Central Ohio Wx
Member
Highly debatable, but generally its because traditional radar can be unreliable (Hollister 2024) and DOW isn't a consistent way to rate tornadoes.
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Current Tropical Systems Erin
Aaron Rider
Member
Well, I'm sure I'm not the only one with a personal opinions list. Grinnell is....well, it's not an EF3 in my list.
(my all time favorite borderline cases are Van Wert 02 and Roanoke 04)
I'm confused - the only damage I've seen from Plevna was the ground scar and some tree damage that looked high-end EF3 max? Is there any imagery of structural damage that warrants an EF4 rating? I'm not saying I disagree with an EF4 rating for Plevna because it was very obviously a violent tornado, but I'd be shocked if they actually just gave it a benefit-of-the-doubt rating in today's day and age.
Aaron Rider
Member
That, plus back in 1950 whatever, how else were you supposed to do it? Fujita was a gift of a man
AJS
Member
Their might be some damage we haven’t seen yet!
Roanoke? As in Virginia? Or somewhere else?
Aaron Rider
Member
Central Ilinois. July 13, 2004. It did extremely impressive damage to a factory. But it was also a gentlemanly tornado in that it chose to be highly photogenic.
Central Ohio Wx
Member
The files they are uploading at DAT are too large to be posted here, but there's some pretty significant EF3 MBS damage.
AJS
Member
I think the damage earlier on in the path may be where the most intense damage may have happened. The tornado actually seemed to have been weakening as it was approaching Plevna from what I saw on radar.
jiharris0220
Member
There’s utterly no way to reliably measure wind speeds from tornadoes in a way that will make it feasible for a rating system.
Unless we find out a way to teleport every DOW to every tornado that touches down and then make those DOW follow those tornadoes throughout their entire path, it’s simply impractical.
I mean, that was then. But this is now. Can't they figure out a way to translate the wind speed on land the way they do with recon in TCs? The one obvious thing is that you can't really fly a place into a tornado...
tornado examiner
Member
It was a metal building system that was pulled out of the ground or something. Not a viable EF4 di.
tornado examiner
Member
Well, there’s the first EF0 di that possibly signifies the beginning of the track.
jiharris0220
Member
The tornado was actually peaking just southwest of Plevna on radar, that’s were the highest GTG was measured, the deepest CC drop was measured, and even where the debris ball was the most prominent.
But obviously what the radar shows vs reality can vary.
So I've heard this sentiment shared quite often and a lot of people really seem to think that radar-measured windspeeds should be the way that we rate tornadoes, but as of right now, I completely disagree. I believe damage is actually the best way to rate a tornado until we get accurate windspeed measurements very close to the ground layer that coincide with damage supportive of the windspeed.
Many windspeed measurements in tornadoes are taken high up in the vortex with little to no ground friction playing a role. This was the case in many of the tornadoes with windspeed measurements exceeding 200 mph. I know for a fact it's the case with Minden/Harlan 2024, where it was taken 600 m AGL. But there are some, like Sulphur 2016, El Reno 2011, and Greenfield 2024 that had windspeed measurements taken less than 50 m AGL (Sulphur and El Reno especially, they were less than 20 m AGL)! but there's more to it than that. Sulphur had EF3 damage coinciding with the 200 MPH reading and Greenfield also had EF3 damage coincident with the 300 mph reading. The only two tornadoes that had their windspeeds measured >200 MPH that did in fact inflict damage that was reminiscent of an EF5 rating was Moore 1999 and El Reno 2011 - two of the most violent tornadoes we've ever seen - while every other one failed to do this.
The question is, why is the damage coincident with these extreme windspeed measurements sometimes not lining up? I don't know if researchers know the exact answer to this, but since this is the case in reality, it's not a good idea to incorporate windspeeds only. Something we can all agree on is that an EF5 needs to be doing extremely violent damage on the ground. If a tornado has >200 MPH windspeeds measured, but doesn't do anything close to what other EF5s have done in the damage layer, then it does not deserve EF5 on merit of windspeeds alone. EF5 tornadoes need to be similar in the sense that they pose the same threat to life and property as other EF5s, and if a tornado is not capable of sweeping a well-built home off its foundation and scouring the ground, nubbing and debarking trees, etc. then it does not deserve EF5 IMO.
One thing I can get behind is using extreme windspeed measurements with damage, even contextual, that supports said windspeed. If there is a tornado that has >270 MPH windspeeds measured and doesn't impact any structures, but left a trail of extreme ground scouring in an open field worse than Moore 2013, it absolutely should deserve an EF5 rating, and we should definitely use the windspeed measurements to support said rating. But all I'm saying is that we can't use windspeeds alone, tornadoes are way too complicated as of now to simply give any tornado we see with >200 mph windspeeds EF5.
EDIT: Red Rock 1991 also had >200 MPH windspeeds taken, but it wasn't rated F5. I don't know what contextual damage it did so I can't really comment on that.
AJS
Member
I just went back and looked at the radar loop and you’re right. I must’ve got Grinnell and Plevna mixed up.
I will note that sometimes the radar doesn’t correlate with the damage shown at the ground. Cayce, KY was relatively early on in the Mayfield tornado’s path and the velocity signature didn’t actually look that intense, and i’d argue that’s where some of the more intense contextual damage throughout the path happened.
tornado examiner
Member
Oh that’s nws Jackson announcing they collectively made the choice to upgrade London to EF4 based on “THE OVERALL LOOK OF THE DAMAGE”
Why can’t every other office do the same?
Why can’t every other office do the same?
AJS
Member
Dang, can’t say i’ve seen another NWS WFO do the same with any other tornado.
tornado examiner
Member
Like seriously in their pns they didn’t mention any specific DI