Melissa Harris-Perry: You're listening to The Takeaway. I'm Melissa Harris-Perry. If you're anything like me, the 1990s blockbuster movie Twister is responsible for the sum total of your knowledge about tornadoes. Twister is one of those bad movies that's just so good to watch. In it, Helen Hunt and Bill Paxton play storm chasers, attempting to deploy a groundbreaking tornado research device during a really severe outbreak of tornadoes in Oklahoma.
Helen Hunt: Cow.
Jami Gertz: I got to go, Julia. We got cows.
Helen Hunt: Another cow.
Bill Paxton: Actually, I think that was the same one.
Melissa Harris-Perry: Now, while the science of Twister is questionable in some big ways, it did generate a lot of interest in meteorology and environmental science, and that's a good thing, given how little we still know about tornadoes. Unlike other natural disasters, including hurricanes, tornadoes are much more difficult to predict. In some cases, tornado warnings come only minutes before it hits.
To help us understand why that is and more, I spoke with Jeff Weber, a scientist at the University Corporation of Atmospheric Research. He told me that this year has already been a pretty active tornado year, with tornadoes hitting a number of states in recent weeks, from Illinois to Alabama, to North Carolina, where I'm based.
Jeff Weber: What we have going on right now in the atmosphere is what we call an amplified jet stream, an amplified wave train. What this means is that the jet stream, which generally runs from east to west across the country, has got a lot of north and south components to it. When it does this amplification, it brings very cold air from the north down to the Gulf Coast, and it brings very warm moist air up to the northern tier states. This adds to instability because you're bringing this warm moisture to interact with colder, drier air. Those are exactly the ingredients that we need for tornadoes.
Melissa Harris-Perry: This seems like the kind of thing that, granted, I would not be able to see and tell, but folks with specialized knowledge would be able to look at and see it happening on the map and say, "This looks like we'll have increased tornadoes this week." Is that how it works?
Jeff Weber: That's exactly right. We continue to strive to get better warnings once the tornadoes are on the ground to warn people to take shelter. However, what we've been able to do is look at conditions one to three days in advance. We can say, "Well, the conditions are going to be right for tornadic activity in this area, either tomorrow or the next day." That gives people a little bit of a heads up to be aware of the fact that tornadoes could be present in their area.
It's not as definitive as a true warning, because we just say, "Tornadoes are likely to occur in your area," and we continue to strive to have better warnings once the tornadoes are on the ground, but this is a way for people to at least be aware of the fact that there is a possibility for tornadoes in their area in the coming days.
Melissa Harris-Perry: How much advance notice do people typically get when a tornado is on the way?
Jeff Weber: NOAA is striving for a 13-minute warning for people once the tornadoes on the ground. Average is around 15 minutes, but there are times when it's far less than that. There are times we have three to five minutes of warnings. Tornadoes that occur in remote areas where we don't have as good coverage with radar, those not going to be detected as easily or as quickly. There are a lot of nuances and subtleties to how much of advanced warning you're going to get.
Melissa Harris-Perry: Have we seen tornadoes happening more frequently in places that are surprising to you or other scientists?
Jeff Weber: To some degree, yes. Now, I'll be so bold as to say with a warming climate as we go into a climate-changing environment, tornadoes likely to become more intense, but the location of where they occur may change. The interaction of that cold, dry air with the warm moist air might shift in some ways that are not to be determined at this point.
We're fairly well-versed in what atmospheric parameters are needed for tornado. What we're struggling with is, what is the trigger? What is the catalyst that makes some storms go tornadic and others that seem to be very similar, or if not identical to us at this point in time, don't spawn tornadoes? That's the real question.
Jeff Weber: Why are tornadoes harder for scientists to observe compared with other natural disasters?
Melissa Harris-Perry: Tornadoes are very elusive. We have very few datasets on tornadoes primarily because they are short-lived, and we don't know exactly where they're going to show up, so we can't get our sensors and our machines in place to observe them. Also, most of the tornadoes are on the scale that we can't observe from space.
The highest resolution of our geostationary Earth satellites is 500 meters. Oftentimes tornadoes are not that wide. We can't observe them from space like we can other phenomena such as hurricanes or mid-latitude winter cyclones. We can see that from space, we get a lot of information that way, whereas tornadoes are a smaller-scale phenomena. They're shorter-lived, and we have not an exact location where they're going to descend. It's very difficult to study these with a complete dataset.
Both hurricanes and tornadoes are incredible atmospheric phenomena, but they're dramatically different because, at least as far as studying them. Hurricanes, they'll trek across the Atlantic or across the Gulf of Mexico for days, and so we have the opportunity to watch and observe them. We can get instruments into the actual hurricane itself, we can fly planes through the eyewall, we can drop dropsondes into the eye.
We can actually get a lot of information about these systems as they're coming onshore. That's enabled us to both improve the tracking of hurricanes as well as the intensification of hurricanes over the past couple of decades.
Whereas tornadoes, as you mentioned, they come out of the sky, and they might be on the ground for eight minutes, and then they're gone. It's very difficult to marshal the resources to study that tornado because they are so short-lived, and we don't know where they're going to pop up. Studying tornadoes is far more elusive than studying hurricanes and other types of atmospheric phenomena.
Melissa Harris-Perry: What are some of the big ways we might achieve better tornado forecasting?
Jeff Weber: What's taken place in the past couple of decades are these large field experiments, VORTEX1 and VORTEX2. VORTEX1 was in the late 90s, and VORTEX2 was in 2010. At these times, we get dozens of universities to bring their faculty and students as well as their equipment and sensors into the planes to try to study tornadoes.
In 2010, with literally dozens of people and cars with temperature and wind sensors and Doppler on Wheels, which is a radar that can move and be mobile and get really good imagery of the tornadoes, there was only one tornado during that field season for these people to intercept and connect with. That tornado still is the most well-documented tornado and it's our best dataset of a tornado, but like hurricanes, they're not all the same. Granted, we have this great dataset of this one tornado that was in Wyoming in Nebraska, but we know tornadoes come in a variety of flavors. We even know that some tornadoes don't even spin cyclonically. About 2% or 3%, two or three out of every 100 tornadoes spin the other way.
Melissa Harris-Perry: Jeff Weber, I so appreciate this opportunity to talk with you. I'm actually pretty proud of myself that I made it through the whole thing without asking you about Twister. Here we go. Jeff Weber, a scientist at the University Corporation for Atmospheric Research. Thank you so much for joining us today.
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