Significant Tornado Events

[WhirlingWx]

Looking at the above information about super outbreaks, I can't help but think about the following:

IIRC, for quite some time after 4/3/1974, that storm was thought to be a one-in-500- or even a one-in-1000-year storm. But more recent detailing of tornado history (along with some more recent events like the 2011 Super Outbreak) has shown that there have been quite a few other outbreaks that could (at least theoretically) be classified as "super outbreaks" (as per the above discussions), and a such these types of outbreaks are likely much more common than previously thought.

This makes me wonder: what might a true once-in-a-millennium outbreak be like? Now obviously this question is hard to answer for sure, as we only have a fragmented history (at best) of tornadoes and tornado outbreaks going back a few centuries at most, with a consistently detailed history only going back about a few decades or so; thus, we can only speculate and perhaps extrapolate on how a "millennial outbreak" might play out.

My own personal envisioning of such an event would basically take the concentrated tornado-per-area densities of outbreaks such as 4/11/1965 and 4/27/2011 and have this density occur over a much larger area (perhaps larger even than 4/3/1974), all while occurring over a period of less than 24 hours. In other words, an onslaught of hundreds of tornadoes, perhaps a couple hundred being rated as significant (EF2+), and far more officially rated as violent (EF4+) than even 4/3/1974 (and all such ratings either fitting quite well or being underrated). "Apocalyptic" would be putting it mildly, to say the least! (Of course, it must be said that we must hope to never witness such an outbreak in our lifetime!)

There would also probably be some VLTs on par with the Tri-State tornado, but instead of just one perhaps several. Assuming you're still going for the apocalyptic angle, of course.

I too have pondered this, haha, but I struggle to fathom how it would even be physically possible from a meteorological standpoint. Just how many things have to go right for something like this to even occur? Needing an atmosphere that's unstable enough to support several rounds of storms, and then the shear in place over the course of the entire day (i.e. no issues with a mistimed LLJ or anything). Would we have outflow boundary + gravity waves + confluence band galore to set off wave after wave of OWS supercells and then juice a couple of those cells up further on the outflow boundaries to produce Hackleburg-type results? Plus a triple point rider? Finally add in an Easter 2020/early morning April 27th combined version of a QLCS/embedded supercell line to bookend the start and end of the day, and bam.

Uhhh... I got a little carried away there. I can't even begin to imagine the end result of something like that, and don't really want to.

 

[Austin Dawg]

The ratings from Palm Sunday 1965 make no sense to me. Some of the "F4s" from that date deserved an F5 rating way more than some of the questionable F5s in the late 1960s and 1970s.

I was just a toddler and my parents and I lived in Zion, IL in North Chicago. My Mom talked about that event as her worst experience until 2011. I believe there was a tornado that went over the house that never touched down but made a big mess of the things in the backyard including taking the grill, smashing it, and throwing it in the neighbor's yard.

She talked about it because my Dad was teasing her while the storm approached and actually got on the roof so "he could see it better". She shut the front door and headed for the basement and he almost ran over her when she started down the steps.

 

[speedbump305]

I realized something. Each April 27 EF5 has been known to have done something no other EF5 has ever done. I can name them right now

Hackleburg: Ripped the Concrete roof off a underground storm shelter
Smithville: Unearthed an underground pipe
Rainsville: Pulled up sidewalk pavement
Philadelphia: The 24 inch trench: i know EF5s can produce extremely deep scouring, but philadelphia scouring is by far the deepest

 

[speedbump305]

I realized something. Each April 27 EF5 has been known to have done something no other EF5 has ever done. I can name them right now

Hackleburg: Ripped the Concrete roof off a underground storm shelter
Smithville: Unearthed an underground pipe
Rainsville: Pulled up sidewalk pavement
Philadelphia: The 24 inch trench: i know EF5s can produce extremely deep scouring, but philadelphia scouring is by far the deepest

I know Rochelle pulled a concrete walkway a few inches from it’s starting point, but didn’t pull it up

 

[Casuarina Head]

April 20, 1920 (Unusual morning tornado event affected the same area as 4/27, see clipping below for a damage description from an EF4 Tornado that affected Neshoba (Hit by Philadelphia Tornado on 4/27/2011)and Winston Counties (Hit by Louisville on 4/28/14) on that day)

March 21, 1932 (Numerous violent tornadoes did massive damage across Alabama and Tennessee. Bottom clipping shows violent tornado damage at Paint Rock, AL. You might be able to see the tornado track in the background going up the mountain. Tornadoes on this day affected locations struck on 4/27 (Bridgeport, Cullman - Arab, Tuscaloosa))

March 21, 1952 (Several rather short-tracked but violent tornadoes devastated several Ozark Towns. Especially hard hit were Dierks (pictured below), Cotton Plant, Judsonia, and Henderson, TN)

That newspaper clipping from 20 April 1920 is remarkable. Apparently the New Deemer F4 dug half-foot-deep “trenches” and hurled mature trees tens of yards (more?), just like the Philadelphia EF5 in ‘11. It also swept homesites clean of sizeable debris. According to Thomas P. Grazulis’ description in Significant Tornadoes, that tornado bisected Neshoba County and tracked along the southernmost edge of Philadelphia, whereas the EF5 of 27 April 2011 developed on the northern outskirts of Philadelphia, but otherwise both tornadoes’ paths roughly paralleled each other’s. In every other respect these events appear to be possible clones, based on forensic evidence, including extensive debarking of trees. The Waco and Brownsboro F4s in Alabama on the same date, along with the Meridian F4 in MS, also produced extreme damage to mature oaks and pines. Detailed descriptions of damage from the 1932 outbreak are more sparse than in 1920, but personally, I am willing to bet that both 20 April 1920 and 21 March 1932 each featured at least one (E)F5.

Regarding 21 March 1952: once again, the official records seem to be largely incorrect. The conditions on that date were supportive of multiple long-trackers, and several of the “brief” tornadoes belonged to the same family, so I suspect that several of the short-tracked spin-ups on that date were actually the same tornado. For example, the tornadoes at England, Tollville, and Cotton Plant are listed separately in the official database, as are the tornadoes at Hickory Plains, Georgetown, and Hickory Ridge, but Significant Tornadoes links each of these, respectively, to singular, long-lived F4s, each with path lengths of sixty-five to seventy miles. The first long-tracker struck the northwest side of England, passed near Tollville and Hazen, devastated the outskirts of Cotton Plant, and then struck Hillemann before dissipating, though it may have continued even farther. The second long-tracker touched down near Wattensaw and tracked through Hickory Plains, Georgetown, McCrory, and Hickory Ridge before dissipating near Fisher. Several of the brief touchdowns in MO and TN are also listed as long-tracking F2+ tornadoes in Significant Tornadoes.

Sayler Park actually appears to be more intense than I recalled: some trees in the image (upper left) appear to have been totally debarked.

For the Plains, I would also consider 27 April 1912, 5 May 1960, 20 May 1949, 13 March 1990, 26 April 1991, 3 May 1999, and 24 May 2011 to be local “Super Outbreaks.”

 

[MNTornadoGuy]

That newspaper clipping from 20 April 1920 is remarkable. Apparently the New Deemer F4 dug half-foot-deep “trenches” and hurled mature trees tens of yards (more?), just like the Philadelphia EF5 in ‘11. It also swept homesites clean of sizeable debris. According to Thomas P. Grazulis’ description in Significant Tornadoes, that tornado bisected Neshoba County and tracked along the southernmost edge of Philadelphia, whereas the EF5 of 27 April 2011 developed on the northern outskirts of Philadelphia, but otherwise both tornadoes’ paths roughly paralleled each other’s. In every other respect these events appear to be possible clones, based on forensic evidence, including extensive debarking of trees. The Waco and Brownsboro F4s in Alabama on the same date, along with the Meridian F4 in MS, also produced extreme damage to mature oaks and pines. Detailed descriptions of damage from the 1932 outbreak are more sparse than in 1920, but personally, I am willing to bet that both 20 April 1920 and 21 March 1932 each featured at least one (E)F5.

Regarding 21 March 1952: once again, the official records seem to be largely incorrect. The conditions on that date were supportive of multiple long-trackers, and several of the “brief” tornadoes belonged to the same family, so I suspect that several of the short-tracked spin-ups on that date were actually the same tornado. For example, the tornadoes at England, Tollville, and Cotton Plant are listed separately in the official database, as are the tornadoes at Hickory Plains, Georgetown, and Hickory Ridge, but Significant Tornadoes links each of these, respectively, to singular, long-lived F4s, each with path lengths of sixty-five to seventy miles. The first long-tracker struck the northwest side of England, passed near Tollville and Hazen, devastated the outskirts of Cotton Plant, and then struck Hillemann before dissipating, though it may have continued even farther. The second long-tracker touched down near Wattensaw and tracked through Hickory Plains, Georgetown, McCrory, and Hickory Ridge before dissipating near Fisher. Several of the brief touchdowns in MO and TN are also listed as long-tracking F2+ tornadoes in Significant Tornadoes.

Sayler Park actually appears to be more intense than I recalled: some trees in the image (upper left) appear to have been totally debarked.

For the Plains, I would also consider 27 April 1912, 5 May 1960, 20 May 1949, 13 March 1990, 26 April 1991, 3 May 1999, and 24 May 2011 to be local “Super Outbreaks.”

Don’t forget 5/8/1965, that was basically the “Super Outbreak” for the northern Plains.

 

[buckeye05]

That newspaper clipping from 20 April 1920 is remarkable. Apparently the New Deemer F4 dug half-foot-deep “trenches” and hurled mature trees tens of yards (more?), just like the Philadelphia EF5 in ‘11. It also swept homesites clean of sizeable debris. According to Thomas P. Grazulis’ description in Significant Tornadoes, that tornado bisected Neshoba County and tracked along the southernmost edge of Philadelphia, whereas the EF5 of 27 April 2011 developed on the northern outskirts of Philadelphia, but otherwise both tornadoes’ paths roughly paralleled each other’s. In every other respect these events appear to be possible clones, based on forensic evidence, including extensive debarking of trees. The Waco and Brownsboro F4s in Alabama on the same date, along with the Meridian F4 in MS, also produced extreme damage to mature oaks and pines. Detailed descriptions of damage from the 1932 outbreak are more sparse than in 1920, but personally, I am willing to bet that both 20 April 1920 and 21 March 1932 each featured at least one (E)F5.

Regarding 21 March 1952: once again, the official records seem to be largely incorrect. The conditions on that date were supportive of multiple long-trackers, and several of the “brief” tornadoes belonged to the same family, so I suspect that several of the short-tracked spin-ups on that date were actually the same tornado. For example, the tornadoes at England, Tollville, and Cotton Plant are listed separately in the official database, as are the tornadoes at Hickory Plains, Georgetown, and Hickory Ridge, but Significant Tornadoes links each of these, respectively, to singular, long-lived F4s, each with path lengths of sixty-five to seventy miles. The first long-tracker struck the northwest side of England, passed near Tollville and Hazen, devastated the outskirts of Cotton Plant, and then struck Hillemann before dissipating, though it may have continued even farther. The second long-tracker touched down near Wattensaw and tracked through Hickory Plains, Georgetown, McCrory, and Hickory Ridge before dissipating near Fisher. Several of the brief touchdowns in MO and TN are also listed as long-tracking F2+ tornadoes in Significant Tornadoes.

Sayler Park actually appears to be more intense than I recalled: some trees in the image (upper left) appear to have been totally debarked.

For the Plains, I would also consider 27 April 1912, 5 May 1960, 20 May 1949, 13 March 1990, 26 April 1991, 3 May 1999, and 24 May 2011 to be local “Super Outbreaks.”

No

 

[MNTornadoGuy]

Also something interesting about the May 8, 1965 tornado outbreak is that the two VLT F4s from the event such as the Primrose tornado were actually families of several intense tornadoes with multiple F4s including at least one F5 in the case of Primrose. The Primrose tornado family was also accompanied by a satellite tornado.

 

[buckeye05]

What I’m trying to say is there is no way to definitively determine if there was intense debarking of any kind from that grainy, aerial, black and white photo. But if you have no ability to objectively analyze a damage photo, you’re just always going to see exactly what you’re looking for.

When that’s the case, every tree is “debarked” and all ground is “scoured”. Some things never change apparently.

 

[locomusic01]

So, back in the day I'd planned on writing an article on tornado climatology drawing from the available research + some maps and graphs and such that I cobbled together. I totally forgot about it until I started looking through my saved drafts on my blog. Probably won't ever do anything with it, so I figured I might as well post it here.

To be clear, I have no idea if there's even anything useful here lol. I haven't read it since the last time I worked on it, which was like.. 2012 or 2013 maybe? And it's obviously not close to being finished so I dunno where it cuts off. Anyhow, y'all are welcome to check it out if you want. I published it as a password-protected page because I don't want it actually showing up in my posts. Password is "talkweather" without the quotes:

(Also I just realized I missed a chance to rename it "An Outdated Tornado Climatology," which is a little disappointing.)

An Updated Tornado Climatology

The weather junkie's fix.

stormstalker.wordpress.com

 

[pohnpei]

A few more, this one is from Oak Grove/Mt Hope. While some clean up has taken place, you can track the debris motion from the scarring. The houses on on the bottom of the image had no chance.

I wish we had better pictures of the Moulton area. The tornado was not as wide there, but just as vicious as it was in Hackleburg. Once again clean up had begun here, but the ground is blasted and you can see the track of the main votes across the area. Interesting enough, based on the aerial photos that were available before, the tornado almost lifted between Mt Hope and Moulton, with only minor tree damage until the tornado found the high gear again.

I also noticed it in aerial footage used to be on youtube but seems lost now. The damage in some parts between MT Hope and Moulton was quite minor. I also didn't find damage point on damage viewer about this section and radar also showed some signs of recycling at this point. Maybe tornado quickly recycled in this area or maybe the lack of DI lead to minor damage in this section. It's really hard to know.

 

[MNTornadoGuy]

I also noticed it in aerial footage used to be on youtube but seems lost now. The damage in some parts between MT Hope and Moulton was quite minor. I also didn't find damage point on damage viewer about this section and radar also showed some signs of recycling at this point. Maybe tornado quickly recycled in this area or maybe the lack of DI lead to minor damage in this section. It's really hard to know.

Probably just weakened

 

[pohnpei]

What I’m trying to say is there is no way to definitively determine if there was intense debarking of any kind from that grainy, aerial, black and white photo. But if you have no ability to objectively analyze a damage photo, you’re just always going to see exactly what you’re looking for.

When that’s the case, every tree is “debarked” and all ground is “scoured”. Some things never change apparently.

I remember Grazulis once said vehicle damage was the best way to determine tornados' intensity with only black-and-white photos available just because the reason that in many occasions, whether trees debarked or not, whether houses well built or not, whether ground scoured or not was hard to figure through these photos.

 

[buckeye05]

I remember Grazulis once said vehicle damage was the best way to determine tornados' intensity with only black-and-white photos available just because the reason that in many occasions, whether trees debarked or not, whether houses well built or not, whether ground scoured or not was hard to figure through these photos.

Exactly. There are a some old photos where you clearly can see debarking, but it’s not the norm. Trying to deduce any degree of debarking from that earlier Sayler Park, OH aerial photo is just laughable.

 

[locomusic01]

Exactly. There are a some old photos where you clearly can see debarking, but it’s not the norm. Trying to deduce any degree of debarking from that earlier Sayler Park, OH aerial photo is just laughable.

For the most part, w/older events I think photos are mainly useful for verifying/adding context to eyewitness accounts. Of course, actually linking photos to such accounts is often easier said than done.

 

[buckeye05]

For the most part, w/older events I think photos are mainly useful for verifying/adding context to eyewitness accounts. Of course, actually linking photos to such accounts is often easier said than done.

Yup, for older events, the best way to get an accurate idea of what happened is having a combination of both personal accounts and photos. But like you said, that isn't easy. I'm wary of text-only accounts too, as old journals and newspapers will often dramatize or talk-up the severity of damage, or simply mis-report what happened. In these cases, the photos that eventually surface sometimes reveal a less intense event than what images our minds conjure up when reading the written accounts.

 

[Marshal79344]

I realized something. Each April 27 EF5 has been known to have done something no other EF5 has ever done. I can name them right now

Hackleburg: Ripped the Concrete roof off a underground storm shelter
Smithville: Unearthed an underground pipe
Rainsville: Pulled up sidewalk pavement
Philadelphia: The 24 inch trench: i know EF5s can produce extremely deep scouring, but philadelphia scouring is by far the deepest

I know the 1893 Pomeroy Tornado ripped up an underground pipe and produced Philadelphia-like trenches. Going on a limb and saying that Philadelphia's Scouring is by far the deepest is foolish. Several similar trenches have been mentioned in newspapers from before 1990, yet none were actually measured. Cordova and Smithville also produced similar trenches that were never measured. Greensburg also sucked up concrete pavement. Vilonia also ripped an underground storm shelter out of the ground completely, although it was improperly anchored.

 

[speedbump305]

I know the 1893 Pomeroy Tornado ripped up an underground pipe and produced Philadelphia-like trenches. Going on a limb and saying that Philadelphia's Scouring is by far the deepest is foolish. Several similar trenches have been mentioned in newspapers from before 1990, yet none were actually measured. Cordova and Smithville also produced similar trenches that were never measured. Greensburg also sucked up concrete pavement. Vilonia also ripped an underground storm shelter out of the ground completely, although it was improperly anchored

I’ve never actually seen the Cordova scouring before, but i’ve heard they were little trenches, but very deep, Pomeroy iowa was very violent and is well worth its F5 rating. I’ve never seen those Greensburg or Vilonia images, but if it was improperly anchored; it indicates a lesser intensity. I’ll say this, Smithville, Cordova, and Philadelphia have all produced trench scouring, but pretty much only Philadelphia’s has been measured. Do you happen to have those Greensburg and Vilonia images?

 

[buckeye05]

I know the 1893 Pomeroy Tornado ripped up an underground pipe and produced Philadelphia-like trenches. Going on a limb and saying that Philadelphia's Scouring is by far the deepest is foolish. Several similar trenches have been mentioned in newspapers from before 1990, yet none were actually measured. Cordova and Smithville also produced similar trenches that were never measured. Greensburg also sucked up concrete pavement. Vilonia also ripped an underground storm shelter out of the ground completely, although it was improperly anchored.

I thought Vilonia ripped the door off an above ground storm shelter, if you’re referring to the one that failed in Mayflower and resulted in a fatality?

Also, I had no idea that Greensburg damaged concrete/pavement. Are there photos of this?

 

[pohnpei]

It's weird that Smithville and Cordova's scouring had aerial photos with no ground view and Philadelphia's scouring had ground view with no aerial photo. I really hope to find both aerial and ground photos of them.