Enhanced Fujita Ratings Debate Thread

[UK_EF4]

any competent survey team would rate it an EF-5.

I think the problem is that a lot of the survey teams nowadays are not 'competent' in that sense. All you really need to do is look at Vilonia, or Chickasha, or Goldsby, or even Fairdale/Rochelle - these are arguably comparable structural and even contextual damage, that would have almost certainly received F5 ratings in the past. Additionally, I think almost all of these events were expected to receive EF5 ratings - but didn't, for reasons varying in validity. I completely agree that Xenia deserves its rating and exhibits textbook E/F5 damage. But I really wouldn't put anything past survey teams this day and age.

 

[NorthGaWeather]

Doubt it. Good construction quality is absolutely necessary for an EF5 rating, and that wasn't present in Xenia. To be honest I'm not sure how I feel about that, but unless I'm misunderstanding something, that is how the EF scale works.

I’m no expert on Xenia, but that’s my opinion based off of what I’ve read/seen. You’re certainly entitled to your opinion. I do believe Brandenburg, Guin, and 1st Tanner were stronger candidates that day.

 

[NorthGaWeather]

I think the problem is that a lot of the survey teams nowadays are not 'competent' in that sense.

I completely agree with you and I think it is a major problem. I’ve observed it in practice. But there are some really well trained and experienced individuals out there that provide great context and ultimately well done surveys. I think a fairly consistent job is done for EF-0 to most EF-3 tornadoes, but it flies out the window in the upper bound EF-3 or greater ratings.

 

[Tempestas Tonitrua]

I think the problem is that a lot of the survey teams nowadays are not 'competent' in that sense. All you really need to do is look at Vilonia, or Chickasha, or Goldsby, or even Fairdale/Rochelle - these are arguably comparable structural and even contextual damage, that would have almost certainly received F5 ratings in the past. Additionally, I think almost all of these events were expected to receive EF5 ratings - but didn't, for reasons varying in validity. I completely agree that Xenia deserves its rating and exhibits textbook E/F5 damage. But I really wouldn't put anything past survey teams this day and age.

My own theory is there’s a certain avoidance to be “that survey team” that ends the EF5 drought. The rating will get nitpicked to death by the ASCE and others.

As it stands now you’d need Smithville 2.0 to break the drought. Inconceivable destruction that only the worst nitpickers can take apart.

This is all rooted, in my opinion, in the ASCE’s post-review of Joplin - I think that really irked and spooked a lot of survey teams and caused the entire NWS to lose the plot. One only needs to look at the release date of their findings: June 8, 2013.

 

[joshoctober16]

I don’t normally engage in EF scale debates because it’s pointless…especially when comparing F scale ratings; however, I think this is incorrect. I realize there have been some significant discrepancies between offices and even individuals within those offices that make this seem like reality, but it simply isn’t. EF-5 ratings are attainable, IMO, and will occur again. Based on everything I’ve seen regarding Xenia, any competent survey team would rate it an EF-5.

I will say, I’ve been on surveys where the team was very strict to the EF scale and favored lower bound estimates. I’ve also experienced others where a seasoned individual assigned ratings that favored high end wind speeds based off their experience. There is a lot of subjectivity at times.

well its easy, is villonia 2014 rated EF5? yes or no?
if no then xenia would not be rated EF5 today, along with 95% of all past F5.

1:did the xenia tornadoes F5 damage get impacted by any debris? (not a single little part of debris from other homes hitting into it)
2:was there more then 1 true EF5 damage in todays rules? (image under is what tim marshal says)

3:were every single tree within 100 yards all down and or debarked?

... now that i think about it is there any damage evidence that this even ever happened to any tornado? the 4 tim marshal rules to 2+ homes , and the 100 yards tree thing? and not a single debris crashing into said EF5 damage?

this is why me and likely TH2002 are saying no tornadoes are going to be rated EF5. at least until the next EF scale, or they upgrade bremen and villonia to EF5, then the whole tree rule thing can be tossed out....

 

[NorthGaWeather]

well its easy, is villonia 2014 rated EF5? yes or no?
if no then xenia would not be rated EF5 today, along with 95% of all past F5.

1:did the xenia tornadoes F5 damage get impacted by any debris? (not a single little part of debris from other homes hitting into it)
2:was there more then 1 true EF5 damage in todays rules? (image under is what tim marshal says)

I have next to zero understanding of the facts around Vilonia (or have forgotten them) so I don't know what to tell you. I did say "competent survey team".

I'm curious now, which 2-3 F-5 tornadoes from 1953-1999 would be rated EF-5? You have 50 to choose from.

Good for Tim. Requiring multiple EF DI's has never been a standard practice.

3:were every single tree within 100 yards all down and or debarked?

... now that i think about it is there any damage evidence that this even ever happened to any tornado? the 4 tim marshal rules to 2+ homes , and the 100 yards tree thing? and not a single debris crashing into said EF5 damage?

this is why me and likely TH2002 are saying no tornadoes are going to be rated EF5. at least until the next EF scale, or they upgrade bremen and villonia to EF5, then the whole tree rule thing can be tossed out....

I've never heard this supposed every single tree down rule.

I disagree with your conclusion, as we are going to see EF-5 tornadoes again, but I can understand why you feel that way based off of some perceived slights in past surveys. Things aren't perfect with the system.

 

[joshoctober16]

I have next to zero understanding of the facts around Vilonia (or have forgotten them) so I don't know what to tell you. I did say "competent survey team".

I'm curious now, which 2-3 F-5 tornadoes from 1953-1999 would be rated EF-5? You have 50 to choose from.

Good for Tim. Requiring multiple EF DI's has never been a standard practice.


I've never heard this supposed every single tree down rule.

I disagree with your conclusion, as we are going to see EF-5 tornadoes again, but I can understand why you feel that way based off of some perceived slights in past surveys. Things aren't perfect with the system.

ah for the tree thing here so ya using that logic most past F5 get downgraded, and to make it more of a slap in are face, they were in a ditch.... and they were skinny, unlike a wide non ditch tree, it will stand up to stronger winds.

 

[NorthGaWeather]

ah for the tree thing here View attachment 25214View attachment 25215View attachment 25216View attachment 25217 so ya using that logic most past F5 get downgraded, and to make it more of a slap in are face, they were in a ditch.... and they were skinny, unlike a wide non ditch tree, it will stand up to stronger winds.

Yeah, that’s faulty logic on their part with the tree thing and not how ratings are applied in other CWA. I’ve never seen the multiple DI’s in practice.

 

[Cood101]

Correct me if I'm wrong, but I do believe that even Tim Marshall has said EF5s are still possible with the current scale as is. I believe he used Jarrell and Joplin as examples of the damage he would agree to as EF5 worthy?

My only qualms with the Enhanced Fujita scale is as follows. As a scientific, damage scale, there should not be EF-U unless something truly did damage that is immeasurable. Qualified measurements of wind effect on an object or surface can be correctly, if not close-range estimated by mathematical formulas, even if it's not a DI on the current scale.

Likewise, Radar or Doppler Wind measurements should be considered within reason. It seems widely accepted that the windspeeds recorded on the DOW from May 3rd, 1999 are correct and measured the fastest winds on earth from the 1999 Moore F5. I understand ground friction and surface winds will not match those aloft where these have been measured. If something is on the line of High EF4/Low EF5 damage at ground level, however, and a DOW recorded say 240mph winds at 300m AGL, I would think that would be something to be weighted more towards EF5.

My final thought is this discussion on tree damage. Fujita ascribed the multi-vortex nature of tornadoes as an explanation on why major damage can be done to one area and little to no damage can be done 50-100 yards away. Unless it's something such as a question of debris load vs wind load, the spotty nature of damage shouldn't be a red flag on its own. .

Saying all of this, I do also understand damage estimates are being done within the realm of both established practices, established ratings, and what is shown on the current DI guide. This isn't a grand conspiracy by the ASCE or Tim Marshall or anyone else as much as a system with flaws that we have in current use. I'm awaiting the revised EF scale to see what ideas are accepted in the final edition and what is denied as a DI or measurement analysis when it comes to the end-all,be-all of a final rating.

 

[Tempestas Tonitrua]

Correct me if I'm wrong, but I do believe that even Tim Marshall has said EF5s are still possible with the current scale as is. I believe he used Jarrell and Joplin as examples of the damage he would agree to as EF5 worthy?

My only qualms with the Enhanced Fujita scale is as follows. As a scientific, damage scale, there should not be EF-U unless something truly did damage that is immeasurable. Qualified measurements of wind effect on an object or surface can be correctly, if not close-range estimated by mathematical formulas, even if it's not a DI on the current scale.

Likewise, Radar or Doppler Wind measurements should be considered within reason. It seems widely accepted that the windspeeds recorded on the DOW from May 3rd, 1999 are correct and measured the fastest winds on earth from the 1999 Moore F5. I understand ground friction and surface winds will not match those aloft where these have been measured. If something is on the line of High EF4/Low EF5 damage at ground level, however, and a DOW recorded say 240mph winds at 300m AGL, I would think that would be something to be weighted more towards EF5.

My final thought is this discussion on tree damage. Fujita ascribed the multi-vortex nature of tornadoes as an explanation on why major damage can be done to one area and little to no damage can be done 50-100 yards away. Unless it's something such as a question of debris load vs wind load, the spotty nature of damage shouldn't be a red flag on its own. .

Saying all of this, I do also understand damage estimates are being done within the realm of both established practices, established ratings, and what is shown on the current DI guide. This isn't a grand conspiracy by the ASCE or Tim Marshall or anyone else as much as a system with flaws that we have in current use. I'm awaiting the revised EF scale to see what ideas are accepted in the final edition and what is denied as a DI or measurement analysis when it comes to the end-all,be-all of a final rating.

He also said in an article last year about the EF5 drought there’s no difference between a high end EF4 and an EF5. Which kind of tells me everything I need to know

 

[TH2002]

Correct me if I'm wrong, but I do believe that even Tim Marshall has said EF5s are still possible with the current scale as is. I believe he used Jarrell and Joplin as examples of the damage he would agree to as EF5 worthy?

My only qualms with the Enhanced Fujita scale is as follows. As a scientific, damage scale, there should not be EF-U unless something truly did damage that is immeasurable. Qualified measurements of wind effect on an object or surface can be correctly, if not close-range estimated by mathematical formulas, even if it's not a DI on the current scale.

Likewise, Radar or Doppler Wind measurements should be considered within reason. It seems widely accepted that the windspeeds recorded on the DOW from May 3rd, 1999 are correct and measured the fastest winds on earth from the 1999 Moore F5. I understand ground friction and surface winds will not match those aloft where these have been measured. If something is on the line of High EF4/Low EF5 damage at ground level, however, and a DOW recorded say 240mph winds at 300m AGL, I would think that would be something to be weighted more towards EF5.

My final thought is this discussion on tree damage. Fujita ascribed the multi-vortex nature of tornadoes as an explanation on why major damage can be done to one area and little to no damage can be done 50-100 yards away. Unless it's something such as a question of debris load vs wind load, the spotty nature of damage shouldn't be a red flag on its own. .

Saying all of this, I do also understand damage estimates are being done within the realm of both established practices, established ratings, and what is shown on the current DI guide. This isn't a grand conspiracy by the ASCE or Tim Marshall or anyone else as much as a system with flaws that we have in current use. I'm awaiting the revised EF scale to see what ideas are accepted in the final edition and what is denied as a DI or measurement analysis when it comes to the end-all,be-all of a final rating.

I don't think there's any kind of "grand conspiracy" surrounding tornado ratings. I DO think that since it has been such a long time since an EF5 rating was assigned, there is an uneasiness and stigma surrounding which survey team ends up being "the one" to end the EF5 drought.

I also agree that Tim Marshall does get too much hate in the weather weenie community, as I have conversed with him multiple times - the surveys he has worked on are not always case in point (Westminster, Vilonia, Matador etc) but others were very reasonable (Greensburg, Parkersburg, Joplin etc). But regardless of what one makes of his "there's no difference between a high-end EF4 and an EF5" remark, I don't understand why people see him as the supreme telepathic damage survey bogeyman who "intimidates people" to rate tornadoes lower than EF5. There ARE some people like John Robinson who let their own personal biases get in the way of accurate damage surveys, but I don't think Marshall is one of those people.

Would also add that I don't think there's one sole reason contributing to the EF5 drought - the ASCE's "findings" in Joplin and the Vilonia survey certainly cast a conservative shroud over damage survey teams for a few years, and surveys that followed including Fairdale, Chapman and Camp Crook may have been affected by this. Of course, those surveys also had their own follies:

• The QRT consultation in Fairdale was rushed and not even done in person
• The Chapman survey skipped multiple structures and NWS Topeka said it would have been rated EF5 only if it had struck the town directly
• There was absolutely no QRT consultation or any attempt to analyze what wind speeds could have caused the extreme damage to vehicles and farm machinery in Camp Crook

And that really explains it. Some mets like the ones at NWS Jackson actually see damage surveying as an important part of their profession, and others like NWS Memphis and Fort Worth simply don't care.

 

[andyhb]

Speaking of John Robinson, lol...

Imagine focusing on trees still standing 100 yards away from the slabbed homes and not commenting on extraordinary tree damage like this throughout the path in Vilonia.

 

[TH2002]

Imagine focusing on trees still standing 100 yards away from the slabbed homes and not commenting on extraordinary tree damage like this throughout the path in Vilonia.

Speaking of those trees...