Severe WX April 29-May 2nd, 2022 Severe Weather Threat

[Shakespeare 2016]

He gave a detailed explanation of the slabbed pet shop's construction flaws just the other day. That's a type of building that is vulnerable to progressive structural failure, meaning once one part of the structure fails and wind gets inside, the whole structure goes. Any kind of building that lacks interior walls is susceptible to that type of failure. Something tells me if this wasn't in your backyard, you wouldn't be pushing back against the high-end EF3 rating so much.

Also, what about "making politicians happy"? Please elaborate. I'd love to here some actual details and evidence of this alleged correlation between low tornado ratings and the agenda of US politicians. I'd love for you to explain to me what the actual motive is, and demonstrate that you aren't just parroting things you have heard from other people without any evidence or understanding what the allegations actually entail. Can you?

So what a completely debarked tree should be rated EF4 period.

 

[Shakespeare 2016]

There was quite impressive context near the house but let's just completely ignore that and worry about the construction of the house or building.

 

[buckeye05]

So what a completely debarked tree should be rated EF4 period.

What does that have to do with anything that I just said? I have seen photos of severe debarking in Andover, but nothing stripped clean of all bark. Also, go ahead, explain the "making politicians happy" thing. Waiting for your explanation.

I think you're letting "in my back yard" bias skew your objectivity here.

 

[andyhb]

Lol why are we doing this again...

 

[Shakespeare 2016]

What does that have to do with anything that I just said? I have seen photos of severe debarking in Andover, but nothing stripped clean of all bark. Also, go ahead, explain the "making politicians happy" thing. Waiting for your explanation.

I think you're letting "in my back yard" bias skew your objectivity here.

Chuck Doswell told me more than 10 years ago that politicians come into play with tornado ratings.

 

[andyhb]

Enhanced Fujita Ratings Debate Thread

https://en.wikipedia.org/wiki/Enhanced_Fujita_scale Please be respectful and mature, obey forum rules but it was brought up in the damage report for this last severe wx event and I think we had a big discussion on TW before the forum crash. I'd like to see some examples of what you think were...

talkweather.com

 

[eric11]

tornado near Hermleigh TX

 

[Evan]

Explanation from Bradley Ketcham of NWS Wichita explaining why they went with high-end EF3 instead of EF4. Same conclusion I reached after looking at the DAT. Had one of the subfloors been ripped off though, it would have been rated EF4.
View attachment 13746

Don't get me started. Beyond nauseated at the current mediocre state of construction. And, folks, it's not just residential.

 

[eric11]

I guess NWS Wichita is now calling QRT? there're some damage points remain as EF3+ on DAT.Plus there're nearly 966 structures damaged or destroyed in Andover alone, it may take a long long time to evaluate all these damage points.
btw it seems that calling QRT has now become a growing trend when it comes to EF4/EF4+ tornado.
here's a closer look of some anchoring on DAT

 

[Shakespeare 2016]

I guess NWS Wichita is now calling QRT? there're some damage points remain as EF3+ on DAT.Plus there're nearly 966 structures damaged or destroyed in Andover alone, it may take a long long time to evaluate all these damage points.
btw it seems that calling QRT has now become a growing trend when it comes to EF4/EF4+ tornado.
here's a closer look of some anchoring on DAT
View attachment 13747View attachment 13748View attachment 13749View attachment 13750

Where did you hear that NWS Wichita is going to call in a QRT?

 

[eric11]

Where did you hear that NWS Wichita is going to call in a QRT?

just a guess, cuz some damage points on DAT remain as EF3+ not EF3 with detailed winds. Also earlier this year I remember having seen someone on Twitter said the QRT was now more engaged in EF4 rating not only for those controversial cases.

 

[Evan]

What does that have to do with anything that I just said? I have seen photos of severe debarking in Andover, but nothing stripped clean of all bark. Also, go ahead, explain the "making politicians happy" thing. Waiting for your explanation.

I think you're letting "in my back yard" bias skew your objectivity here.

I have nothing but empathy for this perspective. I grew up in Pleasant Grove, so the 2011 Tuscaloosa tornado was beyond an IMBY bias for me. A number of the homes demolished by that tornado are ones that I played in or visited as a child/teenager. One of the few fatalities in Pleasant Grove was someone who I went to church with as a teenager and knew quite well. She was visiting her brother. He survived. Her infant child survived. She didn't. It can be extremely challenging for people to objective in the aftermath of these situations. I don't know that I'll ever accept that the Tuscaloosa tornado was anything less than an EF-5 even though I fully comprehend why it was rated the way it was.

The emotions after an event like this are indescribable. I don't know if Blake S. still posts here, but he and I grew up about a mile away from each other and went to HS together. He knows what it was like to see our neighborhood in Pleasant Grove in the days after 4/27.

The Tuscaloosa tornado, and April 27th, in general, was a 9/11-esque event for me. I had witnessed an EF-3 in Arkansas, and a number of other tornadoes previously, but seeing one destroy places you are emotionally attached to meant it was extremely difficult to be objective. I went to my best friend's neighborhood in Concord immediately after the Tuscaloosa tornado (we're talking 5-10 minutes after the tornado passed through) and that particular neighborhood ended up with over 10 fatalities. To say I'll never forget the scenes from that moment are an understatement. His parents were home when the tornado hit and I still don't understand how they survived when several people on their street were killed.

I say all that to say, I commiserate with Shakespeare2016. However, I sincerely promise him that you, Andy, and others are just being objective. And it's going to be a serious struggle for him to be objective right now. It's the nature of something this personal.

Unfortunately, construction quality in the United States has suffered major quality issues for quite some time now. It's been repeatedly in my face, recently, as I've been working internally in a $150+ million structure my previous employer commissioned (I was part of the engineering team that commissioned parts of the building), over the past month or so.

Shakespeare2016, I promise you the posters here aren't trying to denigrate the damage that happened to area in which you live. As I'm sure you're aware, quality of construction is simply something that is a key part of how tornadoes are rated and compared. Everyone knows the process is far from perfect, but I think the posters on Talkweather are united in wanting to see accurate, replicable, and fair ratings.

 

[Shakespeare 2016]

I have nothing but empathy for this perspective. I grew up in Pleasant Grove, so the 2011 Tuscaloosa tornado was beyond an IMBY bias for me. A number of the homes demolished by that tornado are ones that I played in or visited as a child/teenager. One of the few fatalities in Pleasant Grove was someone who I went to church with as a teenager and knew quite well. She was visiting her brother. He survived. Her infant child survived. She didn't. It can be extremely challenging for people to objective in the aftermath of these situations. I don't know that I'll ever accept that the Tuscaloosa tornado was anything less than an EF-5 even though I fully comprehend why it was rated the way it was.

The emotions after an event like this are indescribable. I don't know if Blake S. still posts here, but he and I grew up about a mile away from each other and went to HS together. He knows what it was like to see our neighborhood in Pleasant Grove in the days after 4/27.

The Tuscaloosa tornado, and April 27th, in general, was a 9/11-esque event for me. I had witnessed an EF-3 in Arkansas, and a number of other tornadoes previously, but seeing one destroy places you are emotionally attached to meant it was extremely difficult to be objective. I went to my best friend's neighborhood in Concord immediately after the Tuscaloosa tornado (we're talking 5-10 minutes after the tornado passed through) and that particular neighborhood ended up with over 10 fatalities. To say I'll never forget the scenes from that moment are an understatement. His parents were home when the tornado hit and I still don't understand how they survived when several people on their street were killed.

I say all that to say, I commiserate with Shakespeare2016. However, I sincerely promise him that you, Andy, and others are just being objective. And it's going to be a serious struggle for him to be objective right now. It's the nature of something this personal.

Unfortunately, construction quality in the United States has suffered major quality issues for quite some time now. It's been repeatedly in my face, recently, as I've been working internally in a $150+ million structure my previous employer commissioned (I was part of the engineering team that commissioned parts of the building), over the past month or so.

Shakespeare2016, I promise you the posters here aren't trying to denigrate the damage that happened to area in which you live. As I'm sure you're aware, quality of construction is simply something that is a key part of how tornadoes are rated and compared. Everyone knows the process is far from perfect, but I think the posters on Talkweather are united in wanting to see accurate, replicable, and fair ratings.

I am in my 40s and have been studying tornado damage for 20+ years. No I am not a professional or anything but there does seem to be a pattern in how tornado damage is rated. Maybe I am being too subjective. I guess it is just hard for me to wrap my mind around how a tornado less than EF4 can bend or possibly can even snap anchor bolts and mostly debark trees. To me it seems like the EF-SCALE is a construction scale and not a damage scale.

 

[pohnpei]

I am in my 40s and have been studying tornado damage for 20+ years. No I am not a professional or anything but there does seem to be a pattern in how tornado damage is rated. Maybe I am being too subjective. I guess it is just hard for me to wrap my mind around how a tornado less than EF4 can bend or possibly can even snap anchor bolts and mostly debark trees. To me it seems like the EF-SCALE is a construction scale and not a damage scale.

It is a construction scale basically. Because it's really hard to earn EF4 rating without construction in reality. We always say that a tornado capable of doing EF4 damage etc which literally means It isn't a damage scale.

 

[pohnpei]

I remember that Pampa 1995 was rated F4 simply due to photogrammetry. There was no structure damage higher than F3 and the rating was pretty much acceptable by most of people and Grazulis even consider It as strongest tornado of all time mostly due to visual appearance.
Btw, this period shot by Reed even wasn't the peak intensity of Andover tornado. It did 165+mph damage later part of its life when It was a much soild stovepipe.
So I would choose to be more open on the rating stuff. Sometimes, it's hard to be certain that this tornado has to be 165mph or has to be 170mph. These arguments were good but I believe we are still far away from judging tornados' intensity unequivocally.

 

[Sawmaster]

So you disagree with the survey?

Read my post again carefully, especially the words "shoddy construction". I can't disagree with Mr. Ketchum when the plates are only nailed down. More than this, being around 2 years old it's certain to have been constructed with nail guns. 40 years ago the hand-driven 16d nails were longer and larger in diameter therefore holding better. Initial resistance to pulling seems about the same, but once the nail begins pulling out, there is a large difference with the gun's smaller "16d equivalent" nails losing their holding power rapidly, while that's slower and more progressive with the hand-driven nails. The thinner diameter of gun nails deforms more easily under a side-load ("in shear"), the heads are more easily pulled off, and they break more easily under bending yet they are treated the same in surveys as far as I can tell as I've found no mention of this anywhere ever. It seems only the initial pull resistance has been considered and that's not enough. But even with hand-driven nails and toe-nailing, without anchor bolts all is lost. EF-3 is appropriate there and if anything were changed it should go lower, not higher. People who build like this piss me off but practices like this are common now and I'm not in a position to make anything better except in my own work.

On the pet shop it would take a special investigation to rate, but it's inherently weak as it seemed to be built, and a rarely encountered type too, so they'll probably just skip it.

Yes I sometimes disagree with their rating assessments, but only when I can clearly see something wrong in how it was done using real-world standards, not just taking specifics written on paper somewhere as 'gospel'. When I disagree I can show exactly why in detail, not some generalized 'paint-brush-stroke" meant to cover everything. If you really want to be badly bored I can show you why and how one nail on a building has an effect on the whole structure all the way to the opposite side right down to the ground the foundation sits on. Buildings are a system where everything works together and small details can matter a lot or almost not at all, and the true story is in understanding that.

Phil

 

[A Guy]

It is a construction scale basically. Because it's really hard to earn EF4 rating without construction in reality. We always say that a tornado capable of doing EF4 damage etc which literally means It isn't a damage scale.

While I have some level of agreement with the rating (say, 50:50), though I have concerns with some of the logic behind it - it does once again ask the question of what they are trying to achieve with the EF Scale.

Also thanks for posting that tweet. While that analysis there will have mile-wide error bars the fact is a photogrammetry study could clear up a lot of mysteries around the low-level windspeed in tornadoes. And it should be so much easier than it used to be, you could use software and satellite images for locations and tracking movements and high quality footage is coming out our earholes. A far cry from Fujita tracing frames by hand from grainy 8-mm film

 

[MNTornadoGuy]

While I have some level of agreement with the rating - though I have concerns with some of the logic behind it - it does once again ask the question of what they are trying to achieve with the EF Scale.

Also thanks for posting that tweet. While that analysis there will have mile-wide error bars the fact is a photogrammetry study could clear up a lot of mysteries around the low-level windspeed in tornadoes. And it should be so much easier than it used to be, you could use software and satellite images for locations and tracking movements and high quality footage is coming out our earholes. A far cry from Fujita tracing frames by hand from grainy 8-mm film

Something that might hinder ratings based on photogrammetry is that the EF-scale is based on 3-second wind gusts and the speed of debris/clouds in a tornado might not be measuring that.

 

[A Guy]

Something that might hinder ratings based on photogrammetry is that the EF-scale is based on 3-second wind gusts and the speed of debris/cloud debris in a tornado might not be measuring that.

It then asks more questions - how accurately does a 3-second wind gust characterise damage causing wind? If there is a 200 mph wind for 2 seconds and zero for 1 will the resultant damage be closer to high-end EF-2 (133 mph 3-sec average) or high end EF-4 (200 mph max)? Surely there must be a paper on this somewhere, it's a fundamental issue that must have been considered at some point.

In that Smithville video in the April 27 thread the video maker remarked on the very narrow (10-15 m wide) core, noting that the damage may have been created in as little time as a second. He presumably assumed the core is roughly circular (I can think of reasons it may not be). Something that provides food for thought is that Fujita original based the F scale on wind run rather than wind speed - the numbers are similar but the conception different.

 

[Sawmaster]

I remember that Pampa 1995 was rated F4 simply due to photogrammetry. There was no structure damage higher than F3 and the rating was pretty much acceptable by most of people and Grazulis even consider It as strongest tornado of all time mostly due to visual appearance.
Btw, this period shot by Reed even wasn't the peak intensity of Andover tornado. It did 165+mph damage later part of its life when It was a much soild stovepipe.
So I would choose to be more open on the rating stuff. Sometimes, it's hard to be certain that this tornado has to be 165mph or has to be 170mph. These arguments were good but I believe we are still far away from judging tornados' intensity unequivocally.

Hear hear! And bravo!

We have to consider the goal when we decide how to assess things. Are we seeking to determine windspeeds by the damage left behind as Fujita intended? If a weaker building is surrounded by larger stronger ones it will see less damage at a given windspeed than if it were out in the open or in a position where winds were channeled into it, so damages alone can't tell the whole story nor can windspeeds always correlate exactly to damage. And with photogrammetry opportunities and DOW we now have means at hand which Fujita and Grazulis were short of, so where do we fit them in? Using my example shows that windspeeds at say 50m height may not show the same damage effects on the ground so what are windspeeds worth to us as a standard? Should we instead determine destructiveness, as that's what really affects us?

We are indeed still a long way away from perfection but the EF scale and how the ratings are determined seem to me to be good overall as long as we integrate improvements in methods as technology advances. Accuracy matters but in practicality if winds are one MPH into a higher rating there will be nearly no difference in the effect on us were they one MPH and one rating lower. I wish more people would understand that as we spend too much time and energy arguing semantics when we should be spending that time and energy on achieving a greater understanding of tornadoes so we can better deal with them.

Phil