Enhanced Fujita Ratings Debate Thread

[WeathermanLeprechaun]

The homes were (almost 100%) built below-quality in town as an individual damage assessment shows, so I’m completely fine with 180-185. The parking stops Ethan has already said shouldn’t be used and other than that there isn’t much going for it besides DOW readings over obviously-not-EF5 damage.

And this is why I dislike DOW readings. Rarely what they record actually correlate to the ground. It's great science but it means nothing if these winds didn't touch the ground

 

[Aaron Rider]

The homes were (almost 100%) built below-quality in town as an individual damage assessment shows, so I’m completely fine with 180-185. The parking stops Ethan has already said shouldn’t be used and other than that there isn’t much going for it besides DOW readings over obviously-not-EF5 damage.

Can someone remind me why the Greenfield parking stops shouldn't be used? I forget

 

[Grand Poo Bah]

I think the only valid path for Greenfield to receive an EF5 would be the parking stops, due to Joplin’s precedent and windspeed calculations being well in excess of 200 mph for them. Debris granulation and debarking in Greenfield were evident, but didn’t really have the EF5 look to me. There is one tree in town that was 100% debarked, but there’s a significant caveat to said tree; its branches are relatively intact, which is a very strange observation. I really don’t know what to make of that, the tree was likely dead, or it could’ve been something else entirely. Either way, strange presentation of damage in town.

Also, I’ve heard that a manhole cover was removed in town too, but I haven’t seen any pictures of that DI, so I’m assuming someone just lied or something. At the end of the day, though, if Greenfield received the rating, it’d easily be the weakest EF5 damage-wise, and it’s not even close IMO. Honestly, that’s part of the reason why I don’t think it’s that big of an issue.

Manhole cover

 

[Grand Poo Bah]

And this is why I dislike DOW readings. Rarely what they record actually correlate to the ground. It's great science but it means nothing if these winds didn't touch the ground

I mean, it's entirely possible Greenfield is what 320 mph 1-5 second wind gusts look like on the ground. The lack of expected intensity in the damage can realistically be attributed to the short duration.

 

[Grand Poo Bah]

Can someone remind me why the Greenfield parking stops shouldn't be used? I forget

If ratings were assigned based on a probability curve the parking stops would move the distribution upwards without being the total deciding factor of the rating. They're the perfect example of how unresolved doubt is currently treated as a ceiling. Even if there was a debris collision or some other element that helped move them, it doesn't eliminate the extraordinary evidence of them being moved, and it's still an exceptionally rare DI.

 

[slenker]

One thing that does need to be emphasized is the fact that the wind parcel responsible for the 300+ mph reading was very likely accelerated to that velocity after ground contact, assuming it made direct contact with the ground in the first place. It’s extremely unlikely that it was 300 mph the entire time. Definitely doesn’t omit it from being 200+ at the surface though, in fact it was very likely in that range at the surface.

I wouldn’t be against an EF5 rating for Greenfield, I just think there are much worse examples of the EF scale’s misapplication than this (if you can even call it a misapplication). Specifically, the ratings where the EF scale was very obviously misapplied. Vilonia, Chickasha, Goldsby, Matador, Linton, Lake City, arguably Bassfield and Mayfield, etc. are the tornadoes that truly emphasize the misapplication of the scale IMO.

 

[Eoline]

One thing that does need to be emphasized is the fact that the wind parcel responsible for the 300+ mph reading was very likely accelerated to that velocity after ground contact, assuming it made direct contact with the ground in the first place. It’s extremely unlikely that it was 300 mph the entire time. Definitely doesn’t omit it from being 200+ at the surface though, in fact it was very likely in that range at the surface.

I wouldn’t be against an EF5 rating for Greenfield, I just think there are much worse examples of the EF scale’s misapplication than this (if you can even call it a misapplication). Specifically, the ratings where the EF scale was very obviously misapplied. Vilonia, Chickasha, Goldsby, Matador, Linton, Lake City, arguably Bassfield and Mayfield, etc. are the tornadoes that truly emphasize the misapplication of the scale IMO.

I wouldn’t even call Greenfield a misapplication - for what the EF scale is intended to do (rate verified structural, contextual and vegetative damage) the rating is completely fine.

 

[Grand Poo Bah]

I wouldn’t even call Greenfield a misapplication - for what the EF scale is intended to do (rate verified structural, contextual and vegetative damage) the rating is completely fine.

Aren't parking stops and sewer systems engineered structures too, though?

 

[slenker]

I wouldn’t even call Greenfield a misapplication - for what the EF scale is intended to do (rate verified structural, contextual and vegetative damage) the rating is completely fine.

I edited my comment before your reply, I didn’t mean to insinuate it was.

 

[eep]

If ratings were assigned based on a probability curve the parking stops would move the distribution upwards without being the total deciding factor of the rating. They're the perfect example of how unresolved doubt is currently treated as a ceiling. Even if there was a debris collision or some other element that helped move them, it doesn't eliminate the extraordinary evidence of them being moved, and it's still an exceptionally rare DI.

IIRC they were pretty structurally weak (I think their anchoring was worn down) for parking stops and weren't good evidence like in Joplin. Washington 2013 is a real instance of one of them getting lofted and it probably actually being an EF5 worthy DI.