Persistent Weak Layers and forecasting.

[plugboots]

Huge avalanche in la grave this morning.

Go check out pictures/videos of this if you can, it's pretty amazing. Nothing I could find on the news yet, but my friends there are posting a lot of FB stuff
https://www.facebook.com/ecrin.skier...eric&ref=notif

[adrenalated]

IMO we overcomplicate the PWL problem, and we do so because we're looking for a solution that doesn't exist. I do not think more information is the answer. It is a common affliction with all informed and motivated b/c users (but moreso with newer ones IMO) to scour the earth for the key piece of information that will allow them to rationalize/nuance/thread their way into "grey area" terrain. There is no grey area during a PWL instability - you're either in/under avalanche terrain or you're not, and if you're in it, you are rolling the dice. I'm beginning to latch onto the idea that teaching PWL alongside more manageable problems like windslab, storm slab etc. confuses the issue.

The difference with wily vets IMO is not some ninja knowledge about the micro feature over there that ripped in 1992, it's simply that they have recognized that there is no outfoxing this problem, and have finally accepted that they can only "win" by avoiding it. At that point it becomes a game of identifying avalanche terrain (pretty easy) and avoiding it (the hard part).

It's really simple in theory - do not fuck with avalanche terrain during a PWL instability. In practice, it is much harder to apply. I took higher level classes because I thought it would unlock more terrain, and it took 10+ years and L2 education to fully understand that there are no keys to the steep/deep castle during PWL. If I'm being 100% honest, I'm not there yet as I will catch myself trying to game my way into something on the margin occasionally.

Just wanted to repost this because it's excellent.

Just because the freshie pow pow on West Whistledick hasn't slid in 30years does not mean in is not gonna slide and kill me today.

My mantra lately has been "if it's steep enough to slide, someday it will."

[bodywhomper]

Got any more info that that? Are you talking about local connect terrain below 30* or a propensity of avalanches failing on PWLs to run on terrain <30*. If the later, I'm very interested as that is not part of my risk reduction paradigm.

I’m talking about connected terrain/slab. Like a slab pulls out on a steeper slope >30* but cohesiveness/strength of the slab has it pulling from low angle adjacent terrain.

[MakersTeleMark]

Why did the FUAC stop their 3-day program? I took it about 15/16 years ago and found it to be very useful and affordable. Affordable in a way that it won’t kill your budget to take it annually or every few years and useful where you’ll gain new levels of understanding each time you take it.

Something that I sometimes read in the forecast discussions but I feel many seem to miss is that some slabs that sit on and release from PWLs will pull out on slopes much less than 30*, depending on multiple circumstances. Discussion is pretty common about the potential of triggering the slab from below, but there’s also potential that the slab will pull out from an above flat ridge line and very low angle areas along the flanks.

This is literally my back yard from a couple days ago:

[Foggy_Goggles]

I’m talking about connected terrain/slab. Like a slab pulls out on a steeper slope >30* but cohesiveness/strength of the slab has it pulling from low angle adjacent terrain.

Thanks, I'm no different than anyone else in that I'm at risk of doing it wrong. Just making sure I wasn't missing something.

[bodywhomper]

Thanks, I'm no different than anyone else in that I'm at risk of doing it wrong. Just making sure I wasn't missing something.

Sry I wasn’t more clear in my earlier post. Using smartphones are pretty poor for written communication.

I’m definitely at risk of doing it wrong, too! Several seasons ago, I stumbled onto a pwl from the bottom. I was touring outside a forecast area. When I broke through a second growth forest on an ascent onto a large 30+* slope, I dug a quick hand pit, and I saw something funny and unexpected in the snowpack. I got out my shovel and saw, my columns kept failing when I isolated them about 1.5’ down. Repeated 3 times with same results. I carefully turned around and descended my uptrack.

[east or bust]

Considering that many avalanche paths behave similarly year after year I think that is an excellent tool. No idea where the funding would come from though.

Funding? It would be incredibly easy to log conditions and resulting avalanches in a searchable database, moving forward. Going back through the last 20 years? Yea fuck that.

I’d also tend to agree with foggy on this - the nerd in me thinks the idea is really cool, but at the end of the day what would it really accomplish? Seems like just another irrational method to green light something.

To me this seems similar to a log kept by a fisherman - weather, locations, time of day, species, size of fish caught or not caught, etc. Based on the log, it would heavily influence one’s decision to go fishing on certain days, in certain locations. Thing is, at the end of the day there’s absolutely no certainty of catching anything. With some type of avy log we’re essentially talking about the same exact thing, except instead of catching fish, you may be getting avalanched.

This goes back to the overall topic of risk tolerance. The bottom line is if you’re skiing anything steep enough to slide you’re accepting that risk, even on benign days with a low forecast.

This is the general model we use in construction for hazard prevention and control:



Let’s break these down as it relates to our situation...

ELIMINATION:
Stay the fuck home! There is absolutely no way you’ll find yourself in an avalanche.

SUBSTITUTION:
Varying levels of this..
1: Go bowling
2: Meadow skipping
3: Low angle under 30°

ENGINEERING CONTROLS:
This one does not relate as well, but the idea here is isolation from the hazard.. IE guards on blades, putting up fencing or a rope line 6’ from a drop off, ventilation, etc. For us, this could be avalanche mitigation work in the form of ski cutting, dropping a cornice, or professional techniques (bombing).

ADMINISTRATIVE CONTROLS:
Limit your exposure to the hazard through procedure, warning signs, etc.
Spread the F out when traveling through avalanche terrain. Add more signage to trailheads and resort boundary gates. Another form of this is safety or avalanche training in general. NOTICE HOW FAR DOWN THE LIST THIS IS.

PERSONAL PROTECTIVE EQUIPMENT:
Beacon
Avy bag
Avalung
Shovel and probe could be lumped in here as well


I know this has been brought up multiple times already, but a high functioning group will out perform an individual mind every.fucking.time. There are a lot of really smart individuals on this board, and I’m tempted to see what the collective could put together in a JHA (job hazard analysis) style format for what we all love to do. If there’s any interest in this, I can create a google doc with a general template that we can all contribute to.

[homemadesalsa]

Nice one, east or bust. I like the format for risk analysis.

And once again it bounces down to rest at the feet of my same theme: you gotta exercise discipline to go through all parts of your assessment, then discipline to stay within the lines of what the assessment tells you. My question is: how do we better teach and model discipline in this sport that is fueled by desire?

If you look back in some old and fabulous threads on this Slide Zone by Cookie Monster (how do I tag him?), he talks about risk in the backcountry being a balancing act between Desire and Uncertainty. https://www.tetongravity.com/forums/...rtaintyhttp://

[skifishbum]

To me this seems similar to a log kept by a fisherman - weather, locations, time of day, species, size of fish caught or not caught, etc. Based on the log, it would heavily influence one’s decision to go fishing on certain days, in certain locations. Thing is, at the end of the day there’s absolutely no certainty of catching anything. With some type of avy log we’re essentially talking about the same exact thing, except instead of catching fish, you may be getting avalanched.

This goes back to the overall topic of risk tolerance. The bottom line is if you’re skiing anything steep enough to slide you’re accepting that risk, even on benign days with a low forecast.

aint never made it past the first page of my fishing log

skiing neither
ive hung it out and had different risk tolerances at differnt times
https://www.tetongravity.com/forums/...-TR?highlight=
i guess it was 15 years yesterday
some lessons take mur learnins
but yeah lo dont mean no

The issue is about route finding and safe travel, in other words, how to get around the mountains in winter.
Looking at the slide path in Wilson glade will reveal flagged trees all the way across the base with alleys from previous large slides cut out between the trees.
Haven't seen the monsters since early nineties? but avalanches run in 10-20-50-100 year cycles. Rather than focusing on danger ratings and filming video after video of digging snow pits for you tube, the focus should be on how in the hell you get around.
Don't need to spend half an hour digging when the hollow layer can be felt with a pole plant.
Terrain features can and do suggest safe paths on the up, which is where majority of the time is spent.

wow ftw
but they always tell me how many views their viddys have when they ask for monies
more monies more views more sumthins

[jono]

Good thread. It's interesting that we focus on mentoring and education in a year that's seen so many examples of experienced people dying on familiar terrain, though. Aging on the TRGs? Not to diminish the value of mentoring, but I think the best lessons to learn 1 on 1 are not about PWL's or any hazards that hide from your senses until they don't.

Mentoring is great for learning how to read the signs around you in the mountains, how to dig or ski cut etc. Maybe I'm a robot, but I feel like learning to tame the urge to hyper-rationalize a green light when there's a LPHC hazard is a perfect job for the bulletin--it's just less nuanced than most things that mentoring does really well.

If there's anything to be adjusted educationally, I think it's emphasizing the fundamental difference between LPHC hazards and things that are sensible by watching conditions. The fact that LPHC creates a more wicked learning environment. I see that as a strike against keeping a log of unusual/LPHC slide locations, since weather (among other things) is unlikely to match year to year. LPHC has more to do with knowing this year's snowpack than the last century's slides, which could be a red herring. We've probably seen examples of that this year.


Slight tangent, but I'd like to hear some wiser people's thoughts on "LPHC" including not just PWLs but also crusts with an unusually slick surface. We got a rain crust here that came during a very brief warming, followed by cold such that the surface stayed smooth--no corn cycles, little wind, and literally shiny slopes for days before the next snow fell--cold and not sticky. Seems likely to seal the pack for a while, so there's a hoar layer under it for a PWL but the new snow seems less bonded, too, and at one point the bulletin warned about 25+ degree slopes.

I've ski cut a couple test slopes and dug one hasty pit that showed failure on the 16th tap in the hoar layer. No signs of sliding on that rain found by me--yet (too fluffy/no higher slabs at that point). But I feel like even if the hoar heals the potential bed surface may still be a LPHC hazard that should be managed the same way as a PWL. Am I just looking for red lights?

[raisingarizona13]

I think if you are relying on forecasts to make decisions to ski avalanche prone slopes you may already be in over your head.

[MakersTeleMark]

I think if you are relying just on forecasts to make decisions to ski avalanche prone slopes you may already be in over your head.

FIFY.

[altacoup]

UAC started doing this about a week ago, not sure if it was before/after the 6th. But this is the bottom of today's PWL section:


"Particularly dangerous areas would include Snake Creek, upper American Fork, upper Mill Creek, and much of the Park City ridgeline."


I agree, for touring parties that (unfortunately or whatever) don't have all the information descriptions like this up front are helpful to create "no go" zones. It seems like most in this thread would agree that any and all aspects/elevations with a PWL are no go, but for someone that may not know that, or understand the issue fully, I think what UAC is doing is going to prove helpful.

The day of the accident the UAC listed upper mill creek as a particularly dangerous area. Lots of skiers in the Wasatch poo poo the UAC and think they’re too conservative. To each their own


Sent from my iPad using TGR Forums

[altacoup]

IMO we overcomplicate the PWL problem, and we do so because we're looking for a solution that doesn't exist. I do not think more information is the answer. It is a common affliction with all informed and motivated b/c users (but moreso with newer ones IMO) to scour the earth for the key piece of information that will allow them to rationalize/nuance/thread their way into "grey area" terrain. There is no grey area during a PWL instability - you're either in/under avalanche terrain or you're not, and if you're in it, you are rolling the dice. I'm beginning to latch onto the idea that teaching PWL alongside more manageable problems like windslab, storm slab etc. confuses the issue.

The difference with wily vets IMO is not some ninja knowledge about the micro feature over there that ripped in 1992, it's simply that they have recognized that there is no outfoxing this problem, and have finally accepted that they can only "win" by avoiding it. At that point it becomes a game of identifying avalanche terrain (pretty easy) and avoiding it (the hard part).

It's really simple in theory - do not fuck with avalanche terrain during a PWL instability. In practice, it is much harder to apply. I took higher level classes because I thought it would unlock more terrain, and it took 10+ years and L2 education to fully understand that there are no keys to the steep/deep castle during PWL. If I'm being 100% honest, I'm not there yet as I will catch myself trying to game my way into something on the margin occasionally.

Excellent post. Titus used to always say, I’m sure he still does “if snow is the problem terrain is the answer”. For me, PWL means my terrain answer is between the ropes.


Sent from my iPad using TGR Forums

[jono]

I think if you are relying on forecasts to make decisions to ski avalanche prone slopes you may already be in over your head.

Gotta agree with MTM's adjustment there. But obviously there are things a forecast is better suited for and things it's not going to do well.

The point I'm slowly circling is that LPHC risks are not particularly well-suited to personal, tactile learning (where personal experience bias is at its most dangerous). And conversely, LPHC risk management benefits tremendously from very large datasets. Because that's what it takes to understand a low-probability problem (or to discover it at all, if probability is low enough: think Higgs boson or super rare vaccine side effects).

Obviously the ability to detect a PWL without triggering it consequentially helps. But if it solved the problem we wouldn't have to say "the information doesn't exist."

[rod9301]

Excellent post. Titus used to always say, I’m sure he still does “if snow is the problem terrain is the answer”. For me, PWL means my terrain answer is between the ropes.


Sent from my iPad using TGR Forums

Very true

Sent from my Redmi Note 8 Pro using Tapatalk

[Foggy_Goggles]

Too me, this is the virtual screaming from the tree tops.

[MTT]

Alot of work went into this report. This is the first one I have read top to bottom multiple times. I hope it saves some lives. Maybe that will be the legacy?

I am very inexperienced in modern back country skiing.
The part about tech bindings in lock mode keeping your skis on and pulling You down
I had never heard or thought about that.
When I went from free rides to beasts the idea that there was a potential downside never crossed my mind.

[MakersTeleMark]

Too me, this is the virtual screaming from the tree tops.

That doesn't bug me one bit. What does, is that the same old folks are doing the same old thing.

And we are not in UT, we are here. This really is what we manage every day. This is just for the newbs. UT has a lot of catching up to do. Jeebus, we have been dealing with all season long PWL for over a decade.

I have been out a lot. I know it's old school, but I haven't seen one person dig this season. The spacial variability is astonishing, but no one wants to take a deep dive other than point it, but maybe not far enough. Too soon?

Avi forecasts don't spook me. I am the first one to get out after that crown and question myself experientially.

Data are matters things.

[Gunder]

I am willing to bet that just about everyone killed so far this year was fully aware of the potential hazard and current danger ratings. Yet they all still ended up in the wrong spot at the wrong time. All if not almost all of these fatalities involved people that where quite experienced. The problem is not a lack of education, or a lack of awareness. The bigger issue is people need to learn how to walk away from an objective and learn how to say NO in a group. This is where the problem lies. People get caught up in "powder panic" or an objective mindset and reason goes right out the window. We need to promote that walking away from something is just as cool as riding a an awesome line

[total_immortal]

Agree about people needing to learn to say no and lack of awareness is not really a major issue. Just speculating, but I wonder if expert halo has played into some of the recent incidents. Perhaps a train of thought along the the lines "the avy center is being conservative this year because of all the new skiers" and then being less careful than usual along with the false sense of security a pwl will lure you into. Not sure that's the case but an interesting thought

[MakersTeleMark]

I am willing to bet that just about everyone killed so far this year was fully aware of the potential hazard and current danger ratings. Yet they all still ended up in the wrong spot at the wrong time. All if not almost all of these fatalities involved people that where quite experienced. The problem is not a lack of education, or a lack of awareness. The bigger issue is people need to learn how to walk away from an objective and learn how to say NO in a group. This is where the problem lies. People get caught up in "powder panic" or an objective mindset and reason goes right out the window. We need to promote that walking away from something is just as cool as riding a an awesome line

It's beyond that. Of course they knew. They just didn't really know, because they have always cheated the system. I see it and speak to people on a daily basis about this and they don't care. It's throwing a brick against a brick wall. Time is the only leveler. Nothing I can do to change it other than a very sly, man of few many words, maybe tone it down a bit suggestion. There will be many more, and more friends of mine. It's not group think at all, it's pure ego. I can prove it to you, although you might not be able to handle it.

[sfotex]

I am willing to bet that just about everyone killed so far this year was fully aware of the potential hazard and current danger ratings. Yet they all still ended up in the wrong spot at the wrong time. All if not almost all of these fatalities involved people that where quite experienced. The problem is not a lack of education, or a lack of awareness. The bigger issue is people need to learn how to walk away from an objective and learn how to say NO in a group. This is where the problem lies. People get caught up in "powder panic" or an objective mindset and reason goes right out the window. We need to promote that walking away from something is just as cool as riding a an awesome line

I know out in the 'Satch this season there's not a ton of low angle terrain options with coverage without a conga line of people on the skin track. I think the people in the recent accident out here just wanted to go for a walk without tripping over people.

[altacoup]

^^^

Today agree. In the last 5+ years as the backcountry has got more crowded I’ve toured a lot less. One goes to the BC for led crowds. And the amount of people since the proliferation of better gear (I love it to) leads one into making decisions based on avoiding crowds not terrain and snow. Fuck the last tracked BC terrain in LCC is patsy because it’s mainly accessed by lift riders booting up.

[Foggy_Goggles]

^^^
Put me down for "my traditionally safe routes are overrun. I am at risk of making bad decisions, because I am trying to get away from people". It's not linear, but has been happening around here for at least 25 years. Hell, we used to go into the Berthoud Pass sidecountry as soon as the ski area was tracked.

I like to think that I've moved past making emotion driven mistakes due to the fact that I just won't ski tracks in the BC, but that is probably not true. Get up earlier and walk further is part of the answer. As is a snowmobile and a powsurf. And learning to have fun at the ski area again. Along with trying to get into other activities that stop me jonesing.

I'm generally against creating all these sub-demographics of backcountry skiers. But if the question is, "why do people keep fucking up" I can speak to this user group because it is me.

We are 45+ now, we progressed F1s>Trackers...Treckers/Freerides and have just skied a stupid amount of powder in our lifetimes. We are (hopefully) the definition of experienced and yet we are very at risk.

This is why I took issue with the A3 piece about new users. In Colorado at least, this is not the profile of the accidents this year.

We all need to kick the tires on our own brains to this about what might put us at risk of fucking up!