US, when we all know damn well that simply isn't true.

A Case 1070 similar to Davis' beloved tractor, as it would have appeared before the tornado...

And this is the largest piece that remained of it, found a mile and a half away from Davis' ranch across the state line in Montana. Other pieces from the tractor were recovered from as far as three miles away.

Other images of impressive contextual damage including scouring, debarking and the outbuilding that had its foundation sucked up:

This is one of the rare cases where, although there wasn't any genuine EF5 damage to homes or other well-built structures, the context paints a pretty clear picture imo. Grazulis rated this tornado a high-end EF4 in SigTor2022, which I can accept - but honestly, this is a case like Rainsville where the contextual damage tells the story more than anything else.

Dude no way! Ever since I heard about this happening Ive wondered about photos of that tractor, but seeing the scouring even further proves this thing was a monster. Something I do think about is possibly applying the methods derived from a study surrounding farm equipment being lofted in the 2023 Didsbury Alberta EF4 done by the NTP. I just really wonder if the true winds required to do that can be estimated using those calculations as reference; Im no math person, I would do those if I could. I wonder why the NWS doesn't do some of that level of math work for unique damage; perhaps they do, its just not published like the NTP does. But NTP did similar work for another rural tornado, being Alonsa 2018 (EF4); which both of these studies proved these two tornadoes potentially had EF5 level winds. I fully think we need to start crunching numbers for tornado damage on a much finer scale

 

[joshoctober16]

time for a new EF scale controversy

and its now about tornadoes not even being rated EF0 at this point it seems (not being surveyed).

 

[Aaron Rider]

time for a new EF scale controversy

and its now about tornadoes not even being rated EF0 at this point it seems (not being surveyed).

We're going to have to crowd fund surveys, aren't we?

 

[Juliett Bravo Kilo]

We're going to have to crowd fund surveys, aren't we?

Thanks to the geniuses in charge currently, yes.

 

[ColdFront]

We're going to have to crowd fund surveys, aren't we?

I don’t think you’ll see surveying going away but I could reasonably see some sort of push for “private sector” firms to be contracted to carry out the surveys or complete privatization of surveying. I bet HAAG engineering would be chomping at the bits for that. Not saying that will happen but I can imagine a push for it with all the other changes.

 

[TH2002]

Cross-posting from the April 1-2 severe thread, but including more photos. Here's a well-anchored home destroyed by the Potosi, MO tornado given EF3/165. Let the discussion begin.

 

[Grand Poo Bah]

I charted some data and the results are extremely telling.

Here's total tornadoes per year since 1980



Here's (E)FU-(E)F1 Rated Tornadoes



Here's (E)F2-(E)F3



And Here's (E)F4-(E)F5



Here's all four overlayed with each other.



Compare 2011 to 2024. Close to the same amount of tornadoes, but an enormous lack of EF4/EF5s. 2004 was the last time there was a discrepancy this large and 500 of those tornadoes were from two hurricane outbreaks, and one November outbreak. We're trending even below that today. You can even see the exact moment the rating system changed in 2013.

Are we just supposed to accept this climatology? This data suggests tornadoes have become far less violent over the last 40 years.

Edit: Somehow didn't include (E)F0 ratings in the original charts so i've updated with corrected information.