Significant Tornado Events

[Juliett Bravo Kilo]

Going through Grazulis' new book again and naturally had to read his entry on Jarrell. Here it is:






Pretty sure 250 mph on the old scale is high-end F4 and EF5 on the new scale, so not sure how he thinks those are F3. He also makes emphasis on how many homes were unanchored or poorly anchored and how destruction of them may have helped to sweep away properly-anchored homes (on the other page of this entry) so...yeah.

Interesting he speculates that it may have started out as a landspout; not sure I've heard of any other case of a landspout transforming into a violent multivortex tornado.

 

[Juliett Bravo Kilo]

The entry on Pampa, TX 1995 is also interesting. To quote "The F4 rating is subjectively based on the movement of industrial equipment weighing up to 30 tons. Only strong F2 to minimal F3 damage was done to homes, as the tornado had weakened by the time it arrived in the residential area. Some rough photogrammetry of the rotational speed of the funnel by the Tornado Project indicated that about 100 feet above ground level, the rotation was in the 200-250 mph range, not counting a very high vertical wind component, probably well in excess of 100 mph".

This is weird, as I thought that Grazulis had calculated wind speeds up to 300 mph with Pampa right above ground level. Also, an interesting discussion I had with a YouTuber awhile back revealed that the tornado was initially slapped with an F3 rating but later upgraded to F4 but that the damage results of it were "accidentally" discarded a year or so after the event. Similar stuff happened with the Hoover, Allison and Kellerville, TX tornadoes of 6/8/1995 too. Sounds like another Vilonia deal happened here.

 

[buckeye05]

Going through Grazulis' new book again and naturally had to read his entry on Jarrell. Here it is:

View attachment 27029


View attachment 27030

Pretty sure 250 mph on the old scale is high-end F4 and EF5 on the new scale, so not sure how he thinks those are F3. He also makes emphasis on how many homes were unanchored or poorly anchored and how destruction of them may have helped to sweep away properly-anchored homes (on the other page of this entry) so...yeah.

Interesting he speculates that it may have started out as a landspout; not sure I've heard of any other case of a landspout transforming into a violent multivortex tornado.

The assertion that Jarrell only swept away poorly anchored homes is completely false. A mix of poorly-anchored AND well anchor-bolted slab homes were essentially vanished at Double Creek. I guess Grazulis only read that engineering report that solely focuses on the poorly-anchored ones and assumed that was the case for each home in the subdivision. What a gross misinterpretation and misreporting of information. Makes me trust his research a little less tbh.

Edit: Didn’t see the bit about the debris loading argument. Still, that’s an absolute nothing-burger of a statement. Go find me a a non-debris-loaded EF5 that has hit a residential area. Doesn’t exist because it isn’t possible.

“But it was full of debris”. Yeah, no s**t, any violent tornado is. Unless there is a traceable object that clearly caused collateral damage, this will always be a meaningless statement that can be used to be dismissive of any tornado that hits multiple structures. Always roll my eyes when I hear it.

 

[Juliett Bravo Kilo]

The assertion that Jarrell only swept away poorly anchored homes is completely false. A mix of poorly-anchored AND well anchor-bolted slab homes were essentially vanished at Double Creek. I guess Grazulis only read that engineering report that solely focuses on the poorly-anchored ones and assumed that was the case for each home in the subdivision. What a gross misinterpretation and misreporting of information. Makes me trust his research a little less tbh.

Edit: Didn’t see the bit about the debris loading argument. Still, that’s an absolute nothing-burger of a statement. Go find me a a non-debris-loaded EF5 that has hit a residential area. Doesn’t exist because it isn’t possible.

“But it was full of debris”. Yeah, no s**t, any violent tornado is. Unless there is a traceable object that clearly caused collateral damage, this will always be a meaningless statement that can be used to be dismissive of any tornado that hits multiple structures. Always roll my eyes when I hear it.

Yeah, I'm not sure what's happened with him. Some of his stuff in the new book is really good (he does challenge some tornado ratings) but other stuff is blatantly wrong. Some of his entries I wonder if either somebody else wrote them or he was under pressure to say something that he personally doesn't agree with. Still, glad to have the book.

 

[locomusic01]

I think the key bit in his summary is that the tornado "may have caused F5 damage in any subdivision." To me it doesn't read as downplaying it so much as acknowledging what we already know, which is that applying a strict engineering perspective results in clearly high-end tornadoes being underrated. If the poorly built houses in Jarrell were surveyed today they probably would "deserve" an EF3-EF4 rating by current standards.

That said, there absolutely were pretty well-constructed homes too (I've posted photos many times), and I have no doubt it's one of the few tornadoes that'd be rated EF5 even today. Tim Marshall himself has said multiple times Jarrell was the most violent tornado he's surveyed. Personally I'm also somewhat skeptical of the idea that its slow movement/long residence time was a major factor, but I may be in the minority there.

Anyway, I get the point I think he's making, but I'm not sure it's terribly relevant and it would've been nice to see it approached more critically.

 

[jiharris0220]

I think the key bit in his summary is that the tornado "may have caused F5 damage in any subdivision." To me it doesn't read as downplaying it so much as acknowledging what we already know, which is that applying a strict engineering perspective results in clearly high-end tornadoes being underrated. If the poorly built houses in Jarrell were surveyed today they probably would "deserve" an EF3-EF4 rating by current standards.

That said, there absolutely were pretty well-constructed homes too (I've posted photos many times), and I have no doubt it's one of the few tornadoes that'd be rated EF5 even today. Tim Marshall himself has said multiple times Jarrell was the most violent tornado he's surveyed. Personally I'm also somewhat skeptical of the idea that its slow movement/long residence time was a major factor, but I may be in the minority there.

Anyway, I get the point I think he's making, but I'm not sure it's terribly relevant and it would've been nice to see it approached more critically.

These two homes in Jarrell would most definitely get ef5 even today.

The one on the left was made of reinforced masonry and well anchored.
The one on the right was made up of four-inch thick concrete w/six inch reinforcing mesh and tin lining.

 

[Juliett Bravo Kilo]

These two homes in Jarrell would most definitely get ef5 even today.

The one on the left was made of reinforced masonry and well anchored.
The one on the right was made up of four-inch thick concrete w/six inch reinforcing mesh and tin lining.
View attachment 27041View attachment 27042

Unless of course surveyors were instructed to "accidentally" miss these homes in their survey.

 

[Rover44sc]

Unless of course surveyors were instructed to "accidentally" miss these homes in their survey.

What’s the rationale again for purposely lowballing a tornado rating. Does it have to do with insurance or not wanting a town to be associated with an F5 tornado?

 

[locomusic01]

These two homes in Jarrell would most definitely get ef5 even today.

The one on the left was made of reinforced masonry and well anchored.
The one on the right was made up of four-inch thick concrete w/six inch reinforcing mesh and tin lining.
View attachment 27041View attachment 27042

The latter home was actually a pier and beam foundation (although it was at least secured with straps, which is better than a lot of similar cases). Not quite what it appears at first glance:

In the log that came with the survey photos I think there are probably like a half-dozen homes mentioned altogether that seem to be at least well-anchored, including bolts + washers every 4ft. on center in some cases. Sadly a bunch of the photos are missing and there's not much detail on the rest of the construction, but I think you'd have to work really hard not to come away with at least a few EF5 damage points even if you ignored the insane contextual damage.

 

[Juliett Bravo Kilo]

The latter home was actually a pier and beam foundation (although it was at least secured with straps, which is better than a lot of similar cases). Not quite what it appears at first glance:

In the log that came with the survey photos I think there are probably like a half-dozen homes mentioned altogether that seem to be at least well-anchored, including bolts + washers every 4ft. on center in some cases. Sadly a bunch of the photos are missing and there's not much detail on the rest of the construction, but I think you'd have to work really hard not to come away with at least a few EF5 damage points even if you ignored the insane contextual damage.

In this day and age I'm sure some survey teams would just ignore feats of damage like this and write high-end EF4 with 200 mph wind speed maximum. Funny but not funny because it's true.

 

[locomusic01]

What’s the rationale again for purposely lowballing a tornado rating. Does it have to do with insurance or not wanting a town to be associated with an F5 tornado?

Personally I don't think it's a deliberate thing, I just think surveys have gotten so hyper-focused on engineering analysis that it doesn't leave much room for common sense or reasonable interpretation. It's a little like using a radar gun that only goes up to 100 mph and trying to measure a Bugatti Chiron going flat-out. You know damn well it's going a whole lot faster than that, but because you can't measure it accurately, you just sort of shrug your shoulders and record it at 100 mph anyway.

 

[Juliett Bravo Kilo]

Personally I don't think it's a deliberate thing, I just think surveys have gotten so hyper-focused on engineering analysis that it doesn't leave much room for common sense or reasonable interpretation. It's a little like using a radar gun that only goes up to 100 mph and trying to measure a Bugatti Chiron going flat-out. You know damn well it's going a whole lot faster than that, but because you can't measure it accurately, you just sort of shrug your shoulders and record it at 100 mph anyway.

I thought Vilonia's rating of EF4 was because of pressure from John Robinson on the survey team, specifically. Not sure what his deal was, but there you go.

 

[SpotlightForRareTornadoes]

1970 was nearly 55 years ago.....

 

[Juliett Bravo Kilo]

I think the key bit in his summary is that the tornado "may have caused F5 damage in any subdivision." To me it doesn't read as downplaying it so much as acknowledging what we already know, which is that applying a strict engineering perspective results in clearly high-end tornadoes being underrated. If the poorly built houses in Jarrell were surveyed today they probably would "deserve" an EF3-EF4 rating by current standards.

That said, there absolutely were pretty well-constructed homes too (I've posted photos many times), and I have no doubt it's one of the few tornadoes that'd be rated EF5 even today. Tim Marshall himself has said multiple times Jarrell was the most violent tornado he's surveyed. Personally I'm also somewhat skeptical of the idea that its slow movement/long residence time was a major factor, but I may be in the minority there.

Anyway, I get the point I think he's making, but I'm not sure it's terribly relevant and it would've been nice to see it approached more critically.

Grazulis thankfully doesn't seem to think the slow forward speed was a factor, so at least he has that part right.
I do wonder what it is that made Jarrell as powerful as it was. That and Loyal Valley, TX. Those southwest-moving super cells seem to produce really powerful tornadoes.

 

[pohnpei]

I think we've seen a Jarrell-esque very slow moving tornado this year on April 30 near Hillister OK with a 125kt vrot couplet. With that slow speed and powerful radar presentation, the damage wasn't near violent level, let alone compaing to Jarrell.

Another tornado this year near Hawley TX on May 2 was also very slow moving with 7 mph average speed and clearly violent motion on videos. It caused violent damage but nothing Jarrell level things.

Yet another tornado this year near Robert Lee TX this year was also very slow moving and it had a 95kt vrot couplet on radar. It caused intense tree damage but nothing in par with Jarrell's damage.

I believe all three slow mover mentioned hear could be very intense to violent level tornado but it just proved again and again that the damage of Jarrell can not be made by any ordinary violent tornado with very slow speed.

 

[Juliett Bravo Kilo]

Grazulis' entry on Loyal Valley, TX a slow-moving F4 that did Jarrell-like damage. I think this thing was overshadowed by Bridge Creek-Moore a week earlier and likely would've been rated F5 if it hadn't occurred so close to a historic outbreak like 5/3/1999.



It's entry on NWS San Angelo: https://storymaps.arcgis.com/stories/d29dcc647edb4aba89e6ad621e01502f

Interestingly, In 2023, they stated this was the strongest tornado ever recorded in their forecasting area and that "considerations were made for an F5 rating". However, the survey found that the structures impacted were not built well enough to ultimately warrant the F5 rating.

I'd like to see the structures that were deemed not to be F5 worthy. It's radar signature is crazy:

 

[andyhb]

Am definitely wondering a bit about the Hawley rating. Contextual evidence certainly supports an upgrade to EF4 given the severity of the tree damage, vehicles being tossed and mangled, etc. That house that was essentially wiped off its foundation had some anchor bolting. There was also another home in the process of being constructed that was wiped clean that was given 165 mph, but its connections to the foundation were more questionable. Still, given the presence of multiple supporting DIs, seems a good candidate for an upgrade.

 

[Tanner]

Am definitely wondering a bit about the Hawley rating. Contextual evidence certainly supports an upgrade to EF4 given the severity of the tree damage, vehicles being tossed and mangled, etc. That house that was essentially wiped off its foundation had some anchor bolting. There was also another home in the process of being constructed that was wiped clean that was given 165 mph, but its connections to the foundation were more questionable. Still, given the presence of multiple supporting DIs, seems a good candidate for an upgrade.

Weren't they consulting with the same survey team that conducted Matador? If that's the case, forget an upgrade.

 

[Juliett Bravo Kilo]

Damage pics from Ethridge, TN I've never seen before:







Footage of the tornado itself:




More pics here:

The Deerfield-Ethridge Tornado of 1995

Today (May 18) is the 20th anniversary of the 1995 Deerfield-Ethridge Tornado. On May 18, 1995, an F-4 tornado cut a huge, 29-mile path of destruction across Piney, Deerfield, Brace, and Ethridge, …

lawcohistory.com

This tornado passed over the same area in TN that the 1998 "forgotten F5" did 3 years later.

 

[Juliett Bravo Kilo]

Found this pic of Loyal Valley off Twitter; perhaps from a survey video?





This might be of the funnel itself, reminds me of Jarrell:



Found a gif of its fascinating radar evolution but it won't upload, naturally.