Educating Backcountry Skiers - Deep Instabilities

[CookieMonster]

Over the last 8 years, I've spent a lot of time speaking publicly in various forums about avalanche safety, especially about the uncertainty that arises from the geophysical aspects of various avalanche problems. For what it's worth, I've rarely been shy about it, even when my views were inaccurate, controversial, or wrong. I feel like public discussion of these ideas and concepts is far more beneficial to the group as a whole than private conversations in which only a few voices are heard.

For the benefit of the community, and to ensure that the voices from this community are heard and have a chance to participate, I think we should keep the discussion online. I totally agree with your message about thread drift, and I've created a new topic as a result.

CookieMonster,

I did not make clear the implications of my very opinionated comments about educational updates as separate from update in bulletin format. With respect to what I had in mind from an educational point of view, I'd say that PS and DPS problems are grossly disrespected by many people I have met in the recreational community (yes myself included) and if problem character is found to have an incredible correlation with loss of life in fatal accidents (with more research from different regions, etc), then I think that is important to emphasize in training.

We should talk offline about bulletin applications & format ... it's a severe thread drift, for one, and for two it starts unraveling a giant can of worms when it comes to various aspects of what you and I are seeing in recreational BC skiing right now, and we may be seeing different things, or seeing the same things with different takes. I appreciate the link to your blog. Let's talk offline via email/phone about your opinions about what we / the recreational community isn't getting.

* Avalanche safety courses in North America already include training on difficult avalanche problems such as persistent weak layers.
* Many extremely well-known avalanche accidents involved persistent weak layers.
* February 2003 Strathcona-Tweedsmuir Avalanche in Glacier National Park.
* February 2003 La Traviata Avalanche in the Selkirk Mountains.
* April 2013 Sheep's Creek Avalanche in Colorado.

* Persistent weak layers are the subject of decades of research, including heavy research over the last decade by Bruce Jamieson's group at ASARC University of Calgary, Dave McClung's group at University of British Columbia, and Jordy Hendrikx's group at the University of Montana.
* There is a lot of literature about persistent weak layers in the proceedings of the last 6 or 8 ISSWs, and annually in the professional journals of the Canadian Avalanche Association and the American Avalanche Association.
* Every year, when applicable, professional avalanche forecasters devote significant time and resources to persistent weak layers in their forecast areas.

It is my contention that there are no deficits in research and training with respect to persistent weak layers.

* The fact that avalanches running on persistent weak layers constitute a statistically significant portion of avalanche fatalities is related to the intersection of the geophysical aspects of the problem and variations in human perception.
* It is well-known that humans are have terrible perception and forecasting abilities when it comes to low-frequency, high-consequence events.
* This is a problem for professionals and amateurs alike, but professionals are far more *skilled* at dealing with these problems, are far more likely to strictly follow protocol, and use their knowledge of the geophysical aspects of the problem internalize the futility of trying to forecast avalanches on persistent weak layers.

In light of these facts, what changes to avalanche education and the North American Public Danger Rating would you like to see?

[SchralphMacchio]

Thanks CM. I hadn't seen your PM or this thread before I sent my PM to you.

I would extend discussion to the USFS Bulletin model in general, as the NA Public Danger Rating in and of itself is what it is, and it was designed with specific goals in mind that I may not fully understand. Do you think that is reasonable for this thread?

[CookieMonster]

Thanks CM. I hadn't seen your PM or this thread before I sent my PM to you.

I would extend discussion to the USFS Bulletin model in general, as the NA Public Danger Rating in and of itself is what it is, and it was designed with specific goals in mind that I may not fully understand. Do you think that is reasonable for this thread?

Yes, this thread should definitely discuss those subjects.

[covert]

Yo Cook Mon,

I got your email address and I'm going to find it and send you something, because I'm hoping you'd be willing to sound off on my podcast. But this issue has been on my mind too, and I think I can add to your question.

I'm more interested in the DPS problem. Persistent slab problems don't necessarily meet the low p high q bar in the same way as a DPS problem. As skiers, we know we can get away with hitting it during a DPS problem cycle. I don't think the traditional advice of avoiding avalanche terrain confronts that.

So how do we gather evidence that supports or opposes a decision to ski avalanche terrain during a DPS problem cycle. Is that possible or is the uncertainty too great? Is it a risk acceptance issue? Is there a middle ground? Perhaps focusing on the role of margins?

Right now we are in a 'tell teens not to have sex' or a 'just say no' paradigm. That don't work. Pardon my French but people will fuck and do drugs, because...well you know.

[summit]

CM LIVES!

[TahoeJ]

So how do we gather evidence that supports or opposes a decision to ski avalanche terrain during a DPS problem cycle. Is that possible or is the uncertainty too great? Is it a risk acceptance issue? Is there a middle ground? Perhaps focusing on the role of margins?

Right now we are in a 'tell teens not to have sex' or a 'just say no' paradigm. That don't work. Pardon my French but people will fuck and do drugs, because...well you know.

This sounds great. Would love to hear this type of discussion.

[kootenayskier]

Skiing when a DPS is an issue requires a technical appreciation of the characteristics of the issue, the experience skill and flexibility to identify objectives that provide satisfying skiing experiences within a sensible safe margin of error, and the discipline to keep below this threshold, day after day, despite the lack of and often contrary feedback. Many of us ski daily through DPS winters without issue. I'm aware of some of the the many complicated reasons why humans don't/won't/can't do this, but I don't accept that these are necessarily the responsibility of the community. Poor choices sometimes have serious consequences, and those that can't accept this probably shouldn't ski in the backcountry.

[doebedoe]

Looking forward to this thread -- and hopefully CM being on the Slide cast. I enjoy informed opinionated people arguing.

[doebedoe]

... Many of us ski daily through DPS winters without issue....

I think the point is that you could ski DPS for years, daily, without issue and it's still not evidence you made the right judgement/risk assessment or decision. I think the thrust of covert's question (correct me if I'm wrong!) is: how do we know if we made a good assessment and decision during a DPS cycle, or if we just got lucky?

I ride my bike to work daily without a helmet. It is still a low p high q event. Every day I ride (but I ride "smartly"! -- good decisions, safe distances, calm streets) is no more evidence for it being a good decision.

[kootenayskier]

I think the point is that you could ski DPS for years, daily, without issue and it's still not evidence you made the right judgement/risk assessment or decision. I think the thrust of covert's question (correct me if I'm wrong!) is: how do we know if we made a good assessment and decision during a DPS cycle, or if we just got lucky?

I ride my bike to work daily without a helmet. It is still a low p high q event. Every day I ride (but I ride "smartly"! -- good decisions, safe distances, calm streets) is no more evidence for it being a good decision.

It's not a decision to be justified (or not) with evidence, it's an attitude to adopt and a process to be followed. There are limits to what we can know.

[LeeLau]

It's not a decision to be justified (or not) with evidence, it's an attitude to adopt and a process to be followed. There are limits to what we can know.

And to some extent it's an acceptance of low probability high consequence. The alternative is to not ski backcountry; or to not ski slopes of over xx %; or [insert other options]

What's interesting is when DPS or PWKLs are present in maritime climates where the mindset might not be so attuned to monitoring and tracing. For me; this was the 2012-3 season in Whistler/Duffey. I chose to not ski steep slopes (for me this meant slopes over 45 deg) and when warmer weather came in (around mid - April) and potentially began waking up buried instabilities I hung up the skis and started doing trailwork thus removing my own human heuristic shortcomings and coastal lack of education about how to deal with DPS/PWKLs from the equation

[covert]

What's interesting is when DPS or PWKLs are present in maritime climates where the mindset might not be so attuned to monitoring and tracing. For me; this was the 2012-3 season in Whistler/Duffey.

This is now in Hakuba on the eve of a Freeride World Tour event. Glad that's not my problem.

[homemadesalsa]

You guys know that I deeply appreciate this conversation.

The role of margins is central to the discussion. I bet there's some material from the finance world out there. I think we are circling the beast, getting closer to understanding the elephant by the blind men, especially illuminated by the implementation of strategic mindset. To me it comes down to creating a pause moment inbetween fast and slow thinking. I use these paired questions as I am too ADD to go any deeper: "What do you WANT to do?" then, "What do you think you OUGHT to do?"

Seems a lot like addiction behavior therapy- the steep powder addiction is strong, you know.

Keep it coming...

[covert]

Sooo, here's a question, since you brought up mindset...***thread drift alert***...

I see mindset as a sort of purposeful bias. A technique for priming one to approach problems from a particular perspective. If the evidence does not fit your AM mindset, should you change it? If you do, does that not defeat the purpose of establishing a mindset?

We're Stepping Out and timid, yet shit is not going down. Our obs don't support timidity. Seems like we could step up. Seems like go time.

Mindset is a forecast, neh? Do we adjust our mindset to fit the current assessment? Isn't that a Pandora's Box that sets us up for the bias we were trying to slay?

[kootenayskier]

You guys know that I deeply appreciate this conversation.

The role of margins is central to the discussion. I bet there's some material from the finance world out there. I think we are circling the beast, getting closer to understanding the elephant by the blind men, especially illuminated by the implementation of strategic mindset. To me it comes down to creating a pause moment inbetween fast and slow thinking. I use these paired questions as I am too ADD to go any deeper: "What do you WANT to do?" then, "What do you think you OUGHT to do?"

Seems a lot like addiction behavior therapy- the steep powder addiction is strong, you know.

Keep it coming...

Slowing down and ditching the jargon would be a great start. By definition "Persistent" issues in the snowpack don't change quickly, and so the constancy of your approach, despite varying irrelevancies, is key.

[covert]

Slowing down and ditching the jargon would be a great start. By definition "Persistent" issues in the snowpack don't change quickly, and so the constancy of your approach, despite varying irrelevancies, is key.

What do you mean by "ditching the jargon?"

[goldenboy]

I'm not smart enough to know how you could make something work for all users on a national or international level. TYhis post will probably come off as babble, since my thoughts on it aren't very organized.

The info is there, but it's in the discussion or the avalanche problems section. Either way, the "skimmers" might not get much past the danger rating. Newbies might not be able to truly differentiate what to do when dealing with storm slabs or dealing with a PWL. Maybe "scary moderate" or "mod X" needs to become a thing, just like "runout" or "X" is a thing for rock climbs. It might help people slow down and think. Or it might make forecasters lose their hair while they battle the different danger ratings for the day and then have to battle over whether or not it needs an X.

On the other end, experienced skiers can become numb to it. How many times has a 25 year CO backcountry skier like me heard about it? How many ways could an avy center say it? Sure, it's easier to convey at times with videos and photos compared to when I started and was calling a number with a landline, but still... And then there's the mixed messages of low probability events. If an avy center is crying wolf and meanwhile you see bold lines going down with no problems, whether on Instagram or in person, human nature says you're going to step it up, too. And you probably won't die and you'll probably have a great run, until you don't.

[adrenalated]

Just a couple random thoughts, I'm far from an expert here...

-I would contend that if there is a trend of educated people ignoring the travel advice of experts in respect to low probability/high consequence PS and DPS problems, then there is a deficiency in the education. What that is and how to fix it, I am not qualified to say.
-in my AIARE L1 that I took 10 years ago, there was minimal or no emphasis on different management strategies for different types of avalanche problems. Unfortunately I have not have a chance to re-take or shadow L1 since then and don't know exactly how the curriculm has evolved. Also, the group I took my L1 with kinda sucked (though I still learned a ton at the time).
-in my AIARE L2 in 2015 there was considerable emphasis placed on managing different avalanche problems differently

[TahoeJ]

I've noticed the CAIC making efforts in their bulletins to prevent message fatigue... but they can only do so much. I wonder if a rating of "moderate with extreme consequences" would be a useful approach? People would probably fatigue to that just the same.

[baron]

Keep up the info train> there are serious instabilities that hide in snowpacks> and I see many backcountry users ,totally ignore all kinds of red flags.

[Foggy_Goggles]

Like GoldenBoy, my thoughts are disorganzied. The longer I play this game and the more I pay attention to how the more "inexperienced" learn, the more I think that it is all about making good decisions.

The problem of a shitty feedback loop promoting bad decision making is heightened with the DPS issue. One has to be really good at ignoring all the heuristic traps, be really stubborn and convicted regarding your decision making, and talk about it with your partners.

[kootenayskier]

I've noticed the CAIC making efforts in their bulletins to prevent message fatigue... but they can only do so much. I wonder if a rating of "moderate with extreme consequences" would be a useful approach? People would probably fatigue to that just the same.

The CAA bulletins I read make it very clear whenever we're dealing with a Persistent Weak Layer, and nobody who checks them on a regular basis could be unaware. But the variations in poor decision-making are simply too numerous, complicated and ingrained to address with the limited tools (bulletins and short form classes) that organizations have available. It's possible to imagine the sort of long term, intensive education and mentoring process that could actually be effective, but not how to implement it in any broad sense. We're therefore left with absolute personal responsibility, while accepting that periodic tragedies are not only inevitable, but are perversely the only (partially and temporarily) effective motivators we have. Scaring the stupid out of them works, until it doesn't.

[klar]

What is the difference between a deep persistent weak layer and a persistent weak layer in terms of actual definition - how deep is deep? - and suggested behaviour when each is present?

Euro terminology seems a little different. We have "old snow problems". If these are buried deeply, the bulletins may say something like "the old snow problem still exists but is hard to trigger" or "the old snow problem is now reactive once again because the snowpack is transitioning to a spring situation (or whatever)". There is no particular distinction between "old snow problems" that are deep and those that are not. (maybe we just never get that much snow)

[Foggy_Goggles]

Klar, this is from the Colorado Avalanche Information Center

http://www.tetongravity.com/forums/s...-Instabilities

Persistent Slab
Release of a cohesive layer of soft to hard snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

The best ways to manage the risk from Persistent Slabs is to make conservative terrain choices. They can be triggered by light loads and weeks after the last storm. The slabs often propagate in surprising and unpredictable ways. This makes this problem difficult to predict and manage and requires a wide safety buffer to handle the uncertainty.

How they form

Persistent Slabs form when a persistent weak layer is buried by additional layers of snow. The problem persists after storm and wind slab instabilities have stabilized. The persistent weak layer can cycle through periods of sensitivity from reactive to nonreactive due to changes in weather conditions such as new precipitation, wind loading, strong solar radiation, and/or rapid changes in air temperature.

This Persistent Slab was triggered remotely, failed on a layer of faceted snow in the middle of the snowpack, and crossed several terrain features.

Where they are

The spatial distribution of Persistent Slabs is dictated by the distribution of the culprit weak layer. The weak layer distribution is dictated by the weather patterns responsible for its creation. Thus, Persistent Slab distribution can range from widespread across terrain to very specific terrain features. They can occur at all elevations and on all aspects. Persistent Slabs can be triggered remotely, and on low-angle to steep slopes. Consult the backcountry avalanche forecast to determine where in the terrain this problem exists.

A Persistent Slab avalanche that propagated over several terrain features.

Timing

Persistent Slabs can be a problem during any time of the snowy season. Anytime you have a slab resting over a reactive persistent weak layer, you have a Persistent Slab problem. This problem can develop during the fall and last well into the spring.

Recognition

Persistent Slabs can be distinguished from Storm and Wind Slabs by how the fracture lines fail in the terrain. Unlike storm instabilities, Persistent Slabs are commonly triggered remotely, from flat areas, and failures can propagate across terrain features like ridges, ribs, and gullies. It is possible to have a Persistent Slab problem that is susceptible to human triggering but not produce many spontaneous avalanches. The lack of avalanche activity does not always indicate the absence of a Persistent Slab problem. You can look for persistent weak layers in snow profiles, and perform snowpack tests to gauge sensitivity and distribution of a Persistent Slab problem. Consult the backcountry avalanche forecast to determine where in the terrain this problem exists.

Treatment and Avoidance

Persistent Slabs can be triggered by light loads and weeks after the last storm. They are commonly trigged remotely and they often propagate across and beyond terrain features that would otherwise confine wind and storm slabs. Failures often propagate in surprising and unpredictable ways. This makes this problem difficult to predict and manage and requires a wide safety buffer to handle the uncertainty. Intimate slope-scale knowledge and tracking of culprit persistent weak layers and avalanche activity over space and time will aid in assessing the severity and extent of this problem. The best ways to manage the risk from Persistent Slabs is to make conservative terrain choices.

Search results for: deep persistent slab
Deep Persistent Slab
Release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer, deep in the snowpack or near the ground. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage. They commonly develop when Persistent Slabs become more deeply buried over time.

Deep Persistent Slabs are destructive and deadly events that can take months to stabilize. You can trigger them from well down in the avalanche path, and after dozens of tracks have crossed the slope.

How they form

Deep Persistent Slabs form when a persistent weak layer is deeply buried under a thick hard slab of snow created by numerous storm events. This problem commonly develops when an early season persistent weak layer like depth hoar or crust-facet combinations become more deeply buried over time.

Where they are

The spatial distribution of Deep Persistent Slabs (like Persistent Slabs) is dictated by the distribution of the thick slabs and the culprit weak layer. The slab and weak layer distribution are dictated by the weather patterns responsible for their creation. Thus, Deep Persistent Slab distribution can range from widespread across terrain to specific terrain features, but are confined to areas with a deep snowpack. They can occur at all elevations and on all aspects, and can be triggered on low-angle to steep slopes. Consult the backcountry avalanche forecast to determine where in the terrain this problem exists.

Timing

Deep Persistent Slabs can be a problem during any time of the snowy season but the most common period is mid-winter through spring since it takes some time to develop a thick slab via multiple snow events. The problem takes weeks to months to develop, and can then persist for weeks or months.

Recognition

Unfortunately, there is often little direct evidence of a Deep Persistent Slab problem until a large destructive avalanche releases. The lack of avalanche activity even with dozens of tracks on a slope does not indicate the absence of a Deep Persistent Slab problem. Observing deeply buried weak layers in snow profiles, and gauging sensitivity with appropriate deep layer snowpack tests like Deep Tap Tests and Propagation Saw Tests can be helpful in assessing the presence of this problem.

Treatment and Avoidance

Deep Persistent Slabs are very difficult to predict and manage. They are low-probability high-consequence events. If you are caught in one, you are unlikely to survive. Often the only evidence of the problem arrives too late as a large, deadly, and unexpected avalanche. The only real effective risk management strategy is to avoid areas where you suspect a Deep Persistent Slab. They are most commonly triggered from shallow spots in the snowpack. Avoiding these areas is one way to reduce risk. Give yourself a wide safety buffer to handle the uncertainty, potentially for the remainder of the season.

Geek Stuff from "Decision Making in Avalanche Terrain"
https://avalanche.state.co.us/wp-con...istentslab.pdf

[bodywhomper]

^^^That sounds subjective to me^^^

Personally, I do not like the use of the term "slab". The persistence is the weak layer (hoar, NSF, etc.) and not the slab.

TahoeJ, "mod-X" has been an idea debated by the pros in the past, sometimes openly on forums (e.g. ttips). I'm not sure about the current status of that debate.