Show notes
This episode features an insightful discussion with Dr. Elizabeth DiGangi, a Lightning Scientist at AEM, who shares her expertise on severe weather patterns, the findings of the AEM 2023 United States Lightning Report, and the potential impact of storms on wind turbines. Dr. DiGangi provides valuable insights into the formation of tornadoes, hail, and lightning, as well as the measures wind farm operators can take to mitigate risks associated with severe weather. Reach out at https://aem.eco/contact-us/ !
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Allen Hall: Welcome to the Uptime Wind Energy Podcast, your go to podcast for the latest insights and discussions on the wind energy industry. I'm your host, Allen Hall, along with my co host, Joel Saxum. The U. S. Heartland has recently experienced a series of severe weather events, including violent tornadoes, intense lightning strikes, and large hail.
These extreme conditions pose significant challenges to the wind energy industry, as wind turbines are particularly vulnerable to the forces of nature. We are thrilled to have with us a very special guest, Dr. Elizabeth DiGangi a Lightning Scientist at AEM, and AEM is based in Germantown, Maryland. Dr. DiGangi holds a Doctor of Philosophy in Meteorology from the University of Oklahoma. bringing a wealth of knowledge and expertise to our discussion. In this episode, Dr. Daganji will share her insights on the recent severe weather patterns, the findings of the AEM 2023 United States lightning report, and the potential impact of these storms can have on wind turbines.
She will also discuss the measures wind farm operators can take to mitigate the risks associated with severe weather and ensure the longevity and efficiency of their turbines. Turbines, whether you're a wind energy professional, a meteorology enthusiast, or simply interested in the intersection of weather and renewable energy.
This episode promises to be both informative and engaging. Join us as we explore the challenges and opportunities presented by severe weather with the wind energy industry with Dr. Elizabeth DiGangi from AEM, Dr. DiGangi. Welcome.
Dr. Elizabeth DiGangi: Thank you very much. I'm happy to be here.
Allen Hall: You've come at a really good time in a sense and also a really bad time is that there's been so much Horrible weather in the middle of the united states where most of the wind energy is created tornado after tornado and the storm chasers Have been putting a lot of that up on youtube and some of them saw 10 11 tornadoes in an afternoon It looks like movies What drives the quantity of tornadoes, like we just saw is that something special about the storm, or is it just a confluence of independent actions?
Dr. Elizabeth DiGangi: It's something special about the storm environment. Whether or not okay, so to start with, the type of storm that produces a tornado has to have, in almost every case unless you're getting little, like dust devil equivalents, a storm that is producing a tornado has a rotating updraft. So the air that goes in and up that's feeding the storm, spins while it goes up.
And that helps the storm achieve what we call a quasi steady state. Like it almost behaves like a spinning solid. If you had a cylinder that you were just twirling. There's like a similar kind of analogous physics going on. And that helps these storms persist for a long time. Obviously you can either have isolated supercell thunderstorms that produce tornadoes, which are characterized by these rotating updrafts.
These also are the storms that produce the largest hail. They tend to have very strong updrafts and a lot of capacity to like make this severe weather. And then you can also get linear or quasi linear convective systems that get little embedded rotations in them where they can spin up like those are the sort of short term tornadoes that like go for a little bit and they're like an EF1 or an EF2 tops and then dissipate after five or ten minutes.
But the line might produce more. So those are the two modes that it happens. But when you have an outbreak like this is like a convergence Both like air, like atmospheric convergence in a literal sense and just the convergence of so many factors that optimize the whole, like a whole region for tornado production.
The two big key things are three key things are heat, moisture. lift, there's a fourth thing, something called wind shear. The heat, moisture, and lift generally are pretty easy to come by in the central plains and of the U. S. In this time of year because you have warmer, moist air from the Gulf of Mexico that kind of comes up into the plains, and then usually that air mass ends up up against a drier, air mass to the further west, like from the mountains and stuff.
And that's where you get like the term dry line. It's literally like the line where it goes from being humid to dry. And along the boundaries like that and along warm fronts I think this system was probably had a frontal situation going on because there's like a larger scale atmospheric flow driving it.
But along these boundaries, that's where the lift comes in because you get convergence of air near the surface. And it's warm, and it's moist, and it's less dense than the air it's coming in contact with, so it goes up. The wind shear is the thing that makes it spin. Wind shear is defined is just the way the wind changes with height.
If you have winds coming in from the southeast at the surface, and as you go up through the atmosphere, because the things going on at a high level and a mid level are different than at the surface, the that wind shifts, in a clockwise direction until it is now when you're up in near the jet stream, the jet streams flowing from west to east.
And that is what primes, that's what makes it so that the storm can spin because the air is then turning as it goes up along those boundaries.
Allen Hall: It's how the wind industry works here. The mere fact that wind is that dry air is coming from the west. And, which makes it great for wind turbines, is hitting the Gulf Coast humidity, boom.
That's where the action gets really violent. And that happens, does that happen only in a particular time of year? You don't see that in December and January.
Dr. Elizabeth DiGangi: Yeah, and it's much more typical in springtime. Usually by mid to late June, you get in the U S here, we'll get like a big high pressure system that kind of sits over the middle of the country and you can get good wind from that too.
It's just spinning counterclockwise instead of clockwise or clockwise instead of counterclockwise. And the, but that kind of prevents storms from happening during the day. During the summer is when you tend to get those nocturnal systems that happen because you get, can, you get like smaller, weaker storms maybe up in like the high plains and in the mountains and then they flow downhill and as they are moving and night comes on, they merge together and then you get these big convective systems that just cruise across the central and northern plains at night.
It's just a different convective regime. But springtime is just when the jet stream is in the right spot and there's that nice dry line set up and you get The right flow off the gulf and everything's in place.
Allen Hall: That explains a lot. So the thunderstorms we received in August, I lived in Wichita for a number of years.
The thunderstorms you get in August are nothing like the thunderstorms you get in April. They are different animals.
Joel Saxum: The troubling thing here though is for the wind industry is that because of the the taking advantage of the wind, of course, right? There, the wind turbine farms are placed.
In an area that is prone to tornadoes as well, right? Like I was watching this, a meteorologist on Twitter I was watching put out a map of all of these tornado outbreaks. Where all the warnings were, and the tornado warnings, tornado watches, all this stuff. And like the patterns of those, okay, that was weird how homogeneous the patterns were almost like, it was like, you just moved over a little bit and they were in the same exact path all the way from basically Northern Texas to Wisconsin.
But you saw every place they popped up on the map. I was like, Oh, I know wind farms there. Oh, there's wind farms there too. Oh, there's a wind farms there too. So you start I started calling, I started legitimately texting my insurance industry friends Hey guys. Be ready for Monday morning, because it's coming.
Allen Hall: And we should take those alarms that go off, and the sirens that go off, and now you're getting, receiving texts from systems like AEM produces, that tells you, hey, there's a tornado in the area you better take action. I know you get a little complacent, especially when we lived in Wichita, weirdly enough, that Tornadoes were so frequent that people would just sit on the patio and watch them go by but that's a bad rule of thumb, right?
You should not do that. Particularly if you're in a wind farm, you should get the heck out of there. Those are serious, right?
Dr. Elizabeth DiGangi: If you were like in and around a wind farm when there was a tornado blowing over, that is the, there is a lot of potential very heavy debris that could be slamming into you.
That's the danger is not necessarily the tornado itself,