Significant Tornado Events

[joshoctober16]

I think that tornado was the 2017 Chifeng tornadoes

oh i think you are right i should correct that

 

[joshoctober16]

the one labled (d) i feel should of been rated EF5, it was a pilger like event in china apparently

 

[Juliett Bravo Kilo]

DOW did conf that most tornadoes have winds over 136+ mph compared to NWS 65+ mph rating.

im honestly starting to think we are all underestimating tornadoes, what i mean is each time theres a wind mesurment + damage at the same spot, there is some wierd stuff that i notice.

heres a spreadsheet of what i mean

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EF3 winds making EF0 damage and EF5 winds making EF3 damage

and to make things worse the IF scale now has a wind measurement DI
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ive seen people say before that the winds gust for the Andover tornado was only for 1 second and not 3 seconds, and that it was 10-20 meters.... well here ya go it lets you rate stuff from 0 to 60 meters, it lets you use 1 second wind gust as well.

note Andover was at 118 ms, thats apparently a IF5 on any wind gust speed... also note some people feel like the 118 ms is a mistake, i mean it could be but its not going to make much of a difference when your that high up, a whole 10 ms difference still has the 1 second gust at IF5

and note for Andover, it didn't hit a poorly built home, and it never event swept clean the house, most walls were still standing from this 118 ms spot, and note this measurement was from a part of debris from this house it self.

i feel like 290+ mph winds are likely what you would find if you had a wind measurement of some kind at a all the official EF5 di.

Good stuff right here, I've been looking for something like this.
I do think most tornadoes achieve EF2 intensity at some point in their lives, and most mesocyclones probably reach EF5 intensities but those velocities never reach the ground the majority of the time.

 

[Juliett Bravo Kilo]

Despite the impressive debarking, the ground scouring it did was just as impressive as other tornados on that day, regardless to say about asphalt scouring and other stuff. I did what it can did. But also the criteria nowadays already become a very personal things due to the major absence of fairness of rating from officials. One can tend to agree with all of NWS's rating and accept there was no EF5 in last 10 years like Grazilis and one can only believe in DOW's find and believe at very least 20% of all supercell tornados were violent tornados with a large percent of them have EF5 winds. (Also things very worth noticing is quite a few tornados with winds well into EF5 level on DOW don't have EF5 fashion contextual or structural damage like: Red Rock(little debarking and F3 house damage nearby), El Reno 2013, Mulhall, Spencer, Sulphur, Bennington 2013)

I even saw Extremeplanet once said he think most tornados have 200+mph winds once in their lifetime. Though I don't agree with this but I respect his opinion.

For ringgold, tornadotalk give its EF5 rating for damage in that valley. The rating was based on major debarking, granulation that on par with other EF5 tornados on that day. And they do point out that one of house in the valley maybe well built though the evidence wasn't clear enough. But on the hand I do notice that tornadotalk's team tend to have a more liberal rating criteria than most people on this forum like they give plenty of EF5 damage points for Cullman tornado which normally don't belong to the EF5 discussion in this tread. Though I also have hesitation of judgement like this but like I said before, do understand that everyone nowadays can have their own criteria and opinions if there are relative coherent logic in it.
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On extremeplanet he has a post about how outer circulation in single-vortex or multivortex tornadoes likely never achieves more than 200 mph or so, and the 200 mph+ velocities are in the narrow subvortices within multivortex tornadoes. I do recall him saying something how most tornadoes likely achieve EF2 intensity at the very least & that lost of mesocyclones probably have EF5 velocities & while detectable by radar they don't usually reach the ground. One of these two things might be what you're thinking of.

 

[Juliett Bravo Kilo]

Canton lake. It did contextual damage meet with that level. Despite DOW being like 185-190mph, it deployed too far away from tornado with lowest scan too high. The highest wind was observed at 195m AGL which is highly unlikely being the strongest tornado inside tornados. (tornados usually have strongest tornado very near the ground)

Usually the strongest winds are higher up, they decrease the lower you get due to ground friction and the like. So perhaps 200+ speeds were higher up in the circulation but not at ground level, fyi.

 

[pohnpei]

Usually the strongest winds are higher up, they decrease the lower you get due to ground friction and the like. So perhaps 200+ speeds were higher up in the circulation but not at ground level, fyi.

No, that's not true. There were numerous foundings, from model and observation proved that tornado winds increase towards ground.

The strongest winds in tornadoes are very near the ground - Communications Earth & Environment

The majority of radar measurements of wind speed in tornadoes underestimate the actual wind intensity by measuring regions relatively high above the ground; very low-level radar observations find the strongest winds very close to the ground

www.nature.com

This article on Nature was an important one

Very rare that DOW can scanned lower than 10m level but when that did it they still found the highest wind was at the lowest level. (pic below, May 25 2012 case)
In terms of so little case was scanned at very low level. One can not exclude even more extreme profile can exist on other tornados(In my personal assumption: especially these did major ground scouring)


Not all tornados would have that types of profile, especially for those not fully condensed and weak tornados(mentioned in article above). But for mature and fully condensed supercell tornados,they almost always had their highest wind lower than 50m level and many of them can be much lower. Numerical models found that highest winds inside tornados were just above the inflow layer. The depth of inflow layer varies from case to case but typically around 10-20m. That feature makes tornados a very unique weather system on earth which contrast to all the other weather systems(winds increase from height) and being one of the reason why it can make such extreme damage while other systems can't

Friction actually can reduces cyclostrohic balance which causes a strengthening in the horizontal PGF and weakening of the centripetal force. That causes increases in convergent flow at the sfc and the increased stretching which causes the winds at the ground to be substantially stronger

 

[Juliett Bravo Kilo]

No, that's not true. There were numerous foundings, from model and observation proved that tornado winds increase towards ground.

The strongest winds in tornadoes are very near the ground - Communications Earth & Environment

The majority of radar measurements of wind speed in tornadoes underestimate the actual wind intensity by measuring regions relatively high above the ground; very low-level radar observations find the strongest winds very close to the ground

www.nature.com

This article on Nature was an important one
View attachment 22660
Very rare that DOW can scanned lower than 10m level but when that did it they still found the highest wind was at the lowest level

View attachment 22661

Interesting, for a long time it was thought to be the opposite. Now this research comes out. It makes me wonder about velocities reached by Red Rock and Spencer (among others) given what this article says.

 

[pohnpei]

Interesting, for a long time it was thought to be the opposite. Now this research comes out. It makes me wonder about velocities reached by Red Rock and Spencer (among others) given what this article says.

Spencer's winds were at 30-50m level which at least close to the highest wind level. Red Rock was scanned at 150-190m. So it's extremely remarkable to get that wind at that height. There was only one tornado I know had that level winds at ＞150m height which was 11 El Reno but it was captured much further than Red Rock.
It's very hard or almost impossible to simply convert winds at 150-190m height to 15-30m or even lower height. Using the empirical formula would lead to at least 360mph+ winds at 15m AGL. But the profile varies from case to case so one can't be sure of this and what can be sure is Red Rock most likely had higher winds below the lowest scan level of DOW based on other examples and lots of research done about this project.

 

[Juliett Bravo Kilo]

Spencer's winds were at 30-50m level which at least close to the highest wind level. Red Rock was scanned at 150-190m. So it's extremely remarkable to get that wind at that height. There was only one tornado I know had that level winds at ＞150m height which was 11 El Reno but it was captured much further than Red Rock.
It's very hard or almost impossible to simply convert winds at 150-190m height to 15-30m or even lower height. Using the empirical formula would lead to at least 360mph+ winds at 15m AGL. But the profile varies from case to case so one can't be sure of this and what can be sure is Red Rock most likely had higher winds below the lowest scan level of DOW based on other examples and lots of research done about this project.

Red Rock and Bridge Creek-Moore 1999 likely had wind speeds in excess of 300 mph right at the ground or inches above it, the more I think about it. El Reno 2011 likely did too.

 

[pohnpei]

Red Rock and Bridge Creek-Moore 1999 likely had wind speeds in excess of 300 mph right at the ground or inches above it, the more I think about it. El Reno 2011 likely did too.

Yes, for El Reno 2011, the 295.5mph winds was at 22m AGL level which was relatively low but it had 75m resolution because it's about 4miles away from Raxpol. The tornado very likely strengthen even further when it moved further away from Raxpol when they change their strategy.

I've posted this before but it's just unbelievable. This reading was captured when it's at least 6miles away from Raxpol which automatically lead to ＞100m resolution and it was at ＞700feet and it's not even close to the famous drilling platform. It just has to be extremely powerful at this time based on these.

Just for reference, Dr.leigh's simulation have 143m/s storm relative horizontal winds(not counting around 17m/s forward speed) and 99m/s vertical winds around this time.

 

[TH2002]

Here's an interesting question that popped into my head: Everyone knows the oldest photo of a tornado was taken in 1884, but what is the oldest photo of tornado damage? For years I thought the 1878 Wallingford tornado fit this bill, but I came across a couple damage photos from the September 28, 1876 Isle of Wight, UK F3 tornado:

...and an album from the March 10, 1876 Hazel Green, WI F3.

The oldest damage photo I've come across so far is this one from the July 4, 1874 Lewistown, PA tornado:

 

[UK_EF4]

These photos have now fully convinced me that El Reno 2011 is on the same level as Bridge Creek in terms of intensity. Insane damage photos there. Imagine if this thing had received an EF4 rating if it occurred just a few years later.

 

[Ivanthetornadoenthusiast]

Here's an interesting question that popped into my head: Everyone knows the oldest photo of a tornado was taken in 1884, but what is the oldest photo of tornado damage? For years I thought the 1878 Wallingford tornado fit this bill, but I came across a couple damage photos from the September 28, 1876 Isle of Wight, UK F3 tornado:

...and an album from the March 10, 1876 Hazel Green, WI F3.

The oldest damage photo I've come across so far is this one from the July 4, 1874 Lewistown, PA tornado:

I think Guangzhou tornado from many years back (around 1873 or something) had some damage photos

 

[Juliett Bravo Kilo]

These photos have now fully convinced me that El Reno 2011 is on the same level as Bridge Creek in terms of intensity. Insane damage photos there. Imagine if this thing had received an EF4 rating if it occurred just a few years later.

Apparently the 2 million pound oil rig being rolled is "not necessarily EF5 damage" according to this one presentation I saw mentioned on here a while back. Apparently there's rumors out there of some people advocating for the rating of El Reno 2011 being downgraded now. Man....

 

[TH2002]

Apparently the 2 million pound oil rig being rolled is "not necessarily EF5 damage" according to this one presentation I saw mentioned on here a while back. Apparently there's rumors out there of some people advocating for the rating of El Reno 2011 being downgraded now. Man....

I think people are blowing that slide out of proportion. I'm pretty sure it was trying to showcase what can build confidence for an EF5 rating if there is a lack of traditional EF5 indicators, as there was a lack of traditional indicators in El Reno 2011's case.

Although, at first glance I can see how someone could misinterpret the slide and conclude it was saying "El Reno wasn't necessarily an EF5" though I don't think that's what it was trying to say at all.

But with that said, don't count me as surprised if John Robinson, the ASCE or some other person/organization actually does come out to say "Nah, El Reno 2011 was just a high-end EF4 cause I said so".

 

[Juliett Bravo Kilo]

I think people are blowing that slide out of proportion. I'm pretty sure it was trying to showcase what can build confidence for an EF5 rating if there is a lack of traditional EF5 indicators, as there was a lack of traditional indicators in El Reno 2011's case.

Although, at first glance I can see how someone could misinterpret the slide and conclude it was saying "El Reno wasn't necessarily an EF5" though I don't think that's what it was trying to say at all.

But with that said, don't count me as surprised if John Robinson, the ASCE or some other person/organization actually does come out to say "Nah, El Reno 2011 was just a high-end EF4 cause I said so".

Wonder how long until someone comes along and says something like "Jarrell was a high-end EF4, the more I think about it. I mean, the washers were still there & the bolts weren't evenly spaced & the homes weren't THAT well built, so clearly it couldn't be anything higher".

 

[TH2002]

Wonder how long until someone comes along and says something like "Jarrell was a high-end EF4, the more I think about it. I mean, the washers were still there & the bolts weren't evenly spaced & the homes weren't THAT well built, so clearly it couldn't be anything higher".

Worse - we already have a completely unironic paper that says Jarrell was an F3 - not even F4.

And to prove this is NOT something being blown out of proportion:

A post-storm damage survey was made at Jarrell by a team coordinated by the Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM). We report damage observations and conclude on their basis that the worst damage can be explained by wind speeds corresponding to an F3 rating on the Fujita tornado intensity scale (wind speeds of 71 m/s to 92 m/s). An F4 (93 m/s to 116 m/s) rating, or the F5 (117 m/s to 142 m/s) rating officially issed by the National Weather Service (NWS), need not be assumed to explain that damage.

 

[eric11]

While I'm at it, the Canton Lake EF4 was definitely underrated too. 190 mph velocities were recorded in it & the damage it did strikes me as more violent than EF3:

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Speaking of the asphalt removement done by Canton Lake EF3, Reed Timmer once said it was done near the end stage of the tornado, the road where the asphalt scouring took place was exactly the same road where Reed intercepted. The asphalt scouring was like 100-150m North of his position, he also said he suspected it was done by a powerful subvortex.
You can see trees in the background were almost completely intact, it did some intense ground scouring on grassland and then quickly dissipated, which add more confidence to Reed's guessing.

 

[Juliett Bravo Kilo]

Speaking of the asphalt removement done by Canton Lake EF3, Reed Timmer once said it was done near the end stage of the tornado, the road where the asphalt scouring took place was exactly the same road where Reed intercepted. The asphalt scouring was like 100-150m North of his position, he also said he suspected it was done by a powerful subvortex.
You can see trees in the background were almost completely intact, it did some intense ground scouring on grassland and then quickly dissipated, which add more confidence to Reed's guessing.
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Where'd you find these pics? Do you have any pics of damage to homes or farmsteads on land from this tornado? I can only find damage around the lake.
Also if this damage was done near the end stage the tornado was likely narrowing which can cause the wind speeds to accelerate so that could have played a role here (along with subovrtex).

 

[wolfywise]

Something that keeps nagging at me is the idea that the forward motion of a tornado matters, at least in whats relevant to a rating.
We have countless videos showing that tornadoes basically do all of their damage within the first second of even touching a structure. At best being slow moving just mulches the dirt more and maybe granulates the debris a bit.

Edit: I never got an answer to this question when I asked it back in April, but I have been feverishly hunting down the source of this Minneola KS EF3 photo (2019) since basically the same day. I only ever saw it once, during the event, and since then I have never been able to find the original source. Which sucks because its one of my favorite tornado photos (the colors and mood are exquisite); of one of my favorite tornadoes.
Any ideas?