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One significant tornado event that intrigues me is the April 10, 2011 Merrill, WI tornado. Aside from being the strongest tornado in an early-season tornado outbreak where the peak tornado season is usually in the summer, the tornadoes occurred with patches of snow still on the ground.
Video taken as the tornado was forming that possibly shows patches of snow still on the ground in the background (though unfortunately it's very difficult to tell for sure):


NWS Green Bay page with information on all of the tornadoes including the Merrill EF3. In one of the pictures snow can be clearly seen; seeing a wedge tornado and snow on the ground in the same picture is interesting to say the least.


Wow, I had no idea there was any footage of that, least of all of its formation! Central and northern (and most of southern, but not as bad) Wisconsin is heavily forested and dangerous chase terrain (although probably not much different from Dixie Alley in that regard). I was living in Milwaukee at the time and remember being annoyed that the outbreak seemed to be skipping the southern part of the state and thus was out of my chase range. Some of the wording on the initial Day 2 outlook was very ominous, making it sound like we were staring at a nearly unprecedented regional outbreak of long-lived tornadic supercells (basically exactly what would happen to Dixie Alley 2 1/2 weeks later; or another Palm Sunday 1965). As it turned out it wasn't quite that bad, but still a very significant outbreak by Wisconsin standards especially for April. Of course, this was only six years after our state record-setting tornado outbreak happened on a slight risk day in mid-August.
 

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Wow, I had no idea there was any footage of that, least of all of its formation! Central and northern (and most of southern, but not as bad) Wisconsin is heavily forested and dangerous chase terrain (although probably not much different from Dixie Alley in that regard). I was living in Milwaukee at the time and remember being annoyed that the outbreak seemed to be skipping the southern part of the state and thus was out of my chase range. Some of the wording on the initial Day 2 outlook was very ominous, making it sound like we were staring at a nearly unprecedented regional outbreak of long-lived tornadic supercells (basically exactly what would happen to Dixie Alley 2 1/2 weeks later; or another Palm Sunday 1965). As it turned out it wasn't quite that bad, but still a very significant outbreak by Wisconsin standards especially for April. Of course, this was only six years after our state record-setting tornado outbreak happened on a slight risk day in mid-August.
There's quite a bit of footage on YouTube of the Merrill tornado though that video seems to be the only one that catches the tornado forming. Is the previous outbreak you're talking about the one that spawned the Stoughton tornado?
 

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One significant tornado event that intrigues me is the April 10, 2011 Merrill, WI tornado. Aside from being the strongest tornado in an early-season tornado outbreak where the peak tornado season is usually in the summer, the tornadoes occurred with patches of snow still on the ground.
Video taken as the tornado was forming that possibly shows patches of snow still on the ground in the background (though unfortunately it's very difficult to tell for sure):


NWS Green Bay page with information on all of the tornadoes including the Merrill EF3. In one of the pictures snow can be clearly seen; seeing a wedge tornado and snow on the ground in the same picture is interesting to say the least.

That one was the strongest for that day, but not for the whole outbreak. It was a two day event, and there was an EF4 in Iowa on the first day. What’s interesting about the EF4, is that it was a smaller satellite tornado to a larger, long-tracked EF3 wedge. The EF4 was actually pulled into and absorbed by the larger EF3.

I also remember tracking the nighttime Kaukauna, WI EF2 from that same outbreak
 

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If I narrowed down my list to a top 10 Ivanovo and San Justo probably wouldn't make the cut though I still believe Hesston/Goessel and Bakersfield Valley were exceptionally violent. Ivanovo and San Justo were undoutedbly violent F5 tornadoes, though as you mention not as violent as some other F5/EF5 tornadoes. If I had to choose from the four, Bakersfield Valley was probably the most violent. Hesston/Goessel were still exceptionally violent although they may not make a top 10.
How is Hesston/Goessel that impressive?? The homes they impacted weren’t well anchored, and every bit of damage the produced could be attributed to a tornado of F4 strength imo.

In fact, Goessel was rated F5 based on a pseudo-scientific method that involved doing wind speed calculations based on spiral shaped scour marks left in farms fields. This type of surveying has since been shown to be junk science.

With that said, if there were other more impressive incidents of damage that I’m unaware of along the paths of these two tornadoes, I’m all ears.
 
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That one was the strongest for that day, but not for the whole outbreak. It was a two day event, and there was an EF4 in Iowa on the first day. What’s interesting about the EF4, is that it was a smaller satellite tornado to a larger, long-tracked EF3 wedge. The EF4 was actually pulled into and absorbed by the larger EF3.

I also remember tracking the nighttime Kaukauna, WI EF2 from that same outbreak
I meant the strongest in Wisconsin on that day of the tornado outbreak, my bad.

Did you shoot any footage of the Kaukauna tornado?

How is Hesston/Goessel impressive?? The homes they impacted weren’t well anchored, and every bit of damage the produced could be attributed to a tornado of EF4 strength imo.
In my opinion the F5 ratings were well deserved. The Hesston tornado completely destroyed large industrial buildings and the Goessel tornado produced some of the most extreme ground scouring ever documented.
 

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This what my list of what was probably the most violent tornadoes in recorded history (not in order):
Smithville MS 2011
Jarrell TX 1997
Hackleburg AL 2011
Philadelphia MS 2011
Sherman TX 1896
Tri-State Tornado 1925
New Richmond WI 1899
Fergus Falls MN 1919
Rochester MN 1883
Pomeroy IA 1893
El Reno OK 2011
San Justo Argentina 1973
Bridge Creek OK 1999
Moore OK 2013
Parkersburg IA 2008
Jackson MS 1966
Woodward OK 1947
Aetna KS 1927
Andover KS 1991
Comanche KS 1860
Maysville PA 1860
Wheatland PA 1985
Guin AL 1974
Brandenburg KY 1974
Tanner AL 1974
Udall KS 1955
Beecher MI 1953
 

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That one was the strongest for that day, but not for the whole outbreak. It was a two day event, and there was an EF4 in Iowa on the first day. What’s interesting about the EF4, is that it was a smaller satellite tornado to a larger, long-tracked EF3 wedge. The EF4 was actually pulled into and absorbed by the larger EF3.

I also remember tracking the nighttime Kaukauna, WI EF2 from that same outbreak
There is evidence that the EF4 wasn't a satellite and was instead related to a separate mesocyclone.
 

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I meant the strongest in Wisconsin on that day of the tornado outbreak, my bad.

Did you shoot any footage of the Kaukauna tornado?


In my opinion the F5 ratings were well deserved. The Hesston tornado completely destroyed large industrial buildings and the Goessel tornado produced some of the most extreme ground scouring ever documented.
No, I live in Ohio. I just remember tracking the event from home.

I just don’t get what you’re saying though. Metal industrial buildings can be badly mangled by high-end EF2 winds due to their large surface areas, flat surfaces, and bendable construction materials. Damage to these types of buildings are only impressive when the metal framing is actually sheared the off at the base and twisted completely off the foundation (Wheatland, PA and Parkersburg,IA). The Hesston damage was nowhere close to that.

The assertion that Goessel produced extreme ground scouring is simply false. There was no actual scouring. As I mentioned, this rumor started from junk-science techniques based on spiral shaped marks left in fields. In reality, this isn’t actually “scouring” of any kind, but is actually cycloidal rowing of plant material that is deposited on the ground between suction vortices. These markings provide no use for identification of wind speed, but at the time it was thought they did. Surveyors mistakenly extrapolated some ridiculously high wind speed by examining these spiral marks. This was erroneously reported as evidence of extreme intensity, and eventually transformed into an internet rumor that there was extreme scouring near Goessel.

All in all, both Hesston and Goessel have been waaaay overhyped intensity wise over time to a combination of pseudo science, misinformation and internet rumors.
 

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No, I live in Ohio. I just remember tracking the event from home.

I just don’t get what you’re saying though. Metal industrial buildings can be badly mangled by high-end EF2 winds due to their large surface areas, flat surfaces, and bendable construction materials. Damage to these types of buildings are only impressive when the metal framing is actually sheared the off at the base and twisted completely off the foundation (Wheatland, PA and Parkersburg,IA). The Hesston damage was nowhere close to that.

The assertion that Goessel produced extreme ground scouring is simply false. There was no actual scouring. As I mentioned, this rumor started from junk-science techniques based on spiral shaped marks left in fields. In reality, this isn’t actually “scouring” of any kind, but is actually cycloidal rowing of plant material that is deposited on the ground between suction vortices. These markings provide no use for identification of wind speed, but at the time it was thought they did. Surveyors mistakenly extrapolated some ridiculously high wind speed by examining these spiral marks. This was erroneously reported as evidence of extreme intensity, and eventually transformed into an internet rumor that there was extreme scouring near Goessel.

All in all, both Hesston and Goessel have been waaaay overhyped intensity wise over time to a combination of pseudo science, misinformation and internet rumors.
Did some more research, you are absolutely right. A tornado left similar cycloidal rowing in a field in Darke County, Ohio on August 20, 2016. The tornado was rated EF0. The April 22, 2020 Madill, OK EF2 tornado badly damaged steel reinforced metal industrial buildings.

So Goessel is probably overrated. Cycloidal ground marks can occur even with weak tornadoes. Hesston swept away homes (were none of the homes well-bolted to their foundations?), threw vehicles hundreds of yards tearing the bodies from the vehicle frames in the process, deposited checks 100 miles away, and scoured grass from the ground (not cycloidal field marks, actual ground scouring). That being said, those damage instances are either unsubstantiated, or aren't clear instances of F5 damage so Hesston may be overrated as well.
 
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eric11

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One significant tornado event that intrigues me is the April 10, 2011 Merrill, WI tornado. Aside from being the strongest tornado in an early-season tornado outbreak where the peak tornado season is usually in the summer, the tornadoes occurred with patches of snow still on the ground.
Video taken as the tornado was forming that possibly shows patches of snow still on the ground in the background (though unfortunately it's very difficult to tell for sure):


NWS Green Bay page with information on all of the tornadoes including the Merrill EF3. In one of the pictures snow can be clearly seen; seeing a wedge tornado and snow on the ground in the same picture is interesting to say the least.

You're right,there's snow occurred both before and after the event, It's not rare to get snow in an early or late cool season tornado outbreak.But seeing all of this destructions covered with snow makes me feel a little bit strange, just like viewing the West Liberty WV EF3 damage on 3/2/2012.
Merrill tornado "snow tree damage"
29983aba45919a8e26a3f8db791eefc8.jpg
This tornado went directly into the town and mowed down thousands acres of hardwood and softwood forests outside town.At some point, I'm sure it was capable of reaching Violent tornado strength just examining these big, hardwood pine trees with only fat tree trunks and little branches or leaves left behind, though debarking or denuding was hard to find, which I believe there weren't enough debris to finish some debarking.
-d069f2cf81e2c4aa03e6ff25860f706.jpg

63c37dad98a60346cf7a37ed7f879a8c.jpg

-7ec11b9d5b8a47d9cedc605fe8f4b78f.jpg
Light ground scouring could also be found in open fields near the town's factory.
fd402f5a136ddf0b95f7983bcc713a2.jpg
Fire hydrant got pulled out of the ground
6023eadf0ef69cfc6b9600e906ea9dcd.jpg
Not quite clear though what damage indicator earned this one an EF3 rating, I'm guessing some poorly-anchored house got leveled or AWC.I viewed some videos after the tornado and it's really hard to find impressive house damage or bare slabs and foundations.Most houses in the town suffered from some roof or walls damage except for this one below.
-699f0432a5efbeebc2bc0851a55aa23b.jpg
-483e18ca8e0cf744ec37558ebc7ecb02.jpg
I'm assuming that this tornado was a fast-moving type and its size was close to some big cone or"tight wedge" so that there's barely 5-10 seconds for a single home to be destroyed.Multi-Vortex structure and violent upward motion can be seen in the video you published just like some the birth time of dixie monsters.
Merrill Tornado mature stage
-466301ec65848cd5a1d40092ded3c916.jpg
 
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eric11

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That one was the strongest for that day, but not for the whole outbreak. It was a two day event, and there was an EF4 in Iowa on the first day. What’s interesting about the EF4, is that it was a smaller satellite tornado to a larger, long-tracked EF3 wedge. The EF4 was actually pulled into and absorbed by the larger EF3.

I also remember tracking the nighttime Kaukauna, WI EF2 from that same outbreak
Ah ha finally someone could mention this extraordinary event.I once looked deeply into the Pocahontas tornado family and I would say this is a tornado event AT LEAST the same as the "Big Four" or the DDC level, maybe the most impressive tornado family in Iowa history?However due to the lack of observers and most tornadoes occurred in rural areas at nighttime, little attention could be paid attention to this event.
This mother supercell was responsible of producing 13 tornadoes according to NWS Des Moines while in some sources maybe 15,16 or even more tornadoes was documented because there were tons of short-lived cyclonic/anticyclonic satellite tornadoes/vortices in rural areas could not be well documented and left no trailes of damage.
703ae54decf97f4b.jpg
The first and biggest tornado,rated low-end EF3,aka Tornado"D", was the dominat tornado of the family ,which was called the Sac/Varina tornado.Exact width of the tornado remains a mystery.Wikipedia lists this one 1.5 miles wide,NWS lists it 1 miles wide.What's astonished me is that SDB lists it 2-3 MILES WIDE!
One storm chaser captured this monster over a mile away which shows a full big dark wedge like Greensburg
-401ee80b6e243e34bc2a34ce82842171.jpg
7e681b624514bd90ede4d4b8fe3fef94.jpg
The tornado managed to level a few farm houses in open farm lands, however, exact quality and anchoring remains unknown.Not sure the 140mph rating was given after close inspection or just a quick glance.Trees around this site was debarked with only tree trunks standing.Combines was rolled and embedded into the muddy scoured field.
452c72ae826ae59a29a987542d767bbe.jpg
IMG_20210227_135104.jpg
69089874d58a2105bd03647db340ad44.jpg
-3474f476bef8f4f587b0648fe8418a20.jpg
-5af58eb091fd7c7c.png

-4d8e8c3947ad61683257808e86e4d60.jpg
IMG_20210128_230929.jpg
 
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No, I live in Ohio. I just remember tracking the event from home.

I just don’t get what you’re saying though. Metal industrial buildings can be badly mangled by high-end EF2 winds due to their large surface areas, flat surfaces, and bendable construction materials. Damage to these types of buildings are only impressive when the metal framing is actually sheared the off at the base and twisted completely off the foundation (Wheatland, PA and Parkersburg,IA). The Hesston damage was nowhere close to that.

The assertion that Goessel produced extreme ground scouring is simply false. There was no actual scouring. As I mentioned, this rumor started from junk-science techniques based on spiral shaped marks left in fields. In reality, this isn’t actually “scouring” of any kind, but is actually cycloidal rowing of plant material that is deposited on the ground between suction vortices. These markings provide no use for identification of wind speed, but at the time it was thought they did. Surveyors mistakenly extrapolated some ridiculously high wind speed by examining these spiral marks. This was erroneously reported as evidence of extreme intensity, and eventually transformed into an internet rumor that there was extreme scouring near Goessel.

All in all, both Hesston and Goessel have been waaaay overhyped intensity wise over time to a combination of pseudo science, misinformation and internet rumors.
Here's some previous postings on Hesston and Goessel, Hesston does appear to have partially scoured grass in some areas but that's about it. Some of the vehicle damage is pretty impressive but perhaps it's nothing an F4 couldn't have done? Not sure.



This link has a pretty comprehensive collection of damage photographs from the Hesston tornado. Also, there is a section labeled 'Stucky Photographs' that is the only comprehensive collection of Goessel damage photographs I've been able to come across.

 
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buckeye05

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Ah ha finally someone could mention this extraordinary event.I once looked deeply into the Pocahontas tornado family and I would say this is a tornado event AT LEAST the same as the "Big Four" or the DDC level, maybe the most impressive tornado family in Iowa history?However due to the lack of observers and most tornadoes occurred in rural areas at nighttime, little attention could be paid attention to this event.
This mother supercell was responsible of producing 13 tornadoes according to NWS Des Moines while in some sources maybe 15,16 or even more tornadoes was documented because there were tons of short-lived cyclonic/anticyclonic satellite tornadoes/vortices in rural areas could not be well documented and left no trailes of damage.
View attachment 6160
The first and biggest tornado,rated low-end EF3,was the dominat tornado of the family ,which was called the Sac/Varina tornado.Exact width of the tornado remains a mystery.Wikipedia lists this one 1.5 miles wide,NWS lists it 1 miles wide.What's astonished me is that SDB lists it 2-3 MILES WIDE!
One storm chaser captured this monster over a mile away which shows a full big dark wedge like Greensburg
View attachment 6152
View attachment 6153
The tornado managed to level a few farm houses in open farm lands, however, exact quality and anchoring remains unknown.Not sure the 140mph rating was given after close inspection or just a quick glance.Trees around this site was debarked with only tree trunks standing.Combines was rolled and embedded into the muddy scoured field.
View attachment 6161
View attachment 6159
View attachment 6154
View attachment 6155
View attachment 6156

View attachment 6158
View attachment 6162
Yeah, I always figured that the huge main Iowa EF3 was a “default EF3” due lack of anchoring. It definitely swept away and leveled multiple homes, and I feel it was likely capable of producing EF4 damage. At the very least, a higher wind speed estimate than 140 would have likely been appropriate imo.

The smaller EF4 completely debarked trees, threw a large combine hundreds of yards and mangled it, swept away a farm house, and actually threw the home’s concrete porch slab across the street and shattered it. Pretty violent stuff.

Regarding Merrill, I have no issue with the EF3. No it didn’t level many homes, but that’s not really the benchmark for EF3 type damage. It certainly ripped the roofs and exterior walls from many homes, and that’s enough for at least low-end EF3. I remember seeing news video of one house in Merrill that was actually pushed off its foundation and dragged a considerable distance with two people inside, who survived in this one of the few interior rooms that was left intact.
 

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This what my list of what was probably the most violent tornadoes in recorded history (not in order):
Smithville MS 2011
Jarrell TX 1997
Hackleburg AL 2011
Philadelphia MS 2011
Sherman TX 1896
Tri-State Tornado 1925
New Richmond WI 1899
Fergus Falls MN 1919
Rochester MN 1883
Pomeroy IA 1893
El Reno OK 2011
San Justo Argentina 1973
Bridge Creek OK 1999
Moore OK 2013
Parkersburg IA 2008
Jackson MS 1966
Woodward OK 1947
Aetna KS 1927
Andover KS 1991
Comanche KS 1860
Maysville PA 1860
Wheatland PA 1985
Guin AL 1974
Brandenburg KY 1974
Tanner AL 1974
Udall KS 1955
Beecher MI 1953
I would like to ask that do you have information about Maysville PA and Comanche KS tornado 1860?
 

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The only EF4(tornado"J")is the third tornado of the family and the second satellite tornado to the big wedge(tornado"D"),so that I believe the EF4 and the mother tornado,the big wedge EF3(tornado"D") above are from the same meso instead of different mesos.
Tornado"J" took an unusual southeastward track over open farm lands,which went far away from the main tornado(tornado"D") .On normal occasion,satellite tornadoes would drop down on the east side of the main tornado,parallel to it for a while,before rotating around the mother tornado and get absorbed.
-1017e7e329e38efb2acc2f6b09893326.jpg
Tornado"J" then encountered tornado"I"(an EF2 on the top left of the track map).Tornado"I" was the fifth satellite tornado of the family and quickly get absorbed as tornado"J" approaching.
-1b34103418d8033859845147442824dd.jpg
-34cad56585f4c48c.jpg
After Tornado"I"merged with Tornado"J",Tornado"J"quickly strengthend and produce EF4 damage as a farm house with poor Rock anchoring got completely leveled.A 14 ton combine was thrown 100 yrd, rolled 8 times before deeply embedded into the scoured field.House debris Impact was also noticed on the tractor.Tree fiber was embedded into the trunk.Ground scouring marks could be seen through air.
-4d971e016f5e258648bb47dc1e3c2d30.jpg
6adedd300c568af9f617ae71f3308ee6.jpg3d5ebe81a7a3c26abcd16dede069811f.jpg
523dffd4587e8de0c1627048212b0586.jpg
Apart from that,The twins in the screenshot of that famous video, I believe,might be Tornado "H"and "G".Tornado "G" is the right one in the screenshot while Tornado "H" is the left one, developing a minute late behind Tornado"G".Tornado"H" is also a rare anticyclonic tornado which made this twins a rare anti/cyclonic pair just like DDC event and Simla CO event,which gives a resonable explanation why this pair was paralleling and mutual excluding each other instead of merging like those cyclonic pairs.
2e3e0ab65920c359.png
-1b34103418d8033859845147442824dd.jpg
From Tornado"G" to Tornado "J",four satellite tornadoes dropped down successively in less than two mintues, meaning there are 4-5 tornadoes on the ground simultaneously(considering main tornado"D").I just can't imagine how this will be like if it happens in daylight, watching 4-5 tornadoes churning on the ground.
 

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Yeah, I always figured that the huge main Iowa EF3 was a “default EF3” due lack of anchoring. It definitely swept away and leveled multiple homes, and I feel it was likely capable of producing EF4 damage. At the very least, a higher wind speed estimate than 140 would have likely been appropriate imo.

The smaller EF4 completely debarked trees, threw a large combine hundreds of yards and mangled it, swept away a farm house, and actually threw the home’s concrete porch slab across the street and shattered it. Pretty violent stuff.

Regarding Merrill, I have no issue with the EF3. No it didn’t level many homes, but that’s not really the benchmark for EF3 type damage. It certainly ripped the roofs and exterior walls from many homes, and that’s enough for at least low-end EF3. I remember seeing news video of one house in Merrill that was actually pushed off its foundation and dragged a considerable distance with two people inside, who survived in this one of the few interior rooms that was left intact.
I couldn't find the news video but some long distance debris dragging marks did exist in the center of the town
-566ce23dce1e83a3775cf66ab1f73168.jpg
 

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In fact, Goessel was rated F5 based on a pseudo-scientific method that involved doing wind speed calculations based on spiral shaped scour marks left in farms fields. This type of surveying has since been shown to be junk science.
I've seen you state this a couple of times. Do you actually have any studies showing so?
 

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I've seen you state this a couple of times. Do you actually have any studies showing so?
I could probably if I dug around, but it’s more just kind of common knowledge in the current era of tornado damage surveying, and have known NWS met professionals to discount it entirely in recent decades. I trust their word over dated methods of analysis. Spiral marking analysis was simply dropped entirely since implementation of the EF scale, and may have ceased even earlier than that.

That’s because as another mentioned earlier, it’s now known that even EF0-EF1 tornadoes produce dramatic cycloidal marks in open fields as long as there are suction vortices and loose vegetation that can be strewn in a spiral. All these markings are really indicative of is a multiple-vortex structure, which even weak tornadoes frequently exhibit.

There are specific events that show this lack of correlation too. A good example is Charles City. There was a newspaper article published at the time showing how spiral marking analysis was used to conclude some ludicrous wind speed estimate for the Charles City, IA F5 of 1968. I forget the exact number, but I think they placed it over 400-500 MPH, which isn’t thought to even be possible in tornadoes. Also, the damage it produced wouldn’t even be rated EF5 today, so whatever math they were using, was clearly flawed. Also of note, the Parkersburg, IA EF5 produced insane cycloidal scouring, but it was most intense near the end of the path, where structural damage had lessened to EF2-EF3. The very intense markings occurred just because there was more loose corn stubble to blow around in this area.
 

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I could probably if I dug around, but it’s more just kind of common knowledge in the current era of tornado damage surveying, and have known NWS met professionals to discount it entirely in recent decades. I trust their word over dated methods of analysis. Spiral marking analysis was simply dropped entirely since implementation of the EF scale, and may have ceased even earlier than that.

That’s because as another mentioned earlier, it’s now known that even EF0-EF1 tornadoes produce dramatic cycloidal marks in open fields as long as there are suction vortices and loose vegetation that can be strewn in a spiral. All these markings are really indicative of is a multiple-vortex structure, which even weak tornadoes frequently exhibit.

There are specific events that show this lack of correlation too. A good example is Charles City. There was a newspaper article published at the time showing how spiral marking analysis was used to conclude some ludicrous wind speed estimate for the Charles City, IA F5 of 1968. I forget the exact number, but I think they placed it over 400-500 MPH, which isn’t thought to even be possible in tornadoes. Also, the damage it produced wouldn’t even be rated EF5 today, so whatever math they were using, was clearly flawed. Also of note, the Parkersburg, IA EF5 produced insane cycloidal scouring, but it was most intense near the end of the path, where structural damage had lessened to EF2-EF3. The very intense markings occurred just because there was more loose corn stubble to blow around in this area.
I think you're referring to this
-621632c1ddc3911c.jpg
-9deb4d5260dd753.jpg
Cycloidal Marks estimating wind techniques was usual in early years, I remember 1957 Dallas TX tornado was estimated around 280mph for its marks.
Here's an excellent example to prove your theory"whatever tornado strength could make cycloidal marks".The following pics are Cycloidal Marks from different tornadoes of different strength in 8/24/2016 tornado outbreak.
woodburn IN EF3
-698aa09e3b028d8d.jpg
unknown EF2
668aceb773c70a33.jpg
unknown EF1
-264049bbc99047e8.jpg
unknown EF0
-4185d10badbb58df.jpg
 
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