Enhanced Fujita Ratings Debate Thread

[KCweatherboy]

The 10% hatched tornado threat today in July in Illinois made me look up Plainfield, and tbh based on today's track record of rating tornadoes it would probably end up as a high-end EF3. The F5 rating was based on extreme ground scouring and a tractor-trailer being thrown 1150ft, which I think is fully valid. Imagine using contextual damage and meteorological information to rate a meteorological event...

 

[TH2002]

The 10% hatched tornado threat today in July in Illinois made me look up Plainfield, and tbh based on today's track record of rating tornadoes it would probably end up as a high-end EF3. The F5 rating was based on extreme ground scouring and a tractor-trailer being thrown 1150ft, which I think is fully valid. Imagine using contextual damage and meteorological information to rate a meteorological event...

The rating was based on scouring in a corn field which is a bit questionable to say the least. I agree with the F5 rating because it caused vehicle damage and debarking consistent with some of the highest-end tornadoes and swept away a few anchor-bolted homes, but then again pretty much all violent tornadoes outside of DGX and DMX’s survey areas would get a HE EF3 rating these days. Low end EF4 is about as strong as they come now.

 

[KCweatherboy]

The rating was based on scouring in a corn field which is a bit questionable to say the least. I agree with the F5 rating because it caused vehicle damage and debarking consistent with some of the highest-end tornadoes and swept away a few anchor-bolted homes, but then again pretty much all violent tornadoes outside of DGX and DMX’s survey areas would get a HE EF3 rating these days. Low end EF4 is about as strong as they come now.

Yes I agree and that's the key, the damage lines up with other highest-end tornadoes, and the tornado was therefore rated as such. This is how things should work imo.

and yes I was being a bit of a smarta** in my initial post, but I just wanted to highlight again how bad Matador was.

 

[pohnpei]

The 10% hatched tornado threat today in July in Illinois made me look up Plainfield, and tbh based on today's track record of rating tornadoes it would probably end up as a high-end EF3. The F5 rating was based on extreme ground scouring and a tractor-trailer being thrown 1150ft, which I think is fully valid. Imagine using contextual damage and meteorological information to rate a meteorological event...

Also wind speed wise, it was rated ＞260mph at that time and probably near 170mph nowadays. That's a huge difference. I don't know what's actual wind it contains and it may not be as high as 260mph. But I'm pretty sure thay the actual wind would be much more closer to 260mph rather than 170mph realistically.

 

[JBishopwx]

Not sure where to post this, but from Tim Marshall.

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[tornado examiner]

Hopefully it actually does lead to more consistently accurate ratings

 

[Tomcats Forever!]

Not sure where to post this, but from Tim Marshall.

Join our Cloud HD Video Meeting

Zoom is the leader in modern enterprise video communications, with an easy, reliable cloud platform for video and audio conferencing, chat, and webinars across mobile, desktop, and room systems. Zoom Rooms is the original software-based conference room solution used around the world in board...

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Passcode: amsnwameetView attachment 21679

Was anybody able to watch?

 

[UK_EF4]

Was anybody able to watch?

Yeah, here are some of the things summarised:

-Final draft expected within the next 2 years.
-30 DIs (for now) - including vehicles (This stuff was already known)
-Incremental wind speed increases between DoDs with wind speeds now round to nearest 5mph (as opposed to 1mph on the old scale)

For wood framed residences:

DoD 10 has EXP 200mph, LB 160mph, UB 240mph - though this DI might be subject to change
-On that subject, LB,EXP and UB are now renamed to "weaker than typical resistance, normal, and stronger than typical resistance". Stronger than typical includes things like hurricane clips, closer anchor bolt spacing, reinforced gable ends.

Also some discussion about the EF5 debate:

Said that Jarrell, Joplin, Moore are "the 5s" and that to be rated a 5 they should be comparable to those tornadoes. Also mentioned how Mayfield had a fast dwell speed which meant buildings couldn't be fully destroyed (which obviously wasn't the case everywhere, e.g: Bremen), and that construction in Rural KY is not up to standard (which is certainly true).

That's about everything I can remember, other people may be able to contribute more.

 

[Tomcats Forever!]

Yeah, here are some of the things summarised:

-Final draft expected within the next 2 years.
-30 DIs (for now) - including vehicles (This stuff was already known)
-Incremental wind speed increases between DoDs with wind speeds now round to nearest 5mph (as opposed to 1mph on the old scale)

For wood framed residences:

DoD 10 has EXP 200mph, LB 160mph, UB 240mph - though this DI might be subject to change
-On that subject, LB,EXP and UB are now renamed to "weaker than typical resistance, normal, and stronger than typical resistance". Stronger than typical includes things like hurricane clips, closer anchor bolt spacing, reinforced gable ends.

Also some discussion about the EF5 debate:

Said that Jarrell, Joplin, Moore are "the 5s" and that to be rated a 5 they should be comparable to those tornadoes. Also mentioned how Mayfield had a fast dwell speed which meant buildings couldn't be fully destroyed (which obviously wasn't the case everywhere, e.g: Bremen), and that construction in Rural KY is not up to standard (which is certainly true).

That's about everything I can remember, other people may be able to contribute more.

At least it souns like he doesn't buy into those bunk studies about Jarrell and Joplin.

 

[CheeselandSkies]

I noticed he mentioned Mayfield but carefully avoided bringing up Vilonia.

 

[tornado examiner]

I noticed he mentioned Mayfield but carefully avoided bringing up Vilonia.

Hiiiighly sus…

 

[notsoencrypted]

Hiiiighly sus…

Might just be that Vilonia is now almost 10 years ago, whereas Mayfield is much more recent and thus is more well-known in the public, especially with the factory collapse being a significant news item for quite a while.

Or that he had limited time and there's not something as quick to state/explain as it was for Mayfield. Or simply didn't want to open additional cans of worms. There's lots of reasons to not discuss something that still could be relevant, and while it can be frustrating, it doesn't make it necessarily suspect.

 

[pohnpei]

https://www.essl.org/cms/wp-content/uploads/20230506_IF-scale_v0.99.9d.pdf

I noticed that very few people here talked about IF scale developed by ESSL this year.So now Europe mainly use IF scale rather than old F scale or EF scale.
The most important feature for IF scale is it has very different definition for winds inside tornados.

The IF-scale wind speeds listed are understood to be the instantaneous three dimensional wind speed at the height of the observed damage rather than 3 second horizontal winds at 10m level defined by EF scale. IF scale have 9 classes as IF5 the highest with wind speed ＞290mph.
To me, it's easy to see which one is better. The fact that three second is way too long for tornado wind definition is the main reason why many people feel that wind speed given by NWS is " a little bit low" in high end tornados. I think the document above speak perfectly why instantaneous winds should be used rather than 3 or 1 second winds. It could circle around the inner core of a tornado once or more in most cases for a blast of a 100m/s wind in 3 seconds. Using 3 second winds as a standard is worse than using one hour sustained wind in hurricane intensity measurement.

Tornados have updrafts which called vertical winds and it can contribute more than horizontal winds in damage in many cases. I think these are ovbious fact. And winds at damage level is also a better definition than winds at a certain 10m level.(In fact, most FR12 are under 10m in US)



For building DODs, IF scale focus more on sturdiness of buildings rather than function of buildings so it didn't divide school or retail store DODs in EF scale. Instead, it developed a sturdiness measurement scale, mostly divided by the thickness of walls of houses and materials used in it.

For contextual DODs, IF scale developed something creative like shipping container dod and so on.

Overall I think it's a very great attempt in damage scale development for tornado rating.

 

[tornado examiner]

Did noaa just lock the damage assessment toolkit behind a paywall? I’m suddenly required to have a functional Arcgis online account too access the newly updated damage assessment toolkit….

 

[UK_EF4]

Did noaa just lock the damage assessment toolkit behind a paywall? I’m suddenly required to have a functional Arcgis online account too access the newly updated damage assessment toolkit….

Wasn't aware of any updated one but the usual link works just fine for me

 

[TH2002]

Did noaa just lock the damage assessment toolkit behind a paywall? I’m suddenly required to have a functional Arcgis online account too access the newly updated damage assessment toolkit….

Damage Assessment Toolkit v2.1.2 requires an ArcGIS subscription. The original DAT at apps.dat.noaa.gov/stormdamage/damageviewer/ still works just fine.

 

[tornado examiner]

Damage Assessment Toolkit v2.1.2 requires an ArcGIS subscription. The original DAT at apps.dat.noaa.gov/stormdamage/damageviewer/ still works just fine.

I for some reason wasn’t able to find the original link for a short time until now…weird…btw…I wonder what that new version changed or added? Does anyone have update details?

 

[UK_EF4]

https://x.com/NWSMobile/status/1725575378117501195?s=20

Not that any of the tornadoes in NWS Mobile are of particular interest in this thread, but a very interesting idea here which would have the potential to lead to similar things in different offices - particular with May 24th 2011 in mind with someone that works there mentioning he would like to upgrade the 2 EF4s to EF5s.

 

[joshoctober16]

The new EF scale looks like 8 steps fowards , 2 steps in place and 2 steps back.

lets start with the good

1:Frame house have been split into 2
2:metal building systems have been sub split into (non hurricane zone and hurricane zone)

3:the 2 mobile home di have been merged

4:tree fall pattern(forest damage or multi-tree) di added (helpful to stop underrating tornadoes)
5:Farm silos and grain bins have di (farm silos helpful for less underrated tornadoes)
6:center pivot irrigation system is now di
7:Wind Turbines di added

8:radar ratings can be used?
(this one is not 100% sure but it looks like it will be in, unsure how it will look like
9:frame houses wind speed make more sense for the poor/strong build ones



that is all the big good things the new EF scale will be able to do, there are a bunch of other smaller good updates , and 2 that are kind of.... both a upgrade and downgrade?

 

[Tanner]

The new EF scale looks like 8 steps fowards , 2 steps in place and 2 steps back.

lets start with the good

1:Frame house have been split into 2
2:metal building systems have been sub split into (non hurricane zone and hurricane zone)
View attachment 22216
3:the 2 mobile home di have been merged
View attachment 22217
4:tree fall pattern(forest damage or multi-tree) di added (helpful to stop underrating tornadoes)
5:Farm silos and grain bins have di (farm silos helpful for less underrated tornadoes)
6:center pivot irrigation system is now di
7:Wind Turbines di added
View attachment 22223
8:radar ratings can be used?
(this one is not 100% sure but it looks like it will be in, unsure how it will look like
9:frame houses wind speed make more sense for the poor/strong build ones
View attachment 22224


that is all the big good things the new EF scale will be able to do, there are a bunch of other smaller good updates , and 2 that are kind of.... both a upgrade and downgrade?

Where did you find this? I would love to see more of it!