Enhanced Fujita Ratings Debate Thread

[TH2002]

LOL. Back on topic. Super serious. What do you think the chances are the new EF scale adds a DI for the "functionality of Jacuzzis"? @joshoctober16 here's another contextual for your list! I think Marshall is really onto something here.
View attachment 30027

Or how about the DI "literally rolled Ted Fujita over in his grave"? How many rotations for an EF5 rating?

If I'm not mistaken, bathtubs are usually made of fiberglass or cast iron, and behave weirdly in tornadoes. There's the famous story of a woman surviving a near direct hit by the Jarrell F5 in a bathtub, and yet weaker tornadoes like the 2011 Almena, KS EF3 have flipped and/or damaged them:

So by this same logic, does that mean Almena was an EF5 and Jarrell was a 170MPH EF4? I don't think so.

 

[joshoctober16]

If I'm not mistaken, bathtubs are usually made of fiberglass or cast iron, and behave weirdly in tornadoes. There's the famous story of a woman surviving a near direct hit by the Jarrell F5 in a bathtub, and yet weaker tornadoes like the 2011 Almena, KS EF3 have flipped and/or damaged them:

So by this same logic, does that mean Almena was an EF5 and Jarrell was a 170MPH EF4? I don't think so.

from what i understood the jarrell tornado threw her with the bathtub before the EF5 winds hit that spot.

 

[Grand Poo Bah]

Guys I was being sarcastic lol. Or maybe... Is this why the 2014 Smithfield, NY tornado was rated EF2



On a more serious note. I took a look at Greenfield's damage survey and started circling all the homes without pictures. It was too many so I had to start circling the homes with pictures instead.



141 homes surveyed
Only 32 had pictures taken (22%)
31 homes had EF4 damage
14 Had pictures taken (45%)
43 Had EF3 Damage
11 Had Pictures (26%)

How is this acceptable? It'd be one thing if they at least wrote descriptions of the houses, but they didn't. It's just blank. This is the best they could document the second strongest tornado of all time?



Red was rated EF4, orange is EF3, Blue didn't even receive a rating.



These don't have pictures. The third to the right looks well constructed and is right on a main road. How did they not document it?

agree with vilonia but wait were goldsby survey missing stuff?

Yes. Out of the 16 houses with a DOD of 10 only 5 were documented in the toolkit. 8 were described as being well built with anchor bolts.

Edit:
I've attached a picture showing where the overhead pictures are located along the damage path. Does anyone have the ability to (or want to) question the NWS Des Moines office about it? One of the reasons ratings continue to be wrong is probably because people don't keep the pressure on while the rating is still preliminary. people should want to know why it's being rated this way now, not after it's too late and the surveyors can deflect blame. @TH2002, thoughts?

 

[Sawmaster]

If I'm not mistaken, bathtubs are usually made of fiberglass or cast iron, and behave weirdly in tornadoes. There's the famous story of a woman surviving a near direct hit by the Jarrell F5 in a bathtub, and yet weaker tornadoes like the 2011 Almena, KS EF3 have flipped and/or damaged them:

So by this same logic, does that mean Almena was an EF5 and Jarrell was a 170MPH EF4? I don't think so.

On tubs, the old ones were cast iron weighing about 160lbs and up. Steel tubs came along somewhere after WW2 but didn't entirely replace cast until about 1960. Those weigh about 1/4 of cast iron and are still common. Fiberglass tubs became common in the 80's and weight little.

What makes tubs a good 'safe spot' for tornadoes? They are tightly fitted to walls on 3 sides; the older ones have weight; and the older ones also tied in the drains to heavy cast iron drain pipes, so probably the most solidly secured object in homes. Cast iron and steel tube offer a lot of debris impact protection versus the usual sheetrock walls. On old homes with plaster walls or tiled walls, you have that weight/ thickness/ hardness in your favor too. New tilebacker doesn't give you that same strength or weight. Fiberglass tubs with modern PVC or ABS plastic drains don't perform nearly as well, especially for debris protection but if it's all you've got and it's in a good interior spot it's probably the safest place in the average house.

Toilets also survive fairly well with cast iron drain piping because of weight and attachment to the drains, again modern plastic drain pipes don't hold as well. Older installs used 3/8X24 bolts of brass or steel; newer uses 14/20 bolts which will sometimes pull through the holes with the washers. The ceramic also offers better impact protection than sheetrock.

And if you ask nicely, the tornado might scrub those hard-to-reach spots on your back for you...

 

[SouthFLwx]

Guys I was being sarcastic lol. Or maybe... Is this why the 2014 Smithfield, NY tornado was rated EF2

View attachment 30029View attachment 30030

On a more serious note. I took a look at Greenfield's damage survey and started circling all the homes without pictures. It was too many so I had to start circling the homes with pictures instead.

View attachment 30031

141 homes surveyed
Only 32 had pictures taken (22%)
31 homes had EF4 damage
14 Had pictures taken (45%)
43 Had EF3 Damage
11 Had Pictures (26%)

How is this acceptable? It'd be one thing if they at least wrote descriptions of the houses, but they didn't. It's just blank. This is the best they could document the second strongest tornado of all time?

View attachment 30032

Red was rated EF4, orange is EF3, Blue didn't even receive a rating.

View attachment 30034

These don't have pictures. The third to the right looks well constructed and is right on a main road. How did they not document it?


Yes. Out of the 16 houses with a DOD of 10 only 5 were documented in the toolkit. 8 were described as being well built with anchor bolts.

Edit:
I've attached a picture showing where the overhead pictures are located along the damage path. Does anyone have the ability to (or want to) question the NWS Des Moines office about it? One of the reasons ratings continue to be wrong is probably because people don't keep the pressure on while the rating is still preliminary. people should want to know why it's being rated this way now, not after it's too late and the surveyors can deflect blame. @TH2002, thoughts?

View attachment 30035

Greenfield’s rating is fine and NWS Des Moines did a great job surveying this tornado. I think the main reason why they didn’t include damage photos for many of the DIs was because they wanted to respect the homeowners privacy and refrained from making pictures of their destroyed homes available to the public. I remember they did the same thing with the Winterset tornado.

 

[jiharris0220]

Greenfield’s rating is fine and NWS Des Moines did a great job surveying this tornado. I think the main reason why they didn’t include damage photos for many of the DIs was because they wanted to respect the homeowners privacy and refrained from making pictures of their destroyed homes available to the public. I remember they did the same thing with the Winterset tornado.

If I’m not mistaken, I’m pretty sure you have to ask for permission to take a close up photo of someone’s house if destroyed.

It’s heavily frowned upon people taking close up videos/pictures of a destroyed property shortly after a disaster, and also, I’m not sure what pictures have to do with the accuracy of a rating.

No close up photos doesn’t mean the NWS surveyors didn’t do a thorough inspection of the property, obviously since there wouldn’t be so many ef4 DIs.

It would be different if there were no DIs on obviously impacted structures, like with vilonia’s case.

 

[joshoctober16]

If I’m not mistaken, I’m pretty sure you have to ask for permission to take a close up photo of someone’s house if destroyed.

It’s heavily frowned upon people taking close up videos/pictures of a destroyed property shortly after a disaster, and also, I’m not sure what pictures have to do with the accuracy of a rating.

No close up photos doesn’t mean the NWS surveyors didn’t do a thorough inspection of the property, obviously since there wouldn’t be so many ef4 DIs.

It would be different if there were no DIs on obviously impacted structures, like with vilonia’s case.

i could of sware that it was stated the alabama part of the smithville tornado wasnt rated EF4+ because there was no close up evidence .... if this is the case we need a way to rate a tornado EF5 ... WITHOUT getting close to a home .... if you cant then remove the EF5 rating. its already starting to get hard to rate stuff EF4 as well.

 

[jiharris0220]

i could of sware that it was stated the alabama part of the smithville tornado wasnt rated EF4+ because there was no close up evidence .... if this is the case we need a way to rate a tornado EF5 ... WITHOUT getting close to a home .... if you cant then remove the EF5 rating. its already starting to get hard to rate stuff EF4 as well.

You can survey a home without taking photos.

Using solely photos for evidence to rate a tornado is loosely accurate at best, and it’s reserved for rural areas, (or lazy damage surveys).

Most of the time if a surveyor takes a photo of a home it’s just for public clarity sake, which again, I assume after being granted permission to do so.

 

[slenker]

Greenfield’s rating is fine and NWS Des Moines did a great job surveying this tornado. I think the main reason why they didn’t include damage photos for many of the DIs was because they wanted to respect the homeowners privacy and refrained from making pictures of their destroyed homes available to the public. I remember they did the same thing with the Winterset tornado.

It certainly seems like a hot take with the amount of people that believe Greenfield should have been rated EF5, but I personally believe Greenfield’s rating was completely fine as well, because the survey didn’t actually leave the confines of the EF scale the way it is defined. I don’t think anything in Greenfield genuinely justifies an EF5 rating. The winds recorded were certainly insanely impressive, but I’d be willing to bet a lot more justified HE EF4’s and maybe even some EF3’s have windspeeds around that level above the ground. If the tornado went through Greenfield at peak intensity it would maybe have had a better shot at getting an EF5 rating.

 

[SouthFLwx]

It certainly seems like a hot take with the amount of people that believe Greenfield should have been rated EF5, but I personally believe Greenfield’s rating was completely fine as well, because the survey didn’t actually leave the confines of the EF scale the way it is defined. I don’t think anything in Greenfield genuinely justifies an EF5 rating. The winds recorded were certainly insanely impressive, but I’d be willing to bet a lot more justified HE EF4’s and maybe even some EF3’s have windspeeds around that level above the ground. If the tornado went through Greenfield at peak intensity it would maybe have had a better shot at getting an EF5 rating.

This also goes to show that the EF scale probably does underestimate tornadic wind speeds if winds of 300+mph were recorded in Greenfield, but it didn't inflict EF5 damage.

 

[Grand Poo Bah]

If everyone here believes Greenfield's rating was fine then any hope of fixing the system, or the culture around it, is hopeless. and I'm out. 180 MPH winds can't sweep 60 houses away and shred them into splinters in less than a minute. Can 180 MPH clean the slab of a poorly built house? Maybe (though i doubt it can in 10 seconds). Can it do that to 60 houses? Zero chance. It's physically and mathematically impossible.

 

[slenker]

If everyone here believes Greenfield's rating was fine then any hope of fixing the system, or the culture around it, is hopeless. and I'm out. 180 MPH winds can't sweep 60 houses away and shred them into splinters in less than a minute. Can 180 MPH clean the slab of a poorly built house? Maybe (though i doubt it can in 10 seconds). Can it do that to 60 houses? Zero chance. It's physically and mathematically impossible.

Show me the mathematical calculations that say it’s impossible. The EF scale’s windspeed measurements are based on wind physics and engineering math. The math is telling us 165 MPH winds are capable of sweeping badly built homes off their foundations, and I tend to trust math more than subjective opinion.

Yes, the EF scale is consistently underrating windspeeds/intensities, but again, most of the windspeed measurements we have are not at ground level. There’s also an upward component to wind vectors that tends to exaggerate damage in tornadoes.

I trust our surveyors. I just think the scale isn’t great. The people responsible are working on fixing it to the best of their abilities.

 

[joshoctober16]

Show me the mathematical calculations that say it’s impossible. The EF scale’s windspeed measurements are based on wind physics and engineering math. The math is telling us 165 MPH winds are capable of sweeping badly built homes off their foundations, and I tend to trust math more than subjective opinion.

Yes, the EF scale is consistently underrating windspeeds/intensities, but again, most of the windspeed measurements we have are not at ground level. There’s also an upward component to wind vectors that tends to exaggerate damage in tornadoes.

I trust our surveyors. I just think the scale isn’t great. The people responsible are working on fixing it to the best of their abilities.

im wondering if they are using the wind speed of the 0.1% chance of having this damage happen instead of having a 25-75% chance for the failure to start i remember a old presentation that shows one DOD was 100% wrong
edit(its DOD4 DOD8 and DOD9, both are 100% wrong in terms of well built frame houses, there is also DOD6 and DOD7 to note as well, but hey at least DOD2 is accurate)

 

[slenker]

im wondering if they are using the wind speed of the 0.1% chance of having this damage happen instead of having a 25-75% chance for the failure to start i remember a old presentation that shows one DOD was 100% wrong. -image-
edit(its DOD4 DOD8 and DOD9, both are 100% wrong in terms of well built frame houses, there is also DOD6 and DOD7 to note as well, but hey at least DOD2 is accurate)

It's definitely not a probability thing. The math we do on structures involves using forces to determine what wind load certain structures can take before they give out. It isn't a "0.1%" thing. I would guess that the problem with the math we use to calculate the windspeed estimations is taking place in an overly idealized world and is not taking enough into account. Most of the time, the calculations I see from wind engineers are both unidirectional and uniform in magnitude on the object being affected and this simply does not ever occur in the real world, especially when talking about the extremely complex wind dynamics within the vortex of a tornado.

But also, I can understand why the math is this way. It's because attempting to take the factors I mentioned into account would probably become so mathematically ridiculous that a computer wouldn't be able to do it. That's why this problem is so difficult to solve.

These graphs do look very legitimate and I do trust them. I'm not familiar with what the dashed lines mean so I can't comment on them. But yes, we can clearly see that with higher EF numbers, the windspeeds are off. I fully understand that. That is why, again, they are trying to fix it with the new scale.

 

[SouthFLwx]

If everyone here believes Greenfield's rating was fine then any hope of fixing the system, or the culture around it, is hopeless. and I'm out. 180 MPH winds can't sweep 60 houses away and shred them into splinters in less than a minute. Can 180 MPH clean the slab of a poorly built house? Maybe (though i doubt it can in 10 seconds). Can it do that to 60 houses? Zero chance. It's physically and mathematically impossible.

The tornado was proven to have had winds of 300+mph when it was in Greenfield, and as I said earlier, the EF scale definitely underestimates tornadic wind speeds. However, the surveyors had to stay within the confines of the scale and survey the damage without incorporating radar-measured wind speeds because that would be inconsistent with previous surveys and go against the entire point of the scale, which is rating the damage. The damage in Greenfield is definitely on the level of a mid-high end EF4 and the rating reflects that.

 

[Sawmaster]

I won't comment on Greenfield directly as I don't know enough about it. But I don't trust all the surveyors, who we've clearly seen are inconsistent across different offices. And some we know are biased too. I can't say why this is, only that it certainly is an issue.

I'm all for integrating measured winds into the ratings as there seems to be some notable discrepancies between those and the damage found sometimes. The big problem here is that we'd have to alter the way damage is rated where measurement wasn't done to match the instances where it was done. You can't change what nature has done, only how you use the data you can derive from that. We should constantly be seeking ways to improve the system instead of ignoring errors until the next big push for upgrades.

And I'll close with this: You get respect only if you give it. Name-calling and disparaging personal comments against other members doesn't belong here. If you can't take or give criticism civilly then you should go elsewhere with your thoughts.

 

[slenker]

I won't comment on Greenfield directly as I don't know enough about it. But I don't trust all the surveyors, who we've clearly seen are inconsistent across different offices. And some we know are biased too. I can't say why this is, only that it certainly is an issue.

I do agree that I definitely can't trust every single one; John Robinson coming to mind specifically. But I do trust the bulk opinion of them, and the scientists responsible for a lot of ratings, because I do research in astronomy, not meteorology/engineering, lol.

And I'll close with this: You get respect only if you give it. Name-calling and disparaging personal comments against other members doesn't belong here. If you can't take or give criticism civilly then you should go elsewhere with your thoughts.

Completely agreed. This is an online forum and we're all trying to level with each other here. No reason to be getting upset with each other.

 

[Jordan]

Hi all, new here

andover was only able to remove the whole roof and a few walls with 264 mph winds , its to extra note the tornado winds were there for over 12 seconds and the core was over that house for more then 8 seconds.

Hi, what was the construction of the building you are talking about?

 

[joshoctober16]

Hi all, new here

Hi, what was the construction of the building you are talking about?

unsure but its whatever home is in this drone video


however it wont matter if its well built or poorly built since the core stays on this building for over 5 seconds and wasn't able to swept it clean , while the debris from this home was moving around 118 MS

after it hit it seems most of the roofs are gone but most walls are still standing , how can 235-260 mph 5 second gust not even cause swept clean to lets assume ... a well built home.

while it hard to tell how much of the walls are standing from this angle it seems to be DOD6 to DOD8 on the new EF scale, meaning only a 100-190 mph 3 second gust happen.


interesting thing to note 15 second after this tornado went out of the drone frame it hit the YMCA building then crossed the road , after it crossed the road it started to swept away buildings and cause ground scouring.

 

[Jordan]

View attachment 30097
View attachment 30098
unsure but its whatever home is in this drone video


however it wont matter if its well built or poorly built since the core stays on this building for over 5 seconds and wasn't able to swept it clean , while the debris from this home was moving around 118 MS
View attachment 30099
after it hit it seems most of the roofs are gone but most walls are still standing , how can 235-260 mph 5 second gust not even cause swept clean to lets assume ... a well built home.
View attachment 30100
while it hard to tell how much of the walls are standing from this angle it seems to be DOD6 to DOD8 on the new EF scale, meaning only a 100-190 mph 3 second gust happen.

View attachment 30101
interesting thing to note 15 second after this tornado went out of the drone frame it hit the YMCA building then crossed the road , after it crossed the road it started to swept away buildings and cause ground scouring.

View attachment 30097
View attachment 30098
unsure but its whatever home is in this drone video


however it wont matter if its well built or poorly built since the core stays on this building for over 5 seconds and wasn't able to swept it clean , while the debris from this home was moving around 118 MS
View attachment 30099
after it hit it seems most of the roofs are gone but most walls are still standing , how can 235-260 mph 5 second gust not even cause swept clean to lets assume ... a well built home.
View attachment 30100
while it hard to tell how much of the walls are standing from this angle it seems to be DOD6 to DOD8 on the new EF scale, meaning only a 100-190 mph 3 second gust happen.

View attachment 30101
interesting thing to note 15 second after this tornado went out of the drone frame it hit the YMCA building then crossed the road , after it crossed the road it started to swept away buildings and cause ground scouring.

I'll reply to the rest of this in a bit, where did you get the screenshot of the presentation? And the DOD graph?