Enhanced Fujita Ratings Debate Thread

[slenker]

You're studying physics though, right? May be a good topic for a thesis way down the road! Lol.

I’m in astrophysics, so it’s very different than meteorology. I have a much higher understanding of that than this sort of topic - the field is vast, and even the branches of branches of branches within the topic of physics are capable of differing wildly from each other - that most certainly applies here. My understanding of meteorology is limited to severe weather and tropical weather only, and it’s quite surface level. I do love this field, but I love almost every natural science, and I picked astronomy within physics.

Sorry for small thread derail btw. I won’t discuss this further unless it’s outside of this thread.

 

[Grand Poo Bah]

I’m in astrophysics, so it’s very different than meteorology. I have a much higher understanding of that than this sort of topic - the field is vast, and even the branches of branches of branches within the topic of physics are capable of differing wildly from each other - that most certainly applies here. My understanding of meteorology is limited to severe weather and tropical weather only, and it’s quite surface level.

Sorry for small thread derail btw. I won’t discuss this further unless it’s outside of this thread.

Ahhh that makes sense. Extremely dope, though. Astro physics and quantum mechanics are another huge interest of mine.

.It's not really off topic if it's discussing tornado damage and windspeeds though, is it? But I hear you and respect the decision. If you look at those equations and make some calculations I'll be dying to hear the results, so definitely DM me.

 

[joshoctober16]

Sterling city I argue had Ef5 winds, the contextuals weren’t as bad as Matador but were definitely “low end Ef5”.

Regarding Hollister/El Reno 2013, there has been many tornadoes that had deceitfully strong TVS but end up doing comparatively unimpressive damage at the surface.

In reality, tornadoes (particularly wedges) fail to develop a violent core, the vast majority of times a wedge just contains meso vortices; which can be strong in their own right (El Reno 2013 and Greenfield for example).

But due to the nature of meso vortices, the extreme velocities they achieve are simply too brief to do any real damage, which is why many tornadoes on radar look extreme on velocity but DOD is far less despite the fact.

Wedge tornadoes like Smithville, Bridge creek, Bassfield, Piedmont, (just to name a few) are examples of wedges that do contain a violent core, (which I would think looks like a secondary stove pipe shaped column hidden inside the main condensation funnel, that does the extreme damage).

It’s no coincidence that in violent wedges, the area of extreme damage looks like it occurred from a separate smaller tornado inside of the broad damage swath.

A lot of tornadoes that exhibit ef5 level damage look relatively “unimpressive” on radar velocities even while in close proximity, and even ones that do fail to match or surpass other TVS on weaker tornadoes.

This also isn’t a coincidence, violent cores likely do have weaker max wind velocities compared to meso vortices, but unlike those, violent cores are much larger in size and more importantly, last more than a second.

i have a other theory that might be close to this...

here is 2 hypothetical tornados situation

if there were 2 tornadoes to have happened and the first thing we both know about them is super good low level radar measurement.

Tornado 1
horizontal winds: 390 mph
Vertical upwards winds: 55 mph
vertical downdraft core winds: 40 mph
Other notes: has a few suction vortices , the tornado seems to have a non tight wind field, almost feeling more like a hurricane.
horizontal + vertical winds: 445 mph

Tornado 2
horizontal winds: 232 mph
Vertical upwards winds: 232 mph
vertical downdraft core winds: 160 mph
Other notes: has a lot of suction vortices , the tornado seems to have a super sharp wind field, there is quite a lot of wind change with all the updrafts and downdrafts and suction vortices.
horizontal + vertical winds: 464 mph

the damage survey for both have not come out and there are not photos yet, however 2 big surveys are planned for the next day, what do you expect to see for the damage for both tornadoes?

 

[A Guy]

Carful with the width/intensity relationship, I mean for one, maximum width definitely doesn’t always correlate to max intensity.

Although more importantly, the relationship obviously takes into account the maximum width, but by doing so, it ignores that the fact the area where extreme damage occurs is substantially smaller than the observed maximum width of damage.

Which again, is done by a violent inner core, it is a well known fact that wedge tornadoes, although rare, contain violent cores, which is responsible for the incredible feats of damage.

I need to make it clear though that meso vortices can in fact exhibit extreme damage cases, but again, in the vast majority of tornadoes, these meso vortices simply fail to produce any violent contextual damage due to their instantaneous nature.

For your second point, while there are/can be direct relationships which maximum TVS/debris height and actual DOD, in many cases, there’s simply no relationship. Although some of this can be contributed to the fact the tornadoes often peak in areas where radar beams can’t detect.

'Doesn't always' doesn't discount the relationship. Human height is directly related to weight, even though there's short fat and tall skinny people. I'm not aware of any research relating location of max width vs location of max damage, and even there you have the issue of absolute width vs weaker tornadoes. The fact that the most intense damage is limited is limited to part of the total width doesn't 'ignore' anything.

Grabbing some figures from a conference presentation by Sam Emmerson, the relationship between NEXRad Vrot+TDS height and rating is clear even if there's a lot of overlap between the probability areas of ratings. The two figures are done by different statistical techniques:



You said specifically "A lot of tornadoes that exhibit ef5 level damage look relatively “unimpressive” on radar velocities even while in close proximity, and even ones that do fail to match or surpass other TVS on weaker tornadoes". Emmerson shows that with high Vrot+TDS the chance of EF4 is very high, while when it's low, it's low:

This paper which talks about the Garden City KS tornado describes what Im trying to convey nicely.

The Garden City, Kansas, Storm during VORTEX 95. Part II: The Wall Cloud and Tornado

Abstract On 16 May 1995, a supercell storm produced an F1 tornado near Garden City, Kansas, during VORTEX (Verification of the Origins of Rotation in Tornadoes Experiment). This event provided the first opportunity to synthesize data collected by a new airborne radar platform called ELDORA...

journals.ametsoc.org

Particular figure 6, explaining swirl ratio dynamics.
My point regarding that in wedge tornadoes, the vast majority of the time, vorticity is broken down into meso vortices that rotate around a central axis, (the parent funnel). This is the structure within most tornadoes, which is why damage ends up paling in comparison to observed extreme radar velocities.
The part that I highlighted is what Im talking about with the rare breed of wedge tornadoes that manage to balance out wind shear (horizontal winds) and updraft (vertical motion) to create a singular vortex within the parent wedge funnel.
This is what I mean by a violent core, and this is where the extreme damage in wedges come from, not the actual parent funnel itself.
I’ve never seen a case where the outer parent funnel (the wedge) produce any impressive damage by itself. The violent damage always comes from either an inner core, or more oftenly but still rare, meso vortices that actually manage to cause violent damage.

Condensation funnel width (the actual 'wedge') isn't the tornado's width. The tornado's the air, not the water vapour. You can't assert "I’ve never seen a case where the outer parent funnel (the wedge) produce any impressive damage by itself" and "not the actual parent funnel itself" without knowing the width of the actual funnel, which may be much smaller than the surveyed width. For example, Moore 2013:



Photogrammetric studies of tornadoes are, unfortunately, rare these days. I'm not aware of any exploring a relationship between surveyed width and visual width, though Roger Wakimoto says he hasn't found one between visual width and damage contours, off a small sample. But to say that wedges 'have an inner violent core' you must be sure that the wedge itself isn't the close to the size of the inner violent core you're looking for.

With respect to the vortex structure, I'm aware of the literature about how it affects intensity. I have one study (Refan et al 2017) with a small sample but real world swirl ratio determinations are rare. Doppler studies also have problems of resolution, bias from debris centrifuging (overstates swirl ratio) and undersampling of the boundary layer. The Spencer tornado was found to have either or two-cell or multi-vortex structure and a strong translation effect. Treefall analysis of Joplin and Tuscaloosa found a surprisingly high radial (lower swirl) component (roughness potentially being important). Simply eyeballing tornadoes isn't going to do it.

If we go back to your original statement: "In reality, tornadoes (particularly wedges) fail to develop a violent core". I think the most systematic evidence we have - the damage ratings and surveyed widths (which are not the same as Wurman's radar widths) shows 'particularly wedges' is wrong. There's hundreds of weak, narrow tornadoes for every few 'drillbits'. Whereas wedges, which as you say are rare, seem to account for a relatively higher proportion of violent damage.

 

[joshoctober16]

'Doesn't always' doesn't discount the relationship. Human height is directly related to weight, even though there's short fat and tall skinny people. I'm not aware of any research relating location of max width vs location of max damage, and even there you have the issue of absolute width vs weaker tornadoes. The fact that the most intense damage is limited is limited to part of the total width doesn't 'ignore' anything.

Grabbing some figures from a conference presentation by Sam Emmerson, the relationship between Vrot+TDS height and rating is clear even if there's a lot of overlap between the probability areas of ratings. The two figures are done by different statistical techniques:

View attachment 43581 View attachment 43582

You said specifically "A lot of tornadoes that exhibit ef5 level damage look relatively “unimpressive” on radar velocities even while in close proximity, and even ones that do fail to match or surpass other TVS on weaker tornadoes". Emmerson shows that with high Vrot+TDS the chance of EF4 is very high, while when it's low, it's low:

View attachment 43583



Condensation funnel width (the actual 'wedge') isn't the tornado's width. The tornado's the air, not the water vapour. You can't assert "I’ve never seen a case where the outer parent funnel (the wedge) produce any impressive damage by itself" and "not the actual parent funnel itself" without knowing the width of the actual funnel, which may be much smaller than the surveyed width. For example:

View attachment 43579

Photogrammetric studies of tornadoes are, unfortunately, rare these days. I'm not aware of any exploring a relationship between surveyed width and visual width, though Roger Wakimoto says he hasn't found one between visual width and damage contours, off a small sample. But to say that wedges 'have an inner violent core' you must be sure that the wedge itself isn't the close to the size of the inner violent core you're looking for.

With respect to the vortex structure, I'm aware of the literature about how it affects intensity. I have one study (Refan et al 2017) with a small sample but real world swirl ratio determinations are rare. Doppler studies also have problems of resolution, bias from debris centrifuging (overstates swirl ratio) and undersampling of the boundary layer. The Spencer tornado was found to have either or two-cell or multi-vortex structure and a strong translation effect. Treefall analysis of Joplin and Tuscaloosa found a surprisingly high radial (lower swirl) component (roughness potentially being important). Simply eyeballing tornadoes isn't going to do it.

If we go back to your original statement: "In reality, tornadoes (particularly wedges) fail to develop a violent core". I think the most systematic evidence we have - the damage ratings and surveyed widths (which are not the same as Wurman's radar widths) shows 'particularly wedges' is wrong. There's hundreds of weak, narrow tornadoes for every few 'drillbits'. Whereas wedges, which as you say are rare, seem to account for a relatively higher proportion of violent damage.

what was the debris height of the Hollister tornado?

 

[jiharris0220]

'Doesn't always' doesn't discount the relationship. Human height is directly related to weight, even though there's short fat and tall skinny people. I'm not aware of any research relating location of max width vs location of max damage, and even there you have the issue of absolute width vs weaker tornadoes. The fact that the most intense damage is limited is limited to part of the total width doesn't 'ignore' anything.

Grabbing some figures from a conference presentation by Sam Emmerson, the relationship between Vrot+TDS height and rating is clear even if there's a lot of overlap between the probability areas of ratings. The two figures are done by different statistical techniques:

View attachment 43581 View attachment 43582

You said specifically "A lot of tornadoes that exhibit ef5 level damage look relatively “unimpressive” on radar velocities even while in close proximity, and even ones that do fail to match or surpass other TVS on weaker tornadoes". Emmerson shows that with high Vrot+TDS the chance of EF4 is very high, while when it's low, it's low:

View attachment 43583



Condensation funnel width (the actual 'wedge') isn't the tornado's width. The tornado's the air, not the water vapour. You can't assert "I’ve never seen a case where the outer parent funnel (the wedge) produce any impressive damage by itself" and "not the actual parent funnel itself" without knowing the width of the actual funnel, which may be much smaller than the surveyed width. For example:

View attachment 43579

Photogrammetric studies of tornadoes are, unfortunately, rare these days. I'm not aware of any exploring a relationship between surveyed width and visual width, though Roger Wakimoto says he hasn't found one between visual width and damage contours, off a small sample. But to say that wedges 'have an inner violent core' you must be sure that the wedge itself isn't the close to the size of the inner violent core you're looking for.

With respect to the vortex structure, I'm aware of the literature about how it affects intensity. I have one study (Refan et al 2017) with a small sample but real world swirl ratio determinations are rare. Doppler studies also have problems of resolution, bias from debris centrifuging (overstates swirl ratio) and undersampling of the boundary layer. The Spencer tornado was found to have either or two-cell or multi-vortex structure and a strong translation effect. Treefall analysis of Joplin and Tuscaloosa found a surprisingly high radial (lower swirl) component (roughness potentially being important). Simply eyeballing tornadoes isn't going to do it.

If we go back to your original statement: "In reality, tornadoes (particularly wedges) fail to develop a violent core". I think the most systematic evidence we have - the damage ratings and surveyed widths (which are not the same as Wurman's radar widths) shows 'particularly wedges' is wrong. There's hundreds of weak, narrow tornadoes for every few 'drillbits'. Whereas wedges, which as you say are rare, seem to account for a relatively higher proportion of violent damage.

1. Human vs height is not the same physics at all with tornado width and physical damage, and is just isn’t a good comparison to make.

2. I disagree, the fact the area of most intense damage is always far smaller than total width means that you’re going to have areas of damage that contradict the expected maximum width. A convenient recent example is the Grinnell tornado, the area of most impressive damage was when it was actually a stovepipe at the end of its path (Ground scouring and tree debarking). When it literally became borderline undetectable by radar. Where nothing of the sort occurred when it was a wedge and most impressive looking on radar in both CC and TVS.

3. Exactly though, there’s a lot of overlap, far too much to the point where relying solely on radar to determine where a tornado has done its most extreme damage is not always going to be accurate. (And Im ignoring damage determined by surveys since some of them aren’t exactly the most reliable when it comes to identifying violent contextuals)

4. This point just says the same thing but differently, that while violent TVS do show a heightened possibility of finding the most intense damage, it’s not certain that’ll be the case at all. Although my main point was that the area of violent damage doesn’t reliably correlate where the TVS is the most intense. And I think it’s important to clarify that what I mean by a lot of ef5 tornadoes have “unimpressive” TVS, I mean that in comparison to the most intense TV signatures known. Matador and Jarrell are good examples of having an “unimpressive” TVS.

5. That’s the thing though, there likely hasn’t, based solely off damage surveys themselves, the area of extreme damage is far smaller than the contour of Ef0-Ef2. Look at the damage path of every violent wedge tornado, and notice that in some, there’s the area of general damage, and in the center you just have area of complete destruction, it’s never just a linear/gradual ramp up in damage. Unless I’ve gone insane this seems to correlate well with a smaller inner core inside the parent funnel (Wedge).
(And just to clarify, the physical wedge, not visible wedge)

6. This last point seems to miss what I was trying to convey, when I say most wedge tornadoes fail to develop a violent core, in no way did I even mention that non wedges produce violent damage more often.

To clear up any confusion, meso vortices can in fact inflict extreme damage as well, but the area of damage is consequently more random and patchy rather than consistent. Violent tornadoes can produce that sort of damage just from meso vorts alone. Which I can assume is where the confusion came from when you responded to my point about “most wedges fail to develop a violent core” which is true. Core structures inside wedges are rare, again, most wedges are dominantly meso vortex structures, and these meso vortices can produce violent damage, but aren’t considered a core.

 

[Grand Poo Bah]

the damage survey for both have not come out and there are not photos yet, however 2 big surveys are planned for the next day, what do you expect to see for the damage for both tornadoes?

I think the answer for both surveys would be a three foot deep crater/trench where a town used to be? The winds you're talking about about are theoretically possible but definitely mathematically improbable.

 

[Grand Poo Bah]

1. Human vs height is not the same physics at all with tornado width and physical damage, and is just isn’t a good comparison to make.

2. I disagree, the fact the area of most intense damage is always far smaller than total width means that you’re going to have areas of damage that contradict the expected maximum width. A convenient recent example is the Grinnell tornado, the area of most impressive damage was when it was actually a stovepipe at the end of its path (Ground scouring and tree debarking). When it literally became borderline undetectable by radar. Where nothing of the sort occurred when it was a wedge and most impressive looking on radar in both CC and TVS.

3. Exactly though, there’s a lot of overlap, far too much to the point where relying solely on radar to determine where a tornado has done its most extreme damage is not always going to be accurate. (And Im ignoring damage determined by surveys since some of them aren’t exactly the most reliable when it comes to identifying violent contextuals)

4. This point just says the same thing but differently, that while violent TVS do show a heightened possibility of finding the most intense damage, it’s not certain that’ll be the case at all. Although my main point was that the area of violent damage doesn’t reliably correlate where the TVS is the most intense. And I think it’s important to clarify that what I mean by a lot of ef5 tornadoes have “unimpressive” TVS, I mean that in comparison to the most intense TV signatures known. Matador and Jarrell are good examples of having an “unimpressive” TVS.

5. That’s the thing though, there likely hasn’t, based solely off damage surveys themselves, the area of extreme damage is far smaller than the contour of Ef0-Ef2. Look at the damage path of every violent wedge tornado, and notice there’s the area of general damage, and in the center you just have area of complete destruction, it’s never just a linear/gradual ramp up in damage. Unless I’ve gone insane this seems to correlate well with a smaller inner core inside the parent funnel (Wedge).
(And just to clarify, the physical wedge, not visible wedge)

It’s also important to state that obviously all wedges have a meso vortex structure inside the parent funnel. The structure type inside of these tornadoes change and don’t just stay one mode (Refer back to figure 6).

Meso vortices can in fact inflict extreme damage as well, but the area of damage is consequently more random and patchy rather than consistent.

6. This last point seems to miss what I was trying to convey, when I say most wedge tornadoes fail to develop a violent core, in no way did I even mention that non wedges produce violent damage more often.

Do you have any theories as to why a lower TVS sometimes coincides with violent damage like in Grinnell, for example? Do you think it's because tornadoes rope out from the top down? Or maybe debris loading (granulated debris having lower velocities than rain drops)?

Here's a good example of what you're talking about with the damage gradient. It's interesting the most intense damage is in the dead center rather than more scattered like you'd expect with a multi vortex structure. The purple circle in the second image represent the condensation funnel. As the condensation funnel got wider, the core winds stayed the same width.





Greensburg was different in that the left side of the tornado had more extreme damage than the right or center, and there was lots of variability rather than defined contours, which is probably indicative of a multi vortex structure.





Bringing this back on topic with the EF scale, it's tough to say whether the differences in ratings between houses (outlined in Figure 6) was due to engineering scrutiny, or actual differences in winds/observed damage, because the EF scale is useless.

 

[jiharris0220]

Do you have any theories as to why a lower TVS coincides with violent damage like in Grinnell, for example? Do you think it's because tornadoes rope out from the top down? Or maybe debris loading (granulated debris having lower velocities than rain drops)?

Here's a good example of what you're talking about with the damage gradient. It's interesting the most intense damage is in the dead center rather than more scattered like you'd expect with a multi vortex structure. The purple circle in the second image represent the condensation funnel

View attachment 43584
View attachment 43591


Greensburg was different in that the left side of the tornado had more extreme damage than the right or center, and there was lots of variability rather than defined contours, which is probably indicative of a multi vortex structure.

View attachment 43590View attachment 43588

View attachment 43589

Exactly what I’m talking about, a rare group of wedge tornadoes develop a central core, and it’s these tornadoes that cause the most extreme feats of damage known.

Obviously though when this being say said, I don’t mean that tornadoes that lack a violent core don’t produce extreme damage.

All wedge tornadoes have a meso vortex structure, but only few manage to develop a central core structure.

Greensburg and Joplin are examples of meso vortex structures that never developed a violent core, but the meso vortices are what did the extreme damage.

Smithville, Bass-field, Jarrel, Bridge creek, Moore 2013, and Piedmont are examples of wedges that did manage to develop a violent core.

The main point being that despite how impressive a TVS looks, it doesn’t always correlate to where the most extreme damage is going to be because in the vast majority of cases, meso vortex structures simply can’t produce a consistent swath of extreme damage due to the instantaneous nature of violent winds.

 

[Grand Poo Bah]

If they do have evidence of that happening I've never seen it. Perhaps ask the commenter about it?

Also, there is photographic evidence that Jarrell scoured concrete. Even if it didn't obliterate mesquites, that's still insane, so the #10 spot on my list is justified.

I asked and got a reply. I'm not a tree expert, so have no way of verifying if it's actually mesquite in any of these images.

"Bakersfield. (Those things sticking up from the ground are rootballs and the brown streaks are granulated tree)"


Bridgecreek-Moore


Piedmont


"Jarrell (there were once multiple trees in this first image)", and apparently the tree in the second image is mesquite? idk


Edit: Regardless, the fact Matador was on par with these extremely violent (E)F5s just solidifies its case as a definite EF5 tornado, and the fact it was rated EF3 is a complete joke.

 

[Lake Martin EF4]

I asked and got a reply. I'm not a tree expert, so have no way of verifying if it's actually mesquite in any of these images.

"Bakersfield. (Those things sticking up from the ground are rootballs and the brown streaks are granulated tree)"
View attachment 43592

Bridgecreek-Moore
View attachment 43598

Piedmont
View attachment 43593View attachment 43595View attachment 43597

"Jarrell (there were once multiple trees in this first image)", and apparently the tree in the second image is mesquite? idk
View attachment 43594View attachment 43596

Edit: Regardless, the fact Matador was on par with these extremely violent (E)F5s just solidifies its case as a definite EF5 tornado, and the fact it was rated EF3 is a complete joke.

I think this calls for an intervention by @locomusic01 or @TH2002, because I'm not fully sure if those are actually mesquites in most of those. They're still some of the most extreme tornado damage photos in history, don't get me wrong, but perhaps they're not of mesquite trees.

 

[Grand Poo Bah]

I think this calls for an intervention by @locomusic01 or @TH2002, because I'm not fully sure if those are actually mesquites in most of those. They're still some of the most extreme tornado damage photos in history, don't get me wrong, but perhaps they're not of mesquite trees.

Even if they are mesquites, that's still an extreme upper echelon of tornadoes Matador is a part of.

 

[jiharris0220]

I think this calls for an intervention by @locomusic01 or @TH2002, because I'm not fully sure if those are actually mesquites in most of those. They're still some of the most extreme tornado damage photos in history, don't get me wrong, but perhaps they're not of mesquite trees.

They’re actually mesquite trees, although it’s hard to tell because they’re the low lying type. (Which I guess in all fairness most of them are.)

Here’s their range provided by this research paper: https://www.researchgate.net/public..._mesquite_trees_and_possible_alternative_uses

 

[NorthGaWeather]

'Doesn't always' doesn't discount the relationship. Human height is directly related to weight, even though there's short fat and tall skinny people. I'm not aware of any research relating location of max width vs location of max damage, and even there you have the issue of absolute width vs weaker tornadoes. The fact that the most intense damage is limited is limited to part of the total width doesn't 'ignore' anything.

Grabbing some figures from a conference presentation by Sam Emmerson, the relationship between NEXRad Vrot+TDS height and rating is clear even if there's a lot of overlap between the probability areas of ratings. The two figures are done by different statistical techniques:

View attachment 43581 View attachment 43582

You said specifically "A lot of tornadoes that exhibit ef5 level damage look relatively “unimpressive” on radar velocities even while in close proximity, and even ones that do fail to match or surpass other TVS on weaker tornadoes". Emmerson shows that with high Vrot+TDS the chance of EF4 is very high, while when it's low, it's low:

View attachment 43583



Condensation funnel width (the actual 'wedge') isn't the tornado's width. The tornado's the air, not the water vapour. You can't assert "I’ve never seen a case where the outer parent funnel (the wedge) produce any impressive damage by itself" and "not the actual parent funnel itself" without knowing the width of the actual funnel, which may be much smaller than the surveyed width. For example, Moore 2013:

View attachment 43579

Photogrammetric studies of tornadoes are, unfortunately, rare these days. I'm not aware of any exploring a relationship between surveyed width and visual width, though Roger Wakimoto says he hasn't found one between visual width and damage contours, off a small sample. But to say that wedges 'have an inner violent core' you must be sure that the wedge itself isn't the close to the size of the inner violent core you're looking for.

With respect to the vortex structure, I'm aware of the literature about how it affects intensity. I have one study (Refan et al 2017) with a small sample but real world swirl ratio determinations are rare. Doppler studies also have problems of resolution, bias from debris centrifuging (overstates swirl ratio) and undersampling of the boundary layer. The Spencer tornado was found to have either or two-cell or multi-vortex structure and a strong translation effect. Treefall analysis of Joplin and Tuscaloosa found a surprisingly high radial (lower swirl) component (roughness potentially being important). Simply eyeballing tornadoes isn't going to do it.

If we go back to your original statement: "In reality, tornadoes (particularly wedges) fail to develop a violent core". I think the most systematic evidence we have - the damage ratings and surveyed widths (which are not the same as Wurman's radar widths) shows 'particularly wedges' is wrong. There's hundreds of weak, narrow tornadoes for every few 'drillbits'. Whereas wedges, which as you say are rare, seem to account for a relatively higher proportion of violent damage.

Great post!

 

[jiharris0220]

Great post!

It definitely is, A Guy is a clever fellow, but the post completely misses my point though, all fault does lie with me for not clarifying what I meant regarding the violent core bit, which is what led to the misunderstanding in the first place.

 

[Grand Poo Bah]

Got curious, and decided to look up how fast water out of a pressure washer moves. Turns out it's about 240 MPH (Source). Now here's a video of a pressure washer debarking a tree.



Considering Doppler radars are measuring the velocities of rain droplets, rather than the actual winds themselves, one COULD surmise that the reason F4s and F5s debark trees in open fields (with an absence of debris) is because of the speed of rain, ground moisture, and sand/dirt inside the core. Seeing as there's no studies about what raw wind speeds are required to debark trees, it'd seem this wind driven rain hypothesis is currently the most likely cause of debarking. The implications of this would be (yet another example of) the original Fujita scale wind speeds being more aligned with reality than the EF scale.

The reason I share Doppler on Wheels' findings so much in here, is because it's literally a multi-million dollar tool designed to take measurements of severe weather events. How its measurements aren't taken at face value as factual wind speeds inside tornadoes has always irked the F out of me. Where's Texas Tech and the ACSE's multimillion dollar tool? What proof do they have for their wind figures? Considering the amount of evidence there is against their determined wind speeds shouldn't the burden of proof be on THEM? The NWS just kind of accepted the enhanced fujita scale, and these engineers have never been required to prove their hypothesis in any meaningful way.

Why do so many meteorologists and scientists, who are well educated on the strict requirements needed to establish theories, just accept these heavily scrutinized, borderline conclusively incorrect, hypothesized numbers as the leading theory of tornado wind speeds? I made a comment about "lighting a fire under the NWS's a$$es" a while back. The sentiment behind that statement was just that someone in authority over there needs to wake tf up and start asking these questions. They're not controversial questions either. They're literally the bare minimum required by modern scientific practices. How are random weather nerds on the internet more fascinated by tornado physics than them, when weather is supposedly their lifetime passion?

 

[joshoctober16]

Do you have any theories as to why a lower TVS sometimes coincides with violent damage like in Grinnell, for example? Do you think it's because tornadoes rope out from the top down? Or maybe debris loading (granulated debris having lower velocities than rain drops)?

Here's a good example of what you're talking about with the damage gradient. It's interesting the most intense damage is in the dead center rather than more scattered like you'd expect with a multi vortex structure. The purple circle in the second image represent the condensation funnel. As the condensation funnel got wider, the core winds stayed the same width.

View attachment 43584
View attachment 43591


Greensburg was different in that the left side of the tornado had more extreme damage than the right or center, and there was lots of variability rather than defined contours, which is probably indicative of a multi vortex structure.

View attachment 43590View attachment 43588

View attachment 43589

Bringing this back on topic with the EF scale, it's tough to say whether the differences in ratings between houses (outlined in Figure 6) was due to engineering scrutiny, or actual differences in winds/observed damage, because the EF scale is useless.

what i was trying to say is , im wondering if super strong velocity tornadoes could be made by tornadoes that seem to barely have any vertical motion (el reno 2013 had this)

compared to Moore 2013 that had very strong upwards motion when doing its violent damage

 

[Grand Poo Bah]

Our Reddit tornado friend posted this picture of completely debarked mesquite from Matador.

 

[Ozonelayer]

I honestly wonder what the most powerful tornadoes from 2007-present would be. I mean there would be some obvious ones like El Reno-Piedmont and Smithville, but the others would probably be harder to pinpoint considering once tornadic winds break into the high end EF-4 catagory, it becomes much harder to distinguish. Mayfield, Moore, Parkersburg, Rainsville, and Matador are probably up there too. Greenfield and Joplin might be up there on the list. And Rolling Fork and Barnsdall probably wouldn't be too high up. (While they were 100% powerful, they were not exceptional like the others I mentioned.)

 

[A Guy]

1. Human vs height is not the same physics at all with tornado width and physical damage, and is just isn’t a good comparison to make.
2. I disagree, the fact the area of most intense damage is always far smaller than total width means that you’re going to have areas of damage that constradict the expected width. A convenient recent example is the Grinnell tornado, the area of most impressive damage was when it was actually a stovepipe at the end of its path. (Ground scouring and tree debarking) where nothing of the sort occurred when it was a wedge.)
3. Exactly though, there’s a lot of overlap, far too much to the point where relying solely on radar to determine where a tornado has done its most extreme damage is not always going to be accurate. (And Im ignoring damage determined by surveys since some of them aren’t exactly the most reliable when it comes to identifying violent contextuals)
4. This point just says the same thing but differently, that while violent TVS do show a heightened possibility of finding the most intense damage, it’s not certain that’ll be the case at all. Although my main point was that the area of violent damage doesn’t reliably correlate where the TVS is the most intense. And I think it’s important to clarify that what I mean by a lot of ef5 tornadoes have “unimpressive” TVS, I mean that in comparison to the most intense TVS known. Matador and Jarrell are good examples of having an “unimpressive” TVS.
5. That’s the thing though, there likely hasn’t, based solely off damage surveys themselves, the area of extreme damage is far smaller than the contour of Ef0-Ef2. Look at the damage path of every violent wedge tornado, and notice there’s the area of general damage, and in the center you just have area of complete destruction, it’s never just a linear/gradual ramp up in damage. Unless I’ve gone insane this seems to correlate well with a smaller inner core inside the parent funnel.
(And just to clarify, the physical wedge, not visible wedge)
6. This last point seems to miss what I was trying to convey, when I say most wedge tornadoes fail to develop a violent core, in no way did I even mention the fact the none wedges produce violent damage more often.

1: it's an analogy about distributions, not literal.
2: that doesn't mean the relationship can't hold in general.
3: the relationship's clearest at the strongest categories and I wouldn't say there's too much overlap. Survey issues could just as easily be making the relationship less, not more clear.
4: I don't have the data to judge exact locational correlations (which could get very problematic due to DI sparseness), you could ask Emmerson. The sample was about four hundred which I'd prefer to a couple of anecdotes.
5: There's no such thing as the 'physical wedge' that's distinct from the 'visible wedge'. 'Wedge' is a description of the condensation funnel and/or debris cloud's shape. The shape depends on factors like humidity, cloud/LCL height etc. as well as pressure drop and gradient. I don't have time to do a literature review, though I've seen at least one case where the doppler max was outside the visible funnel and one paper claim the top of the funnel is a better indicator, but it's not been systematically explored. John T. Snow's 1982 caution "care must be taken in inferring the size or structure of the core from the shape of the condensation funnel" applies.

My example was intended to show that there's no need to invoke a 'hidden violent core', a 'secondary stove pipe shaped column hidden inside the main condensation funnel' or a 'separate smaller tornado inside'. Of course they're not going to neatly coincide (see above). I just think these analogies are based on a poor heuristic that appears to nearly equate surveyed and visual widths, which often isn't the case.

6: you said "in reality, tornadoes (particularly wedges) fail to develop a violent core". 'Particularly' can be reasonably construed as implying wedges are more prone to not developing a violent core than non-wedges.

It definitely is, A Guy is a clever fellow, but the post completely misses my point though, all fault does lie with me for not clarifying what I meant regarding the violent core bit, which is what led to the misunderstanding in the first place.

I don't think I've missed your points (there's about three issues at play here) I just don't agree with many aspects of them.