Significant Tornado Events

[andyhb]

If the same standards used to rate the April 3, 1974 Super Outbreak, I feel like for the April 27, 2011 tornado outbreak these tornadoes would get an F5 rating:
Hackleburg AL
Smithville MS
Tuscaloosa AL
Ringgold GA
Rainsville AL
Bridgeport AL
Philadelphia MS

Pisgah/Flat Rock AL easily.

 

[Robinson lee]

Definitely Mangum, OK from May 20. Was rated EF2, but it produced grass scouring in rural areas and mobile radar recorded EF5 winds as the tornado passed though open fields.

The Odessa, TX EF3 occurred the same day, and produced impressive ground scouring as well, despite hitting next to nothing. The Laverne, OK EF3 from May 23 seems like it was pretty violent too. The house it swept away was unanchored, but there was very little debris left, and it completely stripped a vehicle down to its chassis. Harder to say with those two, but definitely Mangum.

The vehicle damage of laverne is absolutely impressive. For me, such vehicle damage often occurs in high-end ef4 or even EF5 tornadoes. This tornado is definitely underestimated. Its multi vortex shape is similar to saline ef4 in 2012. There may be quite strong wind in the sub vortex and cause very strong vehicle damage

 

[Robinson lee]

The EF3 before Smithville deserves more recognition than it ever received
View attachment 9015

I have some photos of the tornado damage, and the most striking thing, except for scour, is the tree damage of the tornado, indicating that the tornado may have the strength of ef4

 

[Robinson lee]

If the same standards used to rate the April 3, 1974 Super Outbreak, I feel like for the April 27, 2011 tornado outbreak these tornadoes would get an F5 rating:
Hackleburg AL
Smithville MS
Tuscaloosa AL
Ringgold GA
Rainsville AL
Bridgeport AL
Philadelphia MS

For me, I may not think Bridgeport is a suitable candidate. The environment and surrounding damage of tornado are relatively weak. On the same day, Cullman ef4 also damaged the stairs. Although it may take a lot of wind to pull out the stairs due to the failure of fixation, it may not symbolize the wind force of EF5, especially when the surrounding damage is relatively weak.

 

[pohnpei]

For me, I may not think Bridgeport is a suitable candidate. The environment and surrounding damage of tornado are relatively weak. On the same day, Cullman ef4 also damaged the stairs. Although it may take a lot of wind to pull out the stairs due to the failure of fixation, it may not symbolize the wind force of EF5, especially when the surrounding damage is relatively weak.

I agree. Concrete porch being ripped out was violent but this damage alone was not a legitimate indicator for EF5 rating. It can be knocked by heavy debris like flying vehicle, not by wind itself. Especially it you consider the contextual damage overall was not very impressive.
Some seemingly unusual damage can just done by coincidence event in volatile tornado environment when contextual damage was not that strong. For example, Newton EF3 tornado on April 27 2011 did damage to highway bridge and nearby asphalt. But the overall contextual damage like damage of trees surrounding was pretty weak. An article of tornadotalk also had an analysis of this unusual damage.

Newton, MS EF3 Tornado – April 27, 2011 – Tornado Talk

www.tornadotalk.com

 

[speedbump305]

The damage to the Bridge was extremely unusual.

 

[speedbump305]

in my opinion, These would be the tornadoes to get an EF5 rating in 1974

Hackleburg Phil Campbell
Smithville
Philadelphia
Tuscaloosa
Ringgold
Rainsville
Flat Rock

 

[Brice Wood]

Dimmit Texas tornado of 2017
When this tornado turned to into a wedge was it the tornado itself or the whole meso just extremely low or to the ground?

 

[MNTornadoGuy]

I believe that most of the official European F5s should not be rated as such and here's why:

6/29/1764 - Woldegk, Germany:
The F5 rating was based on a large residential house 100 ft long and 7-40 ft wide that was “reduced to its lowest floor.” This could have been F5 damage however this home was “not yet fully developed.” Since it was under construction the integrity is questionable.

4/23/1800 - Hainichen, Germany:
The damage descriptions that the ESWD appeared to have sourced the rating from do not describe any potential structural F5 damage. Appears to have been rated based on descriptions of trees being debarked. You shouldn't be able to give a tornado an F5 rating solely based on tree debarking.

8/19/1845 - Montville, France:
“At other places, the buildings were as if pulverized and the place was completely cleaned” Flammarion (1872) - This statement could mean potential F5 damage if these buildings were homes or some other type of sturdy structure. This tornado is probably the most deserving of an F5 rating out of all the official European F5s.

7/24/1930 - Montello, Italy:
The F5 rating appears to be based on a large church that lost most of the central walls. Trees and vegetation around the church had almost all leaves and the bell tower was still completely intact. The Canadian EF-scale has a DI for “Heritage Churches” which is similar to this structure and it would be likely rated as a 143-165 mph EF3.

6/24/1967 - Palluel, France:
Grazulis in his F5/F6 tornado document says that the damage that was used to rate this tornado as an F5 was more F3 in nature. The rating was possibly based on a car being moved over 300 ft.

6/9/1984 - Ivanovo, Russia:
All the homes that were swept away were mostly frail wood-frame homes that were poorly anchored to their foundation. There is no evidence that reinforced concrete buildings were swept away.

 

[zvl5316]

I believe that most of the official European F5s should not be rated as such and here's why:

6/29/1764 - Woldegk, Germany:
The F5 rating was based on a large residential house 100 ft long and 7-40 ft wide that was “reduced to its lowest floor.” This could have been F5 damage however this home was “not yet fully developed.” Since it was under construction the integrity is questionable.

4/23/1800 - Hainichen, Germany:
The damage descriptions that the ESWD appeared to have sourced the rating from do not describe any potential structural F5 damage. Appears to have been rated based on descriptions of trees being debarked. You shouldn't be able to give a tornado an F5 rating solely based on tree debarking.

8/19/1845 - Montville, France:
“At other places, the buildings were as if pulverized and the place was completely cleaned” Flammarion (1872) - This statement could mean potential F5 damage if these buildings were homes or some other type of sturdy structure. This tornado is probably the most deserving of an F5 rating out of all the official European F5s.

7/24/1930 - Montello, Italy:
The F5 rating appears to be based on a large church that lost most of the central walls. Trees and vegetation around the church had almost all leaves and the bell tower was still completely intact. The Canadian EF-scale has a DI for “Heritage Churches” which is similar to this structure and it would be likely rated as a 143-165 mph EF3.

6/24/1967 - Palluel, France:
Grazulis in his F5/F6 tornado document says that the damage that was used to rate this tornado as an F5 was more F3 in nature. The rating was possibly based on a car being moved over 300 ft.

6/9/1984 - Ivanovo, Russia:
All the homes that were swept away were mostly frail wood-frame homes that were poorly anchored to their foundation. There is no evidence that reinforced concrete buildings were swept away.

I remembered there was also possible F5 in Poland. And although officially rated EF4, I think the violent tornado hit Mira, Italy in 2015 would definitely be rated as F5 if it happened before 2000.

 

[ARCC]

Close ups seem to indicate mixed use of anchor bolts and cut nails at that particular house. Not sure if that's what was meant by two anchoring systems or not, as one can be considered an anchoring mechanism, while the other not so much.

No, I believe the term used was “Storm straps”. I don’t think it was hurricane straps used in trusses and the like, but it could have been and I just assumed it was for foundation anchoring. I wish I could remember, but it was ten years ago and all lost in the forum crash.

 

[andyhb]

I have had strong suspicion that Houston/New Wren MS tornado (the one preceding Smithville) was greater than EF3 and MEG did a poor job of surveying/documenting it. Those damage pics only increase the validity of that notion.

 

[zvl5316]

I believe that most of the official European F5s should not be rated as such and here's why:

6/29/1764 - Woldegk, Germany:
The F5 rating was based on a large residential house 100 ft long and 7-40 ft wide that was “reduced to its lowest floor.” This could have been F5 damage however this home was “not yet fully developed.” Since it was under construction the integrity is questionable.

4/23/1800 - Hainichen, Germany:
The damage descriptions that the ESWD appeared to have sourced the rating from do not describe any potential structural F5 damage. Appears to have been rated based on descriptions of trees being debarked. You shouldn't be able to give a tornado an F5 rating solely based on tree debarking.

8/19/1845 - Montville, France:
“At other places, the buildings were as if pulverized and the place was completely cleaned” Flammarion (1872) - This statement could mean potential F5 damage if these buildings were homes or some other type of sturdy structure. This tornado is probably the most deserving of an F5 rating out of all the official European F5s.

7/24/1930 - Montello, Italy:
The F5 rating appears to be based on a large church that lost most of the central walls. Trees and vegetation around the church had almost all leaves and the bell tower was still completely intact. The Canadian EF-scale has a DI for “Heritage Churches” which is similar to this structure and it would be likely rated as a 143-165 mph EF3.

6/24/1967 - Palluel, France:
Grazulis in his F5/F6 tornado document says that the damage that was used to rate this tornado as an F5 was more F3 in nature. The rating was possibly based on a car being moved over 300 ft.

6/9/1984 - Ivanovo, Russia:
All the homes that were swept away were mostly frail wood-frame homes that were poorly anchored to their foundation. There is no evidence that reinforced concrete buildings were swept away.

The tie-1 tornadoes outside North America in my think:
8/29/1969, Tianjin, China: A village in Tianjin suburb suffered from Udall level fatality rate, scouring in corn field and concrete factories were nearly leveled.
1/10/1973, San Justo, Argentina: Short track & low moving speed, but the whole city destroyed including some well-built buildings.
7/26/2014，Khangai, Mongolia: Perfect performance on video, grass scouring, and a truck was carried to 500m+away & severely distorted.
7/8/2015, Mira, Italy: A villa was nearly leveled and the debris was cut to small pieces.
6/23/2016, Funning, China: 4.1km wide wedge. 2nd floor swept away in some concrete-and-brick FR12. Extreme damage in vehicle.

 

[MNTornadoGuy]

The tie-1 tornado outside North America in my think:
8/29/1969, Tianjin, China: A village in Tianjin suburb suffered from Udall level fatality rate, scouring in corn field and concrete factories were nearly leveled.
1/10/1973, San Justo, Argentina: Short track & low moving speed, but the whole city destroyed including some well-built buildings.
7/26/2014，Khangai, Mongolia: Perfect performance on video, grass scouring, and a truck was carried to 500m+away & severely distorted.
7/8/2015, Mira, Italy: A vila was nearly leveled and the debris was cut to small pieces.
6/23/2016, Funning, China: 4.1km wide wedge. 2nd floor swept away in some concrete-and-brick FR12. Extreme damage in vehicle.

I do wonder how slow-moving San Justo actually was as multiple sources say it only took "seconds" to pass through town and the track was probably much longer as a map of the damage clearly shows that the tornado extended outside of town.

 

[warneagle]

I believe that most of the official European F5s should not be rated as such and here's why:

6/29/1764 - Woldegk, Germany:
The F5 rating was based on a large residential house 100 ft long and 7-40 ft wide that was “reduced to its lowest floor.” This could have been F5 damage however this home was “not yet fully developed.” Since it was under construction the integrity is questionable.

4/23/1800 - Hainichen, Germany:
The damage descriptions that the ESWD appeared to have sourced the rating from do not describe any potential structural F5 damage. Appears to have been rated based on descriptions of trees being debarked. You shouldn't be able to give a tornado an F5 rating solely based on tree debarking.

8/19/1845 - Montville, France:
“At other places, the buildings were as if pulverized and the place was completely cleaned” Flammarion (1872) - This statement could mean potential F5 damage if these buildings were homes or some other type of sturdy structure. This tornado is probably the most deserving of an F5 rating out of all the official European F5s.

7/24/1930 - Montello, Italy:
The F5 rating appears to be based on a large church that lost most of the central walls. Trees and vegetation around the church had almost all leaves and the bell tower was still completely intact. The Canadian EF-scale has a DI for “Heritage Churches” which is similar to this structure and it would be likely rated as a 143-165 mph EF3.

6/24/1967 - Palluel, France:
Grazulis in his F5/F6 tornado document says that the damage that was used to rate this tornado as an F5 was more F3 in nature. The rating was possibly based on a car being moved over 300 ft.

6/9/1984 - Ivanovo, Russia:
All the homes that were swept away were mostly frail wood-frame homes that were poorly anchored to their foundation. There is no evidence that reinforced concrete buildings were swept away.

I personally think the idea of rating tornadoes from the 18th and early 19th century at all is kind of ridiculous. Retroactively rating tornadoes even in the 20th century where there's photographic evidence is contentious, so trying to rate damage that predates the existence of photography is just nonsensical.

Like I mentioned earlier in the thread, I'm working on translating Gottlob Burchard Genzmer's report on the Woldegk tornado (it's taking a while because it's from 1765 and the German is a bit archaic). I appreciate it as a historical document, but from what I've read so far, I think the scientific value is relatively limited because the understanding of meteorology at that point was so primitive. Basing any rating, much less an "official" F5 rating on reports from that era is highly questionable, imo.

As far as the more recent ones, I don't know enough about Palluel to have an opinion on it (although most of the photos I've seen are clearly below F5 standard), but I tend to agree with you about Ivanovo. I don't know if the surveys the Soviets carried out (and the coverage in the pre-glasnost Soviet media) are good enough evidence to support an F5 rating. I generally agree with your assessment that most of the structural damage photos are impressive but most of the structures looked frail. Home construction was obviously quite poor in most of rural Russia, which is comparable to historical tornadoes in the rural south where the structures are too weak to support an F5 rating. Even the more substantial urban buildings in the Soviet Union and Eastern Europe weren't reinforced properly (as was demonstrated by other events, like the 1977 earthquake in Romania and the 1988 earthquake in the Armenian SSR), so destroyed apartment blocks and factories aren't a strong basis for an F5 rating either. I'm not discounting the possibility that the tornado reached F5 strength, but I don't think the evidence is anywhere near conclusive. Maybe there's some good stuff buried in the Russian archives that wasn't allowed to see the light of day since this was before glasnost, but based on what we have, I don't think you can go above F4.

 

[warneagle]

I remembered there was also possible F5 in Poland. And although officially rated EF4, I think the violent tornado hit Mira, Italy in 2015 would definitely be rated as F5 if it happened before 2000.

The tornado you're talking about in Poland was the Lublin tornado on 20 July 1931, which is covered in this article (along with a couple of photographs). I don't think there are many other damage photographs, but it's officially rated F4 and there's no real evidence of any F5 damage.

 

[zvl5316]

I personally think the idea of rating tornadoes from the 18th and early 19th century at all is kind of ridiculous. Retroactively rating tornadoes even in the 20th century where there's photographic evidence is contentious, so trying to rate damage that predates the existence of photography is just nonsensical.

Like I mentioned earlier in the thread, I'm working on translating Gottlob Burchard Genzmer's report on the Woldegk tornado (it's taking a while because it's from 1765 and the German is a bit archaic). I appreciate it as a historical document, but from what I've read so far, I think the scientific value is relatively limited because the understanding of meteorology at that point was so primitive. Basing any rating, much less an "official" F5 rating on reports from that era is highly questionable, imo.

As far as the more recent ones, I don't know enough about Palluel to have an opinion on it (although most of the photos I've seen are clearly below F5 standard), but I tend to agree with you about Ivanovo. I don't know if the surveys the Soviets carried out (and the coverage in the pre-glasnost Soviet media) are good enough evidence to support an F5 rating. I generally agree with your assessment that most of the structural damage photos are impressive but most of the structures looked frail. Home construction was obviously quite poor in most of rural Russia, which is comparable to historical tornadoes in the rural south where the structures are too weak to support an F5 rating. Even the more substantial urban buildings in the Soviet Union and Eastern Europe weren't reinforced properly (as was demonstrated by other events, like the 1977 earthquake in Romania and the 1988 earthquake in the Armenian SSR), so destroyed apartment blocks and factories aren't a strong basis for an F5 rating either. I'm not discounting the possibility that the tornado reached F5 strength, but I don't think the evidence is anywhere near conclusive. Maybe there's some good stuff buried in the Russian archives that wasn't allowed to see the light of day since this was before glasnost, but based on what we have, I don't think you can go above F4.

I think buildings' fortify to earthquakes could not represent their resistance to tornadoes and high wind. FR12 in Japan are specially designed to overcome earthquakes. But due to the light material used, they could be easily lifted and leveled by EF2s.
Here is the JEF2 (equvilent to F-scale) damage of a tornado spawned by Typhoon Hagibis in Chiba, Japan.

 

[buckeye05]

I have had strong suspicion that Houston/New Wren MS tornado (the one preceding Smithville) was greater than EF3 and MEG did a poor job of surveying/documenting it. Those damage pics only increase the validity of that notion.

Over the past decade, MEG has always given me the impression that they do half-baked survey work, in addition to losing many important damage photos. You can tell when a WFO doesn’t take particular interest in damage surveys, and with MEG, it shows.

 

[warneagle]

I think buildings' fortify to earthquakes could not represent their resistance to tornadoes and high wind. FR12 in Japan are specially designed to overcome earthquakes. But due to the light material used, they could be easily lifted and leveled by EF2s.
Here is the JEF2 (equvilent to F-scale) damage of a tornado spawned by Typhoon Hagibis in Chiba, Japan.

Of course, I was just using the earthquakes as a proxy to demonstrate that construction standards in that part of the world were poor during that time. We don't have a ton of tornadoes to compare how well they would hold up to tornado winds specifically, since violent tornadoes are relatively uncommon in those areas.

 

[zvl5316]

A rare and horrible home video of the EF4 hit Kaiyuan, China in 7/3/2019. I guess this video of direct hit might be one of the best videos outside US. From surveys, the tornado was weakened to EF2-3 due to the influence of elevated buildings before hit this apartment. Luckily everyone in the apartment survived but one person was killed in the village in the close shot.