Bill Burton: It's time for us to take a look at the Science Behind the Forecast as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning. And today's topic is really focused in on preparing for tornadoes, especially as we get closer to the core of the severe weather season.
BB: The tornado season is right around the corner, and unfortunately, the U.S. leads the world in tornadoes. It's not a category you want to lead in, but we do. What do we need to know about them?
TA: Well, in terms of how many tornadoes we see in the U.S. on average, we see around 1,200 twisters per year. That's our average.
The next country in that list is Canada, and they see on average around 60 tornadoes a year. So it is a big difference, and our geography plays a big role in why we see so many tornadoes, because you have the cold dry Canadian air meeting up with the Gulf's warm, humid air right over what we call Tornado Alley, and that interaction creates atmospheric instability and creates the perfect conditions for us to see severe thunderstorms and tornadoes. So for tornadoes to form, you need a couple of things. You need warm, moist air near the ground, cool, drier air, about 10,000 to 30,000 ft in altitude, and you also need wind shear, which is the change in wind speed and direction with altitude. And the topography and geography of the United States helps with all of those things. There was a study that came out in 2024 that highlighted the impact of terrain. Hundreds of miles upwind of tornado formation downstream and it noted that the fact that we have that smooth flat expanse all the way from the Gulf straight on through to the plains helps to contribute to tornado potential because there's nothing stopping the wind and really helping the wind to slow down in any of that space since it's so flat.
BB: That makes sense.
TA: Plus you have, of course, the moisture coming off of the Gulf and in the Great Plains in the Mississippi River Valley, you also have a lot of the crops and vegetation that also puts off moisture and that helps to fuel a lot of the severe thunderstorms and tornadic storms that we see. Something else that contributes to the amount of tornado fatalities that we see in the U.S., the couple of things, of course, the topography, which we just touched on, and the time of day. That plays a big role as well.
A tornado, of course, can form at any time of the day, but specifically, we see them more often between 4 p.m. and 9 p.m., which if you think about it, is also the warmest part of the day. So you have all that fuel at that point as well. Some numbers that I was looking into when I was diving into the data, I found that, of course, a lot of us know that Texas and Kansas have the highest number of tornadoes in the country. Around 135 tornadoes are seen yearly in Texas, but Alabama actually has the highest annual tornado fatalities, averaging around 14 per year. In the past decade, however, Kentucky has seen the highest number of tornado fatalities in the country, with 75 deaths in between 2014 and 2023. 57 of those 75 were just from that long track tornado that hit Mayfield and that that was a nighttime tornado.
BB: Yeah, we will all remember December 2021.
TA: Which is why you'll always hear me say have multiple ways to get alerts. Don't just rely on your phone, have the TV, a weather radio, whatever you need to make sure that you can get alerts day and night as we get further into the severe weather season.
BB: Yeah, when you're sleeping, it's, it just becomes so much more dangerous. You can't be prepared at that point, of course, but now we have a better understanding of why the US gets as many tornadoes as it does, and we have a better understanding of it thanks to this edition of Science Behind the Forecast with WAVE 3 meteorologist Tawana Andrew. Thanks for the knowledge, Tawana.
TA: Of course.
This transcript was edited for clarity.
