1
00:00:06,409 --> 00:00:08,275
So, I think all good tornado talks

2
00:00:08,275 --> 00:00:11,276
need to start with an awesome tornado shot.

3
00:00:11,276 --> 00:00:13,377
And this is not that tornado shot.

4
00:00:13,377 --> 00:00:14,919
Alright, that was the first tornado I ever saw,

5
00:00:14,919 --> 00:00:15,875
and it was really cool,

6
00:00:15,875 --> 00:00:17,003
and it was really scary,

7
00:00:17,003 --> 00:00:18,276
and the reason I'm showing it to you guys

8
00:00:18,276 --> 00:00:19,775
was because that's why I got into the field

9
00:00:19,775 --> 00:00:20,841
in the first place.

10
00:00:20,841 --> 00:00:23,035
So, even though it's a bad photograph,

11
00:00:23,035 --> 00:00:24,845
it was really cool to be out there the first time.

12
00:00:24,845 --> 00:00:27,057
But now I'm taking real tornado footage.

13
00:00:27,057 --> 00:00:28,724
Fast forward a few years here.

14
00:00:28,724 --> 00:00:30,027
This is a few years ago

15
00:00:30,027 --> 00:00:32,191
during a field project called Vortex 2,

16
00:00:32,191 --> 00:00:33,872
where myself and a bunch of other scientists

17
00:00:33,872 --> 00:00:34,944
were out there

18
00:00:34,944 --> 00:00:36,482
surrounding tornadoes with different types of instrumentation

19
00:00:36,482 --> 00:00:40,192
and trying to figure out how tornadoes form.

20
00:00:40,192 --> 00:00:41,109
So, it's a big question

21
00:00:41,109 --> 00:00:42,194
that we're trying to answer.

22
00:00:42,194 --> 00:00:43,489
It sounds like a basic one,

23
00:00:43,489 --> 00:00:45,193
but it's something we're still trying to figure out.

24
00:00:45,193 --> 00:00:46,993
We're also still trying to figure out

25
00:00:46,993 --> 00:00:49,078
what the winds are like near the surface.

26
00:00:49,078 --> 00:00:51,497
We know what the winds are like above building level,

27
00:00:51,497 --> 00:00:53,083
but we really don't know what the winds are like

28
00:00:53,083 --> 00:00:54,336
at the surface

29
00:00:54,336 --> 00:00:55,526
and how that relates

30
00:00:55,526 --> 00:00:57,045
to what we're seeing above building level.

31
00:00:57,045 --> 00:01:00,964
So, most tornadoes form from what we call supercell thunderstorms,

32
00:01:00,964 --> 00:01:02,359
and these supercell thunderstorms

33
00:01:02,359 --> 00:01:03,924
are what you commonly think of as

34
00:01:03,924 --> 00:01:05,553
tornado-racing storms.

35
00:01:05,553 --> 00:01:07,055
They're big, rotating thunderstorms

36
00:01:07,055 --> 00:01:10,357
that happen a lot in the mid section of the United States.

37
00:01:10,357 --> 00:01:11,693
But the problem is

38
00:01:11,693 --> 00:01:13,769
even because they're rotating up above

39
00:01:13,769 --> 00:01:16,113
doesn't mean they're rotating at the surface.

40
00:01:16,113 --> 00:01:17,484
And when we look at these storms

41
00:01:17,484 --> 00:01:18,607
and when we look at these pictures

42
00:01:18,607 --> 00:01:20,359
and when we look at the data that we have

43
00:01:20,359 --> 00:01:22,238
they all kind of look the same.

44
00:01:22,238 --> 00:01:23,406
And it's really problematic

45
00:01:23,406 --> 00:01:25,408
if we're trying to make tornado forecasts or tornado warnings

46
00:01:25,408 --> 00:01:27,193
because we only want to warn on the storms

47
00:01:27,193 --> 00:01:28,660
or forecast on the storms

48
00:01:28,660 --> 00:01:30,617
that are going to actually make a tornado.

49
00:01:30,617 --> 00:01:33,526
One of the big critical distinguishing features

50
00:01:33,526 --> 00:01:34,943
that we think between these storms

51
00:01:34,943 --> 00:01:37,776
is something about the rear flank down draft.

52
00:01:37,776 --> 00:01:39,294
So, these big rotating thunderstorms

53
00:01:39,294 --> 00:01:42,590
have this down draft that wraps around the rear edge of it,

54
00:01:42,590 --> 00:01:44,358
hence the rear-flanking down draft.

55
00:01:44,358 --> 00:01:46,385
But we think how warm that is,

56
00:01:46,385 --> 00:01:47,629
how buoyant that air is,

57
00:01:47,629 --> 00:01:49,431
and then also how strong the updraft

58
00:01:49,431 --> 00:01:50,639
that's wrapping into

59
00:01:50,639 --> 00:01:52,443
makes a big difference on whether or not

60
00:01:52,443 --> 00:01:54,116
there's going to make a tornado or not.

61
00:01:54,116 --> 00:01:55,871
And there's certainly a lot more that goes into it

62
00:01:55,871 --> 00:01:57,871
and I'll tell you a little more about that in a second.

63
00:01:57,871 --> 00:01:59,648
Once you actually get a tornado,

64
00:01:59,648 --> 00:02:01,525
again, the problem that we have

65
00:02:01,525 --> 00:02:03,486
is getting measurements near the surface.

66
00:02:03,486 --> 00:02:05,028
It's really hard to get measurements near the surface

67
00:02:05,028 --> 00:02:08,491
because most people don't want to drive into tornadoes.

68
00:02:08,491 --> 00:02:09,826
There are a few exceptions,

69
00:02:09,826 --> 00:02:11,526
and you might have seen them on TV shows.

70
00:02:11,526 --> 00:02:13,193
But most people don't want to do that.

71
00:02:13,193 --> 00:02:15,526
And even getting instrumentation in the path of the tornado

72
00:02:15,526 --> 00:02:17,109
is pretty tricky, too

73
00:02:17,109 --> 00:02:19,608
because, again, you don't want to be that close to a tornado

74
00:02:19,608 --> 00:02:22,629
because sometimes the winds around the tornado are strong, as well.

75
00:02:22,629 --> 00:02:24,340
So, getting information,

76
00:02:24,340 --> 00:02:25,859
that critical location,

77
00:02:25,859 --> 00:02:27,217
is key for us

78
00:02:27,217 --> 00:02:28,221
because, again, we don't know

79
00:02:28,221 --> 00:02:30,055
if the winds that we're seeing above ground level,

80
00:02:30,055 --> 00:02:31,359
way above building level,

81
00:02:31,359 --> 00:02:32,931
actually map to the surface.

82
00:02:32,931 --> 00:02:33,807
if they're stronger, if they're weaker,

83
00:02:33,807 --> 00:02:37,559
or if they're about the same as what we're saying above buildings.

84
00:02:37,559 --> 00:02:39,276
The way that we get at answering a lot of these questions,

85
00:02:39,276 --> 00:02:42,025
and I'm an observationalist, so I love to get out in the field,

86
00:02:42,025 --> 00:02:43,733
I love to collect data on tornadoes,

87
00:02:43,733 --> 00:02:45,486
we compile a lot of observations.

88
00:02:45,486 --> 00:02:48,194
And I work with this group who operates these mobile radars,

89
00:02:48,194 --> 00:02:49,691
and they're exactly what they say they are:

90
00:02:49,691 --> 00:02:51,326
they're basically a radar on the back

91
00:02:51,326 --> 00:02:52,442
of a big blue truck,

92
00:02:52,442 --> 00:02:54,025
and we drive up really close to tornadoes

93
00:02:54,025 --> 00:02:55,996
to map out the winds, we map out the precipitation,

94
00:02:55,996 --> 00:02:59,442
we map out all these different things that are going on

95
00:02:59,442 --> 00:03:03,130
in order to better understand the processes in these storms.

96
00:03:03,130 --> 00:03:04,172
And that bottom there,

97
00:03:04,172 --> 00:03:05,506
that's what a tornado looks like

98
00:03:05,506 --> 00:03:06,965
when you're looking at it with a mobile radar

99
00:03:06,965 --> 00:03:09,551
and when you're looking at it with a mobile radar real close.

100
00:03:09,551 --> 00:03:11,471
Also, we do a lot of modelling,

101
00:03:11,471 --> 00:03:13,556
so we do a lot of computer models and simulations

102
00:03:13,556 --> 00:03:16,360
because the atmosphere is governed by the laws of physics,

103
00:03:16,360 --> 00:03:18,563
so we can model the laws of physics

104
00:03:18,563 --> 00:03:20,813
and see where the tornado might go,

105
00:03:20,813 --> 00:03:22,525
where the storm might go,

106
00:03:22,525 --> 00:03:24,066
how strong the winds are near the surface

107
00:03:24,066 --> 00:03:25,944
and not actually have to go out in the field.

108
00:03:25,944 --> 00:03:27,569
But, of course, we want to have both

109
00:03:27,569 --> 00:03:28,988
observations and modelling

110
00:03:28,988 --> 00:03:30,739
to move forward with the science.

111
00:03:30,739 --> 00:03:31,859
So, this is,

112
00:03:31,859 --> 00:03:33,192
we showed you that video earlier

113
00:03:33,192 --> 00:03:34,609
that went real quick, too.

114
00:03:34,609 --> 00:03:36,692
This is what it looks like when you look at it with a radar.

115
00:03:36,692 --> 00:03:38,162
So you saw it visually,

116
00:03:38,162 --> 00:03:39,694
but this is what I get really excited about

117
00:03:39,694 --> 00:03:41,027
when I see now in the field

118
00:03:41,027 --> 00:03:42,527
is stuff like this.

119
00:03:42,527 --> 00:03:43,794
And the really exciting thing about

120
00:03:43,794 --> 00:03:45,046
looking at stuff like this

121
00:03:45,046 --> 00:03:46,716
is that this storm,

122
00:03:46,716 --> 00:03:48,924
we caught it from when it didn't make a tornado

123
00:03:48,924 --> 00:03:50,383
to when it made a tornado

124
00:03:50,383 --> 00:03:51,385
to when it intensified

125
00:03:51,385 --> 00:03:52,384
to when it disappeared.

126
00:03:52,384 --> 00:03:54,179
So, this is the one of the really rare data sets

127
00:03:54,179 --> 00:03:55,143
that we have out there

128
00:03:55,143 --> 00:03:58,642
that we're able to study the entire life cycle of a tornado.

129
00:03:58,642 --> 00:04:00,195
I talked about that rear-flying down draft,

130
00:04:00,195 --> 00:04:02,108
how we think that rear-flying down draft is important

131
00:04:02,108 --> 00:04:05,857
because it tilts, there's a lot of spin in the atmosphere,

132
00:04:05,857 --> 00:04:07,526
but the problem with all this spin in the atmosphere

133
00:04:07,526 --> 00:04:09,780
is it needs to be oriented vertically

134
00:04:09,780 --> 00:04:11,281
because that's what tornadoes are doing,

135
00:04:11,281 --> 00:04:12,697
and it needs to orientated vertically

136
00:04:12,697 --> 00:04:13,897
near the ground.

137
00:04:13,897 --> 00:04:15,456
So, we think this rear-flying downdraft,

138
00:04:15,456 --> 00:04:16,979
we think that it just pulses,

139
00:04:16,979 --> 00:04:18,620
and these pulses in this rear-flying draft,

140
00:04:18,620 --> 00:04:20,062
we think are very important

141
00:04:20,062 --> 00:04:21,625
for converging that rotation

142
00:04:21,625 --> 00:04:24,480
and also getting that rotation in the right place.

143
00:04:24,480 --> 00:04:26,211
Other things that we've learned

144
00:04:26,211 --> 00:04:28,398
is that we have gotten a bunch of fortuitous measurements

145
00:04:28,398 --> 00:04:29,992
in the path of the tornadoes

146
00:04:29,992 --> 00:04:31,634
and very near the surface.

147
00:04:31,634 --> 00:04:33,147
And we found out that the winds near the surface

148
00:04:33,147 --> 00:04:35,346
are actually pretty comparable

149
00:04:35,346 --> 00:04:38,350
to what we're seeing 30 to 40 meters above ground level,

150
00:04:38,350 --> 00:04:40,684
so there's not a big reduction in what we're seeing

151
00:04:40,684 --> 00:04:43,728
above the surface to what we're seeing at house level.

152
00:04:43,728 --> 00:04:45,480
And that was a pretty surprising finding for us

153
00:04:45,480 --> 00:04:47,479
because we kind of assumed

154
00:04:47,479 --> 00:04:50,945
the winds decreased pretty substantially near the surface.

155
00:04:50,945 --> 00:04:52,481
So I'm going to end it with this real quick.

156
00:04:52,481 --> 00:04:54,782
This is not the last tornado I ever saw,

157
00:04:54,782 --> 00:04:56,577
but I really like this image

158
00:04:56,577 --> 00:04:59,479
because it was taken with one of those mobile radars I was talking about.

159
00:04:59,479 --> 00:05:01,314
And this is a tornado, not a hurricane,

160
00:05:01,314 --> 00:05:02,832
and this is what it looks like

161
00:05:02,832 --> 00:05:04,397
when you're really close to it.

162
00:05:04,397 --> 00:05:05,584
And I find this amazing,

163
00:05:05,584 --> 00:05:06,836
that we can actually take technology,

164
00:05:06,836 --> 00:05:08,979
take technology this close to these types of storms,

165
00:05:08,979 --> 00:05:10,813
and see this inner workings.

166
00:05:10,813 --> 00:05:13,841
And for those of you who look at tornado images often,

167
00:05:13,841 --> 00:05:15,740
you can see there's a lot going on there.

168
00:05:15,740 --> 00:05:17,095
There's rain spiraling,

169
00:05:17,095 --> 00:05:18,646
and you can actually see the debris cloud

170
00:05:18,646 --> 00:05:20,147
associated with this tornado,

171
00:05:20,147 --> 00:05:21,573
and I look forward to the future

172
00:05:21,573 --> 00:05:22,813
and future technologies

173
00:05:22,813 --> 00:05:24,478
and being able to learn a lot more about these storms

174
00:05:24,478 --> 00:05:26,522
as the world advances

175
00:05:26,522 --> 00:05:28,062
and you guys contribute to the science

176
00:05:28,062 --> 00:05:31,145
and we're able to really learn how tornadoes form.

177
00:05:31,145 --> 00:05:32,230
Thank you!