Enhanced Fujita Ratings Debate Thread

[MNTornadoGuy]

Some other potential candidates from the Mayfield tornado with no DIs. The first one (NE of Mayfield) probably isn't one though as the shrubbery in front appears to be intact and the subflooring is still there. The second one is in Princeton and it could be one if no cleanup has taken place.

 

[TH2002]

Some other potential candidates from the Mayfield tornado with no DIs. The first one (NE of Mayfield) probably isn't one though as the shrubbery in front appears to be intact and the subflooring is still there. The second one is in Princeton and it could be one if no cleanup has taken place.

Is this the same house?

 

[buckeye05]

Some other potential candidates from the Mayfield tornado with no DIs. The first one (NE of Mayfield) probably isn't one though as the shrubbery in front appears to be intact and the subflooring is still there. The second one is in Princeton and it could be one if no cleanup has taken place.

Looks like they both have subflooring still attached tbh. I recognize the second house with the oval-shaped pool from an aerial flyover of Princeton taken the next morning. Was more of a pile of rubble rather than a clean foundation, so another case of debris cleanup making it look worse than it originally was.

 

[MNTornadoGuy]

Actually, are we looking at the same 1st photo? Looks like the cleanest sweep out of all of them. I'm referring to the crawlspace foundation home in the center of the photo. There's no sizable debris within the immediate vicinity.

Oh wait mobile was screwed up the order of photos for me.

 

[buckeye05]

Again, pretty questionable, but this is the closest thing I've seen to an EF5 candidate house in Princeton so far. Appears to have poured concrete basement foundation walls, and has sustained total removal of subflooring. With that said, I see the tell-tale signs of debris cleanup here, and it doesn't look like it was the cleanest sweep to begin with, so I can't be too confident.

 

[MNTornadoGuy]

Again, pretty questionable, but this is the closest thing I've seen to an EF5 candidate house in Princeton so far. Appears to have poured concrete basement foundation walls, and has sustained total removal of subflooring. With that said, I see the tell-tale signs of debris cleanup here, and it doesn't look like it was the cleanest sweep to begin with, so I can't be too confident.
View attachment 11159

I'm pretty sure that these are ground-level photos of that same house:

 

[MNTornadoGuy]

More photographs from that Bremen house. There might be sill plating in the 2nd photo.

 

[A Guy]

I've never seen any of the original sources mention an F4 rating. I wouldn't be surprised if they did, but the Russian sources I've looked that said F5.

Is there anything you can link me to? Maybe a scan of an old newspaper or something?

The recent study of Chernokulsky & Sikhov (2018) specifically cites A.I. Snitkovsky 1987 'Tornadoes in the USSR' as the source for the F4 rating. The source I've seen for the F5 rating is from the European Severe Weather Database, which has been changed subsequently to an F4 rating citing the 1987 source.

Now Wikipedia cites this article hosted on a Ukrainian site, which appears that it may indeed be Snitkovsky 1987. I have a suspicion it may be only part of the original article which is supposed to be 13 pages, as Chernokulsky & Sikhov give specific ratings for each of the tornadoes citing that source, none are listed there, there is only a note that damage indicated that winds exceeded 100 m/s (i.e. F4 under the assumption of the time).

I think it is quite likely that the more recent Russian writing is drawing off later sources, possibly even English language ones (maybe even Wikipedia itself) citing the ESWD rating.

 

[andyhb]

Looks like they both have subflooring still attached tbh. I recognize the second house with the oval-shaped pool from an aerial flyover of Princeton taken the next morning. Was more of a pile of rubble rather than a clean foundation, so another case of debris cleanup making it look worse than it originally was.

I think you're focusing a little too much on the sub-flooring stuff tbh. It's entirely possible for a house to be swept from anchor bolted connections without all of the sub-flooring being removed.

 

[TH2002]

The recent study of Chernokulsky & Sikhov (2018) specifically cites A.I. Snitkovsky 1987 'Tornadoes in the USSR' as the source for the F4 rating. The source I've seen for the F5 rating is from the European Severe Weather Database, which has been changed subsequently to an F4 rating citing the 1987 source.

Now Wikipedia cites this article hosted on a Ukrainian site, which appears that it may indeed be Snitkovsky 1987. I have a suspicion it may be only part of the original article which is supposed to be 13 pages, as Chernokulsky & Sikhov give specific ratings for each of the tornadoes citing that source, none are listed there, there is only a note that damage indicated that winds exceeded 100 m/s (i.e. F4 under the assumption of the time).

I think it is quite likely that the more recent Russian writing is drawing off later sources, possibly even English language ones (maybe even Wikipedia itself) citing the ESWD rating.

Okay, thanks for the info! I swear I remember reading somewhere that "the Russians unofficially awarded the [Ivanovo] tornado an F4 rating" but couldn't find anything to back up that claim.

 

[buckeye05]

I think you're focusing a little too much on the sub-flooring stuff tbh. It's entirely possible for a house to be swept from anchor bolted connections without all of the sub-flooring being removed.

I mean you’re not wrong, but neither of the above photos show that. Sure, not all the floor has to be removed in order to ascertain a high-end rating. I’m assuming you are more referring to something this (pic below)? If so, I’d agree as the small portion of remaining floor doesn’t mean much. My issue is that there appears to be no removal of any kind in the two aforementioned photos, along with many of the other homes at Kentucky Lake.

 

[pohnpei]

Aerial view of that house in Bremen that had part of its concrete foundation shattered. There wasn’t any rebar in the broken foundation though. The tornado peaked in this area on radar and the mangling of vehicles, ground scouring, tree debarking, extensive wind-rowing and debris granulation are solid evidence that the tornado likely reached EF5 intensity in the area. The main thing is likely preventing a higher rating in this area is the poor-construction with most houses having a CMU foundation or poor-anchoring.
View attachment 11150
View attachment 11151
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Was It the in the right side of the first pic?(the empty foundation)

 

[MNTornadoGuy]

Was It the in the right side of the first pic?(the empty foundation)

Yep that is it

 

[Tomcats Forever!]

I'm pretty sure that these are ground-level photos of that same house:

The side of the basement with no concrete wall is also the side that the tornado came from, if that would matter. In other aerials you can see that the other houses directly downstream across the street were not leveled.

 

[pohnpei]

Regardless off structure wise, there were three places where I believe tornado almost certainly reached EF5 level:
Cayce to sw Mayfield: siginificant ground scouring, ground digging, tree damage, possible asphalt damage, debris pattern
UK facility area: significant ground scouring, wind rowing, facility damage south side of the core and high 3 FR12 damage north side of the core, vehicle all tossed around, truck trailer thrown long distance, radar performance
Bremen: Incredible ground scouring, vehicle all tossed with some of them mangled, several houses' foundation blown away, driveway damage, debris pattern, radar performance.

At this point, I really doubt there were any house meet with EF-scale definition of well built in the path, but these areas above were of most abundant with contextual evidence.

 

[andyhb]

 

[buckeye05]

I'm pretty sure that these are ground-level photos of that same house:

Yup that's the one. Closely spaced anchor bolts too. However, another poster mentioned that the back wall of the basement not being concrete, and facing the direction from which the tornado approached. That's significant for obvious reasons.

This is the kind of data that could get things moving, and bring awareness from the right people.

 

[MNTornadoGuy]

I'm surprised the UK building only got 170 mph, I wonder if they will change the DI rating since they removed it. Reinforced concrete was used in the construction of the building.

 

[andyhb]

I still cannot fathom how someone, especially if they had access to the blueprints of that facility, looked at that and decided to give it below the expected bound DOD 10 for an elementary school (176 mph). This is when both the categorization as an ES is questionable at best, and it's clear that building was pretty structurally sound.

 

[MNTornadoGuy]

The NWS's reasoning why that Bowling Green house was given an EF2 rating.