Science!
Here's a picture of a highway sign in Missouri, posted because I was on the lookout as we passed through here for tornado damage. Remember that big tornado last December that dove through my old Kentucky homeland, wrecking Mayfield and Dawson Springs and a bunch of other places? (I mentioned that here.) The earliest version of that tornado started just southeast of Jonesboro, Arkansas, about 53 miles southwest of the spot on I-55 where I took this picture. That tornado crossed the highway right here. This is, in fact, about where it was when I heard about what was happening on social media and started watching the internet radars. I paid closer attention because I knew this highway interchange, and then I followed the storm as it hopped the Mississippi and made its run through places I know even better. Much of the internet chatter after the storm suggested the tornado ran in a constant line all the way into Breckinridge County, Kentucky, another 203 miles away. That would have made this the longest continuous tornado track in history, but the National Weather Service surveys taken a day or two later said the storm lifted for about 14 miles between Reelfoot Lake and the Tennessee-Kentucky line.
This leads me to a bit of a rant about weather science, focusing specifically on the Enhanced Fujita Scale we use to measure the intensity of tornadoes. This dominated the weather-related social media for a few days, and I developed opinions.
First, here's the background. Back in the 1970s, meteorological technology had no way to directly measure the intensity of the wind within a tornado, because weather radar can't see wind. So a scientist named Ted Fujita came up with a system of proxy measurement, where you could look at the damage the tornado caused and indirectly estimate the speed the wind would have to reach to do all that. This became the Fujita Scale, which divided tornados into five categories by the severity of the damage they caused. An F1 was a little tornado that just left broken tree limbs and maybe messed up some roof tiles. An F5 was a monster that wiped a home's concrete slab foundation clean. The scientists fiddled with the system a few times over the years, and in 2007 they adopted a modified version called the Enhanced Fujita Scale, which is still in use today. The main enhancement is the addition of a letter, so that what used to be an F1 is now an EF-1.
And so, along comes this storm running about 260 miles (with a little gap) from Jonesboro, Arkansas, to Falls of Rough, Kentucky. A lot of storm chasers and weather folks went looking around the places hit by this tornado and saw a bunch of concrete slabs wiped clean in Mayfield and Dawson Springs and, most especially, a little town called Bremen in Muhlenberg County, and all these guys said, "My God! That was an EF-5." But then, after a couple of days, the National Weather Service guys who actually measure all this came along behind them and burst their bubbles. "Nope," they said. "What you see here? This clean concrete slab where a judge's house used to be in Muhlenberg County? That's just an EF-4. The best guess we can make on wind speed is 196 miles per hour."
That strikes me as an awfully specific number for something they say has to be vague. But I digress.
Now, the National Weather Service wasn't saying the winds weren't up into EF-5 territory. What it was saying was that it didn't know how high the winds were. The problem is that by their scale and system of measurement, in order for a tornado to be classified as an EF-5, it has to have wrecked a house built to EF-5 standards. In this specific case, the house has to have been bolted into a concrete slab and braced in a certain way. But most homes in Kentucky don't sit on concrete slabs, and those that do aren't built with these bolts. Since none of the wrecked homes fit this criteria, this tornado can't be rated an EF-5. In fact, an EF-5 in Western Kentucky is impossible. No matter how severe a tornado is, it can't be an EF-5.
And the thing about this is that this statement is entirely, 100% correct. Under this system, no place where buildings aren't built to certain specific, rigid standards can ever experience an EF-5. It's simply impossible. This doesn't mean such places can't experience wind speeds that match what an EF-5 is supposed to be. It just means that the housing stock isn't good enough for you to see EF-5 damage.
The result of this, then, is that the Fujita Scale isn't so much a measure of tornado intensity as it is a measure of construction standards. This makes it a lot less useful as an analytical tool than I've always believed.
Never mind that technology with weather radar and satellites has advanced enough to give you other methods to indicate wind speed through more direct measurement, and that you could overlay that data with data collected afterward on the ground and get a much fuller picture of the tornado. The National Weather Service doesn't want to do any of that. Those tools aren't standardized enough, they say, and incorporating that data now would make it more difficult to compare to data collected 10 or 20 years ago. Which I think is a backward way of looking at the issue. But then, nobody asked me.
Of course, some people might be tempted to look at this as an example of how all climate science is wrong ... which must mean the global climate change is a hoax, and the ozone hole isn't real, and the Earth isn't really spherical, and the Moon Landing never happened, and there really isn't some fairy floating around who wants all your teeth. None of that is what I'm saying. There are plenty of valid and precise tools used by weather and climate scientists to explain very well what's going on in the world. What I'm saying is that the Enhanced Fujita Scale, as it exists now, isn't necessarily one of them. It measures the wrong things, and the scientists should rethink that.
Science!
Here's a picture of a highway sign in Missouri, posted because I was on the lookout as we passed through here for tornado damage. Remember that big tornado last December that dove through my old Kentucky homeland, wrecking Mayfield and Dawson Springs and a bunch of other places? (I mentioned that here.) The earliest version of that tornado started just southeast of Jonesboro, Arkansas, about 53 miles southwest of the spot on I-55 where I took this picture. That tornado crossed the highway right here. This is, in fact, about where it was when I heard about what was happening on social media and started watching the internet radars. I paid closer attention because I knew this highway interchange, and then I followed the storm as it hopped the Mississippi and made its run through places I know even better. Much of the internet chatter after the storm suggested the tornado ran in a constant line all the way into Breckinridge County, Kentucky, another 203 miles away. That would have made this the longest continuous tornado track in history, but the National Weather Service surveys taken a day or two later said the storm lifted for about 14 miles between Reelfoot Lake and the Tennessee-Kentucky line.
This leads me to a bit of a rant about weather science, focusing specifically on the Enhanced Fujita Scale we use to measure the intensity of tornadoes. This dominated the weather-related social media for a few days, and I developed opinions.
First, here's the background. Back in the 1970s, meteorological technology had no way to directly measure the intensity of the wind within a tornado, because weather radar can't see wind. So a scientist named Ted Fujita came up with a system of proxy measurement, where you could look at the damage the tornado caused and indirectly estimate the speed the wind would have to reach to do all that. This became the Fujita Scale, which divided tornados into five categories by the severity of the damage they caused. An F1 was a little tornado that just left broken tree limbs and maybe messed up some roof tiles. An F5 was a monster that wiped a home's concrete slab foundation clean. The scientists fiddled with the system a few times over the years, and in 2007 they adopted a modified version called the Enhanced Fujita Scale, which is still in use today. The main enhancement is the addition of a letter, so that what used to be an F1 is now an EF-1.
And so, along comes this storm running about 260 miles (with a little gap) from Jonesboro, Arkansas, to Falls of Rough, Kentucky. A lot of storm chasers and weather folks went looking around the places hit by this tornado and saw a bunch of concrete slabs wiped clean in Mayfield and Dawson Springs and, most especially, a little town called Bremen in Muhlenberg County, and all these guys said, "My God! That was an EF-5." But then, after a couple of days, the National Weather Service guys who actually measure all this came along behind them and burst their bubbles. "Nope," they said. "What you see here? This clean concrete slab where a judge's house used to be in Muhlenberg County? That's just an EF-4. The best guess we can make on wind speed is 196 miles per hour."
That strikes me as an awfully specific number for something they say has to be vague. But I digress.
Now, the National Weather Service wasn't saying the winds weren't up into EF-5 territory. What it was saying was that it didn't know how high the winds were. The problem is that by their scale and system of measurement, in order for a tornado to be classified as an EF-5, it has to have wrecked a house built to EF-5 standards. In this specific case, the house has to have been bolted into a concrete slab and braced in a certain way. But most homes in Kentucky don't sit on concrete slabs, and those that do aren't built with these bolts. Since none of the wrecked homes fit this criteria, this tornado can't be rated an EF-5. In fact, an EF-5 in Western Kentucky is impossible. No matter how severe a tornado is, it can't be an EF-5.
And the thing about this is that this statement is entirely, 100% correct. Under this system, no place where buildings aren't built to certain specific, rigid standards can ever experience an EF-5. It's simply impossible. This doesn't mean such places can't experience wind speeds that match what an EF-5 is supposed to be. It just means that the housing stock isn't good enough for you to see EF-5 damage.
The result of this, then, is that the Fujita Scale isn't so much a measure of tornado intensity as it is a measure of construction standards. This makes it a lot less useful as an analytical tool than I've always believed.
Never mind that technology with weather radar and satellites has advanced enough to give you other methods to indicate wind speed through more direct measurement, and that you could overlay that data with data collected afterward on the ground and get a much fuller picture of the tornado. The National Weather Service doesn't want to do any of that. Those tools aren't standardized enough, they say, and incorporating that data now would make it more difficult to compare to data collected 10 or 20 years ago. Which I think is a backward way of looking at the issue. But then, nobody asked me.
Of course, some people might be tempted to look at this as an example of how all climate science is wrong ... which must mean the global climate change is a hoax, and the ozone hole isn't real, and the Earth isn't really spherical, and the Moon Landing never happened, and there really isn't some fairy floating around who wants all your teeth. None of that is what I'm saying. There are plenty of valid and precise tools used by weather and climate scientists to explain very well what's going on in the world. What I'm saying is that the Enhanced Fujita Scale, as it exists now, isn't necessarily one of them. It measures the wrong things, and the scientists should rethink that.