AEM Lightning Expert on Severe Weather Risks for Wind Farms

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/ ! Sign up
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www.weatherguardwind.comIntelstor - https://www.intelstor.com 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,