Enhanced Fujita Ratings Debate Thread

[WeathermanLeprechaun]

Yeah I’ve had this same conversation with a few friends of mine since this development was announced. Honestly, the conclusion we reached is that we don’t really want El Reno to be upgraded to EF5 because like you said, it didn’t produce damage consistent with an EF5 event. This got me thinking “Why did El Reno 2011 produce some of the most incredible contextual damage ever, while El Reno 2013 came nowhere even close to that even though they occurred in the same vicinity?”

My theory is they were two very different “types” of tornadoes. With El Reno 2013, it’s known that the most violent winds occurred within the fast moving sub-vortices that were whipping around the exterior of the circulation. While these vortices contained unbelievably violent winds, my theory is that they were so small and fast moving, anything they hit only experienced EF5 winds for milliseconds to a few seconds at most. On the other hand, the damage from El Reno 2011 makes it clear that the entire wedge was just one massive wall of EF5 winds. Anything struck by El Reno 2011 probably experienced EF5 winds that lasted anywhere from 20 to maybe even 40 seconds. So in a nutshell, I believe the very different damage intensities were a result of very different dwell times, caused by two tornadoes with very different internal structures. It begs the question, can we really call a tornado EF5 if the EF5 winds it contained were so transient, isolated, and brief that they weren’t actually capable of producing EF5 damage? In fact, I have a hunch that multi-vortex tornadoes frequently produce vortices that contain isolated, small bursts of 200+ MPH winds that never end up producing damage that is indicative of such extreme intensity.

With all that said though, we have to keep in mind that all it would take to get El Reno upgraded to at least EF4, would be some root ball displacements, stubbed and debarked trees, a violent treefall pattern,or even calculation or Monte Carlo physics modeling-derived wind speeds from lofted cars or farm machinery. I mean after all, the entire basis for the proposed eventual Enid upgrade to EF5 comes down to tree damage and a lofted RV, even though the contextual damage there was way more violent than El Reno 2013. Remember, once the new tree scale is fully in place, all it will take for an EF4 or higher rating is a few large trees being ripped out of the ground. That’s not a terribly high bar to clear, and El Reno 2013 probably did something like that at some point.

Yeah. My theory is more tornadoes produce 200+ mph winds than thought and this is quite a common revelation. But how many of those actually sustained those winds consistently. Isolated, millisecond brief spurts are certainly a thing but that's not enough to establish EF5 damage and do it. El Reno 2013 likely contained those type of vortices, but were likely too sporadic to do much. I'd argue this is the same with the Hollister tornado. Mile wide EF1 yet it's entirely plausible its inner vortices were too sporadic to establish truly violent damage.

 

[buckeye05]

Yeah. My theory is more tornadoes produce 200+ mph winds than thought and this is quite a common revelation. But how many of those actually sustained those winds consistently. Isolated, millisecond brief spurts are certainly a thing but that's not enough to establish EF5 damage and do it. El Reno 2013 likely contained those type of vortices, but were likely too sporadic to do much. I'd argue this is the same with the Hollister tornado. Mile wide EF1 yet it's entirely plausible its inner vortices were too sporadic to establish truly violent damage.

Yeah exactly. Other tornadoes that come to mind are Sulphur, OK 2016 and Minden, IA 2024. Both resulted in EF5 mobile radar readings, but neither produced damage even bordering on EF5 intensity. I know recently there’s been some comments from people like Tim Marshall about how the updated EF scale will probably bring mobile radar data back into the rating process. But idk how I feel about that honestly for the reasons we’ve discussed. I suppose it will be useful when the context suggests a higher wind speed. But what about when the damage is clearly below the violent threshold, and there’s a 200+ MPH reading stemming from some random, freakishly intense, fast moving subvortex that lasted 3 seconds and didn’t produce violent damage? Do we still factor that in or not? It does feel like this could sort of re-open a can of worms so to speak.

 

[WeathermanLeprechaun]

Yeah exactly. Other tornadoes that come to mind are Sulphur, OK 2016 and Minden, IA 2024. Both resulted in EF5 mobile radar readings, but neither produced damage even bordering on EF5 intensity. I know recently there’s been some comments from people like Tim Marshall about how the updated EF scale will probably bring mobile radar data back into the rating process. But idk how I feel about that honestly for the reasons we’ve discussed. I suppose it will be useful when the context suggests a higher wind speed. But what about when the damage is clearly below the violent threshold, and there’s a 200+ MPH reading stemming from some random, freakishly intense, fast moving subvortex that lasted 3 seconds and didn’t produce violent damage? Do we still factor that in or not? It does feel like this could sort of re-open a can of worms so to speak.

It is a reading but I feel like it would irritate the same people who call for mobile readings to be factored in. A EF5 doesn't feel like a EF5 to most unless there's multiple well built homes gone, completely debarked trees, and high end contextuals. A measurement doesn't necessarily give you a "oh, that was a EF5" hence why Enderlin is kinda frowned on in this community because there was no traditional EF5 damage within it. There's a lot of variables to discuss on this part of things.

 

[slenker]

Yeah exactly. Other tornadoes that come to mind are Sulphur, OK 2016 and Minden, IA 2024. Both resulted in EF5 mobile radar readings, but neither produced damage even bordering on EF5 intensity. I know recently there’s been some comments from people like Tim Marshall about how the updated EF scale will probably bring mobile radar data back into the rating process. But idk how I feel about that honestly for the reasons we’ve discussed. I suppose it will be useful when the context suggests a higher wind speed. But what about when the damage is clearly below the violent threshold, and there’s a 200+ MPH reading stemming from some random, freakishly intense, fast moving subvortex that lasted 3 seconds and didn’t produce violent damage? Do we still factor that in or not? It does feel like this could sort of re-open a can of worms so to speak.

I think what I'm about to say is certainly not a hot take -- they definitely should only use radar data in conjunction with violent damage. Did the radar scan containing these winds coincide with violent to extremely violent damage? If the answer is yes, then I think it's totally valid. But if not, especially if there isn't any notable ground damage to speak of, then it absolutely cannot be used to justify an EF5 rating, let alone an EF4 rating. When I first joined this forum, I held the belief that radar data shouldn't be used at all, since it really did seem extremely inconsistent with how damage presented itself vs. the what the data insinuated. I was fully on-board with El Reno '13 staying an EF3 back then.

I don't believe it should be an EF5, but I do think it should be an EF4 - that is besides the point though. I've since changed my overall viewpoint because it very obviously still has merit to it, you're getting an actual reading of windspeeds even if they are higher up in the vortex. A vast majority of the time a more intense radar scan does point to a more powerful tornado outside of some weird incidents like Hollister 2024 or that one random tornado in Arkansas earlier this year during the big bust on April 27. There's also a few examples of tornadoes not being super impressive on radar, but still having violent damage like Matador; those tend to be far, far rarer, however. I don't think I can name another other than Matador in that regard off the top of my head. If we swing too hard in the direction of being too reliant on pure windspeed measurements for justifying ratings, then I wouldn't be surprised if there were boneheaded decisions in the other direction, i.e. downgrading a strong tornado based on unimpressive wind measurements even if it very clearly inflicted damage that was representative of its true intensity. With the direction the EF scale is going I highly doubt that would ever occur, though, from what I can tell it would be used very reasonably. If it ever were to happen it would be far in the future.

What I really like about Enderlin's radar data being taken into account is that the most intense scans from that tornado were perfectly in-line with the EF5 damage, which easily makes it a perfect candidate for this. I think this also potentially opens the idea of analyzing the Western Kentucky tornado while it was located in Bremen to this kind of analysis, IIRC it had an absolutely pristine vortex signature coincident with Smithville-level damage there. Maybe that could be used to justify a bump to EF5 even without the church damage being taken into account. I really think that is another tornado that badly needs the bump up outside of the obvious Chickasha/Goldsby and Vilonia tornadoes, it was so clearly an EF5 while it passed through Bremen based on contextual damage.

 

[WeathermanLeprechaun]

I think what I'm about to say is certainly not a hot take -- they definitely should only use radar data in conjunction with violent damage. Did the radar scan containing these winds coincide with violent to extremely violent damage? If the answer is yes, then I think it's totally valid. But if not, especially if there isn't any notable ground damage to speak of, then it absolutely cannot be used to justify an EF5 rating, let alone an EF4 rating. When I first joined this forum, I held the belief that radar data shouldn't be used at all, since it really did seem extremely inconsistent with how damage presented itself vs. the what the data insinuated. I was fully on-board with El Reno '13 staying an EF3 back then.

I don't believe it should be an EF5, but I do think it should be an EF4 - that is besides the point though. I've since changed my overall viewpoint because it very obviously still has merit to it, you're getting an actual reading of windspeeds even if they are higher up in the vortex. A vast majority of the time a more intense radar scan does point to a more powerful tornado outside of some weird incidents like Hollister 2024 or that one random tornado in Arkansas earlier this year during the big bust on April 27. There's also a few examples of tornadoes not being super impressive on radar, but still having violent damage like Matador; those tend to be far, far rarer, however. I don't think I can name another other than Matador in that regard off the top of my head. If we swing too hard in the direction of being too reliant on pure windspeed measurements for justifying ratings, then I wouldn't be surprised if there were boneheaded decisions in the other direction, i.e. downgrading a strong tornado based on unimpressive wind measurements even if it very clearly inflicted damage that was representative of its true intensity. With the direction the EF scale is going I highly doubt that would ever occur, though, from what I can tell it would be used very reasonably. If it ever were to happen it would be far in the future.

What I really like about Enderlin's radar data being taken into account is that the most intense scans from that tornado were perfectly in-line with the EF5 damage, which easily makes it a perfect candidate for this. I think this also potentially opens the idea of analyzing the Western Kentucky tornado while it was located in Bremen to this kind of analysis, IIRC it had an absolutely pristine vortex signature coincident with Smithville-level damage there. Maybe that could be used to justify a bump to EF5 even without the church damage being taken into account. I really think that is another tornado that badly needs the bump up outside of the obvious Chickasha/Goldsby and Vilonia tornadoes, it was so clearly an EF5 while it passed through Bremen based on contextual damage.

Honestly, regarding that Arkansas tor, the VROT really wasn't even that strong on it. I think it barely correlated above EF2 strength at all even at that range. People just hyped it given the insane lack of activity prior given it was a severe underperformance.

 

[buckeye05]

I think what I'm about to say is certainly not a hot take -- they definitely should only use radar data in conjunction with violent damage. Did the radar scan containing these winds coincide with violent to extremely violent damage? If the answer is yes, then I think it's totally valid. But if not, especially if there isn't any notable ground damage to speak of, then it absolutely cannot be used to justify an EF5 rating, let alone an EF4 rating. When I first joined this forum, I held the belief that radar data shouldn't be used at all, since it really did seem extremely inconsistent with how damage presented itself vs. the what the data insinuated. I was fully on-board with El Reno '13 staying an EF3 back then.

I don't believe it should be an EF5, but I do think it should be an EF4 - that is besides the point though. I've since changed my overall viewpoint because it very obviously still has merit to it, you're getting an actual reading of windspeeds even if they are higher up in the vortex. A vast majority of the time a more intense radar scan does point to a more powerful tornado outside of some weird incidents like Hollister 2024 or that one random tornado in Arkansas earlier this year during the big bust on April 27. There's also a few examples of tornadoes not being super impressive on radar, but still having violent damage like Matador; those tend to be far, far rarer, however. I don't think I can name another other than Matador in that regard off the top of my head. If we swing too hard in the direction of being too reliant on pure windspeed measurements for justifying ratings, then I wouldn't be surprised if there were boneheaded decisions in the other direction, i.e. downgrading a strong tornado based on unimpressive wind measurements even if it very clearly inflicted damage that was representative of its true intensity. With the direction the EF scale is going I highly doubt that would ever occur, though, from what I can tell it would be used very reasonably. If it ever were to happen it would be far in the future.

What I really like about Enderlin's radar data being taken into account is that the most intense scans from that tornado were perfectly in-line with the EF5 damage, which easily makes it a perfect candidate for this. I think this also potentially opens the idea of analyzing the Western Kentucky tornado while it was located in Bremen to this kind of analysis, IIRC it had an absolutely pristine vortex signature coincident with Smithville-level damage there. Maybe that could be used to justify a bump to EF5 even without the church damage being taken into account. I really think that is another tornado that badly needs the bump up outside of the obvious Chickasha/Goldsby and Vilonia tornadoes, it was so clearly an EF5 while it passed through Bremen based on contextual damage.

Speaking of Bremen, I think actually the best shot at EF5 there actually comes down to the tree damage. I watched the AMS video presentation on the future of the tree scale, and they said that the best hypothetical example of “higher than normal resistance” needed for EF5 criteria root balling of trees, would be a scenario in which the trees were not in leaf.

The Mayfield/Bremen tornado happened in December and the trees were already completely bare. So the key thing is what happened right on the property of the 190 MPH house in Bremen. Multiple large hardwood maple trees, all of which had no leaves on them, were ripped out of the ground and strewn across the property.


This is absolutely textbook EF5 tree damage, and is a real life example of the exact scenario mentioned in the AMS video presentation. Now here’s where it gets ridiculous. See the grove of trees in the lower left corner? That right there, is the primary reason they went with EF4 instead of EF5. They thought there were too many standing trees in this grove near the home. Yet simultaneously, we have the most perfect example of EF5 tree damage there’s ever been, right there on the same property. Unfortunately, Mayfield happened right before the recent advances in tree damage analysis began. So as a result, the surveyors had EF5 tree damage right in front of them, but they didn’t register it because the concept of EF5 tree damage hadn’t yet been established at this time. The irony is that they went lower bound here at this exact spot, based on tree damage. Really shows you how much damage survey science has changed in just a few years. Anyway, I think Mayfield is a pretty easy upgrade at this stage between the church and the leafless root balling in Bremen.

 

[buckeye05]

Also, I wouldn’t say that there was no evidence of EF5 damage in Enderlin besides the train car. Near the river, there was a well documented area of extremely intense “sandpapering” (particulate induced debarking that occurs without debris loading) and root balling of trees. In addition, while the houses it obliterated were not well anchored, the debris patterns extending away from the foundations were extremely violent. In fact, I distinctly remember seeing one empty foundation near Enderlin that barely had any kind of debris scatter pattern extending away from it. There were just a few random planks of wood left, and that’s really it. I’ve always said that the most impressive kind of debris pattern, is when there is no real debris pattern left behind at all. A sweep that clean is quite rare, and you only really see that kind of thing at the top end of the EF scale. So well before it was upgraded, Enderlin was already providing us with some clues that suggested extreme intensity.

 

[eep]

Yeah exactly. Other tornadoes that come to mind are Sulphur, OK 2016 and Minden, IA 2024. Both resulted in EF5 mobile radar readings, but neither produced damage even bordering on EF5 intensity. I know recently there’s been some comments from people like Tim Marshall about how the updated EF scale will probably bring mobile radar data back into the rating process. But idk how I feel about that honestly for the reasons we’ve discussed. I suppose it will be useful when the context suggests a higher wind speed. But what about when the damage is clearly below the violent threshold, and there’s a 200+ MPH reading stemming from some random, freakishly intense, fast moving subvortex that lasted 3 seconds and didn’t produce violent damage? Do we still factor that in or not? It does feel like this could sort of re-open a can of worms so to speak.

Agree with Sulphur but I thought for Minden and El Reno they were kind of over empty fields at their most intense. Also there are examples of tornadoes that were pretty strange in damage presentation (I recall there was an old SD tornado that swept houses clean while lacking contextuals, or maybe it was the other way around?). I can say confidently though that Henryville 2012 is an example of that erratic vortex behaviour with the pavement carved into a tree, but I kinda think that tornado has some subtle hints it was EF5 intensity at various points.

 

[slenker]

Agree with Sulphur but I thought for Minden and El Reno they were kind of over empty fields at their most intense. Also there are examples of tornadoes that were pretty strange in damage presentation (I recall there was an old SD tornado that swept houses clean while lacking contextuals, or maybe it was the other way around?). I can say confidently though that Henryville 2012 is an example of that erratic vortex behaviour with the pavement carved into a tree, but I kinda think that tornado has some subtle hints it was EF5 intensity at various points.

El Reno is just a very weird tornado in terms of damage presentation. Even if they are over empty fields, an extremely violent tornado is going to make its mark in those areas and it would be fairly obvious one occurred. Great examples of this are Matador, Bakersfield Valley, Bridge Creek and Piedmont while they were over open fields. El Reno simply did not do this. As for Minden, the same thing applies. I do have issues with the altitude that the 200+ mph rating was taken at for Minden in particular. IIRC it was around ~600 m AGL, which is so far above the damage layer that it cannot be used to justify EF5 unless it did tree damage or something that pointed to EF5 intensity while said data was being actively taken. I would maybe support an upgrade to EF4 for it, since it was clearly a violent tornado, but EF5 would be not acceptable.

 

[buckeye05]

Agree with Sulphur but I thought for Minden and El Reno they were kind of over empty fields at their most intense. Also there are examples of tornadoes that were pretty strange in damage presentation (I recall there was an old SD tornado that swept houses clean while lacking contextuals, or maybe it was the other way around?). I can say confidently though that Henryville 2012 is an example of that erratic vortex behaviour with the pavement carved into a tree, but I kinda think that tornado has some subtle hints it was EF5 intensity at various points.

Kinda echoing slenker’s sentiments here, but even if it only hits open fields and vegetation, an absolutely top end tornado is still going to leave its mark, both figuratively and literally. You’re going to have incredible scouring, you’re going to have completely debarked/root balled trees, you’re going to have low lying shrubs completely shredded and debarked. With the Minden and El Reno tornadoes, very detailed ground surveys were conducted, and nothing of note was found. In fact, the El Reno tornado in particular was surveyed on foot from its very beginning to its very end by not just the NWS, but by independent surveyors as well. They found no truly extreme vegetation damage, and found that even in the worst affected areas, surface vegetation was flattened but no real scouring or shredding had occurred. Even more telling, when the exact area where the insane mobile radar windspeed occurred was surveyed on foot, there was no scouring or other evidence of extreme intensity visible in the vicinity.

The bottom line is, these tornadoes did not produce any extreme damage, and rural areas impacted by true EF5 winds would still bear the contextual hallmarks of a high-end event. Nothing like that was found in either of those examples, and this suggests these extreme mobile radar readings are from extremely brief, transient gusts within sub-vortices rather than being a true reading of the tornado’s overall windspeed.