1 00:00:08,920 --> 00:00:11,170 - I'd like to welcome Jason Schafer, 2 00:00:11,170 --> 00:00:14,940 who's with the Northern Vermont University. 3 00:00:14,940 --> 00:00:17,810 This talk is on extreme weather changes 4 00:00:17,810 --> 00:00:20,403 and implications for forest health. 5 00:00:25,040 --> 00:00:27,560 - Thanks everyone, it's great to be here today. 6 00:00:27,560 --> 00:00:30,830 And I just want to say happy 30 year anniversary 7 00:00:30,830 --> 00:00:34,670 to the FEMC, so it's a pleasure to be here. 8 00:00:34,670 --> 00:00:36,190 And I'm here today to talk about 9 00:00:36,190 --> 00:00:38,420 some of our work that we've done with electric utilities. 10 00:00:38,420 --> 00:00:40,460 I want to thank my co-authors, 11 00:00:40,460 --> 00:00:42,510 Kevin Cronin and Connor Pasquale. 12 00:00:42,510 --> 00:00:44,680 Connor is a student at Northern Vermont University, 13 00:00:44,680 --> 00:00:47,640 Kevin's a Research Associate at Northview Weather. 14 00:00:47,640 --> 00:00:49,550 And we're approaching this from 15 00:00:49,550 --> 00:00:51,120 both the research perspective, 16 00:00:51,120 --> 00:00:53,220 but also very applied concept here, 17 00:00:53,220 --> 00:00:57,163 looking at extreme weather and resilience on the power grid. 18 00:00:58,900 --> 00:01:02,730 So our perspective really is the electric grid ecosystem. 19 00:01:02,730 --> 00:01:04,800 And a few things just to get us oriented here 20 00:01:04,800 --> 00:01:07,340 for our frame on this is 21 00:01:07,340 --> 00:01:10,160 most of power outages are caused by weather. 22 00:01:10,160 --> 00:01:12,800 And then a lot of those power outages 23 00:01:12,800 --> 00:01:15,670 are caused by trees, 24 00:01:15,670 --> 00:01:19,750 and trees conflicting with power lines and poles. 25 00:01:19,750 --> 00:01:23,360 And power companies, of course, they're very interested 26 00:01:23,360 --> 00:01:24,840 in being prepared for storms. 27 00:01:24,840 --> 00:01:27,030 But the question that we're trying to answer 28 00:01:27,030 --> 00:01:29,450 is climate change and how extreme weather 29 00:01:29,450 --> 00:01:31,310 is gonna impact power outages, 30 00:01:31,310 --> 00:01:34,410 but also how the vegetation itself may change 31 00:01:34,410 --> 00:01:35,330 under climate change. 32 00:01:35,330 --> 00:01:37,390 And that really is where we're trying to get 33 00:01:37,390 --> 00:01:39,510 out of our silo and learn a little bit more 34 00:01:39,510 --> 00:01:41,860 and share some of our work with your community. 35 00:01:43,630 --> 00:01:47,190 And we are really interested in this 36 00:01:47,190 --> 00:01:51,280 because the costs to maintain vegetation along power lines 37 00:01:51,280 --> 00:01:53,940 are one of the top three cost drivers for electricity. 38 00:01:53,940 --> 00:01:56,370 So when you're paying your bill in the Northeast, 39 00:01:56,370 --> 00:01:58,350 a lot of that is actually for the power companies 40 00:01:58,350 --> 00:02:01,563 to manage vegetation along those right of ways. 41 00:02:03,230 --> 00:02:06,480 A very quick 101 of the electric grid system. 42 00:02:06,480 --> 00:02:08,793 And we have a generation, 43 00:02:09,730 --> 00:02:11,830 somewhere where the energy is being generated 44 00:02:11,830 --> 00:02:13,130 on the left-hand side here. 45 00:02:13,130 --> 00:02:16,740 And then it's stepped down to transmission lines 46 00:02:16,740 --> 00:02:18,480 that take that energy. 47 00:02:18,480 --> 00:02:21,110 And then the, the voltages gets stepped down 48 00:02:21,110 --> 00:02:23,130 in substations and transformers 49 00:02:23,130 --> 00:02:25,820 and then that gets to the distribution system. 50 00:02:25,820 --> 00:02:26,840 So I want you to think about 51 00:02:26,840 --> 00:02:28,420 the distribution and transmission system 52 00:02:28,420 --> 00:02:30,450 as being two different systems that work together 53 00:02:30,450 --> 00:02:34,050 to deliver power to people. 54 00:02:34,050 --> 00:02:35,700 And then the Vermont transmission system, 55 00:02:35,700 --> 00:02:39,370 this work was funded by VELCO, the transmission company. 56 00:02:39,370 --> 00:02:42,050 They own and operate all the transmission lines. 57 00:02:42,050 --> 00:02:43,640 The green lines on this map show 58 00:02:43,640 --> 00:02:45,440 all of the transmission lines. 59 00:02:45,440 --> 00:02:48,530 We've got about 750 miles of lines, 60 00:02:48,530 --> 00:02:50,200 55 substations, 61 00:02:50,200 --> 00:02:55,080 and they own and manage 13,000 acres of right of ways. 62 00:02:55,080 --> 00:02:56,840 And because the transmission infrastructure 63 00:02:56,840 --> 00:02:59,950 is much more important to the backbone of grid, 64 00:02:59,950 --> 00:03:01,840 the right of ways are very large 65 00:03:01,840 --> 00:03:03,950 and rarely do you have problems with trees 66 00:03:03,950 --> 00:03:05,600 conflicting with power lines here. 67 00:03:05,600 --> 00:03:08,050 So, the transmission system is pretty resilient 68 00:03:08,050 --> 00:03:08,883 to extreme weather. 69 00:03:08,883 --> 00:03:11,320 Now, if you have snow loading or really strong winds, 70 00:03:11,320 --> 00:03:13,060 you can take down those wooden structures. 71 00:03:13,060 --> 00:03:15,573 But that is at a much more extreme level. 72 00:03:17,030 --> 00:03:18,610 The distribution grid really 73 00:03:18,610 --> 00:03:20,350 is where our vulnerabilities are. 74 00:03:20,350 --> 00:03:22,620 So the left-hand side shows a color-coded map 75 00:03:22,620 --> 00:03:24,430 just of all the overhead power lines, 76 00:03:24,430 --> 00:03:27,930 which we have about 14,000 miles of distribution lines 77 00:03:27,930 --> 00:03:29,090 in the State of Vermont. 78 00:03:29,090 --> 00:03:31,560 And following like land use percentages, 79 00:03:31,560 --> 00:03:36,430 we also have about 75% of forested along those lines. 80 00:03:36,430 --> 00:03:39,850 And the tree trimming cycles can take five to 10 years. 81 00:03:39,850 --> 00:03:41,660 And I love this picture here in the top right 82 00:03:41,660 --> 00:03:43,910 that shows how we've got power lines 83 00:03:43,910 --> 00:03:47,410 really running through this tree here. 84 00:03:47,410 --> 00:03:49,670 And that's just a recipe for trouble, 85 00:03:49,670 --> 00:03:50,790 some point down the line. 86 00:03:50,790 --> 00:03:53,570 But it takes some utilities almost 10 years 87 00:03:53,570 --> 00:03:55,350 to go through and fully trim 88 00:03:55,350 --> 00:03:57,370 and manage all the vegetation along their lines. 89 00:03:57,370 --> 00:04:00,440 And a 10 year period, you can get a lot of new growth. 90 00:04:00,440 --> 00:04:02,050 So, and you're gonna be doing it all over again. 91 00:04:02,050 --> 00:04:03,930 And then some of the more progressive utilities 92 00:04:03,930 --> 00:04:06,090 that might have more funding or be more on top of it, 93 00:04:06,090 --> 00:04:08,230 and smaller, more urbanized areas 94 00:04:08,230 --> 00:04:09,980 might be able to do this every three years. 95 00:04:09,980 --> 00:04:12,180 But in Vermont, a more rural nature, 96 00:04:12,180 --> 00:04:14,010 we're still on a longer trim cycle 97 00:04:14,010 --> 00:04:19,003 around eight years for the best, the best utility right now. 98 00:04:20,240 --> 00:04:22,490 So if you look at power outages, 99 00:04:22,490 --> 00:04:25,250 and these are from severe storms over a nine year period, 100 00:04:25,250 --> 00:04:27,050 we looked at all power outage data 101 00:04:27,050 --> 00:04:30,050 from Green Mountain Power and Vermont Electric Cooperative. 102 00:04:30,050 --> 00:04:32,430 You see a bi-modal seasonal signal 103 00:04:32,430 --> 00:04:34,800 where there's a peak in the winter, winter time, 104 00:04:34,800 --> 00:04:36,990 or sorry, summertime, from thunderstorms. 105 00:04:36,990 --> 00:04:40,720 And then we have a fall peak with wind and wet snow. 106 00:04:40,720 --> 00:04:43,320 Wet snow storms are predominantly the signal here. 107 00:04:43,320 --> 00:04:45,690 Ice is only 20% of this, of course ice storms, 108 00:04:45,690 --> 00:04:47,300 when they do happen can be very severe, 109 00:04:47,300 --> 00:04:50,923 but their frequency is just much less, right? 110 00:04:52,070 --> 00:04:54,230 Now if you look at this from a duration standpoint 111 00:04:54,230 --> 00:04:56,497 of an impact, this is just the number of events, 112 00:04:56,497 --> 00:04:57,470 and when they occur. 113 00:04:57,470 --> 00:05:00,460 If you look at this from a duration and impact standpoint, 114 00:05:00,460 --> 00:05:03,390 it turns out we have the highest number 115 00:05:03,390 --> 00:05:06,070 of power outage risks to the grid 116 00:05:06,070 --> 00:05:08,640 in October, November, and December. 117 00:05:08,640 --> 00:05:12,040 So over half of all of our customer impacts 118 00:05:12,040 --> 00:05:15,340 from power outages, in terms of the duration of them, 119 00:05:15,340 --> 00:05:18,590 the severity of the storms, happen in those three months. 120 00:05:18,590 --> 00:05:20,090 Which is very interesting because, 121 00:05:20,090 --> 00:05:22,810 you go to January actually has the least number. 122 00:05:22,810 --> 00:05:26,150 So this is where some of those seasonal risk factors 123 00:05:26,150 --> 00:05:29,250 in intersecting vegetation health and tree health 124 00:05:29,250 --> 00:05:30,820 are really important to predict, 125 00:05:30,820 --> 00:05:32,120 and also just to understand 126 00:05:32,120 --> 00:05:34,290 from a climate change perspective. 127 00:05:34,290 --> 00:05:37,120 So some of those risk factors are, 128 00:05:37,120 --> 00:05:39,130 as you could imagine, the tree canopy itself. 129 00:05:39,130 --> 00:05:41,730 If you have leaf on or leaf out periods 130 00:05:41,730 --> 00:05:44,650 in the month of October, you could still have leaves on. 131 00:05:44,650 --> 00:05:46,850 And then also there's another factor 132 00:05:46,850 --> 00:05:50,200 where you just have a whole year of putting on new growth, 133 00:05:50,200 --> 00:05:53,260 and the trees just haven't been hardened by mother nature. 134 00:05:53,260 --> 00:05:55,260 So there's a certain natural hardening 135 00:05:55,260 --> 00:05:56,700 that happens into the season, 136 00:05:56,700 --> 00:05:58,320 and it takes a little bit of time. 137 00:05:58,320 --> 00:06:00,600 And then soil conditions are really important to this too. 138 00:06:00,600 --> 00:06:02,810 Turns out wetter soils are much more vulnerable 139 00:06:02,810 --> 00:06:05,570 because you could have a uprooting of trees that are easier. 140 00:06:05,570 --> 00:06:07,820 And then once you hit January, 141 00:06:07,820 --> 00:06:09,900 our climate's still cold enough for the most part 142 00:06:09,900 --> 00:06:11,500 that the trees just get naturally 143 00:06:11,500 --> 00:06:12,550 a little more resilient to weather. 144 00:06:12,550 --> 00:06:14,820 It's not that we don't have weather in the middle of winter, 145 00:06:14,820 --> 00:06:18,113 it's just that the impacts are, are much more muted. 146 00:06:20,230 --> 00:06:22,520 So another way of looking at this here, 147 00:06:22,520 --> 00:06:25,070 a plot looking at peak wind gusts on the y-axis, 148 00:06:25,070 --> 00:06:27,240 and this is just Julian day of the calendar year. 149 00:06:27,240 --> 00:06:29,160 And these color of these dots is showing 150 00:06:29,160 --> 00:06:31,560 basically the severity of the storms. 151 00:06:31,560 --> 00:06:33,490 So all I want to point out here 152 00:06:33,490 --> 00:06:36,000 is that the magical week of the year 153 00:06:36,000 --> 00:06:38,430 seems to be late October, early November 154 00:06:38,430 --> 00:06:41,500 is where we have these dots that are larger in size 155 00:06:41,500 --> 00:06:42,683 going into the fall. 156 00:06:43,620 --> 00:06:45,300 And we've had a number of large storms then 157 00:06:45,300 --> 00:06:47,810 that tend to produce a lot more outages 158 00:06:47,810 --> 00:06:48,670 during that timeframe, 159 00:06:48,670 --> 00:06:51,480 and you see a much more resilient grid 160 00:06:51,480 --> 00:06:52,850 during the middle of winter. 161 00:06:52,850 --> 00:06:54,940 And even the summertime, a lot of the summertime outages 162 00:06:54,940 --> 00:06:56,090 you can get from thunderstorms, 163 00:06:56,090 --> 00:06:58,890 but they tend to be much more localized and short-lived. 164 00:07:00,550 --> 00:07:02,780 So go looking at some catastrophic ice storms. 165 00:07:02,780 --> 00:07:04,180 This is where we're trying to intersect 166 00:07:04,180 --> 00:07:06,560 looking at some of the forestry research 167 00:07:06,560 --> 00:07:07,960 and understanding catastrophic 168 00:07:07,960 --> 00:07:11,070 and predicting the most catastrophic storms 169 00:07:11,070 --> 00:07:13,220 is probably the most important thing to get right. 170 00:07:13,220 --> 00:07:14,750 So in January of 1998, 171 00:07:14,750 --> 00:07:17,970 we had the most catastrophic ice storm in recent history, 172 00:07:17,970 --> 00:07:20,080 which is around a one in 100 year event. 173 00:07:20,080 --> 00:07:23,050 And then the red areas show heavy damage to the crowns 174 00:07:24,010 --> 00:07:26,630 in the canopy of the forest over Northern New York, 175 00:07:26,630 --> 00:07:28,290 where the cold air was able to work in 176 00:07:28,290 --> 00:07:30,630 across the St. Lawrence Valley. 177 00:07:30,630 --> 00:07:32,440 And then in Maine, we also have this 178 00:07:32,440 --> 00:07:34,110 in southern and central areas. 179 00:07:34,110 --> 00:07:35,750 Not, coastal areas were too warm 180 00:07:35,750 --> 00:07:37,910 to keep this as freezing rain. 181 00:07:37,910 --> 00:07:39,240 And then in Vermont and New Hampshire, 182 00:07:39,240 --> 00:07:41,320 anyone who may remember this storm, 183 00:07:41,320 --> 00:07:42,930 or read some literature on it, 184 00:07:42,930 --> 00:07:45,440 the cold air was actually confined to middle elevations. 185 00:07:45,440 --> 00:07:47,290 The valleys, we didn't have quite enough cold air, 186 00:07:47,290 --> 00:07:49,060 so we had extreme damage 187 00:07:49,060 --> 00:07:51,833 from about 1500 to 3000 feet elevation. 188 00:07:53,330 --> 00:07:56,030 And it ended up being that heavier severe damage 189 00:07:56,030 --> 00:07:59,970 was approximately, you know, 20% of forests here. 190 00:07:59,970 --> 00:08:01,690 And looking into literature ahead of this talk, 191 00:08:01,690 --> 00:08:05,300 we see that in parts of Quebec and in other areas, 192 00:08:05,300 --> 00:08:07,700 that even after 20 years after the storm, 193 00:08:07,700 --> 00:08:10,670 that tree mortality rates remaining pretty high. 194 00:08:10,670 --> 00:08:12,473 So the recovery of this is taking, 195 00:08:13,420 --> 00:08:14,870 taking a fair amount of time. 196 00:08:16,420 --> 00:08:19,100 Another, on the other end of the spectrum 197 00:08:19,100 --> 00:08:20,050 in the warm season, 198 00:08:20,050 --> 00:08:24,060 hurricanes are probably our other most impactful event. 199 00:08:24,060 --> 00:08:26,960 The hurricane of 1938, at least for Vermont, 200 00:08:26,960 --> 00:08:29,030 is where we had the most catastrophic wind storm. 201 00:08:29,030 --> 00:08:30,700 Now, the other thing about meteorology is 202 00:08:30,700 --> 00:08:32,840 that the right hand side of hurricanes 203 00:08:32,840 --> 00:08:35,868 is where we tend to have the most damaging storm 204 00:08:35,868 --> 00:08:37,160 impacts from wind. 205 00:08:37,160 --> 00:08:38,490 If you look at the left-hand side, 206 00:08:38,490 --> 00:08:40,440 you can see this storm survey that looked at 207 00:08:40,440 --> 00:08:43,430 where there was extreme and moderate timber damage. 208 00:08:43,430 --> 00:08:46,050 And you could see that that was over a pretty large area. 209 00:08:46,050 --> 00:08:48,610 This was a category three hurricane 210 00:08:48,610 --> 00:08:51,380 when it made landfall in Long Island. 211 00:08:51,380 --> 00:08:53,110 And it maintain hurricane strength 212 00:08:53,110 --> 00:08:56,520 all the way through parts of Vermont. 213 00:08:56,520 --> 00:09:00,410 This storm also produced over 500 people lost their life, 214 00:09:00,410 --> 00:09:02,810 and storm surges that were close to 20 feet 215 00:09:02,810 --> 00:09:05,140 all the way up to Providence, Rhode Island. 216 00:09:05,140 --> 00:09:07,340 So, storms like this can happen, 217 00:09:07,340 --> 00:09:09,400 they're just not as frequent for them to happen. 218 00:09:09,400 --> 00:09:10,510 It's just a matter of time until 219 00:09:10,510 --> 00:09:12,210 something like this happens again. 220 00:09:14,620 --> 00:09:17,030 So we've summarized quite a bit of work here 221 00:09:17,030 --> 00:09:18,050 over the last 40 years. 222 00:09:18,050 --> 00:09:18,990 Looking at power outages, 223 00:09:18,990 --> 00:09:21,310 we reconstructed this looking backwards, 224 00:09:21,310 --> 00:09:22,450 and here's our main conclusions. 225 00:09:22,450 --> 00:09:24,450 Before I get to the climate aspect of this work, 226 00:09:24,450 --> 00:09:28,030 here's our summary for the power outage work that we found. 227 00:09:28,030 --> 00:09:30,330 At the 20 year trends are showing that 228 00:09:30,330 --> 00:09:32,170 risks have increased by a few percent, 229 00:09:32,170 --> 00:09:33,810 most of that's being driven by wet snow, 230 00:09:33,810 --> 00:09:36,890 a little bit less by wind storms. 231 00:09:36,890 --> 00:09:39,370 And high-impact storms are not necessarily 232 00:09:39,370 --> 00:09:41,210 increasing on their frequency, 233 00:09:41,210 --> 00:09:43,930 but if we sample out and subset 234 00:09:43,930 --> 00:09:45,660 the really high impact storms, 235 00:09:45,660 --> 00:09:49,080 so like the top 1% of storms, 236 00:09:49,080 --> 00:09:51,430 it turns out that they're increasing in intensity 237 00:09:51,430 --> 00:09:55,220 by about 15% riskier, or more risks. 238 00:09:55,220 --> 00:09:58,320 So the most intense storms are becoming more intense, 239 00:09:58,320 --> 00:10:00,070 it would appear with climate change. 240 00:10:00,070 --> 00:10:02,310 We'll talk about why that isn't just a minute. 241 00:10:02,310 --> 00:10:04,410 All right. Catastrophic large-scale storms, 242 00:10:04,410 --> 00:10:05,630 again, the frequency on those 243 00:10:05,630 --> 00:10:08,740 is just a little too low to say a whole lot about. 244 00:10:08,740 --> 00:10:10,210 But I think the big takeaway here, 245 00:10:10,210 --> 00:10:12,950 especially for the warm season, as climate warms, 246 00:10:12,950 --> 00:10:14,320 you add a little bit more fuel. 247 00:10:14,320 --> 00:10:16,710 Your speed limit to how strong storms can get 248 00:10:16,710 --> 00:10:18,300 just to get a little bit higher. 249 00:10:18,300 --> 00:10:20,850 So there could be a potential for those storms 250 00:10:20,850 --> 00:10:24,083 to keep their intensity or maintain stronger. 251 00:10:26,710 --> 00:10:27,543 All right. 252 00:10:27,543 --> 00:10:29,823 So a little bit about climate change signals. 253 00:10:32,670 --> 00:10:34,810 We use the ERA5 reanalysis data 254 00:10:34,810 --> 00:10:36,640 and a variety of methods to come up with this. 255 00:10:36,640 --> 00:10:39,590 I don't want to go into too much detail here. 256 00:10:39,590 --> 00:10:41,810 I'd rather focus on the results. 257 00:10:41,810 --> 00:10:45,360 What we see in Vermont is consistent with the region. 258 00:10:45,360 --> 00:10:47,310 We've got a large warming signal 259 00:10:47,310 --> 00:10:48,900 with temperatures in the last 40 years. 260 00:10:48,900 --> 00:10:51,960 The month of September has actually warmed the fastest. 261 00:10:51,960 --> 00:10:54,110 And the month of fall has actually warmed, 262 00:10:54,110 --> 00:10:56,010 the season of fall is warmed greater 263 00:10:56,010 --> 00:10:56,880 than any of the years. 264 00:10:56,880 --> 00:10:59,930 So what's happening here is that summertime and fall 265 00:10:59,930 --> 00:11:01,350 is just becoming, 266 00:11:01,350 --> 00:11:03,723 warm seasons becoming more prolonged, right? 267 00:11:04,695 --> 00:11:06,270 And then what we see that's showing up 268 00:11:06,270 --> 00:11:07,810 in a variety of areas, 269 00:11:07,810 --> 00:11:08,970 this is also a regional 270 00:11:08,970 --> 00:11:10,700 and large-scale continental signal too. 271 00:11:10,700 --> 00:11:13,960 So falls are getting warmer across most of the country, 272 00:11:13,960 --> 00:11:16,240 and one of the faster warming seasons 273 00:11:16,240 --> 00:11:17,933 of all the seasons that we see. 274 00:11:18,930 --> 00:11:21,330 From a growing season perspective, 275 00:11:21,330 --> 00:11:23,400 what we see is this is growing degree days, 276 00:11:23,400 --> 00:11:27,130 over a 50 degree base, we've got about almost a 10% increase 277 00:11:27,130 --> 00:11:28,880 in net growing degree days 278 00:11:28,880 --> 00:11:31,400 in this last 40 year period in Vermont. 279 00:11:31,400 --> 00:11:34,530 And 60% of those increases are due to August 280 00:11:34,530 --> 00:11:36,530 and September being warmer. 281 00:11:36,530 --> 00:11:38,790 So, we're trying to answer this question of 282 00:11:38,790 --> 00:11:40,750 does this, the growing season getting longer 283 00:11:40,750 --> 00:11:42,790 mean you're gonna put on more growth for your trees 284 00:11:42,790 --> 00:11:45,950 and maybe increase your vegetation management programs. 285 00:11:45,950 --> 00:11:49,060 It would appear that perhaps that a later season increase 286 00:11:49,060 --> 00:11:50,560 in the growing season for most species 287 00:11:50,560 --> 00:11:52,710 is not gonna allow for that. 288 00:11:52,710 --> 00:11:53,720 So that's something that we're, 289 00:11:53,720 --> 00:11:55,240 we're still trying to sort out. 290 00:11:55,240 --> 00:11:56,880 But most of it's, the growing season is 291 00:11:56,880 --> 00:11:59,280 the duration of the season getting longer on the other end, 292 00:11:59,280 --> 00:12:01,030 not the beginning or the end of it. 293 00:12:03,010 --> 00:12:05,290 And then precipitation trends. 294 00:12:05,290 --> 00:12:06,220 It's no big surprise, 295 00:12:06,220 --> 00:12:08,610 as the climate gets warmer in our neck of the woods, 296 00:12:08,610 --> 00:12:09,443 it gets wetter. 297 00:12:09,443 --> 00:12:10,500 We still have enough storm activity 298 00:12:10,500 --> 00:12:13,120 to extract that moisture out of this. 299 00:12:13,120 --> 00:12:15,570 And we know the availability of water 300 00:12:15,570 --> 00:12:18,380 and the evapotranspiration rates are really important 301 00:12:18,380 --> 00:12:21,040 for how much growth you can have. 302 00:12:21,040 --> 00:12:23,130 Just because you have warmer growing seasons 303 00:12:23,130 --> 00:12:24,870 doesn't mean you're necessarily gonna have more growth, 304 00:12:24,870 --> 00:12:28,350 you still need the water capacity to be able to grow. 305 00:12:28,350 --> 00:12:30,370 So let's look at precipitation annually, 306 00:12:30,370 --> 00:12:31,720 it is increasing. 307 00:12:31,720 --> 00:12:33,840 There is a strong seasonality signal to this. 308 00:12:33,840 --> 00:12:36,560 In Vermont, winters are getting warmer. 309 00:12:36,560 --> 00:12:39,240 Our wettest, fastest 11% increase 310 00:12:39,240 --> 00:12:42,720 in annual winter precipitation in the last 40 years. 311 00:12:42,720 --> 00:12:44,450 Otherwise, there was a 2% increase 312 00:12:44,450 --> 00:12:45,780 across the rest of the seasons. 313 00:12:45,780 --> 00:12:47,080 And then on a month to month basis, 314 00:12:47,080 --> 00:12:48,523 it's a little more lopsided, 315 00:12:49,660 --> 00:12:52,080 just given that variability we have in the signals. 316 00:12:52,080 --> 00:12:53,670 But you see what that warming we have 317 00:12:53,670 --> 00:12:55,360 in August and September, 318 00:12:55,360 --> 00:12:57,750 we also tend to have a little bit of drying. 319 00:12:57,750 --> 00:13:00,570 And I mean that was a pretty strong signal with drought 320 00:13:00,570 --> 00:13:02,260 this year that we had. 321 00:13:02,260 --> 00:13:03,760 Just because we're getting more precipitation 322 00:13:03,760 --> 00:13:06,580 doesn't mean we're not more prone to drought signals too. 323 00:13:06,580 --> 00:13:09,063 So speaking of, let me skip ahead here. 324 00:13:10,630 --> 00:13:13,090 We'll talk about drought in a second. 325 00:13:13,090 --> 00:13:16,280 I just want to talk about extreme precipitation events, 326 00:13:16,280 --> 00:13:17,113 right? 327 00:13:17,113 --> 00:13:19,370 What we see is that extreme precipitation events 328 00:13:19,370 --> 00:13:22,540 are more likely in the fall and late summer, 329 00:13:22,540 --> 00:13:24,960 and that's mostly due to tropical systems 330 00:13:24,960 --> 00:13:27,730 interacting with mid-latitude storm systems, 331 00:13:27,730 --> 00:13:30,630 of the peak, again, in that magical month of October. 332 00:13:30,630 --> 00:13:32,690 In a lot of ways, October kind of stood out for us 333 00:13:32,690 --> 00:13:35,480 as the most interesting month in this research. 334 00:13:35,480 --> 00:13:38,000 And then if you look at this spatially across Vermont, 335 00:13:38,000 --> 00:13:39,510 you see is that there's been an increase 336 00:13:39,510 --> 00:13:41,610 in heavy precipitation days as well. 337 00:13:41,610 --> 00:13:43,080 It's not uniformly distributed, 338 00:13:43,080 --> 00:13:46,720 but generally we've got about a 10% increase 339 00:13:46,720 --> 00:13:48,590 in these really heavy precipitation days, 340 00:13:48,590 --> 00:13:51,850 which is defined here as a 24 hour storm 341 00:13:51,850 --> 00:13:55,963 over at least a one inch over the county level basis. 342 00:13:58,430 --> 00:14:01,480 So we're getting, and this increase is actually much faster 343 00:14:01,480 --> 00:14:03,063 than the annual rate increase. 344 00:14:04,430 --> 00:14:07,640 Speaking of drought, looking at long-term drought signals, 345 00:14:07,640 --> 00:14:09,650 red areas, and this, this research shows where 346 00:14:09,650 --> 00:14:13,030 it's been getting a little bit drier tendency for drought 347 00:14:13,030 --> 00:14:15,350 and blue areas maybe not so much. 348 00:14:15,350 --> 00:14:17,620 Putting my meteorologist's hat suit on, 349 00:14:17,620 --> 00:14:19,980 what you'll see is that the reason this happens 350 00:14:19,980 --> 00:14:22,550 is probably because westerly flow, 351 00:14:22,550 --> 00:14:24,890 storms coming from the west tend to break apart, 352 00:14:24,890 --> 00:14:27,440 and they don't tend to bring as much precipitation 353 00:14:27,440 --> 00:14:29,870 to coastal areas before they do that. 354 00:14:29,870 --> 00:14:32,660 Whereas southerly storms tend to bring more precipitation 355 00:14:32,660 --> 00:14:34,270 perhaps up the coast. 356 00:14:34,270 --> 00:14:37,483 So the meteorology is really important for that as well. 357 00:14:38,360 --> 00:14:40,530 And other research has shown, 358 00:14:40,530 --> 00:14:43,330 from your community is that, 359 00:14:43,330 --> 00:14:45,770 of course drought occurring early in the season 360 00:14:45,770 --> 00:14:47,610 when we're putting on more growth 361 00:14:47,610 --> 00:14:50,410 has more negative impacts on growth as well. 362 00:14:50,410 --> 00:14:53,040 So the timing of drought is pretty important 363 00:14:53,040 --> 00:14:54,773 for the overall growth. 364 00:14:57,410 --> 00:15:00,610 So we had done quite a bit of literature review 365 00:15:00,610 --> 00:15:02,630 and trying to figure out one area, 366 00:15:02,630 --> 00:15:04,440 or a few areas where we could dial in on this. 367 00:15:04,440 --> 00:15:05,840 And what really happened was, 368 00:15:05,840 --> 00:15:08,030 quite honestly a lot of themes that came out of this, 369 00:15:08,030 --> 00:15:11,130 and things that were beyond our expertise 370 00:15:11,130 --> 00:15:12,160 or our capabilities, 371 00:15:12,160 --> 00:15:14,930 looking at windthrow biomass, 372 00:15:14,930 --> 00:15:17,230 which is just debris that comes through after wind storms, 373 00:15:17,230 --> 00:15:20,190 and how it affects carbon cycling, and nitrogen cycling, 374 00:15:20,190 --> 00:15:23,200 and nutrients uptake and things like that. 375 00:15:23,200 --> 00:15:24,780 Species dependency on climate change. 376 00:15:24,780 --> 00:15:25,780 That's a really big question 377 00:15:25,780 --> 00:15:27,920 that we're still trying to get at, too. 378 00:15:27,920 --> 00:15:30,470 Age of the forest influencing the resiliency, 379 00:15:30,470 --> 00:15:32,510 old versus newer growth forests. 380 00:15:32,510 --> 00:15:36,400 All of the right of ways are also on the edges of trees, 381 00:15:36,400 --> 00:15:39,160 edges of forests, that's a factor to this. 382 00:15:39,160 --> 00:15:40,420 And then seasonality of this, 383 00:15:40,420 --> 00:15:43,540 trying to sugar out that whole seasonality signal 384 00:15:43,540 --> 00:15:45,840 of what we're getting at here. 385 00:15:45,840 --> 00:15:48,060 Just to wrap up here, I'm kind of curious, 386 00:15:48,060 --> 00:15:49,670 this is just, if anyone wants to reach out with me 387 00:15:49,670 --> 00:15:50,840 maybe outside of this talk, 388 00:15:50,840 --> 00:15:54,840 or if there were any other known major losses in trees 389 00:15:54,840 --> 00:15:58,160 or damage to trees in Vermont for these three storms. 390 00:15:58,160 --> 00:15:59,290 All right. 391 00:15:59,290 --> 00:16:01,500 And here we have power outage profiles for the storm. 392 00:16:01,500 --> 00:16:02,840 In the last decade, 393 00:16:02,840 --> 00:16:06,170 especially that October windstorm of 2017 394 00:16:06,170 --> 00:16:08,090 was the largest power outage storm, 395 00:16:08,090 --> 00:16:08,923 which you could see 396 00:16:08,923 --> 00:16:10,210 on the time series graph shows 397 00:16:10,210 --> 00:16:12,360 that there was over 30% of electric customers 398 00:16:12,360 --> 00:16:13,570 that were without power. 399 00:16:13,570 --> 00:16:16,050 And it took almost a week to restore the power 400 00:16:16,050 --> 00:16:17,400 from that storm. 401 00:16:17,400 --> 00:16:19,920 So December, 2013 ice, and then 402 00:16:19,920 --> 00:16:22,360 December, 2014, wet snow. 403 00:16:22,360 --> 00:16:24,280 So those are the other two big storms 404 00:16:24,280 --> 00:16:27,263 that in the last decade, that kind of intersect our world. 405 00:16:28,480 --> 00:16:30,740 And just to wrap this up here, 406 00:16:30,740 --> 00:16:34,240 what we see is that wind storms appear to be the top causes, 407 00:16:34,240 --> 00:16:35,350 they definitely are for power outages, 408 00:16:35,350 --> 00:16:38,130 and also for the forest damage. 409 00:16:38,130 --> 00:16:39,040 All right, even though you can get 410 00:16:39,040 --> 00:16:41,063 a one-off major ice storm. 411 00:16:42,150 --> 00:16:44,410 Catastrophic wind storms, 412 00:16:44,410 --> 00:16:46,700 they don't appear to be getting more frequent, 413 00:16:46,700 --> 00:16:51,700 but their intensity does appear to be increasing slightly. 414 00:16:51,870 --> 00:16:54,060 And then for ice storms, 415 00:16:54,060 --> 00:16:56,470 what we think is that there's no detectable frequency 416 00:16:56,470 --> 00:16:59,040 or intensity changes to them. 417 00:16:59,040 --> 00:17:00,690 And the climate could still support 418 00:17:00,690 --> 00:17:02,550 major ice storm like '98. 419 00:17:02,550 --> 00:17:03,700 But the other thing we're seeing 420 00:17:03,700 --> 00:17:05,470 is that there's more mixed phase storms, 421 00:17:05,470 --> 00:17:08,120 even though winter's getting warmer, we're still having 422 00:17:08,120 --> 00:17:10,120 low and moderate-end icing in that setting. 423 00:17:10,120 --> 00:17:10,953 That's going up. 424 00:17:10,953 --> 00:17:11,786 The severe icing events, 425 00:17:11,786 --> 00:17:13,240 it's a little harder to get all those ingredients 426 00:17:13,240 --> 00:17:15,053 to come together just right. 427 00:17:16,610 --> 00:17:19,320 Overall, power outage severity has increased 428 00:17:19,320 --> 00:17:21,060 from warmer and wetter storms. 429 00:17:21,060 --> 00:17:23,490 As the widening of that warm season increases, 430 00:17:23,490 --> 00:17:25,500 that fall power outage season 431 00:17:25,500 --> 00:17:27,910 I think that that the vulnerability to vegetation 432 00:17:27,910 --> 00:17:29,930 in major storms is probably gonna increase 433 00:17:29,930 --> 00:17:32,373 in that signal as climate continues to warm. 434 00:17:33,580 --> 00:17:35,130 And then, this was mentioned earlier, 435 00:17:35,130 --> 00:17:36,920 but storms like Superstorm Sandy 436 00:17:36,920 --> 00:17:39,530 is a good ghost of Christmas future in a lot of ways, 437 00:17:39,530 --> 00:17:41,270 is that I think more of the risk lies 438 00:17:41,270 --> 00:17:42,310 probably in the warm season 439 00:17:42,310 --> 00:17:45,180 looking at things like hurricanes 440 00:17:45,180 --> 00:17:46,770 interacting with midlatitude storms, 441 00:17:46,770 --> 00:17:48,183 such as a Superstorm Sandy. 442 00:17:50,560 --> 00:17:52,010 Okay, that's all I have here. 443 00:17:52,010 --> 00:17:53,360 I appreciate being here today, 444 00:17:53,360 --> 00:17:55,433 and being able to share our work with you. 445 00:17:58,430 --> 00:18:01,100 - Jerry Carlson, what's the relationship 446 00:18:01,100 --> 00:18:04,770 between vegetation piece size and power outage? 447 00:18:04,770 --> 00:18:07,780 And how, would, or could you, 448 00:18:07,780 --> 00:18:11,220 could cable installation offset the power outage problems? 449 00:18:11,220 --> 00:18:13,190 - Yeah, so there's a lot of asset hardening 450 00:18:13,190 --> 00:18:14,023 that's happening. 451 00:18:14,023 --> 00:18:15,390 The utilities put up tree wire, 452 00:18:15,390 --> 00:18:18,170 which is basically insulated lines. 453 00:18:18,170 --> 00:18:19,480 And that's constantly being done. 454 00:18:19,480 --> 00:18:21,080 It's just a matter of cost to do that. 455 00:18:21,080 --> 00:18:23,180 And that actually helps quite a bit. 456 00:18:23,180 --> 00:18:25,920 When you've got relatively small branches, 457 00:18:25,920 --> 00:18:28,720 just maybe touching a line and then blowing a fuse, 458 00:18:28,720 --> 00:18:30,713 you avoid a lot of those outages. 459 00:18:32,330 --> 00:18:36,040 The basically the larger, the more dangerous the tree, 460 00:18:36,040 --> 00:18:37,480 the larger the tree, the more mass 461 00:18:37,480 --> 00:18:39,610 that basically you've got to clean up falls in the line, 462 00:18:39,610 --> 00:18:41,510 the more damage you're gonna get. 463 00:18:41,510 --> 00:18:43,140 But Green Mountain Power is, 464 00:18:43,140 --> 00:18:45,680 they actively are investing in a lot of tree wire. 465 00:18:45,680 --> 00:18:47,350 They identified their risk areas, 466 00:18:47,350 --> 00:18:49,630 and the utilities are aware of this. 467 00:18:49,630 --> 00:18:51,380 It's just a matter of their capital expenses, 468 00:18:51,380 --> 00:18:52,673 being able to keep up with this. 469 00:18:52,673 --> 00:18:54,320 There's a pretty big need here. 470 00:18:54,320 --> 00:18:56,480 There's still some old copper wire out there, 471 00:18:56,480 --> 00:18:58,440 even our old systems. 472 00:18:58,440 --> 00:19:00,710 So the grid is, is a power grid, 473 00:19:00,710 --> 00:19:02,730 definitely needs a lot of modernization, 474 00:19:02,730 --> 00:19:04,250 and a little bit more hardening, I think. 475 00:19:04,250 --> 00:19:05,810 If I was to put dollars into the grid, 476 00:19:05,810 --> 00:19:08,260 I would definitely be more aggressive 477 00:19:08,260 --> 00:19:10,610 with the vegetation management, just generally. 478 00:19:12,450 --> 00:19:16,150 - Okay, next one from Joanne Garten. 479 00:19:16,150 --> 00:19:20,940 Do you have any data on what tree species in size diameter 480 00:19:20,940 --> 00:19:23,030 of trees are falling on power lines 481 00:19:23,030 --> 00:19:27,440 perhaps broken up regionally, if not a specific point data? 482 00:19:27,440 --> 00:19:29,360 - Yeah, that's a really good question. 483 00:19:29,360 --> 00:19:32,350 And the answer is, no. 484 00:19:32,350 --> 00:19:35,490 Because the power companies aren't required to report that, 485 00:19:35,490 --> 00:19:37,877 nor are they sophisticated enough to know that. 486 00:19:37,877 --> 00:19:39,820 There's constantly a rush 487 00:19:39,820 --> 00:19:42,520 if there's something broken to fix it. 488 00:19:42,520 --> 00:19:44,530 And what we've found is that, their not their due diligence 489 00:19:44,530 --> 00:19:46,900 with keeping their data is not as good as we'd like it, 490 00:19:46,900 --> 00:19:48,350 because we struggle with the quality 491 00:19:48,350 --> 00:19:49,960 of some of their power outage data. 492 00:19:49,960 --> 00:19:52,590 We've had to make a lot of assumptions with this. 493 00:19:52,590 --> 00:19:53,423 They do map. 494 00:19:53,423 --> 00:19:56,010 They have LIDAR that maps the species types pretty well. 495 00:19:56,010 --> 00:19:58,083 So there's some knowledge of that. 496 00:19:59,060 --> 00:20:03,460 But we don't have good data on exactly the age of the tree, 497 00:20:03,460 --> 00:20:05,330 that the species of the tree, the size of the tree 498 00:20:05,330 --> 00:20:07,330 that may have failed or caused a problem. 499 00:20:07,330 --> 00:20:09,350 Most of the trees are actually danger trees. 500 00:20:09,350 --> 00:20:11,120 So they're actually outside the right of way, 501 00:20:11,120 --> 00:20:12,350 and they fall in. 502 00:20:12,350 --> 00:20:14,000 And they're trees that the power companies 503 00:20:14,000 --> 00:20:15,180 can't do anything about 504 00:20:15,180 --> 00:20:16,710 without permission to the landowners 505 00:20:16,710 --> 00:20:19,200 to take down or do something about. 506 00:20:19,200 --> 00:20:20,470 And no one wants to cut those down 507 00:20:20,470 --> 00:20:21,980 unless they absolutely have to either, 508 00:20:21,980 --> 00:20:23,330 because oftentimes those trees 509 00:20:23,330 --> 00:20:27,070 are prized by landowners as well, 510 00:20:27,070 --> 00:20:28,520 or the towns that they're in. 511 00:20:34,140 --> 00:20:34,973 - Okay. 512 00:20:34,973 --> 00:20:37,973 We don't have any more questions at the moment. 513 00:20:40,410 --> 00:20:43,453 But we have a bit of time to wait a minute, if you'd like. 514 00:20:49,870 --> 00:20:52,823 Again, if you have any questions in the chat. 515 00:20:54,231 --> 00:20:55,064 Okay. 516 00:20:55,064 --> 00:20:55,970 - Oh, it looks like there's another one here. 517 00:20:55,970 --> 00:20:57,120 Yep. (woman laughing) 518 00:20:57,120 --> 00:20:59,643 - Okay. Nancy Harris, 519 00:21:01,050 --> 00:21:04,140 given that you aren't necessarily seeing an increase 520 00:21:04,140 --> 00:21:05,870 in frequency of extreme events, 521 00:21:05,870 --> 00:21:09,300 do you think it is important to be monitoring the frequency 522 00:21:09,300 --> 00:21:11,430 of moderate events as well? 523 00:21:11,430 --> 00:21:12,550 - Yeah, absolutely. 524 00:21:12,550 --> 00:21:14,120 The moderate events, 525 00:21:14,120 --> 00:21:16,060 so the top end events we talked about, 526 00:21:16,060 --> 00:21:19,130 maybe only account for 15% of all the power outages. 527 00:21:19,130 --> 00:21:20,680 So those moderate and events 528 00:21:20,680 --> 00:21:23,313 probably are somewhere around that 50th percentile. 529 00:21:24,330 --> 00:21:26,560 And oftentimes that's where we're on the fence 530 00:21:26,560 --> 00:21:27,410 as meteorologists, 531 00:21:27,410 --> 00:21:30,830 try to utility companies to plan resources or not. 532 00:21:30,830 --> 00:21:33,170 So we keep our eyes on that pretty closely. 533 00:21:33,170 --> 00:21:35,520 And that's part of our research too. 534 00:21:35,520 --> 00:21:36,630 Absolutely. 535 00:21:36,630 --> 00:21:38,320 But they're probably not causing problems 536 00:21:38,320 --> 00:21:39,153 to the forest at all, 537 00:21:39,153 --> 00:21:40,910 forests are pretty resilient in the way that 538 00:21:40,910 --> 00:21:42,490 that everyone here might be thinking, 539 00:21:42,490 --> 00:21:44,123 or people who do research on this might be thinking about. 540 00:21:44,123 --> 00:21:45,850 It's really the catastrophic storms 541 00:21:45,850 --> 00:21:49,750 that I think from the forestry management side is where 542 00:21:49,750 --> 00:21:51,300 you might be thinking about it.