Dec. 10-11 Severe Weather

[largetornado]

38 minutes ago, andyhb said:

I know, I just posted that for the receipts

Also they apparently rated this EF2? Huh?

The bottom sill plate is missing and broken in places. I also saw another post where an anchor bolt was visible in a CMU foundation but survey noted “no connection.” 
 

this survey is bogus. 

[Buckeye05]

Since it got buried at the bottom of the previous page, I’m gonna say it again. It looks as though many of the questionable ratings we have been seeing are being caused by NWS WFOs outsourcing survey work to people with no meteorological background. That’s insane to me, and people should be aware that it’s happening.

[madwx]

49 minutes ago, largetornado said:

The bottom sill plate is missing and broken in places. I also saw another post where an anchor bolt was visible in a CMU foundation but survey noted “no connection.” 
 

this survey is bogus. 

 

[Buckeye05]

6 minutes ago, madwx said:

 

That doesn’t apply to this situation. The residence in question in Bowling Green was a poured slab foundation with bolts, not CMU. The rebuttal in the above tweet does not address nor de-legitimize the inconsistencies and gaps in logic highlighted by the above poster. 

[Normandy]

Even that example there is not nearly enough information to say an outrageous statement that there are “no connections”. The entire building is gone.  The only thing I can even begin to deduce is it was a wood frame house, with wood framed floors, built on CMU walls with a Crawl space beneath.  And even that assumption is guesswork with no other elements to review.

[madwx]

58 minutes ago, Buckeye05 said:

That doesn’t apply to this situation. The residence in question in Bowling Green was a poured slab foundation with bolts, not CMU. The rebuttal in the above tweet does not address nor de-legitimize the inconsistencies and gaps in logic highlighted by the above poster. 

I wasn't responding to you, I was responding to largetornado's second assertion

[DanLarsen34]

 

[brianc33710]

1 hour ago, DanLarsen34 said:

 

And this thread is about underrated tornadoes. Obviously there are a ton of people wondering why they rated damage EF4 when there appeared to be EF5 & EF3s that others consider EF4s. Ill stay away from spreading what could be inaccurate info though, but there are plenty of pissed off people out there regarding ratings. Thats for sure, Ill leave this at that.

[CheeselandSkies]

While the Mayfield etc tornado may not have (at least officially, to the best of our limited knowledge of the exact nature of the 1925 event) dethroned the Tri-State Tornado for longest track ever; it did dethrone the April 24, 2010 Louisiana-Mississippi tornado (149.25 miles, another tornado that was almost certainly substantially more intense than its official 170 MPH low-end EF4, but in that case there's not much controversy regarding the rating of the actual damage observed, it just didn't hit much outside of clipping Yazoo City) as the longest-tracked tornado in the NEXRAD era.

[brianc33710]

Admttedly Its Wikipedia, but heres a report from the 27 April 2011 Superoutbreak that looks directly taken from the NWS damage surveys. So this is what 10.5 years ago what each significant tornado was rated & why. https://en.wikipedia.org/wiki/2011_Super_Outbreak#Notable_tornadoes

[MidwestChaser]

6 minutes ago, brianc33710 said:

Admttedly Its Wikipedia, but heres a report from the 27 April 2011 Superoutbreak that looks directly taken from the NWS damage surveys. So this is what 10.5 years ago what each significant tornado was rated & why. https://en.wikipedia.org/wiki/2011_Super_Outbreak#Notable_tornadoes

Looks like several of the EF-5s then were classified based on extreme ground scouring. Wasn't that also seen here?

 

[Buckeye05]

24 minutes ago, MidwestChaser said:

Looks like several of the EF-5s then were classified based on extreme ground scouring. Wasn't that also seen here?

 

The only one that was entirely based on ground scouring was the Philadelphia, MS EF5. It dug deep trenches into the ground, which was assumed to have been indicative of 200+ MPH winds back in 2011. Unfortunately, there isn't a "ground scouring" DI, and since NWS many survey teams are much less open to factoring in non-established DIs and contextual evidence in this day and age, such a thing is not going to be a clincher for an EF5 rating anymore. In fact, it might not be factored in at all. Also, yes, the recent Kentucky tornado did produce the same kind of scouring.

[brianc33710]

1 hour ago, CheeselandSkies said:

While the Mayfield etc tornado may not have (at least officially, to the best of our limited knowledge of the exact nature of the 1925 event) dethroned the Tri-State Tornado for longest track ever; it did dethrone the April 24, 2010 Louisiana-Mississippi tornado (149.25 miles, another tornado that was almost certainly substantially more intense than its official 170 MPH low-end EF4, but in that case there's not much controversy regarding the rating of the actual damage observed, it just didn't hit much outside of clipping Yazoo City) as the longest-tracked tornado in the NEXRAD era.

Yeah Hackelburg-Phil Campbell EF5 was almost 130 mi & maxed 1.25 mi wide. 

[DanLarsen34]

 

[Chreeyiss]

23 minutes ago, DanLarsen34 said:

 

I’ve seen wxtwitter abuzz with comments along the lines of “who cares what EF rating the tornado gets when there are lives lost and damage done?”

 

I understand that thought, as there are a lot of people who seem to care only about the damage rating, but the two sentiments aren’t mutually exclusive, as many others have pointed out. What you posted above is why we should still care about the integrity of the EF rating. 
 

Quick googling shows that there have been 631 F/EF 4+’s documented from 1950 to 2017. With an average of 1200 tornadoes per year, and an ef4+ rate of 20% according to the study, that means if we could derive tornado intensity from measures other than just damage, it would only take about 3 years to document the same number of ef4+ tornadoes that we have accumulated over the span of 67 years. 
 

Findings like this demonstrate the impacts of the limitations of the EF scale, and the truncation of a given tornado sample size to less than 5% of what it should be must have some pretty significant impacts on the ability to derive trends and make predictions. 

[Normandy]

if you want photographic evidence of EF5 damage, look no further than the candle factory.  We have an entire steel frame that has been bent and deformed to the point that the steel Columns holding the steel beams collapsed.  steel deformation / bending occurs after 35,000 PSI (or 247 PSF). It takes 306 mph winds to produce 247 PSF.  And yet we are looking at slabbed homes and determining the structures aren’t well built?  As I said before, these folks have no clue what they are looking at and it really is unfortunate.

[nwohweather]

1 hour ago, Normandy said:

if you want photographic evidence of EF5 damage, look no further than the candle factory.  We have an entire steel frame that has been bent and deformed to the point that the steel Columns holding the steel beams collapsed.  steel deformation / bending occurs after 35,000 PSI (or 247 PSF). It takes 306 mph winds to produce 247 PSF.  And yet we are looking at slabbed homes and determining the structures aren’t well built?  As I said before, these folks have no clue what they are looking at and it really is unfortunate.

Exactly! Heck there were reports of asphalt being cracked and foundations suffering catastrophic damage. If you're going to use "improper building" as a reason to withhold an EF5 rating then basically the only chance of an EF5 rating is on the coastline in a hurricane zone. 

Regardless, I've seen an EF4 up close and it's damage. I'm not sure how you can get much worse than that anyways, it's beyond anything you reasonably even expect.

[Buckeye05]

1 hour ago, Normandy said:

if you want photographic evidence of EF5 damage, look no further than the candle factory.  We have an entire steel frame that has been bent and deformed to the point that the steel Columns holding the steel beams collapsed.  steel deformation / bending occurs after 35,000 PSI (or 247 PSF). It takes 306 mph winds to produce 247 PSF.  And yet we are looking at slabbed homes and determining the structures aren’t well built?  As I said before, these folks have no clue what they are looking at and it really is unfortunate.

To be fair, metal warehouse buildings tend to "catch" wind due their lack of interior walls, sharp angles, and wide, flat surface areas, which act as a sail once wind enters the building. Once that happens, the metal exterior sheeting comes off, and the entire metal frame of the building warps, twists, and sometimes causes the overhead metal framing to collapse like dominos. There's a big difference between a metal-framed warehouse building and a metal-framed institutional building, and while the scale is indeed flawed, these two structure types are listed as separate DIs for good reason. Next time there's an EF2 or EF3 in a populated area, compare the damage to metal warehouses along the path to other structures with different construction methods. You'll see that the metal buildings always end up being mangled quite badly, while others nearby may only sustain roof loss. I've seen EF2s move through neighborhood and cause moderate to heavy damage to frame homes, but not totally destroy them, then essentially demolish a metal warehouse in the immediate vicinity. This is no fluke. Truly violent metal warehouse damage only really occurs when the metal support beams themselves are sheared off at their anchor plates, and the entire framing system is pushed or twisted off the foundation. I don't see anything like that in the above photo. To find damage like that, you have to look at events like Parkersburg, Guin, Van Wert, and most infamously Niles/Wheatland.

[Chicago Storm]

I see no use in getting bent out of shape regarding things, given the whole system is flawed…

-EF scale
-Damage indicators
-What can/can’t be used for ratings
-NWS office issues*

*By this I mean there are several issues within the NWS that factor in, such as…
~Staffing issues at times leading to not all potential tornadoes being survey, or at least not all potential tornadoes being surveyed in a proper manner.
~Particular mets within certain offices that do not care whether or not all potential tornadoes are surveyed, or at least do not care about the substantial amount of QLCS spin-ups that occur. ~Offices that are too worried about verification scores, instead of getting the surveyed information correct.


.

[Normandy]

1 hour ago, Buckeye05 said:

To be fair, metal warehouse buildings tend to "catch" wind due their lack of interior walls, sharp angles, and wide, flat surface areas, which act as a sail once wind enters the building. Once that happens, the metal exterior sheeting comes off, and the entire metal frame of the building warps, twists, and sometimes causes the overhead metal framing to collapse like dominos. There's a big difference between a metal-framed warehouse building and a metal-framed institutional building, and while the scale is indeed flawed, these two structure types are listed as separate DIs for good reason. Next time there's an EF2 or EF3 in a populated area, compare the damage to metal warehouses along the path to other structures with different construction methods. You'll see that the metal buildings always end up being mangled quite badly, while others nearby may only sustain roof loss. I've seen EF2s move through neighborhood and cause moderate to heavy damage to frame homes, but not totally destroy them, then essentially demolish a metal warehouse in the immediate vicinity. This is no fluke. Truly violent metal warehouse damage only really occurs when the metal support beams themselves are sheared off at their anchor plates, and the entire framing system is pushed or twisted off the foundation. I don't see anything like that in the above photo. To find damage like that, you have to look at events like Parkersburg, Guin, Van Wert, and most infamously Niles/Wheatland.

I disagree.  Warehouses like this actually do the opposite as what you are stating.  The lack of interior bearing walls, methods of roofing attachment, and methods of exterior wall attachment of warehouse buildings means that a violent tornado is likely to remove the building skin and roof within second.  It would be akin to peeling off a sheet of paper, leaving the structural frame completely exposed.  Once the structural system is completely exposed, there is no "wind catching" whatsoever.  The deformation you are seeing is the winds deforming the structural system with whatever PSF is required to deform the steel.  In general this is 35,000 PSI of force, which is produced by 306 MPH winds.  

Lets clarify removal of anchor plates as well.  Anchor plates are the means by which steel columns transfer load to the foundation structure.  Steel beams are connected to said columns using moment connections or fixed bolted connections.  In this case because seismic is not a concern, fixed bolted connections are likely being used.  If a steel frame, which acts as one rigid body, is being deformed to the point of collapse.....you can bet an EF-5 is the culprit.  Winds below 200 mph are simply not enough to mangle a low-story, wide base steel structure that has beams up to 2'-0" deep.  Focus on the structural system, not the overall building damage. 

 

Wind catching is more of what you are seeing here:  Where a structure is so tall that the wind exerts large amount of force on the upper half of a structure that the mid point deforms.  In this case, it absolutely does NOT take 35,000 PSI to deform the steel because there is additional force being generated by the top heavy structure moving laterally.

https://www.columbian.com/news/2017/feb/20/storms-damage-san-antonio-area/

 

EDIT:

Here is a great video that illustrates how insane it is that a steel structure can be deformed to the point of collapse by winds.  This is our famous gas station video of hurricane charley.  it is widely assumed that winds in this video reached somewhere between 140 - 150 mph sustained.  That is well below the EF-5 threshold obviously, and notice what happens to the steel frame:  Nothing.  The same kind of process happens when a tornado hits a warehouse building.  The skin is shredded leaving the structure exposed.  Whether that structure gets deformed further depends on the wind / PSF generated.  Here it was below the threshold to bend steel.  In Mayfield it clearly was not.

 

[SluggerWx]

IMO, we could look at damage to trees and cars since those can be objectively compared across events. You would need to know if a car was parked indoors or outdoors (I think Joplin had a lot of cars parked outside the homes).

Wouldn't this make more sense because a Honda Accord is the same in OK as it is in rural KY?

I wonder if we could come up with a database of high end EF-4 tornadoes and compare vehicle damage?

The same can be said for trees. The 2011 EF-5s in the Southeast have tons of tree damage in pictures. Those damage indicators should be used vs other tornadoes in the Southeast.

Obviously you would need your tree damage indicators to be regionally focused for the common trees in the area.

These indicators could serve us better than quality of home construction.

Sent from my Pixel 3 XL using Tapatalk

[Buckeye05]

3 hours ago, Normandy said:

I disagree.  Warehouses like this actually do the opposite as what you are stating.  The lack of interior bearing walls, methods of roofing attachment, and methods of exterior wall attachment of warehouse buildings means that a violent tornado is likely to remove the building skin and roof within second.  It would be akin to peeling off a sheet of paper, leaving the structural frame completely exposed.  Once the structural system is completely exposed, there is no "wind catching" whatsoever.  The deformation you are seeing is the winds deforming the structural system with whatever PSF is required to deform the steel.  In general this is 35,000 PSI of force, which is produced by 306 MPH winds.  

Lets clarify removal of anchor plates as well.  Anchor plates are the means by which steel columns transfer load to the foundation structure.  Steel beams are connected to said columns using moment connections or fixed bolted connections.  In this case because seismic is not a concern, fixed bolted connections are likely being used.  If a steel frame, which acts as one rigid body, is being deformed to the point of collapse.....you can bet an EF-5 is the culprit.  Winds below 200 mph are simply not enough to mangle a low-story, wide base steel structure that has beams up to 2'-0" deep.  Focus on the structural system, not the overall building damage. 

 

Wind catching is more of what you are seeing here:  Where a structure is so tall that the wind exerts large amount of force on the upper half of a structure that the mid point deforms.  In this case, it absolutely does NOT take 35,000 PSI to deform the steel because there is additional force being generated by the top heavy structure moving laterally.

https://www.columbian.com/news/2017/feb/20/storms-damage-san-antonio-area/

 

EDIT:

Here is a great video that illustrates how insane it is that a steel structure can be deformed to the point of collapse by winds.  This is our famous gas station video of hurricane charley.  it is widely assumed that winds in this video reached somewhere between 140 - 150 mph sustained.  That is well below the EF-5 threshold obviously, and notice what happens to the steel frame:  Nothing.  The same kind of process happens when a tornado hits a warehouse building.  The skin is shredded leaving the structure exposed.  Whether that structure gets deformed further depends on the wind / PSF generated.  Here it was below the threshold to bend steel.  In Mayfield it clearly was not.

 

I mean logic wise it all adds up, but after almost two decades of tracking tornado events, I can say with a high degree of confidence that a mangled industrial building does not = EF5 damage. I’ve seen far too many moderately strong tornadoes twist them up bad, while causing moderate structural damage elsewhere. I don’t think there’s an epidemic of tornadoes reaching EF5 strength directly over industrial buildings, only to be weaker everywhere else along the path. If what you are saying is true, there’d be violent damage surrounding every metal warehouse that’s been destroyed in a tornado, and there simply isn’t. There’s a difference between what you’re describing, versus what actually happens. 

[Buckeye05]

A perfect example is the Marshalltown, IA EF3 of 2018. Most of the path through the town was EF2, with some isolated EF3. Definitely not a violent tornado. Yet, when it hit the Lennox plant in town, it flattened large portions of the structure and metal frame to the ground, and twisted numerous beams and girders. I guarantee the tornado didn’t suddenly reach EF5 strength over that plant while causing lesser damage elsewhere. There are so so so many examples of moderately intense tornadoes demolishing industrial buildings and I don’t have time to list all the examples. You just have to pay attention, and I guarantee you’ll notice the same pattern I mentioned. It’s not really debatable once you start cataloging tornado events in your brain over the years.

[Malacka11]

Aren't airborne debris a major part of this type of metal deformation? Or does that not even matter unless you're talking a tornado strong enough to do it manually?

 

[SchaumburgStormer]

Anytime you have a damage based system, it’s going to be subjective and woefully inaccurate.
 

When you can take any of histories most violent tornados and have them twist corn fields only and hit No structures, and have EF0’s, you are not actually capturing any useful information by classifying them at all. 

[DanLarsen34]

This is a really good thread.  I didn’t know about this quote from the Vilonia survey until now. 

[Amped]

Anyone have a meteorological explanation of why winds from the record 133kt Vrot and the 30kft+ TDS wouldn't have mixed down to the ground?   

[madwx]

1 hour ago, Amped said:

Anyone have a meteorological explanation of why winds from the record 133kt Vrot and the 30kft+ TDS wouldn't have mixed down to the ground?   

Surface friction.  

[brianc33710]

10 hours ago, Normandy said:

I disagree.  Warehouses like this actually do the opposite as what you are stating.  The lack of interior bearing walls, methods of roofing attachment, and methods of exterior wall attachment of warehouse buildings means that a violent tornado is likely to remove the building skin and roof within second.  It would be akin to peeling off a sheet of paper, leaving the structural frame completely exposed.  Once the structural system is completely exposed, there is no "wind catching" whatsoever.  The deformation you are seeing is the winds deforming the structural system with whatever PSF is required to deform the steel.  In general this is 35,000 PSI of force, which is produced by 306 MPH winds.  

Lets clarify removal of anchor plates as well.  Anchor plates are the means by which steel columns transfer load to the foundation structure.  Steel beams are connected to said columns using moment connections or fixed bolted connections.  In this case because seismic is not a concern, fixed bolted connections are likely being used.  If a steel frame, which acts as one rigid body, is being deformed to the point of collapse.....you can bet an EF-5 is the culprit.  Winds below 200 mph are simply not enough to mangle a low-story, wide base steel structure that has beams up to 2'-0" deep.  Focus on the structural system, not the overall building damage. 

 

Wind catching is more of what you are seeing here:  Where a structure is so tall that the wind exerts large amount of force on the upper half of a structure that the mid point deforms.  In this case, it absolutely does NOT take 35,000 PSI to deform the steel because there is additional force being generated by the top heavy structure moving laterally.

https://www.columbian.com/news/2017/feb/20/storms-damage-san-antonio-area/

 

EDIT:

Here is a great video that illustrates how insane it is that a steel structure can be deformed to the point of collapse by winds.  This is our famous gas station video of hurricane charley.  it is widely assumed that winds in this video reached somewhere between 140 - 150 mph sustained.  That is well below the EF-5 threshold obviously, and notice what happens to the steel frame:  Nothing.  The same kind of process happens when a tornado hits a warehouse building.  The skin is shredded leaving the structure exposed.  Whether that structure gets deformed further depends on the wind / PSF generated.  Here it was below the threshold to bend steel.  In Mayfield it clearly was not.

 

Hahaha! I remember driving down to see a close friend the week before Charley hit! And how everyone fled Tampa Bay which got almost nothing for Orlando that had 105 mph wind gusts. He intensified fast as it took its unexpected last minute right turn. 

[brianc33710]

Heres a video from the main office of FNB Bank in Mayfield 10 Dec 21. Im amazed the recordings survived.