Enhanced Fujita Ratings Debate Thread

[buckeye05]

Oh ok well that's good to see. Maybe he just mispoke. The fact he collaborated with Lyza says a lot and changes my perspective on him completely

Jim was actually speaking in support of Tony Lyza’s research and sentiments here, but maybe didn’t articulate it too clearly. Essentially, this video is somewhat of a coded message saying “Ok we’ve been underrating tornadoes, here are some examples of that happening, and here’s where the bar is now for ratings and how to apply the scale in a more accurate way”. None of that was said explicitly, but reading between the lines, that’s the crux of it. He’s using discretion instead of saying “Whoops, we’ve been totally screwing this up for about two decades or so. Sorry about that!”

While Jim has been associated with some questionable EF scale/rating stuff in his earlier years, he’s actually been one of the most reasonable people in the field for a while now. He was one of the first people to promote tree stubbing/debarking as a violent tornado indicator by itself, is a big proponent of factoring in contextual damage and non-DIs, and played a crucial role in assigning EF5 ratings to homes following Moore 2013 in a reasonable manner.

In this most recent presentation, he explicitly instructs NWS surveyors to not play it overly conservative, reminds them that the scale is designed with average houses in mind, and says to not expect “a fortress” when it comes to EF5 house damage. In all, I don’t think we can really ask for better than that, and I’m honestly surprised that Jim is not more celebrated in the armchair tornado damage/EF scale community. Lately, he’s been supporting what many of us have been saying for years, and his voice is exactly what is needed right now.

 

[buckeye05]

Also one more thing I want to circle back to something another user posted about. This sort of got glazed over and buried in the thread, but it’s extremely significant. In the proposed new scale, root ball displacements (trees getting ripped out of the ground and thrown) have an expected damage starting at EF4 and can be rated EF5.



That’s huge! That means we have another way besides the “Enderlin method” to rate tornadoes EF5 independent of any structural damage. While “greater than typical resistance” hasn’t been defined yet, people have pointed out that a tree with no leaves would give the wind less surface area to grab onto. People have also pointed out that this happened in Bremen. How crazy would it be if Mayfield finally gets the rating it deserves based on tree damage?

Also, adjusting to this “new” definition of EF5 damage and this much less conservative approach to damage surveying has honestly left my head spinning. It’s been a bit of an adjustment. So many tornadoes that I’ve said “don’t meet the stringent EF5 criteria”, now can meet that criteria between the standards used in Jim LaDue’s presentation, the upcoming new tree scale, and by using mathematics to calculate windspeed to move heavy objects. I’ve gone from defending Mayfield’s high-end EF4 rating not because I agree with it, but because of the standards being used at that time, to realizing Mayfield now can likely be rated EF5 in some way due to the standards changing. I always go by what the current EF scale practices are, and as a result, my definition for what constitutes as EF4 and EF5 damage has dropped a s**t-ton essentially overnight. Not that this is a bad thing at all, as I just want to see accurate ratings too.

 

[tornado examiner]

Excellent news all around. No complaints from me. Especially when initial internal talks to begin reevaluations of past surveys are ongoing throughout the nws apparently. (no plans yet made though)

 

[joshoctober16]

Chapman wasn’t rated EF5 because the immediate area around the house that was obliterated wasn’t swept clean to the survey team’s liking. It literally came down to some bricks left piled up next to the basement foundation. So their logic was literally “A concrete foundation stemwall literally being ripped apart, bent railroad tracks, cars and multi-ton farm machinery lofted and mangled, and severe scouring and debarking all carry less weight in terms of the rating compared to some loose bricks left on the ground next to the foundation”.

Totally ridiculous, I know. It’s a perfect example of surveyors being totally fine with using some minute contextual factor to downgrade, while ignoring multiple other huge pieces of contextual evidence that just scream for an upgrade. It’s a double standard, and not even a subtle one. That kind of logic can’t just be a one way street. It has to go both ways.

very well built homes that have all the walls down but not swept clean can be rated EF5 on the new scale.

 

[tornado examiner]

very well built homes that have all the walls down but not swept clean can be rated EF5 on the new scale.
View attachment 47163

Have they showed the DOD’s for the concrete block foundation residence DI? I think that's a new one.

 

[Lake Martin EF4]

While “greater than typical resistance” hasn’t been defined yet, people have pointed out that a tree with no leaves would give the wind less surface area to grab onto. People have also pointed out that this happened in Bremen. How crazy would it be if Mayfield finally gets the rating it deserves based on tree damage?

I think Matador also did this IIRC, and to mesquite trees. Possibly guaranteed EF5 there.

 

[WeathermanLeprechaun]

Also one more thing I want to circle back to something another user posted about. This sort of got glazed over and buried in the thread, but it’s extremely significant. In the proposed new scale, root ball displacements (trees getting ripped out of the ground and thrown) have an expected damage starting at EF4 and can be rated EF5.

View attachment 47157

That’s huge! That means we have another way besides the “Enderlin method” to rate tornadoes EF5 independent of any structural damage. While “greater than typical resistance” hasn’t been defined yet, people have pointed out that a tree with no leaves would give the wind less surface area to grab onto. People have also pointed out that this happened in Bremen. How crazy would it be if Mayfield finally gets the rating it deserves based on tree damage?

Also, adjusting to this “new” definition of EF5 damage and this much less conservative approach to damage surveying has honestly left my head spinning. It’s been a bit of an adjustment. So many tornadoes that I’ve said “don’t meet the stringent EF5 criteria”, now can meet that criteria between the standards used in Jim LaDue’s presentation, the upcoming new tree scale, and by using mathematics to calculate windspeed to move heavy objects. I’ve gone from defending Mayfield’s high-end EF4 rating not because I agree with it, but because of the standards being used at that time, to realizing Mayfield now can likely be rated EF5 in some way due to the standards changing. I always go by what the current EF scale practices are, and as a result, my definition for what constitutes as EF4 and EF5 damage has dropped a s**t-ton essentially overnight. Not that this is a bad thing at all, as I just want to see accurate ratings too.

I am actually so happy that this very strict era of surveying is coming to a end. This puts plenty of tornadoes in contention and I'm curious if Matador did this type of tree damage. That tornado has a lot more evidence of higher end intensity now with the new guidelines. This gives many tornadoes that just didn't fit the criteria a very major change in how they are viewed. Without the train in Mayfield, I'm very confident that in Bremen, it was no doubt EF5 intensity.

 

[wolfywise]

Mayfield, by a good margin. Matador, however, is a Top 10 strongest of all time tornado, but I didn't mention it since no EF5 structural damage was caused - although I'm not sure if what it did to that forest meets the EF5 DI in the upcoming forest damage category in the updated EF scale.

Matador deleted and displaced whole groves of honey mesquite, trees with deep roots and very dense wood. Would be EF5-210 on the revised scale's multi-tree DI.

 

[WeathermanLeprechaun]

Matador deleted and displaced whole groves of honey mesquite, trees with deep roots and very dense wood. Would be EF5-210 on the revised scale's multi-tree DI.

Of course this is just ranging it on the scale, but this proves my suspicions Matador was pretty high end. Also, here's this:
The car damage from Matador WILL NEVER cease to amaze me. If you rate it on houses, it maxes out at like mid end EF4, if on contextuals, i think it's EF5

 

[WeathermanLeprechaun]

Honestly, I think the Port Arthur supercell from last year may actually have been more impressive for December. In that tornado people were extremely lucky was over basically marsh land as I believe had that actually hit Port Arthur or anything when it was at full strength it would've done Mayfield level or EF5 level damage. However, since the terrain was so wet there is probably no way to even speculate at all.

I respectfully disagree, I personally think Port Arthur gets a lot of credit just because it exhibited 90 kt VROT. Admittedly, i did think the same as you about it being violent when it was ongoing. More wet terrain would've been easier for the tornado to do severe contextuals where possible, no? I think the ranch it hit was just at peak intensity or close to at least and the rest is (imo) upper level scans that didn't translate to the ground whatsoever. I don't doubt the potential it was briefly EF4 intensity, but just hard to see it reaching EF5 intensity based off all we've got and the only thing that suggests it could've is the radar scans that were looking around 6-7 KFT up. It's just very likely those winds just didn't translate the ground like Hollister which was not a violent tornado, and was just the result of a large, disorganized circulation that couldn't translate its 260 mph GTG (mightve been less, if contaminated) to the ground. Still was very interesting meterologically though!

 

[Xyls]

I respectfully disagree, I personally think Port Arthur gets a lot of credit just because it exhibited 90 kt VROT. Admittedly, i did think the same as you about it being violent when it was ongoing. More wet terrain would've been easier for the tornado to do severe contextuals where possible, no? I think the ranch it hit was just at peak intensity or close to at least and the rest is (imo) upper level scans that didn't translate to the ground whatsoever. I don't doubt the potential it was briefly EF4 intensity, but just hard to see it reaching EF5 intensity based off all we've got and the only thing that suggests it could've is the radar scans that were looking around 6-7 KFT up. It's just very likely those winds just didn't translate the ground like Hollister which was not a violent tornado, and was just the result of a large, disorganized circulation that couldn't translate its 260 mph GTG (mightve been less, if contaminated) to the ground. Still was very interesting meterologically though!

See here's where I completely disagree. These wetland areas are particularly resilient to another type of high wind event which is hurricanes and as such would be less likely to show severe contextuals. This storm spent a decent amount of it's life essentially as a wedge waterspout. Without hitting much. The few structures it did hit did exhibit up to EF3 damage. It's strongest VROT was over wetland areas so I think this is a particularly hard one to judge.

 

[Aaron Rider]

I've made plenty of arguments in favor of Mayfield, but I think another important one is the track length. The tornado was on the ground for at least 165 miles. That's insane. It basically showed people that the Tri State tornado wasn't just a myth (several disconnected tracks and poor surveying) and is actually possible. Plus, It was incredibly violent almost the entire time.

If we're talking about just pure strength I think it still wins. Simply because of the overwhelming amount of evidence to choose from. It removes all doubt of its strength simply by the countless instances of complete and total destruction that occured. Completely debarked trees, cars thrown half a mile, and dozens of emply slabs/subfloors. Collectively it is more impressive than any other tornado this decade. Regardless of the fact each DI occured in different areas.

I'm with you. A tornado producing extreme damage over *hundreds* of miles is just the stuff of legend.