1 00:00:06,369 --> 00:00:08,275 So, I think all good tornado talks 2 00:00:08,275 --> 00:00:11,206 need to start with an awesome tornado shot. 3 00:00:11,206 --> 00:00:13,057 And this is not that awesome tornado shot. 4 00:00:13,057 --> 00:00:14,559 Alright, that was the first tornado I ever saw, 5 00:00:14,559 --> 00:00:16,050 it was really cool, it was really scary, 6 00:00:16,050 --> 00:00:17,526 and the reason I'm showing it to you guys 7 00:00:17,526 --> 00:00:20,470 was because that's why I got into the field in the first place. 8 00:00:20,470 --> 00:00:22,615 So, even though it's a bad photograph, 9 00:00:22,615 --> 00:00:24,875 it was really cool to be out there the first time. 10 00:00:24,875 --> 00:00:27,497 But now I'm taking real tornado footage. 11 00:00:27,497 --> 00:00:28,834 Fast forward a few years here. 12 00:00:28,834 --> 00:00:30,027 This is a few years ago 13 00:00:30,027 --> 00:00:32,191 during a field project called VORTEX2, 14 00:00:32,191 --> 00:00:34,964 where myself and a bunch of other scientists were out there 15 00:00:34,964 --> 00:00:37,352 surrounding tornadoes with different types of instrumentation 16 00:00:37,352 --> 00:00:39,942 and trying to figure out how tornadoes form. 17 00:00:39,942 --> 00:00:41,545 So, it's a big question that we're trying to answer. 18 00:00:41,545 --> 00:00:43,309 It sounds like a very basic one, 19 00:00:43,309 --> 00:00:45,403 but it's something that we're still trying to figure out. 20 00:00:45,403 --> 00:00:47,123 We're also still trying to figure out 21 00:00:47,123 --> 00:00:49,078 what the winds are like near the surface. 22 00:00:49,078 --> 00:00:51,397 We know what the winds are like above building level, 23 00:00:51,397 --> 00:00:53,692 but we really don't know what the winds are like at the surface 24 00:00:53,692 --> 00:00:57,188 and how that relates to what we're seeing above building level. 25 00:00:57,188 --> 00:01:00,964 So, most tornadoes form from what we call supercell thunderstorms, 26 00:01:00,964 --> 00:01:02,359 and these supercell thunderstorms 27 00:01:02,359 --> 00:01:05,336 are what you commonly think of as tornado-raising storms. 28 00:01:05,336 --> 00:01:07,055 They're big, rotating thunderstorms 29 00:01:07,055 --> 00:01:10,227 that happen a lot of times in the midsection of the United States. 30 00:01:10,227 --> 00:01:11,693 But the problem is that 31 00:01:11,693 --> 00:01:14,119 even because they're rotating up above 32 00:01:14,119 --> 00:01:16,113 doesn't mean they're rotating at the surface. 33 00:01:16,113 --> 00:01:17,484 And when we look at these storms 34 00:01:17,484 --> 00:01:18,447 and when we look at these pictures 35 00:01:18,447 --> 00:01:20,359 and when we look at the data that we have 36 00:01:20,359 --> 00:01:21,818 they all kind of look the same. 37 00:01:21,818 --> 00:01:23,126 And it's really problematic 38 00:01:23,126 --> 00:01:25,808 if we're trying to make tornado forecasts or tornado warnings 39 00:01:25,808 --> 00:01:27,193 because we only want to warn on the storms 40 00:01:27,193 --> 00:01:28,660 or forecast about the storms 41 00:01:28,660 --> 00:01:30,617 that are going to actually make a tornado. 42 00:01:30,617 --> 00:01:33,326 One of the big critical distinguishing features 43 00:01:33,326 --> 00:01:34,773 that we think between these storms 44 00:01:34,773 --> 00:01:37,776 is something about the rear flank downdraft. 45 00:01:37,776 --> 00:01:39,294 So, these big rotating thunderstorms 46 00:01:39,294 --> 00:01:42,590 have this downdraft that wraps around the rear edge of it, 47 00:01:42,590 --> 00:01:44,178 hence the rear flanking downdraft. 48 00:01:44,178 --> 00:01:46,385 But we think how warm that is, 49 00:01:46,385 --> 00:01:47,629 how buoyant that air is, 50 00:01:47,629 --> 00:01:49,431 and then also how strong the updraft 51 00:01:49,431 --> 00:01:50,839 that's wrapping into 52 00:01:50,839 --> 00:01:52,443 makes a big difference on whether or not 53 00:01:52,443 --> 00:01:54,116 there's going to make a tornado or not. 54 00:01:54,116 --> 00:01:55,871 And there's certainly a lot more that goes into it 55 00:01:55,871 --> 00:01:57,871 and I'll tell you a little more about that in a second. 56 00:01:57,871 --> 00:01:59,908 Once you actually get a tornado, 57 00:01:59,908 --> 00:02:01,375 again, the problem that we have 58 00:02:01,375 --> 00:02:03,486 is getting measurements near the surface. 59 00:02:03,486 --> 00:02:05,028 It's really hard to get measurements near the surface 60 00:02:05,028 --> 00:02:08,131 because most people don't want to drive into tornadoes. 61 00:02:08,131 --> 00:02:09,736 There are a few exceptions, 62 00:02:09,736 --> 00:02:11,526 and you might have seen them on TV shows. 63 00:02:11,526 --> 00:02:13,193 But most people don't want to do that. 64 00:02:13,193 --> 00:02:17,110 And even getting instrumentation in the path of the tornado is pretty tricky, too. 65 00:02:17,110 --> 00:02:19,368 Because, again, you don't want to be that close to a tornado 66 00:02:19,368 --> 00:02:22,629 because sometimes the winds around the tornado are strong, as well. 67 00:02:22,629 --> 00:02:26,854 So, getting information, that critical location, is key for us. 68 00:02:26,854 --> 00:02:27,871 Because, again, we don't know 69 00:02:27,871 --> 00:02:30,055 if the winds that we're seeing above ground level, 70 00:02:30,055 --> 00:02:31,359 way above building level, 71 00:02:31,359 --> 00:02:32,931 actually map to the surface. 72 00:02:32,931 --> 00:02:34,314 If they're stronger, if they're weaker, 73 00:02:34,314 --> 00:02:37,559 or if they're about the same as what we're saying above buildings. 74 00:02:37,559 --> 00:02:39,276 The way that we get at answering a lot of these questions, 75 00:02:39,276 --> 00:02:42,025 and I'm an observationalist, so I love to get out in the field, 76 00:02:42,025 --> 00:02:43,733 I love to collect data on tornadoes, 77 00:02:43,733 --> 00:02:45,486 we compile a lot of observations. 78 00:02:45,486 --> 00:02:48,024 And I work with this group who operates these mobile radars, 79 00:02:48,024 --> 00:02:49,441 and they're exactly what they say they are: 80 00:02:49,441 --> 00:02:51,739 they're basically a radar on the back of a big blue truck, 81 00:02:51,739 --> 00:02:53,745 and we drive up really close to tornadoes 82 00:02:53,745 --> 00:02:57,186 to map out the winds, we map out the precipitation, 83 00:02:57,186 --> 00:02:59,442 we map out all these different things that are going on 84 00:02:59,442 --> 00:03:03,130 in order to better understand the processes in these storms. 85 00:03:03,130 --> 00:03:04,172 And that bottom there, 86 00:03:04,172 --> 00:03:05,506 that's what a tornado looks like 87 00:03:05,506 --> 00:03:06,965 when you're looking at it with a mobile radar 88 00:03:06,965 --> 00:03:09,181 and when you're looking at it with a mobile radar really close. 89 00:03:09,181 --> 00:03:11,471 Also, what we do is we do a lot of modeling, 90 00:03:11,471 --> 00:03:14,086 so we do a lot of computer models and simulations 91 00:03:14,086 --> 00:03:16,760 because the atmosphere is governed by the laws of physics, 92 00:03:16,760 --> 00:03:18,563 so we can model the laws of physics 93 00:03:18,563 --> 00:03:20,813 and see where the tornado might go, 94 00:03:20,813 --> 00:03:22,275 where the storm might go, 95 00:03:22,275 --> 00:03:24,066 how strong the winds are near the surface 96 00:03:24,066 --> 00:03:25,944 and not actually have to go out in the field. 97 00:03:25,944 --> 00:03:28,929 But, of course, we want to have both observations and modelling 98 00:03:28,929 --> 00:03:30,959 to move forward with the science. 99 00:03:30,959 --> 00:03:34,695 So, this is, I showed you that video earlier that went real quick, too. 100 00:03:34,695 --> 00:03:36,802 This is what it looks like when you're looking at it with a radar. 101 00:03:36,802 --> 00:03:38,042 So you saw it visually, 102 00:03:38,042 --> 00:03:39,554 but this is what I get really excited about 103 00:03:39,554 --> 00:03:40,867 when I see now in the field 104 00:03:40,867 --> 00:03:42,237 is stuff that looks like this. 105 00:03:42,237 --> 00:03:44,720 And the really exciting thing about looking at stuff like this 106 00:03:44,720 --> 00:03:46,446 is that this storm, 107 00:03:46,446 --> 00:03:48,924 we caught it from when it didn't make a tornado 108 00:03:48,924 --> 00:03:50,023 to when it made a tornado 109 00:03:50,023 --> 00:03:50,945 and it intensified 110 00:03:50,945 --> 00:03:52,094 and when it dissipated. 111 00:03:52,094 --> 00:03:53,959 So, this is the one of the really rare data sets 112 00:03:53,959 --> 00:03:54,863 that we have out there 113 00:03:54,863 --> 00:03:58,502 that we're able to study the entire life cycle of a tornado. 114 00:03:58,502 --> 00:04:00,085 I talked about that rear-flying down draft, 115 00:04:00,085 --> 00:04:02,108 how we think that rear flanking downdraft is important 116 00:04:02,108 --> 00:04:05,497 because it tilts, there's a lot of spin in the atmosphere, 117 00:04:05,497 --> 00:04:07,316 but the problem with all this spin in the atmosphere 118 00:04:07,316 --> 00:04:09,820 is it needs to be oriented vertically 119 00:04:09,820 --> 00:04:11,131 because that's what tornadoes are doing, 120 00:04:11,131 --> 00:04:14,088 and it needs to orientated vertically near the ground. 121 00:04:14,088 --> 00:04:16,809 So, we think this rear flanking downdraft, we think that it just pulses. 122 00:04:16,809 --> 00:04:18,760 And these pulses in this rear flanking downdraft, 123 00:04:18,760 --> 00:04:20,310 we think are very important 124 00:04:20,310 --> 00:04:22,065 for converging that rotation 125 00:04:22,065 --> 00:04:25,210 but also getting that rotation into the right place. 126 00:04:25,210 --> 00:04:26,131 Other things that we've learned 127 00:04:26,131 --> 00:04:28,678 is that we have gotten a bunch of fortuitous measurements 128 00:04:28,678 --> 00:04:29,932 in the path of the tornadoes 129 00:04:29,932 --> 00:04:31,454 and very near the surface. 130 00:04:31,454 --> 00:04:33,857 And we found out that the winds near the surface 131 00:04:33,857 --> 00:04:35,586 are actually pretty comparable 132 00:04:35,586 --> 00:04:38,720 to what we're seeing 30, 40 meters above ground level. 133 00:04:38,720 --> 00:04:41,591 So there's not a big reduction in what we're seeing above the surface 134 00:04:41,591 --> 00:04:43,728 to what we're seeing at house level. 135 00:04:43,728 --> 00:04:45,750 And that was a pretty surprising finding for us 136 00:04:45,750 --> 00:04:47,739 because we kind of assumed that 137 00:04:47,739 --> 00:04:50,945 the winds decreased pretty substantially near the surface. 138 00:04:50,945 --> 00:04:52,481 So I'm going to end it with this real quick. 139 00:04:52,481 --> 00:04:54,782 And this is not my last tornado I ever saw, 140 00:04:54,782 --> 00:04:56,577 but I really like this image 141 00:04:56,577 --> 00:04:59,719 because this was taken with one of those mobile radars I was talking about. 142 00:04:59,719 --> 00:05:01,494 And this is a tornado, not a hurricane, 143 00:05:01,494 --> 00:05:02,582 and this is what it looks like 144 00:05:02,582 --> 00:05:04,117 when you're really close to it. 145 00:05:04,117 --> 00:05:05,164 And I find this amazing, 146 00:05:05,164 --> 00:05:06,546 that we can actually take technology, 147 00:05:06,546 --> 00:05:09,299 take technology this close to these types of storms, 148 00:05:09,299 --> 00:05:10,983 and see these inner workings. 149 00:05:10,983 --> 00:05:14,231 And for those of you who look at tornado images often, 150 00:05:14,231 --> 00:05:15,900 you can see there's a lot going on there. 151 00:05:15,900 --> 00:05:18,465 There's rain spiraling, and you can actually see the debris cloud 152 00:05:18,465 --> 00:05:19,967 associated with this tornado, 153 00:05:19,967 --> 00:05:22,437 and I look forward to the future and future technologies 154 00:05:22,437 --> 00:05:25,138 and being able to learn a lot more about these storms 155 00:05:25,138 --> 00:05:26,522 as the world advances, 156 00:05:26,522 --> 00:05:28,372 as you guys contribute to the science, 157 00:05:28,372 --> 00:05:31,445 and we're able to really learn more about how tornadoes form. 158 00:05:31,445 --> 00:05:33,600 Thank you!