Avalanche professional says warm spell played role in snow slide
By Mike Lynch
An avalanche buried two skiers on Wright Peak in the High Peaks Wilderness on February 12.
Despite both being fully buried and potentially killed, they were able to escape relatively unscathed. They survived after one person dug himself out and found his partner using a locator beacon.
The Explorer interviewed avalanche instructor Josh Worth to learn more about the topic and incident. The Keeseville resident trains rescue professionals and others for the National Ski Patrol.
Worth worked at Mammoth Mountain in California’s Sierra Mountains from 2009 to 2016, first as a ski patroller and later as a safety manager. His responsibilities included working on the avalanche control team, triggering snow slides with dynamite and ski cuts.
He visited Wright Peak two days after the recent incident, and did his own assessment.
Here is what he had to say:
Explorer: What is avalanche terrain?
Worth: Avalanche terrain is anywhere steep enough to have an avalanche. Generally speaking places with slope angles of 30 to 45 degrees, with statistics telling us 38 to 40 being prime. However, it must be noted that it can happen with angles as low as 20 degrees, especially with wet slides.
Explorer: Your report said the (Wright) avalanche slid 1000 feet?
Worth: The total length was 1000 feet, but that’s not representative of the size. Most of the snow only went about 600 feet. I estimate the total slide pathway (potential avalanche area) length of about 1,800 feet. With the majority of the snow only going 600 feet, it is nowhere near a large avalanche for that path. Yes, this was really big for here, and very uncommon for here. But it’s not inconceivable that we could have twice as much snow. I think a three-foot-crown (snow-depth at the top of the avalanche) is pretty small. It’s below average. I think everyone else would agree that we have a lower snowpack than average right now.
Explorer: What triggered this recent avalanche on Wright Peak?
Worth: The avalanche was triggered remotely. That means the avalanche broke above the two individuals. Their extra weight on the snow load at the bottom of the start zone caused a fracture several hundred feet above them, which caused more to come down on top of them.
Explorer: Is that a common way for a skier to trigger an avalanche?
Worth: It’s definitely not the most common way. But it’s definitely a common way here in the Adirondacks. More common than out West. Because in many cases (here), to get into avalanche terrain, you have to go up (through) it. There’s no easy way to take a ridge, to stay out of avalanche terrain.
Explorer: What were the snowpack conditions that led to the avalanche?
Worth: Leading up to it, we had some pretty big swings in temperature. Any time you get rapid warming, that’s a red flag. And we also had precipitation that was decidedly on the wet side, which also adds a lot of weight to the snowpack. That, combined with weak layers near the bottom, made for a recipe for these guys to just kind of be in the wrong spot at the wrong time.
Explorer: Why are warming temperatures a red flag?
Worth: It changes the snowpack. Snow is just like us. It doesn’t like change, especially rapid change. So anytime you get rapid warming, snow is changing rapidly. It creates weak layers and increases the likelihood of an avalanche.
Explorer: We seem to hear about avalanches on Wright Peak’s Angel Slides or the new slide (created in 2011) there. It’s more accessible than most slides, so skiers frequent it. Are there other conditions there that lead to it avalanching?
Worth: (The slope angle of) 38 to 40 degrees is prime for an avalanche. And the aspect is also northeast, which is prime for an avalanche. I think like you said that the ease of access to it makes it something that people are gonna go do.
Explorer: Why does the northeastern aspect make it more prone to avalanches?
Worth: Statistics tell us most avalanche accidents occur on north and east facing slopes. North-facing slopes receive very little sun. East-facing slopes only get sun in the morning when temps are colder. A cold snowpack tends to develop more persistent weak layers than a warm snow pack. Because the snow stays colder longer, that is where we find the best snow. People want to ski good snow, so that’s where we ski, and where people tend to become triggers for avalanches.
Explorer: Is the avalanche danger increasing in the Adirondacks because there are more skiers going up slides and potentially triggering them?
Worth: Yeah, yeah. Danger has always been the same, but what’s changed is people going into those areas and recreating. Not that we shouldn’t. We should. But we have more users in the backcountry, especially in the winter period. With new gear, people are going there and want to ski it. They want that nice open soft snow, but they don’t necessarily have the education to know what they’re getting themselves into, potentially.
(Editor’s note: The amount of avalanche terrain has increased significantly since 2011 when Tropical Storm Irene created dozens of new slides in the High Peaks.)
Explorer: What kind of training should people have before skiing in avalanche terrain?
Worth: They need to take a class. It’s not something you can learn from a book. You can learn a lot from a book, but you need to go out there in the field with somebody who knows more than you. And to kind of show you the ways.
Explorer: What gear do you need?
Worth: There’s specific gear you need like avalanche probe, beacon, short shovel, and a good brain.
Explorer: So what’s the process for you when you’re considering skiing a slide? What are the things you do to prepare for that trip to make sure you’re not putting yourself in too much of an avalanche risk?
Worth: That process starts with the first snowfall around here. Pay attention to the weather daily. And pay attention to how the snow is forming (and) track it throughout the season. I may go a little bit over the top, but I pay attention to the weather. And then I can make an assessment based on that, whether I even want to consider going to slide terrain or not. If the weather patterns have been good and things have set up, and I think it might be doable, I go out maybe a day or two before, and I poke around in some steeper treed stuff, see how that snow is reacting. I might go on to something more open, dig some pits, do some tests. You progress slowly, you don’t just go out there and jump into it.
Explorer: Do you think there’s a need for an avalanche center or professional avalanche forecasting in the Adirondacks?
Worth: Yeah, I do. I think there is a need, and I think there’s a community want for one also. I just think we’ve failed as a community to come together and figure out how to get that done. A lot of people want to put that completely on (the state Department of Environmental Conservation). But it’s a big ask. It takes money and DEC doesn’t have a lot of money. So I think, you know, we can look at all these other avalanche centers and kind of come up with what works best for us. But I really think we need to get together as a community and decide what that is. (Editor’s note: There are both government-run and private avalanche centers, and some that are formed through partnerships. For instance, Mount Washington Avalanche Center is a partnership between the Friends of Tuckerman Ravine, the Mount Washington Avalanche Education Foundation, the Mount Washington Volunteer Ski Patrol and the U.S. Forest Service.)
Explorer: What would the avalanche center do on a regular winter week? What type of information are they putting out for the public?
Worth: Weather information (and an) avalanche forecast based on data collected by their forecasters and also citizen observers, (which is examined by trained professionals). It’s important to have that community aspect. A huge component of avalanche centers is education, just getting people to understand that the danger’s there, and how to mitigate it, and travel safely in those areas, when possible.
Explorer: How much avalanche terrain do we have in the Adirondacks?
Worth: For the East Coast, we have a lot of avalanche terrain and what we do have is generally very complex. They’re not straightforward paths, there’s lots of terrain traps. You’re most likely going to get strained through some trees or something. There’s a lot more to consider in our avalanche terrain than in the typical areas.
(This session was edited for accuracy and clarity.)