Low-frequency sound can reveal that a tornado is on its way
bbc.com
bbc.com
I really wish this trope would go away. If you live in an area prone to tornadoes and you "have no warning", then you're just not paying attention. We know tornadoes exist. We know where they tend to frequently occur. The local weather stations in those areas are pretty damn good with warnings. We know days ahead of time that the conditions will be right for potential activity. We can now see potential tornadoes before they are formed. We can track their paths with neighborhood cross street precision.
Nevermind the fact that there's a pretty good indicator when the sky turns dark and the weather changes. Thunder and lightning and wind are essentially the knocking on the door. It's not like it's a sunny day and a tornado just pops out of the sky to say hello.
To say no warning just means they are not paying attention. I don't know what the tornado activity is like where the BBC is from, but it is woefully out of date.
London. The British Broadcasting Corporation is from London, in the UK. And they do have tornados in the UK.
Yes, there are high risk days seen pretty far out, and these get all the chasers hot and bothers.
There are also other days with almost no chance of severe weather when you get a spin up tornado that may only last 10-15 minutes but does a surprising amount of destruction with no warning.
Add to this that in the midwest/tornado alley you have a lot of other storm days without tornadoes. Out of any given day, one out of 8 will be one with rain, actual tornado days (within 100 miles) are far lower.
This twister happened the other day, probably about 20 miles from me. I was aware of the warning and watching the radar; but aside from that I would've had no clue it happened.
We saw the house lights flicker a little bit; there were some clouds to the northwest that looked dark, but not especially menacing, and that was it. Some of the people in the path of that tornado had exactly the same experience, until it was moments away.
This one, in 2021; killed people who were at work. As I recall they warnings had been on and off all day for much of West TN and KY.
https://www.courier-journal.com/story/news/local/2021/12/11/...
I'm sorry that people just choose to ignore the weather, but that cannot be the fault of those literally shouting at them to take shelter (some of the weather people can be a bit enthusiastic). The TFA mentions warning fatigue, but that's a weak excuse. Sure, I like to make fun of the forecast as much as the next person, but when the storms do come, the local weather springs to life and all of the tech comes to the forefront. People choose to ignore the warnings at their own peril, but then feel like it's perfectly fine to then say "but we had no warnings".
The factory one is clearly due to negligence.
But, the parent comment alluded to something about "living in an area prone to tornadoes," which would include areas you described.
So, any storm during tornado season would be enough to take precautions or at least be on alert. No?
The path was 600ft wide at the worst parts. Much of the "line" on the map was unaffected; people whom that storm passed over could have missed it.
I consider myself a very weather aware person living near the edge of tornado alley in Dallas, I get all the alerts, generally keep a strong watch on radar development and storm arrival times (hail is just as much as a concern as tornadoes).
In general if there is a detection of a rotation or a strong hail core on radar, emergency sirens will go on near the affected area. Sometimes it just happens too fast, so if there is another method like the article sounds to detect a strong potential a tornado is forming it will absolutely reduce casualties.
As an example I lived through in October 2019. There was one hour between a Tornado Watch being issued and when the EF2/EF3 hit the ground. Watches generally last a long time and cover a large area so they aren't particularly helpful to me other than to indicate to 'check the radar on the regular'.
Because I was already glued to my phone I saw the warning right away, I was able to text friends that lived a few minutes from the tornado touchdown point that there was a tornado right next to them. Their sirens hadn't gone off yet, by the time they had taken shelter they heard the sirens and the wind kicking up right after. They got off light on damage compared to the rest of their neighborhood but I can't imagine someone out walking their dog or running an errand and then only having 1 or 2 minutes to find shelter. I'm still amazed this thing didn't cause more injuries particularly in the early minutes when the news crews and meteorologist were playing catch up. https://en.wikipedia.org/wiki/Tornado_outbreak_of_October_20...
Maybe this tech would have helped give a clearer indicator versus the usual approach of waiting to see something on radar or manually spotting it. Or maybe some storms will just form too fast to have any useful indicators.
Hell, you know bad things are coming when it is 75F in the morning in December. The last bit of tornado weather telegraphed itself in the morning and didn't touch down until mid afternoon, yet I heard people on motorcycles when the storms hit.
No one is surprised by all the conditions that point toward a tornado. The problem is that in certain areas, the tornado watches are occurring ALL the time and you can't stop every time there is one.
So, yeah, in hindsight everyone saw it coming. But no one thinks THIS time will actually be the time so it does sneak up on people. My father recent went to bed during a tornado warning and one touched down less than a mile away. He got lucky. More reliable indicators of actual tornadoes will be helpful.
And I've been involved in tornadoes on days where there was zero risk of the event. Surprise you're getting a tornado out of a totally random storm that was not predicted.
Tornado alley is where warm air from the gulf collides into cold air coming from the NW. The line where these collide shifts around. Storms can form very unpredictably and rapidly.
On the one hand it's awe inspiring to see a massive thunderhead materialize out of nowhere in just a couple hours. On the other it means what the other commenter is saying is very misleading. Texas, where the other commenter is apparently from, is at the southern end of tornado alley and I believe not quite as dynamic, which may explain their attitude somewhat.
Howdy neighbor! Do you find it mildy calming when looking at the weather warning tweets from Delkus while his avatar is cheersing you with a cocktail?
This tech might provide another layer of confidence for tornadoes, but as you mentioned, the hail is another story in and of itself. I have mixed feelings about the "tornado sirens" being used for hail/severe weather without a tornado. I lean towards it being a good idea. I'm actually in Dallas, not one of the suburbs, so we tend to get protected from tornadoes by the infamous heat dome. Earlier this year, the sirens went off for hail and they were talking about softball size hail and larger west in Arlington. So, yeah, people definitely need to know about that. However, it does remind me of the Hawaii debate on using the tsunami sirens to warn of the fire, but it is totally different in that this hail/tornado siren both mean to seek shelter and not a confusing run towards the danger.
Tweets from Delkus and the Fort Worth National Weather Service are the main way I pay attention to new developments. Typically stuff will get posted there before live TV coverage starts. There's almost always a graphic posted of what the window is they expect for storms to form which helps me understand what I need to pay attention to.
I have a relative in another state whose a meteorologist and he doesn't have nearly as much fun as Delkus's team does online.
As far as over-indexing on preparedness goes, there has been at least twice our kids school has dismissed early in light of a severe weather forecast, however they do this several hours ahead of time (parents can't react that fast anyways). Only for the storms to be your more normal strength T-storm by the time carline starts. I can certainly appreciate the intent, but it's almost never that certain what's going to happen unless the storms are already popping up.
The UK has the most tornadoes per square mile of any country in the world.
They’re just all insignificantly weak :)
The downside to hole in the ground style is that debris could fall on the doors to the shelter and trap you in there for however long until someone happens upon you. So, some supplies might be a good idea.
Your requirement for being built/sold is a bit extreme. It is no different from places being built in flood plains, earthquake prone areas, or wildfire areas. Where it gets nasty is getting the structure insured.
We get severe storm warnings, but there's so many storms in tornado alley to be honest people get fatigue over them and mostly ignore other than maybe changing plans for a bbq. We in no way have some days ahead warning that this severe thunderstorm, out of the several dozen each season, is going to be one that launches a tornado vs a variety of over outcomes.
As far as knowing when a tornado actually forms, yes we can see some indications of rotation or a funnel "hook" on radar but they're also ambiguous with many, many false positives. The most reliable way to know a tornado has formed remains eye witnesses calling it in. We have basically no ability to do something like even a 15 minute warning confident there will actually be a tornado forming.
Please don't blame people for "not paying attention" for something that is not even remotely as clear cut as you're portraying.
This is such a cop out. You can pay attention to the weather and make decisions based on that. People have chosen to carry on like nothing is happening. You can get alerts and warnings and watches issued for areas near you and see if the storm is coming or going. If you get alerts and see the system is to the east of you, then no problem. If you see the storm is southwest of you and still pay no attention to it, that's on you.
If people are single with no others to worry about, then fine, YOLO your life away. If people are "fatigued" with dependents and get caught up in it, it really irresponsible of them.
I never said it was clear cut. I stipulated that the multiday forecasts are sometimes farcically bad. However, when the severe stuff does hit, these guys are all over it. Choosing to ignore them when they are telling you it is there is totally mind boggling. When the severe weather is happening, they can literally show you the streets in the neighborhoods it is impacting or are directly in the path. If that's not your area, then fine, tune it out. But to say "I'm tired of hearing about weather not affecting me" is so so weak.
I really dislike how smug, dismissive, and judgemental you're being. I don't think this is a positive contribution.
You can, though. I grew up attending a summer camp in Iowa, and we did go to the basement anytime there's a _warning_. 24 hours a day, if there's a nearby warning, all 200 campers & staff crammed into a basement singing songs and trying to keep the first-graders from crying.
That said, being able to tell the difference between a tornado warning and "a tornado will be at your house in 10 minutes" is the kind of detail that will almost certainly get folks to move to the basement and save lives.
A "tornado watch" means the potential for a tornado.
A "tornado warning" means there IS a tornado on the ground.
For a _warning_, everyone should take cover.
But watches are sent out frequently, for large areas -- that means that most people won't see that watch turn into a warning.
I think the person I was responding to had them backwards; nobody is hiding in the basement for a tornado _warning_.
The PP was arguing exactly that::
> > > You can't go to the basement every time there's a tornado watch. It's just not a thing.
They were making that argument in response to the top commenter who was arguing that folks should go to the basement on a watch notice:
> > > > > This is such a cop out. You can pay attention to the weather and make decisions based on that. People have chosen to carry on like nothing is happening. You can get alerts and warnings and watches issued for areas near you and see if the storm is coming or going. If you get alerts and see the system is to the east of you, then no problem. If you see the storm is southwest of you and still pay no attention to it, that's on you.
This used to be the rule. Not anymore. Warnings are issued based on radar indications which could be rotation, a funnel that’s not on the ground, or could be a false positive entirely.
Before, I believed it doesn't just sneak up on you but I am not sure anymore. We don't usually see tornadoes, and I don't think they were very big, so maybe that changes things.
One went a couple of blocks to the north of me. The tornado watch came out the day before so I was paying attention. I was standing on the porch watching in that direction. It was storming, but it wasn't a very strong storm. No green, no hail, no strong winds, rain was pretty average. Still didn't know until I started hearing about it through Twitter and a coworker. The warning came 10-15 minutes after he saw it.
The other storm that dropped a tornado went over us while we were at a park. It was sunny when we arrived ~20 minutes earlier. This one did have all of the classic signs - winds picked up out of nowhere, heavy rain, hail, etc. At least it made sense when we heard a tornado touched down.
Maybe it IS a weak argument, but I've seen dozens of tornado warnings where no tornado occurs. There are weeks where a severe t-storm watch is out 4-5 nights and it doesn't rain. Sometimes a severe t-storm warning comes out and it doesn't rain. It's really easy to start ignoring them. I even see winter storm warnings that fizzle out to a couple of inches of snow. The weather report is frequently a bad version of the boy who cried wolf.
But, as you said, not every warning translates into a confirmed tornado on the ground, a limitation of the current radar models.
The issue is that there are 100 tornado warnings for every one that actually matters to you. And the tornado warnings really are tornados, but they mostly take out some trees on the ridge and the occasional barn roof. A lot of those are big, too.
The issue is the capriciousness of the whole thing.
You get used to close calls. They happen all the time. And sometimes those close calls kill a lot of people.
It's not that folks don't pay attention. The fatigue is real. But even more than that is the simple fact that most take out the barn and not the house. The difference between a lot of downed trees and a town wiped out is a couple hundred yards and random chance.
It's hard to rationalize and it's hard not to just accept the risk and just go on with your life.
One did take out the barn about 40 meters away. (it may have been a microburst, it was dark, anyway two buildings were translated one foot to the side and part of the barn roof ended up upside down on the ground next to the barn)
I don't know why people don't pay attention, I'm not surprised, but it puzzles me. When there's severe weather going past you pay attention to what's happening. There was always plenty of warning and plenty of information available.
The information is there, a whole lot of people who do get hurt by tornados are hurt because they're not paying attention to available information. It's not always enough to survive, true.
... and the fact that American houses tend to be built out of wood and drywall and without a basement to use as an improptu bunker to hide in.
We took tornado warnings very seriously. But the thing is, by the time a warning arrived, it was usually too late to make significant changes. The challenge was rather tornado watches. Watches were called rather frequently, well in advance of a storm, and covered expansive parts of the geography. We wouldn't make a lot of behavioral changes because of the watches except to be more vigilant with observing the sky and having a television or radio near to switch on in case the weather did change suddenly. So life essentially has to go on when watches were forecast a day in advance. There really was no other choice; society wouldn't let you operate on your own pace here.
I don't want to liken tornado preparedness/cognizance with a choice to be a smoker or not, because there are a lot of factors that go into it. Education level, risk tolerance, economic standing (e.g., ability to afford a dedicated shelter — few basements in the part of Oklahoma I grew up in), and socialization. There were a lot of folks who were just blase about hazards around them to a fault. I like to think that refinery infrastructure in West Tulsa (https://www.google.com/maps/@36.1248523,-96.027147,7915m/dat...) is a good example of this. This infrastructure belched so much pollution into the local environment, yet nobody gave a damn. The days one could experience the River Parks System (https://www.riverparks.org/) without the overwhelming odor of petroleum refinement were rare. Folks were just used to this kind of thing — a damning case of relative deprivation. Probably carries over to the weather, too.
But thanks to being so far inland, storms were usually very clear on the radar well before they came (100s of kilometers away). The real hazard were storms that developed spontaneously.
OTOH, tornadoes arose plenty in storms that never had announced watches, so it often meant a warning came "out-of-the-blue." To this day, I remain hyper vigilant around any storm that develops even though I live on another continent and in an area without much tornadic activity. Maybe I'm a neurotic outlier. Probably these neurotic genes have better survival fitness than the others, or at least I'll keep fooling myself into believing this …
Modern TVs, not so much. A quick glance doesn't show anyone working to make an RTLSDR tornado detector, which prolly means I just missed it. Seems like it shouldn't be too hard.
"Raspberry Shake", "RS&BOOM" https://manual.raspberryshake.org/boom.html#technical-specif... https://shop.raspberryshake.org/infrasound/
FWIU infrasound may indicate Earthquake, Fire, Tornado; and probably IDK Stampede?
Infrasound: https://en.wikipedia.org/wiki/Infrasound
FWIU the Phononic wave signal is embedded in the Photonic wave signal, and so it may be possible to create even less extensive infrasound sensors;
"Quantum light sees quantum sound: phonon/photon correlations" (2023) https://news.ycombinator.com/item?id=37793791
Then doesn't it have a similar potential for false positives as doppler radar? It might have a lower rate, sure, but it doesn't sound like a silver bullet.
https://www.grasacoustics.com/products/special-microphone/in...
Excerpt: "To achieve a very low low-frequency cut-off of down to 0.09 Hz, a special microphone combined with a special preamplifier and a low-frequency adapter is used. To account for pressure variations close to 0 Hz, a special ambient pressure equalization system with a very long settling time is used."
It’s not true. It’s grossly oversimplified. I could generate a 1hz signal that I can hear. It’s not the same as something at 400hz but it’s clearly audible with proper sound equipment.
Now as that relates to tornadoes I live in a state where there are occasional tornadoes. Every time one has been close you hear the approach.
If you are using sound equipment then you are instrumentally detecting an inaudible frequency.
Am I misunderstanding?
I can imagine "feeling" 1Hz from a big subwoofer, but it's hard to imagine what actually hearing 1Hz would be like. I wouldn't rule it out, though.
You can check with a measurement mic what's audible (& make sure to take measurements at multiple points in space due to the low wave length).
To decrease the lower frequency of the audio interface, you probably have to modify the output DC decoupling capacitors (those act as a high pass; bigger C = lower f).
In case you were looking for a number.
I wonder if existing weather stations might be able to pull this from their existing barometric sensors, with nothing more than software.