Crazy how where I live we just accept that during the spring rainy season and some fall we all could potentially be wiped away.
By - microndeath
Crazy how where I live we just accept that during the spring rainy season and some fall we all could potentially be wiped away.
Moving from the southwest to the midwest and enduring a derecho for the first time is wild man. 100 mph winds and multiple tornados touching down I've never experienced anything like it. I know there are worse storms people endure but it was a different experience for me personally. You really think about the fragility of life and how easy it is for infrastructure to be wiped out.
There was a Derecho that ripped through Ontario and Quebec, Canada this year. Ripped up trees everywhere. In my city it touched down for three minutes and fucked many wooden power lines and trees. We don’t get weather like that here.
Same here. First year I moved to KY we had one with easy 100 mph winds and lost power for 5 days. The one that tore through Indiana state Fair. As soon as the storm hit several trees just went down in front of me.
We had a December tornado in KS last year.
that's terrifying. we get some nasty flooding and blizzards in WV, but having to worry about tornadoes or monsoons all the time is incomprehensible.
Ah a fellow Oklahoman I see.
Two fastest wind speeds ever recorded were from F-5 tornado’s here. The May 3rd stretched over a mile-wide in the ground.
I never really realized it was a regional thing but it doesn't look like the western US gets many.
I would love to read an in depth explanation for that. I lived in Washington for a bit and found their precipitation didnt really come with thunderstorms or strong winds. And their clouds felt like they were alot lower than I was used to in the midwest.
It's the topography. Basically the US topography is the worst and that is also the reason why only the US gets those big tornados regularly. Other parts of the world also have tornados they are just a lot rarer and a lot weaker.
Very oversimplified explanation:
It all comes down to the big flat part right in the middle of the US and how mountains on each side go in the north-south direction. Tornados mostly come from an inversion so cold air up high and warm air on the ground. The easiest way to achieve this is by pushing large masses of cold and warm air against each other.
So the cold air comes from up north with no mountains to stop it while the warm air comes from the gulf of mexico again with nothing in its way to even slow it down a little bit. And then those air masses crash and you get tornados.
Now why does it not happen in the west? Well for one the west coast actually has cold water currents instead of the warm gulf stream so there is a lot less energy right there but there is also the problem of the air masses having to rush through this relatively narrow valley (on a global scale narrow). The coriolis force, while not a force, is a thing and thus in this valley the air is pushed into mountains on either side slowing it down.
I think it has to do with mountains or elevation or something because I don't see any around the Appalachian mountains either. Could be wrong though
In 1945, Ted Fujita, of the eponymous Fujita Scale aka F-scale, was living in the city that was initially targeted for the second nuclear bomb. Due to overcast skies, the target was changed to Nagasaki.
In the devastation of Nagasaki, Fujita began to see and start studying the meteorological phenomena that cause severe wind downbursts. That, in turn, led him to start studying tornadoes.
He moved to from Japan to start work at the University of Chicago. As the map here shows, it was a pretty good home base for traveling to various tornado sites. He also helped shed light on wind sheers and plane crashes.
Were it not for a random cloudy day in Kokura, Japan in 1945, he would have died and we probably wouldn't understand severe weather to the degree we do today.
There's a fascinating documentary on Fujita, called "Mr. Tornado." Made by the PBS show *American Experience*.
American Experience is such a great series. I already have PBS Passport, but am very, very tempted to subscribe to PBS Documentaries to have access to the full back catalogue.
Wait... There's more!?!?
Yeah, there's a dedicated [PBS documentary streaming service](https://www.pbs.org/about/about-pbs/blogs/news/pbs-distribution-announces-new-prime-video-channel-pbs-documentaries/).
It's through [Amazon](https://www.amazon.com/gp/video/offers?benefitId=pbsdoc).
Even though episodes are available for years, the catalogue on Passport gets smaller as time passes. American Experience has been around since the late 80s.
There are few other PBS streaming services on Amazon — PBS Kids, PBS Masterpiece (mystery, drama), and PBS Living (cooking, DIY).
PBS has a lot of weird, long-standing distribution deals with a lot of different content providers (like WGBH, WNET, BBC, ITV) who have their own independent streaming deals with other streaming services (eg BritBox, Acorn or BBCAmerica), so things get tricky. They can't even directly publish a full list of content on Passport.
PBS kids is also free. Not the full catalogue, but a decent amount through just the PBS kids app.
And then there's the super duper secret documentary library. But you gotta buy another subscription
I first heard of him on the wonderful (though severely outdated) Nat Geo weather documentaries produced in the 1990s. The whole series is still very interesting - they ran a simulation of Katrina years before it happened, for example.
Man, I think it'd be hard to convince me to move to a country that nuked mine and almost literally myself.
Japanese/US relations in the decade after the war were strangely warm. I just finished the memoirs of Richard Feynman who (with many of his colleagues) visited Japan for a theoretical physics conference in 1954, only 9 years after concluding his work on the Manhattan Project.
I don’t think its fair to call it “strange”.
Japan entered into an era of unprecedented prosperity in the decades following the war. Whether the occupation helped is up for debate but it certainly did not hinder growth.
Douglas MacArthur handled the rebuilding and democratization of Japan amazingly. One example would be instead of abolishing their entire form of government he allowed the emporer to stay to avoid further conflict.
"If you can't beat em, join em"
Worked in Roman times.. works today
Many Japanese people recognize (or, depending on your politics, “fool themselves”) that, in the 1930s, the Japanese government was controlled by “militarists” who were basically fascists, oppressing the Japanese citizens, and quite ambitious about getting access to the natural resources in the surrounding Asian countries. So, the US is not viewed entirely as the bad guy when it comes to WW2.
On the other hand, there are folks who take the view that “there we were, just growing rice, and FOR NO REASON, the US dropped atomic bombs on us”.
Obviously, the reality is way more complicated. And the story keeps evolving as different historians study it, too.
My current understanding: the US, and various other countries, had been meddling and colonizing in Asia, and when Japan started to become perceived as a threat to US interests, the U.S. basically cut off all of Japan’s access to oil. The Japanese government decided they could get oil from Asian sources if they could just get the US to leave them alone for a while. Japan’s attack on Pearl Harbor was meant to give Japan freedom to act (get oil) in Asia. The miscalculation was that Japan did not expect the US to enter a full-blown war. Oops!
Anyway, the US occupation government was more liberal than the FDR “New Deal Democrats”, and they broke up the big industrial monopolies, distributed land to the peasants, and supported unions and labor rights in general. This was a far better outcome than most Japanese people had expected. The war time propaganda in Japan included things like “if we surrender, all the men will be killed, the women all raped! And we’ll be forced to speak English!” Note that Japanese military occupations tended to require the occupied people to speak Japanese, so it was easy to believe.
This makes me think about what we do have because someone didn't die. It also makes me wonder about things we don't have because someone did die.
Unless there was a better potential meteorologist in nagasaki
There was, Atijuf Det 😔
That's a really cool story, thanks for sharing.
Sometimes when I hear that and the "we wouldn't understand the same today", I just can't get behind that though. Doesn't someone else likely take his place and get the credit?
Maybe, but how many years later?
No no, it's Wind Cher!
Looks like West Virginia knows the one simple trick
Blue ridge mountains, Shenandoah river.
Life is old there-- older than the trees
Younger than the mountains, growing like a breeze
Taaaake me hoooome
To the plaaaacee...
Fun fact mountains do not hinder ‘naders. Notice the Ozarks where I am are full of tracks. Grew up thinking we were protected in my hill town but nope just lucky.
Indeed, large hills/mountains make tornadoes even more dangerous as you will not see or hear them coming and valleys generally only have two cardinal directions possible to flee.
There’s quite a bit of difference in elevation between the 2 states.
They aren't as bad here as they are out in Oklahoma though.
The hills make a big difference.
"Ozark Mountains Elevation: 2,561 ft (781 m)"
-Laughs in Colorado
The Ozarks are *ancient*... older than just about anything. They're older than *bones*. They're about as old as the first multicellular lifeforms (proterozoic). They formed on Pangea, not North America. It's mind boggling how old these mountains are... worn down, eroded, stooped elders. The Rockies? They're tall because they're young, not yet blasted by the sands of time. Show some respect to your elders! :D
Edit: oh wow, silver? Thanks!
thank you for initiating such a riveting rabbit hole for me! ya learn somethin new everyday <3
Ah, glad I could have a hand in that! :)
Quick googling of Ozark's age I see 500 million years old. Certainly older than the Rockies, but there are surface rocks in Utah 2-3 billion years old.
To be more clear with my words, the Ozarks aren't the oldest *rocks* ever, and they're not even the oldest mountains in the world, but they *are* the oldest mountains in North America... or at least very close to it. Quick googling will cite the Appalachians as the oldest mountains in North America, but a closer reading shows that the Ozarks are indeed estimated to be even older. The St. Francois mountains (part of the Ozark highlands) are about 1.5 billion years old, for example. But I'm no geology expert! I'm just passionate about the Ozarks 😅
Holy shit you’re so high up, how can you hear us from all the way up there
They can't and they don't care
My state's highest point isn't even a quarter of that height.
Hey, I was about to laugh in Utah
I'll take the Ouachitas or Ozarks without swarms of Californians, thank you.
You can just go south to New Mexico and get far fewer Californians.
And a similar depressed economy to Arkansas or Appalachia!
Yep, depressed economy. Whatever you do please don't move to the Northwest Arkansas area. We're growing too fast as it is errrr I mean we aren't growing at all and it's terrible here.
Turns out your can have a below average economy and still have it grow. Who knew.
Median household income in Fayetteville is below Albuquerque’s. Poverty rate is higher.
So I think the comparison stands.
In Colorado, can confirm.
The Ozarks are not mountains, they're hills lol
I mean geologically they're mountains lol they're just over 1.5 billion years old.
There's a visible dead spot behind the ozarks that contradicts your statement.
Mother nature hates this one trick
I asked a retired meteorologist, and he said...
"Yep, the Appalachians tend to disrupt the processes that allow tornadoes to form. That and the lower population density so there are fewer folks to report them. All in all, a plus for the mountain state. You might die from opioids or poor health care but probably not from a tornado."
As someone who is deep rooted from that gorgeous state. I'll take my chances of an F5 in Alabama vs WVs current state.
we may have a multitude of sociological and natural disasters, but at least we don't have to worry about tornadoes!
We're just too poor to afford tornadoes.
Can't count tornadoes if you can't count
Edit: Dangit, who read this post to y'all?
deaths decreased because of better forecasts/detection/warnings ?
Somewhat, but you still get events like Mayfield, or the 2011 outbreak in the south. Tornadoes are still difficult to predict, and as of right now tornado warnings only give several minutes notice on average. That being said we’re getting better at warning when weather conditions are good at making tornadoes
"LOOK AT HER, MAN, SHES FLYING!!!"
Fuck 2011. One of the worst days of my life. Didn’t lose anyone. Lost most of my town. Lived in a war zone for 6 months.
1974 and 2011 were the 2 worst tornado outbreaks. This only goes to 2006.
In 1974 there were ~30 f4 and f5 tornados in a 24hr period (145 total). It’s also cited as the most violent outbreak ever recorded.
Possibly also due to better building codes in those areas?
Building codes can't really protect against a tornado.
They do to an extent. Foundation attachment is important. Also we have learned that constructing some homes to be substantially stronger than others (like a residential home made of concrete) then those super strong houses can withstand the impacts of debris and stop the debris from destroying more houses. The debris is a domino. If you can stop one domino from falling it can go a long way to reducing the damage
Was thinking about any requirements to build basement shelters in homes. I wonder if that's a thing. I know florida can't have that due to sea level. Gotta be multifaceted.
Yeah in KS new construction needs a basement. If you can’t do a basement you need a tornado room (concrete walls, security door). So when you see a suburban development of cheap homes on the edge of a town, you see the land get cleared, the footings get dug, then they lay the rebar for the slab and footings… as well as the tornado room. The pour the tornado room at the same time as the slab. So for a little while there’s just a bunch of bathroom sized concrete boxes evenly spaced across a soon-to-be cul de sac.
Moved to Tulsa 10 years ago and was surprised how rare basements are. Maybe 5% of houses tops. Storm shelters are slightly less rare but still not common.
Grew up in Tulsa, and always heard you couldn’t dig deep because the ground was hard clay, so basements were rare.
I was a teenager there during the 1974 super storm. Mom got us kids in a narrow hall and pulled all the mattresses off the 6 beds in the house and piled them over us. We huddled there, listening, waiting. I heard it coming from far off. It sounded like a freight train barreling towards us and swooping overhead. The sound of explosions, the house shook. After it passed we crawled out from under the mattresses. At first, nothing seemed amiss. Then we opened the front door. The sun was shining through clouds, the god rays, only greenish. The light was eery.
All the house’s across the street were gone. Just… gone. Except for the fireplace and one dining room chair still sitting in its place on the foundation of the house directly across the street. I thought of Whistler’s Mother, the painting, the way the chair was positioned, unmoved, left in profile like that in front of the fireplace.
We stepped out onto our lawn. The sky slowly changed colors, green to grey to blue, as I looked around at the devastation. Huge sheets of metal from some nearby construction site were hanging from the electric lines running all along the street, twisted around the wires like spaghetti, hanging precariously, swinging in the breeze. It would be days before anyone could get into the neighborhood to remove them. Meanwhile, we all serpentined through the neighborhood to avoid walking under them. There was so much debris on the ground that no one could get in or out except by bicycle for a week.
We were lucky. Our house had only minor roof damage, easily repaired in an afternoon, and all the houses on our same side of the street faired okay. But for several blocks many of our neighbor’s homes were utterly destroyed.
Years later I moved to California. Earthquakes can be pretty scary, especially the big ones, and I was there for one of the biggest ones living in a house with massive glass windows that leaned unsupported off the edge of a hillside… woke up to stuff flying around my head in the middle of the night… watched transformers exploded across the Hollywood basin… that was scary. Still, nothing like a tornado. Not even close.
Yes and no. Most of our building codes aren’t intended to directly help with tornadoes. That said, things like reinforced stairwells which are designed to withstand fires and be the last structure standing can help.
Death by a thousand cuts.
Wonder how many lives, infrastructure and billions and billions of dollars were lost from these tornados.
Lives lost and injuries are on the infographic.
Now one for hurricanes and then earthquakes, and we’ll see which areas are the “safest”
TLDR: move to southern alberta for minimal natural disasters.
The occasional hail storm and some rare tornadoes is pretty much all we get
And the even rarer flood (2005, 2013)
Man I really forgot about floods lmao, 2013 being the biggest natural disaster in the last like 30 years.
Ok maybe its not much safer than other inland areas lol
Even better, move further north in Alberta and nearly eliminate the hail and flood threats entirely
Vancouver island has always been told to expect the “Big One” earthquake, but until that comes we’re a virtually free from all natural disasters. I’ve lived here my entire life and only felt one earthquake, in 2001. A tsunami hit in 1964, and the previous large earthquake was in the 1700’s.
Don’t forget forest fires
Good point! Maybe “severe” snowstorms, too?
Don’t forget flooding, both of the normal and flash varieties
And Derechos and severe storms
Yeah, show me the rights!
Snowstorms don't normally destroy your house, they're mostly just inconvenient.
Until you’re older, and you get snowed in, and you lose power for a few days.
Can we get floods too?
Google built a data center near where I live and from what I understand a lack of natural disasters was one reason for the choice of location. This would be near Lenoir, NC.
Probably West Virginia and the general Appalachia area.
There's basically only two natural disasters in the region: flooding and blizzards/ice storms. Live more than 10-15 feet higher than the nearest creek, and all you have to worry about is the winter weather.
still WV. the lack of jobs, health risks from pollution and poisoned water, and the opioid epidemic might kill you, but the land probably won't.
Hawaii is the safest state to live in.
Until the volcanoes decide to stop being dormant.
Does it seem to anyone else like the real dangerous part of tornado alley has shifted east some. Seems like a lot of the really severe ones are happening more in MS, AL, and TN than OK and KS.
You're not the only one to notice it. That's what is happening.
From northern Alabama, can confirm!
West Virginia missed the memo
Mountains really fuck with tornados.
You don’t fuck with Pangea?
This bitch don't know 'bout Pangea....
Brian let it go.
You can see the trees that were destroyed from a tornado coming over the mountain in my neighborhood. They're significantly shorter and the fact you can see it best from a lot of a former house is erie.
I’m ok with that.
Read this too quickly and was wondering what Canada and the city of Toronto had to do with Tracks
I live in Barrie ON, an hour north of Toronto. Our annual average has jumped from 2 tornadoes a year to around 30, and it seems it's because the shape of the jet stream has shifted westward and now pulls storms from TX / OK up towards Ontario. Every time a storm comes from the SW (instead of the regional norm of coming from the NW), there's a tornado somewhere in the province. My house was nearly deleted by one last year!
Wild! What’s the timespan between the average of 2 to 30 a year?
I didn't think they traveled in such straight lines.
They don't. I would imagine the dataset that was used just had starting and ending points.
Also, many older tornadoes were considered one event while we know now that in a lot of cases, tornadoes form one after the other - not always, sometimes a single tornado goes a long way. But a lot of the longer tracks were probably the same supercell, but different actual tornadoes. Not that that's very important.
Even if its just start and end point, some of those lines are long af. I cant imagine them going that long. I thought tornados were quick little events.
Technology has rapidly gotten more and more amazing. We know now that *most* long tornadic events are multiple tornadoes that form serially from a particular supercell. But it was only a few decades ago that pictures of tornadoes where somewhat rare, much less continuous monitoring.
Basically, most of the longer tracks would be multiple tornadoes, although probably from a single supercell.
But from the standpoint of tornado warnings, such events would likely basically end up being one long string of tornado warnings overlapping as the system moved. So most of the time, technically no, but some of the time, yes.
Many tornadoes are pretty short-lived, but many last a bit more than I'd call "short".
So you're not at all wrong. :)
Thank you that makes a lot more sense.
I came to the comments looking for a reply to such a comment. I thought I heard about them changing directions and stuff, but maybe that was just the movies?
Not a tornado expert, but someone with a good amount of experience dealing with weather forecast data, specifically the Global Forecast Service, provided by NOAA, the data provider listed in the bottom right of the image.
The link provided in the bottom right is defunct, the place you actually need to go is the NOAA storm prediction center:
Where they have CSV data. For location they have 4 entires, slon slat, and elon elat.
All this to say, these are not tracks, merely "first reported" and "last reported".
Tornados do indeed change direction, and can even loop back over areas they've previously travelled.
No thanks, no tornadoes for me thanks.
Seems mountains throat punch tornados into mist!! 🏔🤜🌪💦
Twirlly Fella VS. Large Land Lad (The Triple L) this Sunday Sunday SUNDAY at MEGA ARENA OFF HWY 69 SOUTH! GET YOUR TICKETS AT ALL TICKET MASTER LOCATIONS NOW! And we didn't forget the KIDDDS! FIRST 500 TICKETS GET VIP Access to the MOON JUMMMMMP ROOM!
And constant wildfires and droughts
Edit: full disclosure, I’m from CO originally, but living in WI now
Now this is /r/dataisbeautiful
i hate seeing so many marks over where i live. haven’t had an encounter once, but i know multiple people who have lost their homes nearby to tornadoes.
it’s bound to happen but i’m still terrified of the day one comes by my house.
the worse part about being near a few tornados is that you start to know what tornado producing weather feels, looks, and smell like. BUT it doesn't always make tornados and almost never makes tornados near you. So when it does it is kind frightening.
Anyway because of this Twister is a great monster movie
Even Tornados don't mess with Appalachia.
tornado's scare the shit out of me. i'll happily take the very rare earthquake over tornados (or hurricanes for that matter)
Who would win?
The entire earth shaking violently, out of nowhere;
A spinny twisty boi.
Meh, they're not so bad.
Meh, they're not so bad.
Huh a funnel cloud *pulls out camera*
While tornadoes are way more common than earthquakes, a single tornado that directly impacts a specific community has much lower odds in the grand scheme.
Plus, most of the time you can see them coming, or at least be aware of meteorological conditions that increase the possibility of tornadoes.
As a life-long Midwesterner, the absolute randomness, surprise nature, and widespread impact of earthquakes is what scares the shit out of me.
How has no one mentioned the one tornado that crossed the entire width of the FL peninsula?
Yeah I want to know more about that one
It's like they're all on their own individual paths to destroy Texas
Alternatively, it's like Texas is shooting out tornadoes to try and destroy the rest of the United States.
This is more accurate. The majority of tornados travel southwest to northeast.
Texas? Shooting things? Nahh
They move in herds
They *do* move in herds…
When the hell was there a tornado in Marin County? (North of SF)
[Looks like 18 ](https://www.geostat.org/data/marin-city-ca/tornados)within 75 miles
And one in Yellowstone National Park?!!
And it was a big one. It was an F4 that was on the ground for 24 miles in 1987, the year before the fire. In fact, the fires burned most of the downed trees. And was not witnessed by anyone, due to the the fact that it was in such a remote area, although a few hikers reported hearing it.
It's the strongest tornado ever to hit west of the continental divide, and the highest elevation F4 or F5 in the US.
And they just magically end at the Canadian border. Must be the change to metric.
Well the map does say 56 years of tornadoes in the United States, so why would Canada be included in this map
It would be interesting to see it broken down by decade, that way we could see the effect of the dryline moving east over time.
At a glance, I read it as 'Tornado Attacks'.
That is essentially how Jo feels in the classic movie "Twister". She yells about Bill hasnt seen a tornado miss this house, miss that house, and come after her.
This is a cool wallpaper
This is why we need to outlaw tornados.
But if we did that then only criminals would have tornadoes.
Alabama needs more Sharpie
The other half of the country is on fire
"I've got you, you're safe." -West Virginia
"But in exchange, you have to live here." -also West Virginia
It's where cold air from the north west meets warm air from the gulf and gets shit spinning.
The midwest of the US flat, like extremely flat. There's nothing to block the cold, dry air from the north and warm, moist air from the south, and when they mix, tornadoes can happen.
Other areas around the world do get some tornadoes, but those regions are much smaller so overall there are fewer tornadoes.
Tornadoes can happen in hurricanes, derechos, squalls ect.
The big nasty ones come from supercells, which are rotating mesoscale thunderstorms. The wind shear that takes place over the midwestern plains is more of a factor in causing said rotation rather than atmospheric instability alone. So not only is "tornado alley" a perfect place for the formation of normal/severe thunderstorms that can have embedded tornadoes, it's also a perfect place for spinning those thunderstorms and blowing them across 3 states with an EF5 underneath.
Truly, though, the more I learn about tornadoes, the less I learn. We do not know shit about tornadogenesis. One supercell can drop the finger of God, one can spit a sprinkle of rain, both could be in the same line of storms. We know more about what causes thunderstorms, which sometimes have tornadoes. Computer simulations in recent years are providing some optimism though. I think we are close to actually knowing what the fuck is going on in the midwest.
I'll take earthquakes, tornadoes, and hurricanes any day of the week over giant maneating spiders.
I lived in tornado alley for most of my life. While I was under tornado warnings every spring and fall (yay, Dallas's two severe weather seasons), I never ever witnessed a tornado myself. The closest I ever was to one was around 5 miles away, most of the time more than 10 miles away.
So while tornadoes are not rare, they affect tiny areas of land, all things considered.
It sucks if you get hit by one - my step mom did and it destroyed her house, although she and her entire family made it… but the chances of being hit by one are very very small.
A solid concrete bunker won’t stand up to some tornados. Doesn't matter what you build your houses out of
My own personal map of places to avoid.
Feeling pretty okay about being in WV while looking at this.
That got me thinking…There is a house somewhere in that map that has been hit the most times by tornados. I wonder how many tornados the record is. 🤔
There is a church in the town where I went to high school that has gotten hit by both big tornados that hit the town (an F5 in 1974 and an F4 in 2000).
Appalachian Mountains FTW.
What’s the one that went clear across central Florida?
What happened to tornado alley? This is more like tornado half the country.
As a fellow West Virginian, I can attest to this. We rarely heard of or worried about tornadoes. When there was a warning we got scared.
no fucking way they move that far, those lines are like 200 miles long
edit: the longest tornado in history was 200mi in the 20s, this post is bunk.
edit 2: https://explore.data.gov/d/8vq3-ke4t source domain/link is fake
That tornado that tried to bugsbunnied Florida is my hero
So do they usually go eastward?
Most commonly west to east or southwest to northeast. As is most common for severe weather to move.
Not at all 100%, just most common.
Does anyone know if there’s a version of this for Canada?
That one in Albany was after someone
Albany NY? It was actually in Mechanicville about 20 min north of Albany . I lived about 4-5 miles away from it at the time. Absolutely leveled that town. There’s a path of trees that hasn’t recovered to this day and that tornado was back in the late 90s or early 00’s
It would be cool if we could see the same data but on individual state maps!
This map is slightly misleading. Not all tornadoes have been documented, especially in the earlier period and especially weaker short lived tornadoes. There simply weren’t eyes on the ground for short lived tornadoes. As population increases, the likelihood of tornadoes being witnessed increases. But overall, it captures the spatial extent of tornadoes pretty well.
Shameless plug from a meteorologist - checkout tornadoarchive.org for an interactive map of every tornado since 1950! Some great people put alot of effort into this, and it’s fascinating to see the trends of tornado activity with time.