Enhanced Fujita Ratings Debate Thread

[Lake Martin EF4]

I definitely agree with contextual in many cases, but there are a few iffy ones to me like Holly Springs. Picher is a tornado I've looked into very extensively and have over 1,500 damage photos of, and I will definitely say I'm sure it reached EF5 intensity. I interpreted your list as one of tornadoes deserving an EF5 *rating*, but if it was an intensity list it's much more agreeable

Actually, you are right in your thought that the list is referring to ratings in most cases, although it could work as an intensity list too (not to mention I use contextuals a lot more liberally than the actual NWS does). If you looked through the Significant Tornadoes thread, you'd probably find some extraordinary things from some of the ones you've deemed not worthy.

As for Holly Springs, let's look at what @TH2002 has to say about it...

Speaking of Holly Springs, here's another one of my "armchair surveys" for that tornado:

Southwest of the Lamar Rd vicinity (where the tornado most probably attained peak intensity) a cluster of four homes was destroyed on Hoover Road. The concrete foundation visible at the bottom was probably poured post-tornado for the home that replaced the manufactured one destroyed in the tornado. A mobile home was also destroyed here, along with another home of unknown construction and a fairly large home (at top) built on a concrete slab. Although none of these homes were exceptionally old (the top three weren't there in the 2007 imagery) I can't infer anything else about their construction or the degree of damage each of them incurred. I will say that the fact there is still debris visible on the slab of the home at the top of the photo (three months after the tornado) makes it less likely in my opinion that it was leveled or swept away, but who knows? No need to mention that this area wasn't surveyed by NWS Memphis.



Three homes were destroyed in the Country Church Road vicinity. Three people died in the poorly constructed home visible in the bottom left of the satellite photo and the ground level photo. The body of one of the victims was found a quarter mile away. One home built on a concrete slab was also destroyed (degree of damage unknown) along with a home of unknown construction, although a new home can be seen in its place. Just northeast of this area the Calvary Baptist Church and several outbuildings at an RV business were heavily damaged or destroyed.


The tornado spent about six and a half miles downing forest and destroying outbuildings before it struck yet another homesite on Medlock Rd, destroying a slab-built home and wiping out several outbuildings (the outbuildings at the bottom center of this photo replace ones that were destroyed in the tornado). This home was very close to the large, verifiably well built home that was given a 170MPH EF4 DI, and ended up being the main basis for the EF4 rating.

This has been said before, but I simply can't put in words how unbelievably half-@ssed MEG's official survey for this historical December tornado was, and it's something I'll never be able to get over. Regardless of its official status though, I can conclude that this tornado was almost certainly an EF5, and hopefully someone like Grazulis can finally give it the recognition it deserves.

-A home swept away near Ashland was bolted to its foundation
-Extensive ground and pavement scouring along with extreme vehicle damage occurred in the Lamar Road vicinity
-Trees were debarked and homes were swept away in the Country Church Road vicinity

 

[Asha627]

Actually, you are right in your thought that the list is referring to ratings in most cases, although it could work as an intensity list too (not to mention I usual contextuals a lot more liberally than the actual NWS does). If you looked through the Significant Tornadoes thread, you'd probably find some extraordinary things from some of the ones you've deemed not worthy.

As for Holly Springs, let's look at what @TH2002 has to say about it...

I have actually not heard of this damage from Holly Springs, interesting. I will say tornadoes like Coleridge are completely undeserving of the rating structurally, but if the EF scale factored in contextuals I'm sure it'd be at the highest rung. I've seen the most extreme damage from most of the tornadoes on your list, and while I do agree that the vast majority of them undoubtedly attained EF5 intensity, they just didn't produce damage that would warrant a 5 using the proper EF scale.

 

[Lake Martin EF4]

they just didn't produce damage that would warrant a 5 using the proper EF scale.

Let's go case by case for some of the most notable...

Vilonia: E Fisher Street home, only marked as "unknown" anchoring because the survey team (seemingly intentionally) did not look into it in depth. Cemetery and Beryl Roads, effectively in their entirety, with no DIs whatsoever. Fish Hooks restaurant. And others, too, I just don't remember them.
Rochelle: One specific house, where the sidewalk was shifted laterally and the house swept away with little/no debris left, coupled with severe contextual damage in the vicinity
Holly Springs: see above
Chapman: A well built farmhouse swept away so violently it snapped part of the foundation. I believe this DI (and a few other DIs) was compared by @TH2002 to Hackleburg, actually. Another house essentially disappeared with no debris remaining. And of course, the railroad.
Camp Crook: The wipeout at the farmstead. Admittedly a bit more contextual than most, but still potentially valid.
Mayfield: Actually surprised you didn't dispute this one. I think this was EF5 mainly based off contextuals, and only 2 DIs are EF5 worthy to me: the church in Mayfield and a particularly weirdly constructed home in Bremen which I gave EF5 after seeing Ethan Morairty give it EF5 in one of his (IMO) few good takes.
Rolling Fork: The Family Dollar. Not EF5 eligible on the current EF scale, but it does qualify as EF5 on the upcoming revision I've posted about.
Matador: One specific well built house swept away, alongside extreme contextual damage. I also posted about this one.

I'll add links and photos to all of them later, but here's the Chapman foundation snapper farmhouse:

It's this home. NWS Topeka didn't survey it, but Marshall did and, surprise surprise, gave it an EF4 rating.


Again, if I wanted to be a pedantic nitpicker I could come up with a million reasons to downgrade it, but I have to disagree with Tim on this one. If the EF5 shoe fits, wear it.

And the Matador EF5 candidate house:

I don’t have one saved unfortunately. It was a basement foundation home with anchor bolts.

Edit: I take that back. I do have one. Does it look like perfect construction? No. But it is poured concrete, anchor bolting is present, the subfloor is gone, and the concrete stemwall is actually broken. I could also settle for very high-end EF4 too, but in my opinion, it’s a rare situation like Rainsville where there’s just enough evidence for EF5 even though the foundation could be better quality. In this case, the contextual damage tells the story more accurately than the construction.

 

[Grand Poo Bah]

I'm saying Philadelphia did not deserve its rating. The tornadoes I listed were just some that I feel do not belong on the original list.

I'll start by asking are you aware of the studies by the Doppler on Wheels team, NOAA, and YALE that all concluded tornadoes are currently underrated significantly?

Doppler on Wheels - Supercell tornadoes are much stronger and wider than damage-based ratings indicate

This study suggests tornadoes are underrated by an average of 1.5 EF rating, or 40 MPH.

NOAA - Comparison of Tornado Damage Characteristics to Low-Altitude WSR-88D Radar Observations and Implications for Tornado Intensity Estimation



The black dots are EF rated tornadoes. The dashed line is actual recorded wind speeds, and the solid line is the distribution of EF rating wind speeds. The gray areas represent overrating and underrating. Zero tornadoes were overrated, and over half were underrated.

Yale - Where Have the EF5s Gone? A Closer Look at the “Drought” of the Most Violent Tornadoes in the United States

A key breakpoint exists between how the legacy Fujita (F) scale and the EF scale handle the complete destruction and sweeping away of single-family homes, with standard “well-constructed” homes being swept away constituting F5 damage on the F scale but only EF4 damage on the EF scale. To illustrate this point, adjusting the lower-bound of EF5 on the EF scale from 201 mph to 190 mph or increasing all 190–200-mph EF4s to >200 mph EF5s to account for this breakpoint in the handling of single-family homes would lead to consistent 5-level rating assignments from 1880 through present day. Furthermore, contextual evidence that was used to aid in identifying 5-level damage in the F-scale and early EF-scale eras could assist in identifying top-tier intensity tornadoes. These findings ultimately lead to questions regarding what the highest possible rating of a tornado should represent from both physical and societal perspectives.

All of these studies illustrate the fact the increased scrutiny with ratings is pointless and counter productive. The EF scale may be a damage scale, but the damage is being underestimated and over scrutinized by degrees of magnitude. I'll let @Lake Martin EF4 and @TH2002 address the pre 2011 tornadoes, but I'll cover some of the rest.

Here are your EF5 Indicators:

1. Tuscaloosa 2011 - Tossed a 36 ton rail car further than any railcar has ever been tossed (400 feet), and tore apart million pound, 150 foot tall bridge trestles and lifted them 100 feet up hill.


2. Henryville 2012 (maybe) - Tore up asphalt and lofted it long distances, creating 2-3 foot impact craters where they landed.


3. Washington 2013- Slabbed entire neighborhoods, including well built, anchored homes


4. Vilonia 2014 - One of the most egregiously underrated tornadoes ever, and the cause of "Vilonia Syndrome", which lead to multiple EF5 candidates being underrated due to lack of impossible contextuals, and build quality standards. One home was completely slabbed that had anchor bolts in both exterior AND interior walls


5. Pilger, NE 2014 - I don't have a ton of pictures (maybe someone else can help), but this one definitely speaks for itself


6. Rochelle-Fairdale 2015 - My favorite quote about this one is for @buckeye05, "As this tornado struck the Deer Creek subdivision to the north of town, numerous EF5 hallmarks occurred. Multiple large, modern, well-anchored homes were swept away, with the debris granulated and wind-rowed long distances. Mowed, short lawn grass was scoured from the yards of several of these homes as well. Most impressively, a concrete sidewalk leading to the front door of one of these homes was actually shifted and pulled away from the driveway and house (photo below). The low-level winds that would have been needed to move this sidewalk would have to have been absolutely insane."


7. Chapman 2016 The most impressive contextuals I've ever seen, it really encapsulates what Ted Fujita said about F5 tornadoes "leaving behind a path of destruction so severe that it could defy explanation due to the sheer force of the winds involved". It literally fused a truck with a combine, moved railroad tracks (it was only 85 degrees that day so I don't want to hear anyone mention thermal expansion), snapped the foundation of a well built brick farm house, and mangled cars in ways that defy explanation.


8. Bassfield-Soso 2020 - Some of the most impressive debarking you'll ever see, it wrapped steel beams around trees, and slabbed a well built home while bending its anchor bolts


9. Mayfield 2021 - Tore apart entire cities and subdivisions, destroyed multiple institutional buildings and steel reinforced concrete/masonry structures in downtown Mayfield, trenched the ground up to 8 inches deep in several spots, tossed a well built reinforced CMU home slab n' all, and much much more. I get increasingly frustrated when people say the tornado didn't hit enough well built structures. The path was so long, and so many structures impacted, the survey team never even came close to observing all of them. Multiple neighborhoods were surveyed and cataloged from the passenger seat of moving vehicles. Dozens of homes were slabbed, and surely some of those homes had top quality construction that was missed.

 

[AJS]

I'll start by asking are you aware of the studies by the Doppler on Wheels team, NOAA, and YALE that all concluded tornadoes are currently underrated significantly?

Doppler on Wheels - Supercell tornadoes are much stronger and wider than damage-based ratings indicate

This study suggests tornadoes are underrated by an average of 1.5 EF rating, or 40 MPH.

NOAA - Comparison of Tornado Damage Characteristics to Low-Altitude WSR-88D Radar Observations and Implications for Tornado Intensity Estimation


View attachment 43470
The black dots are EF rated tornadoes. The dashed line is actual recorded wind speeds, and the solid line is the distribution of EF rating wind speeds. The gray areas represent overrating and underrating. Zero tornadoes were overrated, and over half were underrated.

Yale - Where Have the EF5s Gone? A Closer Look at the “Drought” of the Most Violent Tornadoes in the United States


All of these studies illustrate the fact the increased scrutiny with ratings is pointless and counter productive. The EF scale may be a damage scale, but the damage is being underestimated and over scrutinized by degrees of magnitude. I'll let @Lake Martin EF4 and @TH2002 address the pre 2011 tornadoes, but I'll cover some of the rest.

Here are your EF5 Indicators:

1. Tuscaloosa 2011 - Tossed a 36 ton rail car further than any railcar has ever been tossed (400 feet), and tore apart million pound, 150 foot tall bridge trestles and lifted them 100 feet up hill.
View attachment 43471

2. Henryville 2012 (maybe) - Tore up asphalt and lofted it long distances, creating 2-3 foot impact craters where they landed.
View attachment 43472

3. Washington 2013- Slabbed entire neighborhoods, including well built, anchored homes
View attachment 43473

4. Vilonia 2014 - One of the most egregiously underrated tornadoes ever, and the cause of "Vilonia Syndrome", which lead to multiple EF5 candidates being underrated due to lack of impossible contextuals, and build quality standards. One home was completely slabbed that had anchor bolts in both exterior AND interior walls
View attachment 43474

5. Pilger, NE 2014 - I don't have a ton of pictures (maybe someone else can help, but this one definitely speaks for itself
View attachment 43475

6. Rochelle-Fairdale 2015 - My favorite quote about this one is for @buckeye05, "As this tornado struck the Deer Creek subdivision to the north of town, numerous EF5 hallmarks occurred. Multiple large, modern, well-anchored homes were swept away, with the debris granulated and wind-rowed long distances. Mowed, short lawn grass was scoured from the yards of several of these homes as well. Most impressively, a concrete sidewalk leading to the front door of one of these homes was actually shifted and pulled away from the driveway and house (photo below). The low-level winds that would have been needed to move this sidewalk would have to have been absolutely insane."
View attachment 43476

7. Chapman 2016 The most impressive contextuals I've ever seen, it really encapsulates what Ted Fujita said about F5 tornadoes "leaving behind a path of destruction so severe that it could defy explanation due to the sheer force of the winds involved". It literally fused a truck with a combine, moved railroad tracks (it was only 85 degrees that day so I don't want to hear anyone mention thermal expansion), snapped the foundation of a well built brick farm house, and mangled cars in ways that defy explanation.
View attachment 43477

8. Bassfield-Soso 2020 - Some of the most impressive debarking you'll ever see, it wrapped steel beams around trees, and slabbed a well built home while bending its anchor bolts
View attachment 43478

9. Mayfield 2021 - Tore apart entire cities and subdivisions, destroyed multiple institutional buildings and steel reinforced concrete/masonry structures in downtown Mayfield, trenched the ground up to 8 inches deep in several spots, tossed a well built reinforced CMU home slab n' all, and much much more.

View attachment 43479

I’ve said it before, but the contextual damage in Bremen is a lot more impressive than people remember it to be. The tornado absolutely ravaged that part of Bremen and utterly wiped out that one section. I mean, just look at that ground scouring.

 

[Grand Poo Bah]

I’ve said it before, but the contextual damage in Bremen is a lot more impressive than people remember it to be. The tornado absolutely ravaged that part of Bremen and utterly wiped out that one section. I mean, just look at that ground scouring.

Not only that, but the sheer volume of slabbed homes makes it impossible and borderline ignorant to say every single one was poorly constructed. Dozens of homes were never even surveyed due to the huge amounts of ground the survey team had to cover in such a short amount of time. At least 6 well constructed, anchored homes were observed, with the only pictures being from a drone. Who knows how many were unobserved on top of that. My recent research into Mayfield moved it up to #1 on my personal list of egregiously underrated tornadoes.

 

[AJS]

Not only that, but the sheer volume of slabbed homes makes it impossible and borderline ignorant to say every single one was poorly constructed. Dozens of homes were never even surveyed due to the huge amounts of ground the survey team had to cover in such a short amount of time. At least 6 well constructed, anchored homes were observed, with the only pictures being from a drone. Who knows how many were unobserved on top of that. My recent research into Mayfield moved it up to #1 on my personal list of egregiously underrated tornadoes.

Mayfield in my opinion falls into a weird category, if we are talking about contextual evidence, it is no doubt at the very top of the list of tornadoes that deserve an EF5 rating based on the extreme contextual damage.

 

[Grand Poo Bah]

10. Rolling Fork 2023 - Some of the most extreme debris granulation ever documented. Uprooted and snapped a steel water tower. Slabbed a well built, anchored, floral shop, which the surveyors described as "extremely, extremely destroyed". If "extremely, extremely destroyed" isn't a 5/5 on the "damage scale" what is? It's my favorite question. If the EF scale is truly a damage scale, why doesn't it actually rate the scale of damage?


11. Matador 2023 - Completely debarked and nubbed mesquite trees, which is one of the hardiest trees in North America. No other tornado has ever been recorded achieving this feat. It completely tore well built homes from their foundation, while snapping the foundations. It mangled cars, and separated the engine block from one. The rest of the car was never found. It demolished the Dollar General and ripped its anchors out of the concrete, which is especially impressive considering it was a certified metal building system, designed to resist hurricane force winds up to 150 mph. It also moved and snapped parking bollards out front of the store.


12. Greenfield Iowa - DOW recorded wind speeds of 318 mph. Snapped anchored parking bollards. Left one of the worst scars ever documented from satellite, snapped concrete foundations and ripped up manhole covers, and did all of this while only being a few hundred yards wide and moving at 60 mph. The tornado was in town for less than 60 seconds and was only over each home for a couple seconds each.

 

[Asha627]

Let's go case by case for some of the most notable...

Vilonia: E Fisher Street home, only marked as "unknown" anchoring because the survey team (seemingly intentionally) did not look into it in depth. Cemetery and Beryl Roads, effectively in their entirety, with no DIs whatsoever. Fish Hooks restaurant. And others, too, I just don't remember them.
Rochelle: One specific house, where the sidewalk was shifted laterally and the house swept away with little/no debris left, coupled with severe contextual damage in the vicinity
Holly Springs: see above
Chapman: A well built farmhouse swept away so violently it snapped part of the foundation. I believe this DI (and a few other DIs) was compared by @TH2002 to Hackleburg, actually. Another house essentially disappeared with no debris remaining. And of course, the railroad.
Camp Crook: The wipeout at the farmstead. Admittedly a bit more contextual than most, but still potentially valid.
Mayfield: Actually surprised you didn't dispute this one. I think this was EF5 mainly based off contextuals, and only 2 DIs are EF5 worthy to me: the church in Mayfield and a particularly weirdly constructed home in Bremen which I gave EF5 after seeing Ethan Morairty give it EF5 in one of his (IMO) few good takes.
Rolling Fork: The Family Dollar. Not EF5 eligible on the current EF scale, but it does qualify as EF5 on the upcoming revision I've posted about.
Matador: One specific well built house swept away, alongside extreme contextual damage. I also posted about this one.

I'll add links and photos to all of them later, but here's the Chapman foundation snapper farmhouse:


And the Matador EF5 candidate house:

Vilonia I do not have an opinion on as I know the survey was botched, it has merit for the rating due to unsurveyed homes. The damage near the Rochelle sidewalk is not contextually EF5 intensity in my opinion, I've taken a look at it. Chapman's survey was pretty well done, the NWS noted had the tornado struck more well-built homes it likely would've received an EF5 rating (the home you mentioned did not qualify.) Camp Crook produced low end EF3 damage structurally and the only violent contextuals are from vehicle damage. Mayfield has a good case, as does Rolling Fork. Matador I have not looked into.

 

[Asha627]

I'll start by asking are you aware of the studies by the Doppler on Wheels team, NOAA, and YALE that all concluded tornadoes are currently underrated significantly?

Doppler on Wheels - Supercell tornadoes are much stronger and wider than damage-based ratings indicate

This study suggests tornadoes are underrated by an average of 1.5 EF rating, or 40 MPH.

NOAA - Comparison of Tornado Damage Characteristics to Low-Altitude WSR-88D Radar Observations and Implications for Tornado Intensity Estimation


View attachment 43470
The black dots are EF rated tornadoes. The dashed line is actual recorded wind speeds, and the solid line is the distribution of EF rating wind speeds. The gray areas represent overrating and underrating. Zero tornadoes were overrated, and over half were underrated.

Yale - Where Have the EF5s Gone? A Closer Look at the “Drought” of the Most Violent Tornadoes in the United States


All of these studies illustrate the fact the increased scrutiny with ratings is pointless and counter productive. The EF scale may be a damage scale, but the damage is being underestimated and over scrutinized by degrees of magnitude. I'll let @Lake Martin EF4 and @TH2002 address the pre 2011 tornadoes, but I'll cover some of the rest.

Here are your EF5 Indicators:

1. Tuscaloosa 2011 - Tossed a 36 ton rail car further than any railcar has ever been tossed (400 feet), and tore apart million pound, 150 foot tall bridge trestles and lifted them 100 feet up hill.


2. Henryville 2012 (maybe) - Tore up asphalt and lofted it long distances, creating 2-3 foot impact craters where they landed.


3. Washington 2013- Slabbed entire neighborhoods, including well built, anchored homes


4. Vilonia 2014 - One of the most egregiously underrated tornadoes ever, and the cause of "Vilonia Syndrome", which lead to multiple EF5 candidates being underrated due to lack of impossible contextuals, and build quality standards. One home was completely slabbed that had anchor bolts in both exterior AND interior walls


5. Pilger, NE 2014 - I don't have a ton of pictures (maybe someone else can help), but this one definitely speaks for itself


6. Rochelle-Fairdale 2015 - My favorite quote about this one is for @buckeye05, "As this tornado struck the Deer Creek subdivision to the north of town, numerous EF5 hallmarks occurred. Multiple large, modern, well-anchored homes were swept away, with the debris granulated and wind-rowed long distances. Mowed, short lawn grass was scoured from the yards of several of these homes as well. Most impressively, a concrete sidewalk leading to the front door of one of these homes was actually shifted and pulled away from the driveway and house (photo below). The low-level winds that would have been needed to move this sidewalk would have to have been absolutely insane."


7. Chapman 2016 The most impressive contextuals I've ever seen, it really encapsulates what Ted Fujita said about F5 tornadoes "leaving behind a path of destruction so severe that it could defy explanation due to the sheer force of the winds involved". It literally fused a truck with a combine, moved railroad tracks (it was only 85 degrees that day so I don't want to hear anyone mention thermal expansion), snapped the foundation of a well built brick farm house, and mangled cars in ways that defy explanation.


8. Bassfield-Soso 2020 - Some of the most impressive debarking you'll ever see, it wrapped steel beams around trees, and slabbed a well built home while bending its anchor bolts


9. Mayfield 2021 - Tore apart entire cities and subdivisions, destroyed multiple institutional buildings and steel reinforced concrete/masonry structures in downtown Mayfield, trenched the ground up to 8 inches deep in several spots, tossed a well built reinforced CMU home slab n' all, and much much more. I get increasingly frustrated when people say the tornado didn't hit enough well built structures. The path was so long, and so many structures impacted, the survey team never even came close to observing all of them. Multiple neighborhoods were surveyed and cataloged from the passenger seat of moving vehicles. Dozens of homes were slabbed, and surely some of those homes had top quality construction that was missed.

The tornadoes you listed here are not those that I firmly disagree with regarding an EF5 rating, as many have a good case. Unfortunately, structural issues are present in many of the affected structures, meaning homes undoubtedly exposed to EF5 winds do not quality for an EF5 rating.

 

[Aaron Rider]

Vilonia I do not have an opinion on as I know the survey was botched, it has merit for the rating due to unsurveyed homes. The damage near the Rochelle sidewalk is not contextually EF5 intensity in my opinion, I've taken a look at it. Chapman's survey was pretty well done, the NWS noted had the tornado struck more well-built homes it likely would've received an EF5 rating (the home you mentioned did not qualify.) Camp Crook produced low end EF3 damage structurally and the only violent contextuals are from vehicle damage. Mayfield has a good case, as does Rolling Fork. Matador I have not looked into.

Re: your statement on Chapman

And I remind you there is ample precedent for rating tornadoes highly based on extreme contextual damage. It's not this forum's precedent, it's precedent dating back to Fujita's time and still used occasionally in this era because it's obviously legitimate

 

[Grand Poo Bah]

Yeah, disallowing contextual evidence and common sense to rate tornadoes is for sure a new, made up rule, added for no real reason, and doesn't make any sense whatsoever in the context of categorizing tornadoes and uncovering true wind speeds.

 

[Asha627]

Re: your statement on Chapman

And I remind you there is ample precedent for rating tornadoes highly based on extreme contextual damage. It's not this forum's precedent, it's precedent dating back to Fujita's time and still used occasionally in this era because it's obviously legitimate
View attachment 43486

I agree, which is why I do not currently have a firm stance on Chapman. The mentioned home that it did strike was a home that didn't qualify for an EF5 rating in itself.

 

[Ozonelayer]

10. Rolling Fork 2023 - Some of the most extreme debris granulation ever documented. Uprooted and snapped a steel water tower. Slabbed a well built, anchored, floral shop, which the surveyors described as "extremely, extremely destroyed". If "extremely, extremely destroyed" isn't a 5/5 on the "damage scale" what is? It's my favorite question. If the EF scale is truly a damage scale, why doesn't it actually rate the scale of damage?
View attachment 43480

11. Matador 2023 - Completely debarked and nubbed mesquite trees, which is one of the hardiest trees in North America. No other tornado has ever been recorded achieving this feat. It completely tore well built homes from their foundation, while snapping the foundations. It mangled cars, and separated the engine block from one. The rest of the car was never found. It demolished the Dollar General and ripped its anchors out of the concrete, which is especially impressive considering it was a certified metal building system, designed to resist hurricane force winds up to 150 mph. It also moved and snapped parking bollards out front of the store.
View attachment 43482

12. Greenfield Iowa - DOW recorded wind speeds of 318 mph. Snapped anchored parking bollards. Left one of the worst scars ever documented from satellite, snapped concrete foundations and ripped up manhole covers, and did all of this while only being a few hundred yards wide and moving at 60 mph. The tornado was in town for less than 60 seconds and was only over each home for a couple seconds each.
View attachment 43485

I'd like to add on to the Mayfield portion.

The contextual damage in Bremen was absurd, to the point where debris were granulated and likely mixed with the rainwater to create what appears to be a paste. Ground scouring was extremely impressive too, with it being up to a foot deep in spots along the path. Tree debarking was incredible as well.

Also, about that one CMU home, it wasn't slabbed normally. Usually you have some remaining CMU. However in this case, it was just gone. Not near the foundation, just completely gone, leaving the bare gravel underneath. This is why I firmly believe it should have been rated EF-5, because it was well reinforced and anchored, yet the only trace left was the garage poured foundation and the gravel where the CMU once stood.

 

[Asha627]

Yeah, disallowing contextual evidence and common sense to rate tornadoes is for sure a new, made up rule, added for no real reason, and doesn't make any sense whatsoever in the context of categorizing tornadoes and uncovering true wind speeds.

The EF scale does not include many DIs for purely contextual damage, hence why rating upgrades due to contextual damage are often accompanied by supporting structural damage. This is not the case in many of these tornadoes, meaning they do not qualify for an EF5 rating. The reasoning is not lack of intensity, but lack of qualification on the rating scale.

 

[TH2002]

Chapman's survey was pretty well done, the NWS noted had the tornado struck more well-built homes it likely would've received an EF5 rating (the home you mentioned did not qualify.)

No, NWS Topeka stated it would have been rated EF5 if it had struck Chapman directly. I think it should have been rated EF5 regardless of whether or not it hit a town head on.
The construction quality was there. At least two of the swept away homes were well-built and anchored. One of them was downgraded due to pedantic nitpicking and another was left out of the survey entirely. Doesn’t exactly scream “well done” to me, but hey…

 

[Grand Poo Bah]

The EF scale does not include many DIs for purely contextual damage, hence why rating upgrades due to contextual damage are often accompanied by supporting structural damage. This is not the case in many of these tornadoes, meaning they do not qualify for an EF5 rating. The reasoning is not lack of intensity, but lack of qualification on the rating scale.

All the tornadoes I highlighted definitely had the structural damage to go with the insane contextuals, but you seem to agree most of them were likely EF5 intensity so there's nothing to argue there.

However, the original Fujita scale never had contextual indicators either, but they were used anyways, and explicitly encouraged. Depending on the circumstances, ground-swirl patterns (cycloidal marks), weather radar data, witness testimonies, media reports and damage imagery, as well as photogrammetry or videogrammetry if motion picture recording was available was used to rate tornadoes. The Plainfield, Iowa tornado was rated purely based on damage to corn crops! It's a huge step backwards to act like all these variables have no relevance and can't be used anymore.

I say again, it's a made up rule, with no basis in science whatsoever. Why it was ever adopted by so many offices is beyond understanding. The goal is to uncover true wind speeds, not scrutinize the engineering of individual buildings to absolutely no one's benefit.

 

[Asha627]

All the tornadoes I highlighted definitely had the structural damage to go with the insane contextuals, but you seem to agree most of them were likely EF5 intensity so there's nothing to argue there.

However, the original Fujita scale never had contextual indicators either, but they were used anyways, and explicitly encouraged. Depending on the circumstances, ground-swirl patterns (cycloidal marks), weather radar data, witness testimonies, media reports and damage imagery, as well as photogrammetry or videogrammetry if motion picture recording was available was used to rate tornadoes. The Plainfield, Iowa tornado was rated purely based on damage to corn crops! It's a huge step backwards to act like all these variables have no relevance and can't be used anymore.

I say again, it's a made up rule, with no basis in science whatsoever. Why it was ever adopted by so many offices is beyond understanding. The goal is to uncover true wind speeds, not scrutinize the engineering of individual buildings to absolutely no one's benefit.

I certainly agree and I think the EF scale should incorporate contextual damage

 

[Asha627]

No, NWS Topeka stated it would have been rated EF5 if it had struck Chapman directly. I think it should have been rated EF5 regardless of whether or not it hit a town head on.
The construction quality was there. At least two of the swept away homes were well-built and anchored. One of them was downgraded due to pedantic nitpicking and another was left out of the survey entirely. Doesn’t exactly scream “well done” to me, but hey…

My bad, must've misremembered what they said. Also wasn't aware of anything being left out.

 

[slenker]

No, NWS Topeka stated it would have been rated EF5 if it had struck Chapman directly. I think it should have been rated EF5 regardless of whether or not it hit a town head on.
The construction quality was there. At least two of the swept away homes were well-built and anchored. One of them was downgraded due to pedantic nitpicking and another was left out of the survey entirely. Doesn’t exactly scream “well done” to me, but hey…

I'd actually love to hear what about the survey specifically is nitpicked and badly done, if you have the time to go over it. I definitely believe it considering certain offices and how they conduct surveys. Like, what specifically makes the nitpicking they did "pedantic" or unnecessary? I don't think I've ever seen imagery of the damaged homes from Chapman before either so I can't make any specific remarks about it myself. Was it anchor bolted?

However, the original Fujita scale never had contextual indicators either, but they were used anyways, and explicitly encouraged. Depending on the circumstances, ground-swirl patterns (cycloidal marks), weather radar data, witness testimonies, media reports and damage imagery, as well as photogrammetry or videogrammetry if motion picture recording was available was used to rate tornadoes. The Plainfield, Iowa tornado was rated purely based on damage to corn crops! It's a huge step backwards to act like all these variables have no relevance and can't be used anymore.

It was also rated F5 based on the damage it did to the corn crop in conjunction with extraordinary vehicle lofting and damage, which also cemented it as such a rating. Plus, you had confirmed prior high end F4 structural damage coinciding with noticeably less intense contextual damage. I think that's a great use of context to give a tornado a high-end rating, and it should be something being incorporated more into the process 100%. Also, vortex constriction coinciding with this damage probably helped give the final rating for Plainfield as well.

Mayfield is kind-of an example of this. The most impressive structural damage, AKA the church in Mayfield and the 190 DI in Bremen, did not coincide with the tornado's maximum contextual damage. If that's the case, it becomes absolutely completely reasonable to assume that the tornado was at a higher intensity in the areas of more extreme context, even without the help of structures. And it isn't like the tornado didn't impact structures at these locations either, it did what an EF5 was supposed to and slabbed everything in the most intense damage contour. To me, that makes it entirely reasonable to grant it an EF5 rating.

Also, this isn't a super important point because it's not a part of my argument for why Mayfield deserves EF5, but it's a small little side comment that hopefully gives more clearance to my opinions on the tornado: The fact that this storm was on the ground for 165 miles, maintained a borderline violent intensity for the majority of the path, did what it did to multiple communities, slabbed well-built structures, left behind the contextuals supportive of a maximum-intensity tornado, and still was not granted the rating just completely erodes my confidence in the scale as something that accurately portrays tornadic intensity. This thing was, without a shadow of a doubt, an EF5 at maximum intensity. Radar data supports it, context supports it, and structural damage coinciding with context supports it too. I agree that it is borderline unscientific to not take these features into account when attempting to accurately portray these things.

I can see the other side of the argument, absolutely - you make a scale, you abide by its rules. But when the scale has had a precedent set where context was used far more heavily, and to a completely reasonable degree, why are we all of the sudden stopping that? (This next point is a little off topic from what we were discussing, but while I'm ranting, I'm gonna just air it out) It's no coincidence at all that EF5s disappeared when this happened. Tornadoes are not "getting weaker" at all, I strongly disagree with that take, and people on twitter suggesting that climate change is responsible for weakening tornadoes is a strange hypothesis. Where's the proof of that? You're going to need a lot of research on that topic before even coming close to making that claim something that sounds realistic. I could believe it to be the case, but before jumping to a very bold conclusion like that, I want to see scientific papers on it. A lot of them. Definitely not evidence based on the fact that the scale is becoming more strict.

The scale may be purely based off damage in its purest and most contingent form, but the ultimate goal of the scale is to determine tornado intensity. We've seen in the earlier days multiple examples of context being used in conjunction with structures (Rainsville), even sometimes pure context (Philadelphia, El Reno, Joplin), but for some reason there's a sentiment among many wind engineers and surveyors nowadays to simply omit that idea, unless it's to downgrade the tornado. I literally cannot understand why.

Sorry for the rant.