Severe WX December 10 & 11, 2021 Severe Threat

[Tanner]

This is the exact failure mode I was expecting. Context-based EF5 is no longer a thing. This establishes it.

Hey at least they've been consistent.


Consistently inconsistent

 

[buckeye05]

Honestly, idk even if this comes down to context. There were several totally slabbed homes in Cayce, and the foundation types looked modern and likely to have bolting around the perimeter. Plus, there were several extensively anchor bolted homes swept away in the Gilbertsville/Cambridge Shores area. All of this is just so not ok…

I honestly blame Vilonia for starting a domino effect of skepticism that has landed us in this current situation. That whole disgrace of a survey destroyed every survey team’s confidence and objectivity. It set a terrible precedent, and now we’re still dealing with the BS that has followed.

 

[andyhb]

Didn't Tim only visit Mayfield and Dawson Springs? I didn't see him post pictures from anywhere else.

 

[buckeye05]

Didn't Tim only visit Mayfield and Dawson Springs? I didn't see him post pictures from anywhere else.

That is a good point. The main areas in question are Cayce, Gilbertsville, Cambridge Shores, Bremen, and Earlington, and I don’t think he’s made it to those areas. With that said, his tweet about “NWS says EF4” had a sense of finality to it. Makes me think that the rating is about to be finalized.

 

[TH2002]

I understand it's probably still preliminary and all, but I already think EF5 tornadoes are a thing of the past.

 

[Tanner]

Didn't Tim only visit Mayfield and Dawson Springs? I didn't see him post pictures from anywhere else.

Correct statement.

 

[Shakespeare 2016]

Totally unscientific, but I can’t remember a single preliminary 190 MPH that has ever been upgraded further. I view it as a bad omen at this point. But yeah technically it is preliminary, even though I think no major changes will occur given past experiences:

Smithville was a preliminary 190 mph EF4 until it was upgraded to a 205 mph EF5.

 

[buckeye05]

This might sound stupid, but since we're at the end of the year, will the ratings have to be finalized quicker for entry into NCDC? I remember that the Estill/Nixville, SC tornado was upped from EF3 to EF4 months later. I am wondering if that is an option that NWS Paducah has?

 

[Tanner]

I'm sorry for kind of coming in on the fly, in a bit of an unsettled time as well. I'm Tanner. This site has opened my eyes quite a bit for discussion, analysis, and most importantly cementing knowledge into my youthful brain.

Off topic, I know. Just thought I'd give a small, proper introduction and some acknowledgment.

 

[Tanner]

Smithville was a preliminary 190 mph EF4 until it was upgraded to a 205 mph EF5.

So was Hackleburg, which was also rated EF3 at the beginning if I remember correctly.

 

[Equus]

This effectively renders ratings meaningless, but the maddening inconsistency from WFO to WFO and the dramatically stricter thresholds now mean they've been pretty much meaningless to compare historical events from the start. Grazulis seems a far better authority on the old ratings than the official one

 

[Equus]

Hackleburg was one of the standard "at least EF3" then the Huntsville CWA section went 190 right before BMX went EF5 iirc

 

[wasatch]

My thoughts, exactly - I kinda gave up on the EF scale after Vilonia, this only cements it further (pending unlikely upgrade) - what few improvements it's made have more than been offset by the loss of historical context... Personally I'd like to see tornadoes rated in a way that measures more than maximum speed (which is ultimately no better than an educated guess from an engineer playing God) - but also takes into consideration path length, width, radar measurements (if available) and loss of life and property - it's sort of ridiculous that something like Elie can be considered F5/EF5 but Tuscaloosa or this one are not, when they were of far greater impact, and it's really nothing more than a guess that it didn't quite attain 5 more miles per hour...

 

[locomusic01]

My thoughts, exactly - I kinda gave up on the EF scale after Vilonia, this only cements it further (pending unlikely upgrade) - what few improvements it's made have more than been offset by the loss of historical context... Personally I'd like to see tornadoes rated in a way that measures more than maximum speed (which is ultimately no better than an educated guess from an engineer playing God) - but also takes into consideration path length, width, radar measurements (if available) and loss of life and property - it's sort of ridiculous that something like Elie can be considered F5/EF5 but Tuscaloosa or this one are not, when they were of far greater impact, and it's really nothing more than a guess that it didn't quite attain 5 more miles per hour...

What you're describing is pretty close to Rich Thompson's Destruction Potential Index. It's meant for outbreaks rather than single tornadoes, but it's basically a function of EF-rating, width and length.

The equation is:

With n = number of tornadoes, a = the area (length x width) of the paths and F = rating. Pretty simple and clever idea, but it comes with plenty of problems of its own. Not the least of which being path width - and especially the width of high-end damage - is incredibly variable across a tornado's lifespan.

 

[pohnpei]

I heard from @MNTornadoGuy that Czech tornado this year has been given a consideration of potential upgrade. It just sounds ironic to me that may be the Czech rather than Vilonia or Chapman or Mayfield to finish the EF5 drought.

 

[buckeye05]

Smithville was a preliminary 190 mph EF4 until it was upgraded to a 205 mph EF5.

So was Hackleburg, which was also rated EF3 at the beginning if I remember correctly.

That's true. I guess it was long enough ago that my memory is a little more fuzzy when it comes to how the upgrade process went. That was actually the outbreak that made me start looking into how the rating process works.

 

[eric11]

The dreaded 190 MPH EF4. Don’t hold your breath. They brought Bassfield, MS up to 190, said they’d do further analysis, but never upgraded it any further. Expect a repeat of the same. I’m pretty much resigned to the viewpoint that the days of EF5 ratings are over. It’s simply no longer obtainable by todays ridiculous standards. Moore 2013 was the last EF5, and I guess that’s just the way it is now.

The attitude was totally different when it comes to Jackson and Memphis/Paducah. For the Bassfield one, Jackson rated at least four EF4 damage points just entirely based on extreme tree damage and there're other countless tree damage points, they also climbed through mountains and used drones to evaluate the tree damage in rural area. And look what MEG was doing.....
The questioned house which may obtain an EF5 rating during Bassfield does have some flaws like straight nail anchoring or mainly built in wood, JAX also brought in the QRT to lookly closely into the house, they also interviewed the home owner, trying to figure out every detail about the house.So the 190mph rating seems acceptable for Bassfield, at least I appreciate their attitude.

I can accept there's not even one single house which could meet EF5 criteria in Dawson Springs or Bremen if they surveyed closely, but the truth is, they just quickly glanced over, or even ignored countless of slabs in these small towns and quickly jumped to a ridiculous statement "there's not even one house can be rated EF5, they all have some anchoring/quality issue!" Let alone the MEG.....sorry, I could find no words describe them
I started tracking torndoes since 2013, I might not have known Moore was the last EF5 in the rest of my life at that time.

 

[Shakespeare 2016]

I thought NWS in Paducah hired some wind engineers to see what kind of winds would be required to throw an 18 ton object 3/4 mile.

 

[locomusic01]

This might sound stupid, but since we're at the end of the year, will the ratings have to be finalized quicker for entry into NCDC? I remember that the Estill/Nixville, SC tornado was upped from EF3 to EF4 months later. I am wondering if that is an option that NWS Paducah has?

I believe Rick Smith said earlier the data won't be certified for 60 days. He's not PAH obviously, but I'd assume he would know as well as anyone. Still pretty skeptical we'll see an upgrade either way, but I suppose you never know.

 

[TH2002]

What does a tornado have to do to get an EF5 rating these days? Granulate rail cars to powder or make them disappear entirely, make huge poured slabs vanish without a trace, and (referencing an old Stormtrack thread) take chunks of land and throw them thousands of miles?