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buckeye05

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Just thought I’d bring up something i’ve noticed in a lot of Dixie surveys. Anyone notice that some WFOs, especially Jackson and Birmingham sometimes assign EF3 ratings to homes that sustained complete roof loss, but no exterior wall collapse? I most recently noticed this with the Fultondale EF3. I also distinctly remember it with the 2014 Columbia, MS EF3 as well as others. I do notice this type of thing only seems to occur when there is clear-cut, classic EF3 damage elsewhere along the path. Anyone know what’s behind this?

I’m guessing it has something to do with unusually strong roof clips.
 

MNTornadoGuy

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Just thought I’d bring up something i’ve noticed in a lot of Dixie surveys. Anyone notice that some WFOs, especially Jackson and Birmingham sometimes assign EF3 ratings to homes that sustained complete roof loss, but no exterior wall collapse? I most recently noticed this with the Fultondale EF3. I also distinctly remember it with the 2014 Columbia, MS EF3 as well as others. I do notice this type of thing only seems to occur when there is clear-cut, classic EF3 damage elsewhere along the path. Anyone know what’s behind this?

I’m guessing it has something to do with unusually strong roof clips.
Probably due to hurricane clips and other strong roof clipping.
 

pohnpei

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Just thought I’d bring up something i’ve noticed in a lot of Dixie surveys. Anyone notice that some WFOs, especially Jackson and Birmingham sometimes assign EF3 ratings to homes that sustained complete roof loss, but no exterior wall collapse? I most recently noticed this with the Fultondale EF3. I also distinctly remember it with the 2014 Columbia, MS EF3 as well as others. I do notice this type of thing only seems to occur when there is clear-cut, classic EF3 damage elsewhere along the path. Anyone know what’s behind this?

I’m guessing it has something to do with unusually strong roof clips.
The first tornado came into my mind in recent years was Talala OK EF2 tornado on April 30 2019. NWS Tulsa once mentioned on Twitter that these houses had unusually strong roof attachment. These two pictures below was all rated low end EF2.
jjtLx75y_1556741884168.jpgjjtLx75y_1556741913194.jpg

There were several other cases of rating of particularly well built houses that I can recall:
2011 May 24 Goldsby
This house had anchor bolt every 2 ft(insane!) and largely swept away warranted 195mph rating.
1309207411-IMG_5170.JPG

2011 May 24 Elon AR
This 2 story house are steel-framed structure, 1/4" thick steel i-beams welded to steel plate attached to the foundation with 4 j-bolts each and was rated 166mph.
845405847-1306364835753 (1).jpg

2014 April 28 Louisville
This house along Brooksville Road was particularly well built and was rated 175mph
44 EF4.jpg
There must be much more cases besides these.
 

MNTornadoGuy

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I've done some digging and it appears that Arizona has experienced a lot of significant tornadoes for a western state. I'll list some examples going back to the 1920s. There might have been strong tornadoes before then that I'm not aware of.
9/14/2011 Humpherys Peak EF2
This short-tracked high-elevation tornado produced significant forest damage at elevations of over 10,000 ft.
1612810611056.png

10/14/2006 Camp Navajo F2

Despite being listed as an F1 in Storm Data, the local NWS gave this tornado a low-end F2 rating as it snapped off large pine trees near ground level.
1612811231928.png

10/18/2005 Dinnebito Wash F0
Despite only being given an F0 rating, this tornado was probably stronger at some point as it tracked 30 miles over barren desert. Several outbuildings were destroyed or carried over 100 yards, a filled 55-gallon drum was found empty hundreds of meters away from its original location and there was considerable damage to trees.

10/24/1992 Sunset Crater F2
Around 700 ponderosa pine trees were snapped or uprooted by this 200-yard wide tornado. 260 acres of timber was destroyed.

7/22/1984 Santan Mountain F1
This "large and intense" tornado formed in the Giles Indian Reservation. Due to it occurring in a rural area, no structures were damaged besides some power-lines. 25 wooden power poles were ripped off 4-ft above the ground. The tornado was estimated to be 1500 yards wide.

6/23/1974 Tucson F2
This deadly tornado killed one person as it tore through a mobile home park. Multiple mobile homes disintegrated.
tuscon.jpg

8/30/1971 Tempe F2
This strong tornado injured 41 people as it tore apart mobile homes, unroofed frame homes, and downed power-lines in the town of Tempe.
TornadoTalk Article

8/27/1964 San Xavier F2
This killer rope tornado resulted in one fatality as it hit the San Xavier Mission area. Homes were destroyed and an adobe covenant was severely damaged.
TornadoTalk Article
sanxavier.jpg

4/8/1926 Phoneix F2
This brief cone-shaped tornado destroyed six small homes at the eastern edge of Phoneix.
 

buckeye05

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The first tornado came into my mind in recent years was Talala OK EF2 tornado on April 30 2019. NWS Tulsa once mentioned on Twitter that these houses had unusually strong roof attachment. These two pictures below was all rated low end EF2.
View attachment 5913View attachment 5914

There were several other cases of rating of particularly well built houses that I can recall:
2011 May 24 Goldsby
This house had anchor bolt every 2 ft(insane!) and largely swept away warranted 195mph rating.
View attachment 5911

2011 May 24 Elon AR
This 2 story house are steel-framed structure, 1/4" thick steel i-beams welded to steel plate attached to the foundation with 4 j-bolts each and was rated 166mph.
View attachment 5912

2014 April 28 Louisville
This house along Brooksville Road was particularly well built and was rated 175mph
View attachment 5910
There must be much more cases besides these.
Fascinating! These are all great examples of how buildings of unusually high-quality construction are typically given a higher than expected rating on the scale.

Another one that comes to mind is actually local to me, the Memorial Day 2019 Dayton EF4. The only EF4 structure damage along its path was at the Rivers Edge Apartments, but none were leveled. Our local WFO determined that the apartment buildings were exceptionally well-built, and decided on an EF4 rating there. I checked that area out in person, and not a single structure was leveled, and it did leave me feeling a bit skeptical. I did see legit EF4 tree damage in the woods behind the complex though.

I have to comment on Goldsby, OK though. The only reason that house wasn’t rated EF5 is because a heavy mobile home frame slammed into the house during the tornado. Anchor bolts every two feet is insanely strong anchoring, maybe the best I’ve heard of. I understand collateral damage from large debris strikes is reason for downgrade, but still...bolts every two feet!? I feel like an argument for EF5 can still be made, even with the debris strike.
 
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I've done some digging and it appears that Arizona has experienced a lot of significant tornadoes for a western state. I'll list some examples going back to the 1920s. There might have been strong tornadoes before then that I'm not aware of.
9/14/2011 Humpherys Peak EF2
This short-tracked high-elevation tornado produced significant forest damage at elevations of over 10,000 ft.
View attachment 5915

10/14/2006 Camp Navajo F2

Despite being listed as an F1 in Storm Data, the local NWS gave this tornado a low-end F2 rating as it snapped off large pine trees near ground level.
View attachment 5916

10/18/2005 Dinnebito Wash F0
Despite only being given an F0 rating, this tornado was probably stronger at some point as it tracked 30 miles over barren desert. Several outbuildings were destroyed or carried over 100 yards, a filled 55-gallon drum was found empty hundreds of meters away from its original location and there was considerable damage to trees.

10/24/1992 Sunset Crater F2
Around 700 ponderosa pine trees were snapped or uprooted by this 200-yard wide tornado. 260 acres of timber was destroyed.

7/22/1984 Santan Mountain F1
This "large and intense" tornado formed in the Giles Indian Reservation. Due to it occurring in a rural area, no structures were damaged besides some power-lines. 25 wooden power poles were ripped off 4-ft above the ground. The tornado was estimated to be 1500 yards wide.

6/23/1974 Tucson F2
This deadly tornado killed one person as it tore through a mobile home park. Multiple mobile homes disintegrated.
View attachment 5917

8/30/1971 Tempe F2
This strong tornado injured 41 people as it tore apart mobile homes, unroofed frame homes, and downed power-lines in the town of Tempe.
TornadoTalk Article

8/27/1964 San Xavier F2
This killer rope tornado resulted in one fatality as it hit the San Xavier Mission area. Homes were destroyed and an adobe covenant was severely damaged.
TornadoTalk Article
View attachment 5918

4/8/1926 Phoneix F2
This brief cone-shaped tornado destroyed six small homes at the eastern edge of Phoneix.

I think San Xavier actually killed 2 people and is Arizona's deadliest tornado. I think Arizona gets more tornadoes than we realize, but due to how much of the state is remote wilderness they often go unreported. Out of curiosity, do you know much about significant tornadoes in New Mexico?
 

MNTornadoGuy

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I think San Xavier actually killed 2 people and is Arizona's deadliest tornado. I think Arizona gets more tornadoes than we realize, but due to how much of the state is remote wilderness they often go unreported. Out of curiosity, do you know much about significant tornadoes in New Mexico?
Significant tornadoes have occurred on the high plains in eastern New Mexico. Only one has happened in the west part of the state to my knowledge.
 
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Significant tornadoes have occurred on the high plains in eastern New Mexico. Only one has happened in the west part of the state to my knowledge.
I wonder if more have happened in remote desert/wilderness areas but they went unreported due to the lack of population. I know southwest Texas has gotten quite a bit of violent tornadoes that are mostly unknown due to the remote locations they've occurred in.
 
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I wonder if more have happened in remote desert/wilderness areas but they went unreported due to the lack of population. I know southwest Texas has gotten quite a bit of violent tornadoes that are mostly unknown due to the remote locations they've occurred in.
Concerning Southwest Texas....
The Bakersfield Valley tornado of 1990 was an F4, but should have been rated F5, full stop. This thing picked up 3 oil tanks & threw 3 MILES, 2 of them 600 feet up a hill with a very steep incline.

1.png2.png3.png
 

buckeye05

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Concerning Southwest Texas....
The Bakersfield Valley tornado of 1990 was an F4, but should have been rated F5, full stop. This thing picked up 3 oil tanks & threw 3 MILES, 2 of them 600 feet up a hill with a very steep incline.

View attachment 5920View attachment 5921View attachment 5922
Bakersfield Valley was one of the most violent tornado events ever documented, period.

It’s one of the few events I’ve known to have not only scoured asphalt, but concrete (lower left pic) too. Concrete is waaay more dense and scour-resistant than asphalt. In fact, the only other extensive concrete scouring incident I can recall occurred in Hackleburg, AL in 2011.

The Wilkin, MN EF4 of 2010 also produced some scouring of a concrete barn foundation, but not to the degree photographed in Bakersfield Valley or Hackleburg.
 
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Bakersfield Valley was one of the most violent tornado events ever documented, period.

It’s one of the few events I’ve known to have not only scoured asphalt, but concrete (lower left pic) too. Concrete is waaay more dense and scour-resistant than asphalt. In fact, the only other extensive concrete scouring incident I can recall occurred in Hackleburg, AL in 2011.

The Wilkin, MN EF4 of 2010 also produced some scouring of a concrete barn foundation, but not to the degree photographed in Bakersfield Valley or Hackleburg.
Did Jarrell not produce some concrete scouring in drainage ditches?
 
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Bakersfield Valley was one of the most violent tornado events ever documented, period.

It’s one of the few events I’ve known to have not only scoured asphalt, but concrete (lower left pic) too. Concrete is waaay more dense and scour-resistant than asphalt. In fact, the only other extensive concrete scouring incident I can recall occurred in Hackleburg, AL in 2011.

The Wilkin, MN EF4 of 2010 also produced some scouring of a concrete barn foundation, but not to the degree photographed in Bakersfield Valley or Hackleburg.
What's impressive about the 300 feet of asphalt removed from the road was that there was no evidence found of flooding or debris missile impacts; that said, due to being in a remote rural area it probably wasn't the most well-maintained road. Also, this tornado completely demolished a two-story house constructed of solid adobe brick, which is very impressive. Not sure why it was rated F4 instead of F5, forgot the reason for that.
 

buckeye05

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What's impressive about the 300 feet of asphalt removed from the road was that there was no evidence found of flooding or debris missile impacts; that said, due to being in a remote rural area it probably wasn't the most well-maintained road. Also, this tornado completely demolished a two-story house constructed of solid adobe brick, which is very impressive. Not sure why it was rated F4 instead of F5, forgot the reason for that.
Don’t quote me on this, but as far as I know, while the Bakersfield Valley tornado did level a home or two, they were not swept clean irrc. I believe that most intense winds ended up only impacting vegetation, roads, irrigation ditches, and heavy objects. My guess that these factors lead to the F4 rating (not that I agree with it).

Edit:It was that adobe construction home you mentioned that I was thinking of.

Did Jarrell not produce some concrete scouring in drainage ditches?
That only happened in Bakersfield Valley as far as I know, as pictured in the above. Where did you hear about that in Jarrell? It’s got me curious now.

I forgot to mention, that Jarrell actually did scour away half of a small concrete shed foundation. I’ve seen a photo of it, but I can’t seem find it currently.
 
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The shed photo from Jarrell is this:

shed.jpeg



I found it here: https://stormtrack.org/community/threads/most-violent-tornado-in-history.27178/

Jarrell photos start near the bottom of page 1 and continue halfway through page 2. Also I'm not sure about Jarrell and concrete drainage ditches, I thought it did something like that around the time it did this:

road.jpg


But I probably just misread an article featuring this photograph.
 
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