Enhanced Fujita Ratings Debate Thread

[Shakespeare 2016]

Here is something interesting as it includes several infamous tornadoes and the tornado near Harper, KS on May 12, 2004. https://pohnpeitornado.wordpress.co...obile-radar-observations-and-vortex-dynamics/

 

[Cood101]

Ooh, the Tri-State tornado was referred to as a “boiling cloud” and “wall of death” by people who witnessed it! It was likely a Joplin-type tornado, which didn’t look like a tornado and thus people didn’t take shelter.

That may be where I got that terminology then, but it does show in modern video. "Wall of Death" might be more apt for something like HPC or Vilonia, where it's just a dark mass skirting along.

 

[Aaron Rider]

Eh, at least Hackleburg was recognizable as a tornado. Joplin… not so much.

Joplin was an unintelligible, incomprehensible, monstrous force from the most surreal and powerful side of nature wrapped tightly in a cloak of rain and darkness. I've seen a lot of tornado videos. Nothing has frightened me more than Joplin.

 

[joshoctober16]

I believe the problem fixed now. You can check again.

works now , so much to read , i first did a quick glance and notice this small momment

did not know there was a UNDER 5 meter measurement and it showed it was stronger then above 5 meters.

 

[Lake Martin EF4]

Somewhat related to the topic: just as I stated that Rochelle is rapidly falling out of favor in terms of "universally recognized EF5 candidates", I'd wager good money that NWS Jackson is no longer the definitive "good office". Logan Poole's statement re: Green Apple Florist put the nail in the coffin: the amount of people on Twitter I've seen comparing it to Vilonia's East Fisher Street "EF5 can't be given based off one structure" home is phenomenal and to be honest I'm fairly sure the Rolling Fork tornado will replace Rochelle as a "universally recognized EF5 candidate" just because of that statement - despite the fact that the florist was rated properly and the statement doesn't mean what most think it does. (As stated, a more likely EF5 damage location is the Family Dollar, but that can't be EF4 on the current version of the scale, so there isn't anything in the survey I can really complain with.)

The new "definitive good NWS office" in survey terms is likely going to be Huntsville - many of the other candidates have big, big missteps in their past, perceived or otherwise, that knock them down.

EDIT: Nevermind, I take back my Huntsville endorsement. Forgot they used Goldsby Logic on a home in Flat Rock to avoid EF5. Not sure what office replaces Jackson then. Maybe Dodge City?

 

[tornado examiner]

Somewhat related to the topic: just as I stated that Rochelle is rapidly falling out of favor in terms of "universally recognized EF5 candidates", I'd wager good money that NWS Jackson is no longer the definitive "good office". Logan Poole's statement re: Green Apple Florist put the nail in the coffin: the amount of people on Twitter I've seen comparing it to Vilonia's East Fisher Street "EF5 can't be given based off one structure" home is phenomenal and to be honest I'm fairly sure the Rolling Fork tornado will replace Rochelle as a "universally recognized EF5 candidate" just because of that statement - despite the fact that the florist was rated properly and the statement doesn't mean what most think it does. (As stated, a more likely EF5 damage location is the Family Dollar, but that can't be EF4 on the current version of the scale, so there isn't anything in the survey I can really complain with.)

The new "definitive good NWS office" in survey terms is likely going to be Huntsville - many of the other candidates have big, big missteps in their past, perceived or otherwise, that knock them down.

EDIT: Nevermind, I take back my Huntsville endorsement. Forgot they used Goldsby Logic on a home in Flat Rock to avoid EF5. Not sure what office replaces Jackson then. Maybe Dodge City?

What are you talking about? Nws Jackson would have rated the rolling fork tornado an EF5 if they had the new scale’s di’s to work with for sure so…what?

 

[Lake Martin EF4]

What are you talking about? Nws Jackson would have rated the rolling fork tornado an EF5 if they had the new scale’s di’s to work with for sure so…what?

I'm saying a number of people (incorrectly) believe Rolling Fork was rated unfairly, and may bring it up as a counterpoint if someone mentions NWS Jackson being a good office.

 

[Maxis_s]

I'm saying a number of people (incorrectly) believe Rolling Fork was rated unfairly, and may bring it up as a counterpoint if someone mentions NWS Jackson being a good office.

I agree that it's a stupid point to use when discussing whether Jackson is a "good office", but the florist shop's rating was questionable.
Here's the exact quote by a surveyor in a YouTube video (I'll find the video later, I only have the quote for now)

"So, what gave it the 195 mark? And, the best answer to that is what didn't give it the 200 mark...The Green Apple Florist , essentially a single family home that was modified to built to be a floral shop and it is slabbed to the ground and swept clean. Why not F5? Why not EF5? And two things really stuck out to us from the consensus on why not EF5. One was this building, even though it was extremely, extremely destroyed, I mean on its own, taken out of context, I think most people would agree this would be representative of an EF5 tornado; the damage to that building...If there had even been two of these side-by-side that had suffered the same fate, then maybe we could have had more confidence on that, but we didn't...But it was, to that point that we were very very close and this is probably about as close as you'll get across that threshold, without making it...A question we get a whole lot is like how can you be so sure that it was a five miles per hour from F5, but not quiet there? And the answer to that is is is we aren't. What the EF-scale is, is a damage scale...Is it possible that it had winds that were stronger? Certainly."

The sole reason why there wasn't an EF5 rating was because there wasn't a second DI of similar intensity, which I disagree with (the Dollar General, but that's an EF-scale issue), which made them have some doubts about its actual intensity and ended up being downgraded to 195mph. Whether that's an issue with the survey or the scale itself is debatable, but it's not unreasonable to say that the rating was somewhat unfair.

Speaking of not rating a tornado a higher rating because of only one DI... remember the Evansville, WI tornado in February of last year? That was rated EF2 despite having an EF3 DI because, in the local NWS office's own words, "we do not rate tornadoes based on a single DI". I'll have to dig up that tweet but I vividly remember that.

 

[Grand Poo Bah]

What are you talking about? Nws Jackson would have rated the rolling fork tornado an EF5 if they had the new scale’s di’s to work with for sure so…what?

The new scale was due to be released in 2018. It's still not out and every version we've seen drops wind estimates significantly. It'll either never release, or when it does it'll have the same problems as the current scale.

The lack of EF5s isn't a scale issue. It's an ASCE/texas tech/Tim Marshall issue. We saw the same exact issues with the F scale under their stewardship and we'll see the exact problems with the next scale under their stewardship. Nothing will be fixed until the people sabotaging it are expelled from the process entirely.

 

[Grand Poo Bah]

"One was this building, even though it was extremely, extremely destroyed [...]"

"What the EF-scale is, is a damage scale..."

These are completely contradictory statements.

I'm going to keep emphasizing this point because it's the most important point. If it was truly a damage scale, it would rate the scale of damage. It doesn't do that though. It's an engineering scale, which has exactly zero usefulness to anyone for rating tornadoes.

On a scale of 1 to 5 "extremely, extremely destroyed" sounds like a 5 to me LMAO.

 

[Maxis_s]

The lack of EF5s isn't a scale issue. It's an engineer/texas tech/Tim Marshall issue. We saw the same exact issues with the F scale under their stewardship and we'll see the exact problems with the next scale under their stewardship. Nothing will be fixed until the people sabotaging it are expelled from the process entirely.

That's a harsh way of saying this but I do agree to an extent.
There's a big difference between meteorology and engineering. Engineering is very objective in its calculations; there's no room for subjectivity or variation or unknown variables, everything must be accounted for in calculations. In meteorology, there's a ton of subjectivity and unknown. Sure, we know many things and there's some parts that aren't up to interpretation, but we don't fully know the inner dynamics of tornadoes, how debris impacts structures, whether debris even impacts a structure, the actual winds within a tornado, how winds translate down to the surface, and a whole lot more.
Engineers will, consciously or subconsciously, try and find some form of objectivity in tornadic damage and windspeeds by trying to determine the highest peak windspeeds that is within 99% of certainty. If there's even the slightest amount of doubt or uncertainty or the slightest 0.1% chance that a rating may be too high, they will downgrade it. This is almost completely against the point of the EF-scale which is to estimate the most likely/reasonable peak windspeeds rather than picking the maximum or minimum peak windspeed.

 

[Lake Martin EF4]

The sole reason why there wasn't an EF5 rating was because there wasn't a second DI of similar intensity, which I disagree with (the Dollar General, but that's an EF-scale issue), which made them have some doubts about its actual intensity and ended up being downgraded to 195mph. Whether that's an issue with the survey or the scale itself is debatable, but it's not unreasonable to say that the rating was somewhat unfair.

I'm fairly certain that "no second DI of similar intensity" DI was the floral shop, not Dollar General. TH2002 provided a good explanation behind that statement:

Rolling Fork's rating is fine. The floral shop still had debris left on the slab and, technically speaking, a small part of the building was left standing.

The fact it was even considered a potential EF5 DI just goes to show how above and beyond NWS Jackson went with their survey of this tornado. Unlike other WFO's, they take damage surveying and rating tornadoes accurately very seriously.

I can understand why that quote is a bit a head-scratcher, but I think they were literally just trying to say that seeing another equally swept home would have increased confidence for a potential EF5 rating in the case of that particular DI, considering it was technically not swept completely away - and that if there was another well-constructed building equally swept, it would have also been rated EF5.

If there was ever a tornado that accurately fits the bill of the quote "EF5 winds, EF4 damage" Rolling Fork is pretty much it. Same exact thing for the 2021 Czech tornado. One DI in Mikulčice was considered for an IF5 rating but the tornado was ultimately rated high-end IF4 - which is totally fine imo.

Both Rolling Fork and the 2021 Czech tornado were nearly identical in intensity imo and both straddle the line between a 4 and a 5. If they had been given EF5 and IF5, that would have been fine too.

edit: To add, if the flower shop in Rolling Fork had been swept completely clean, then I would consider it an EF5 DI without question.

Speaking of not rating a tornado a higher rating because of only one DI... remember the Evansville, WI tornado in February of last year? That was rated EF2 despite having an EF3 DI because, in the local NWS office's own words, "we do not rate tornadoes based on a single DI". I'll have to dig up that tweet but I vividly remember that.

Speaking of that one...

A lot of WXtwitter seems to be misinterpreting the surveying directive as explicitly needing more than one damage point of that intensity, as it absolutely does not state that verbatim, and there have been multiple intense tornadoes even in recent years rated on a single damage point of that rating. The directive simply states that one needs enough contextual evidence surrounding that damage point (i.e. a leveled house but trees and sheds around the house not being very damaged = very questionable) to let it stand, which in theory is fair. The issue lies perhaps in the application as it seems like some WFOs don't interpret it the way it's intended to be, and we do occasionally see cases of single points not being recognized.

In this case, going from a low end 3 on a marginal point to a high 2 isn't nearly as egregious as many have been, especially since the structure in question is definitely of a type that could have many legitimate lessening factors, but it drives home the need for some national standardization in the process and application from WFO to WFO and the need to keep preliminary points off the public side of the DAT until the survey is finished lol

Besides, having an explicit policy of needing multiple points to rate a tornado would mean a plains tornado that levels a farm house and nothing else whatsoever would have to be rated EF-U, which would be really really stupid

That whole mess was cleared up…the tornado is still in check for an ef3 rating and no the news did not say that whole you need two di’s…that was said by a non nws person

EDIT: And one more...

Deleted my earlier comment, seems that the NWS basically got gaslighted lol.
I went and checked myself to see if there was any info verifying the “1 DI= no upgrade” claim.
Turns out there’s no such thing (unsurprisingly), yet another rando on twitter spouting nonsense. Honestly that app needs an 18+ age limit or something.

Fairly certain the only time "can't rate a tornado with only 1 DI of that intensity" was used to downgrade in the way you're describing was Vilonia, which appears to have been done with the specific intent of avoiding an EF5 rating and showcasing how John Robinson would have liked the EF scale to be like.

 

[Maxis_s]

I'm fairly certain that "no second DI of similar intensity" DI was the floral shop, not Dollar General

I meant that, in my opinion, the Dollar General should've counted as a second DI of similar intensity, and that it wasn't counted because of the EF-scale and not the surveyors.

 

[Lake Martin EF4]

I meant that, in my opinion, the Dollar General should've counted as a second DI of similar intensity, and that it wasn't counted because of the EF-scale and not the surveyors.

Oh. Yeah, good point. I agree with that, and it is why I count RF as an EF5. I was just responding to the first sentence of your post where you mentioned the "there weren't 2 DIs of this intensity" thing.

 

[Aaron Rider]

Somewhat related to the topic: just as I stated that Rochelle is rapidly falling out of favor in terms of "universally recognized EF5 candidates", I'd wager good money that NWS Jackson is no longer the definitive "good office". Logan Poole's statement re: Green Apple Florist put the nail in the coffin: the amount of people on Twitter I've seen comparing it to Vilonia's East Fisher Street "EF5 can't be given based off one structure" home is phenomenal and to be honest I'm fairly sure the Rolling Fork tornado will replace Rochelle as a "universally recognized EF5 candidate" just because of that statement - despite the fact that the florist was rated properly and the statement doesn't mean what most think it does. (As stated, a more likely EF5 damage location is the Family Dollar, but that can't be EF4 on the current version of the scale, so there isn't anything in the survey I can really complain with.)

The new "definitive good NWS office" in survey terms is likely going to be Huntsville - many of the other candidates have big, big missteps in their past, perceived or otherwise, that knock them down.

EDIT: Nevermind, I take back my Huntsville endorsement. Forgot they used Goldsby Logic on a home in Flat Rock to avoid EF5. Not sure what office replaces Jackson then. Maybe Dodge City?

I'm not familiar with that Flat Rock damage. Please elaborate

 

[Lake Martin EF4]

I'm not familiar with that Flat Rock damage. Please elaborate

Flat Rock, AL-Trenton, GA EF4 Tornado – April 27, 2011 (FREE) – Tornado Talk

www.tornadotalk.com

It's the Perry home. Can't C+P because TT doesn't allow that.

 

[SouthFLwx]

This home got EF3 155. I would personally go with EF4, but it's not that big of a deal.

Oh wow, looks like I called it lol

 

[Lake Martin EF4]

A fun topic I've recently been thinking of: what's the sum total of violent tornadoes that have been downgraded? 6 to 5, 5 to 4, 4 to 3, even 5 to 3 like El Reno. I have a few on hand, but I'm certain there's more:

E/F6 to E/F5:
Lubbock 1970
Xenia 1974

E/F5 to E/F4:
Sunnyside 1965
Union City 1973
Ivanovo 1984
La Plata 2002
Tuscaloosa 2011 (sure looks like this is what happened behind the scenes)
El Reno 2013

E/F4 to E/F3:
Cheyenne 1979
Rainsville-Henagar 1994
Kissimmee 1998
Gallatin 2006
Hopewell 2007
Washington 2009
Bennington 2013
Ciudad Acuna 2015
Maybe the 2018 Brazil E/F4
Bowling Green 2021

E/F5 to E/F3:
El Reno 2013 (RIP)

What others are there that I'm missing?

 

[joshoctober16]

A fun topic I've recently been thinking of: what's the sum total of violent tornadoes that have been downgraded? 6 to 5, 5 to 4, 4 to 3, even 5 to 3 like El Reno. I have a few on hand, but I'm certain there's more:

E/F6 to E/F5:
Lubbock 1970
Xenia 1974

E/F5 to E/F4:
Sunnyside 1965
Union City 1973
Ivanovo 1984
La Plata 2002
Tuscaloosa 2011 (sure looks like this is what happened behind the scenes)
El Reno 2013

E/F4 to E/F3:
Rainsville-Henagar 1994
Kissimmee 1998
Gallatin 2006
Washington 2009
Bennington 2013
Ciudad Acuna 2015
Maybe the 2018 Brazil E/F4
Bowling Green 2021

E/F5 to E/F3:
El Reno 2013 (RIP)

What others are there that I'm missing?

wait the union city tornado was a F5 that was downgraded?

i did hear it as a possible F5 before but first i herd of this.

 

[Lake Martin EF4]

wait the union city tornado was a F5 that was downgraded?

i did hear it as a possible F5 before but first i herd of this.

Yup. Feast your eyes:

The Union City tornado was extremely violent. The NSSL gave the Union City an F5 rating in its report on the tornado but it was downgraded to an F4 for unknown reasons. Farm fields were scoured, a car was separated from its engine with the engine block being carried 328 yards while the frame was carried 874 yards, mobile home frames were wrapped around poles, two homes were completely swept away, a 2000 gallon gasoline tank was carried 874 yards, a 132-154 pound steel container was carried over a mile, trees were debarked and a steel I-beam was carried a long distance.

Union City is a case like Sunnyside, Cheyenne, Kissimmee, Gallatin, Tuscaloosa and arguably Ivanovo where the initial rating was likely correct.