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  1. #26
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    Quote Originally Posted by Foggy_Goggles View Post
    Klar, this is from the Colorado Avalanche Information Center
    okay, so the PS is in the "middle to upper snowpack" and the DPS is "deep in the snowpack or near the ground" and the only other significant difference is that triggering is more likely if the layer is less deep? I agree with bw that "slab" is a weird word to use here, "layer" seems to make more sense.

    i like the "x" idea (https://utahavalanchecenter.org/blog...danger-ratings ), not sure if it would change anything about people's perception. similar debates around here usually end with somone saying "people don't read the forecast anyway".

    we are on our third season in a row with an "old snow" problem, aka (deep?) persistent weak layer, whereas it wasn't a huge issue in the years before that. there have been a lot of accidents related to the "old snow", including some high profile ones with guided groups and/or huge propagation caught on video. think headlines in major newspapers like: "Massive avalanche, several fatalities, experienced mountain guide caught by surprise". my feeling is that a lot of people are more careful now if "old snow" is mentioned in the bulletin, not because the bulletin changed but because people have recently seen what can potentially happen and there is a realization that the issue is not "manageable".
    Ich bitte dich nur, weck mich nicht.

  2. #27
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    Quote Originally Posted by Foggy_Goggles View Post
    Klar, this is from the Colorado Avalanche Information Center
    okay, so the PS is in the "middle to upper snowpack" and the DPS is "deep in the snowpack or near the ground" and the only other significant difference is that triggering is more likely if the layer is less deep? is the difference between deep and not deep somehow refelcted in the danger ratings given for each?

    I agree with bw that "slab" is a weird word to use here, "layer" seems to make more sense.

    i like the "x" idea (https://utahavalanchecenter.org/blog...danger-ratings ), not sure if it would change anything about people's perception. similar debates around here usually end with somone saying "people don't read the forecast anyway".

    we are on our third season in a row with an "old snow" problem, aka (deep?) persistent weak layer, whereas it wasn't a huge issue in the years before that. there have been a lot of accidents related to the "old snow", including some high profile ones with guided groups and/or huge propagation caught on video. my feeling is that a lot of people are more careful now if "old snow" is mentioned in the bulletin, not because the bulletin changed but because people have recently seen what can potentially happen and that the issue is not "manageable".
    Ich bitte dich nur, weck mich nicht.

  3. #28
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    How are people being "more careful" in Europe? What has changed in behavior?

  4. #29
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    They are referred to as Persistent Slab and Deep Persistent Slab because they fit into a larger category of avalanche problems that also include Wind Slab, Storm Slab, Wet Slab, etc. Maybe the problem descriptors focus more on describing avalanche character than weak layer characteristics, but it seems like they try to address both.

  5. #30
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    Quote Originally Posted by bodywhomper View Post
    How are people being "more careful" in Europe? What has changed in behavior?
    I can't speak for all of Europe. In my corner of Tyrol (where we have extremely dedicated people writing the bulletin and providing a lot of information beyond that), my totally subjective impression is that the "old snow" phrasing now raises red flags for more people than a few years ago. This results in more conservative terrain choices and probably some people staying home.

    I suspect this is particularly the case for a subsection of the skitouring population that knows their area well and gets out a lot and may figure that a given tour is fine on a considerable day with a wind problem but not on a considerable day with an old snow problem. These are the kind of people that will typically put the first track in on their backyard tours and if they don't then everybody else is more reluctant.

    Consistent terminology across different countries and languages seems like it would be nice to have. not even the danger level definitions are the same between NA and europe.
    Ich bitte dich nur, weck mich nicht.

  6. #31
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    My understanding is that "deep" refers to any weak layer more than a meter or so down, at least in the US.

  7. #32
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    More random musings...

    I would like to think that unusual conditions would be easier to communicate and heed. A few years back, all the heli companies in interior BC were stating that they were only using 5% of their terrain (or something like that) because of a widespread PWL. With conditions like that, one would think that local skiers would just throw in the towel and start looking forward to bike season. Basically what LL said in a post above. It's tough in a place like CO where it's nearly year in year out.

    We may have the opposite scenario this season in the Crested Butte area, with potentially a safer than normal snowpack thanks to a 100"+ storm. Even in the middle of the storm, forecasters began talking about our snowpack in intermountain terms rather than continental. We went from an extreme rating on 1/11 to moderate on 1/15, which seems like a very rapid stabilization trend for CO. Will people push too fast and too far?

  8. #33
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    I was in the backcountry the other day, I saw a guy who had no gear at all. I asked him if he had any backcountry experience, he said "If I follow others tracks, I'm good". I just said have a good day. No pack, no beacon, no anything.

  9. #34
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    Why does he need a beacon or shovel if he's by himself?

    When I'm solo, I don't carry much either.

  10. #35
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    So when he fucking dies by himself, and no one is there to witness him go down in an avy. It'll help(somewhat) with the initial 48hr recovery instead of wasting man hours.

  11. #36
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    That is why I do it, body recovery. Sometimes I randomly meet up with another solo traveler or see another. I'd be pretty bummed if I encountered an incident and didn't have my tools to help.

  12. #37
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    i haven't done any bc yet but just from reading these threads over the years, i assumed if you were out, solo or not, you would always have all your gear. knowing there is the possibility that other people are in the area and they may have to save your life or you may have the opportunity to save theirs, i can't imagine not carrying the basic tools.

  13. #38
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    Quote Originally Posted by goldenboy View Post
    Will people push too fast and too far?
    To answer your question GB, YES folks are pushing too fast and too far. I'm amazed that folks are skiing the East Vail chutes as much as they are this winter. Years ago folks would have left them alone until late spring.

    The problem with PWL and DSI is that folks want to get into bigger terrain (i.e., steeper, bigger consequences, etc...) NOW, not later for whatever reason. Personally, I like to come home alive with all my partners....

    Basically, folks need to go back to "terrain management" = ski the lower angle slopes with lower consequences terrain when there are PWL/DSI problems.

    I think what's going on with a lot of experienced folks, (prime example Sheep Creek - I was there on the recovery) is having "Perceptual Blindness."

    Perceptual blindness is where even smart experienced people are sure that they are paying attention, can miss what is right in front of them. In the case of Sheep Creek, ALL of the victims had read/listened to the CAIC forecast that talked about slope compression failures as possible that day. They (the victims) had all the correct information about DSI, but somehow chose to ignore the information. If they had followed the information ( and been reading the daily forecast for the previous month) they would have known about the PWL/DSI in the front range area that winter. Terrain management would have kept them away from skinning up the throat of Sheep Creek.

    What we really need to do is get folks into doing better terrain management. Start pulling out your slope meter more. Start looking at the terrain your about to drop into. I personally, think a lot about terrain and consequences more than I do anything else. Its not to say you can't get killed in a small avalanche. But, avoiding high consequence terrain (i.e, terrain traps, etc...) can stack the odds better on your side.
    "True love is much easier to find with a helicopter"

  14. #39
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    Quote Originally Posted by Hacksaw View Post
    To answer your question GB, YES folks are pushing too fast and too far.
    You should re-read my post, as it had to do with how people react to "abnormal" snowpacks, either good or bad.

  15. #40
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    I re-read it and I still think folks pushing to go bigger and further no matter what the conditions.
    "True love is much easier to find with a helicopter"

  16. #41
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    You always carry all of your gear because you might end up saving someone else not in your group, or vice-versa. Duh. Most packs have a dedicated pocket for b / s / p anyway so why bother taking them out?

  17. #42
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    The Sheep Creek incident is fascinating to me because it seems to be a bit of an outlier in terms of the information available to those involved.

    http://www.americanavalancheassociat...3_Feb_2014.pdf

    Normally, message fatigue and uncertainty are really big issues with DPS problems. In the Sheep Creek incident, the forecasts were kinda shouting that uncertainty was decreasing and the likelihood of triggering a deep slab avalanche was increasing. I think it's rare to have that kind of in your face beta for that kind of problem.

    But I don't have the old forecasts at hand, so I may be wrong.

  18. #43
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    Quote Originally Posted by covert View Post
    The Sheep Creek incident is fascinating to me because it seems to be a bit of an outlier in terms of the information available to those involved.
    That's how I remember it. Even before Sheep creek, there was almost a daily report of a big slide in that area. The Vail pass fatality right before Sheep creek perfectly demonstrated low probablility/ high consequence since it didn't release until something like the 40th track. I'm not sure how much more the CAIC could have done the morning of Sheep creek, though there are a few suggestions in the TAR article.

    Off topic, but perhaps an interview with Elizabeth Lamphere on Slide would be a good episode some day. This is at our avy awareness night this year: https://www.youtube.com/watch?v=kfvHGfhtTR4

  19. #44
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    Quote Originally Posted by klar View Post
    okay, so the PS is in the "middle to upper snowpack" and the DPS is "deep in the snowpack or near the ground" and the only other significant difference is that triggering is more likely if the layer is less deep? is the difference between deep and not deep somehow refelcted in the danger ratings given for each?

    I agree with bw that "slab" is a weird word to use here, "layer" seems to make more sense.

    i like the "x" idea (https://utahavalanchecenter.org/blog...danger-ratings ), not sure if it would change anything about people's perception. similar debates around here usually end with somone saying "people don't read the forecast anyway".

    we are on our third season in a row with an "old snow" problem, aka (deep?) persistent weak layer, whereas it wasn't a huge issue in the years before that. there have been a lot of accidents related to the "old snow", including some high profile ones with guided groups and/or huge propagation caught on video. my feeling is that a lot of people are more careful now if "old snow" is mentioned in the bulletin, not because the bulletin changed but because people have recently seen what can potentially happen and that the issue is not "manageable".
    The CAIC recently posted a blog where they discussed how they determine whether a problem is a PS or DPS:

    Quote Originally Posted by CAIC
    DPS avalanches have many characteristics in common with Persistent Slab (PS) avalanches. Both break on persistent weak layers. You can trigger both remotely and from low-angle slopes. Both of these types of avalanches can fail in surprising ways, breaking across and around terrain features that would contain a Storm or Wind Slab avalanche. PS and DPS avalanches have a lot in common, but there are some very important differences that affect how we avoid them and manage our own personal risk.

    DPS avalanches are low probability and high consequence events. The likelihood of triggering a PS avalanche and the size of that avalanche can vary over a wide range. DPS avalanches are a specific creature, very large in size and hard to trigger. We look for three things before we add it to our list of Avalanche Problems. Those three things are:

    Avalanches will be stubborn to trigger, Unlikely or Possible on the Likelihood scale
    Avalanches will be destructive, D3 or larger
    Avalanches will break on deeply buried or basal weak layers

    These criteria capture the low-probability/ high-consequence nature of DPS avalanches. A low Likelihood means there will be very few or no natural avalanches, human-triggered avalanches will be unlikely, and large explosive and cornice triggers will only produce some results (ADFAR2). A D3 (Very Large) avalanche could bury and destroy a car, damage a truck, destroy a wood frame house, or break a few trees. When the likelihood slider drops towards “Unlikely” and the size slider climbs to “Very Large or Historic”, we have a DPS avalanche problem (see image below).

    More detail here (cover article): http://www.americanavalancheassociat...2_Dec_2012.pdf

  20. #45
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    Quote Originally Posted by adrenalated View Post
    The CAIC recently posted a blog where they discussed how they determine whether a problem is a PS or DPS:
    Very interesting, thanks. Much clearer now.
    Ich bitte dich nur, weck mich nicht.

  21. #46
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    Quote Originally Posted by goldenboy View Post
    Maybe "scary moderate" or "mod X" needs to become a thing
    I do this mentally when DPS is among the problem list, I also think it would help others to see it in writing. I don't think it would be too difficult for forecasters to differentiate.

    Quote Originally Posted by goldenboy View Post
    ...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.
    I think this is the crux of the issue. Esspecially now with so much being shared through social media. If I see bold lines skied left and right online, it continues to test my patience while mitigating a DPS. Somebody else said it here a while back but, humans suck at making high consequence low probability decisions. It's just in our blood.

    Covert has referenced Daniel Kahnmen a few times so far in the podcast. If anyone else is interested in a physiologists take on decision making, I highly recommending picking up his book "Thinking fast and slow". I found a used copy on amazon for $4
    Quote Originally Posted by The SnowShow View Post
    Keystone is the new Snowbird

  22. #47
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    I tried the book and it was too dense for my ADD brain. Here's a good summary: http://www.nytimes.com/2011/11/27/bo...ok-review.html

    And I guess I am honestly very pessimistic about human's ability to get educated away from being tempted to tease the deep slab problem. We talk mindsets, better writing the forecast, better education, and so on and so forth. I think that the "young immortal" is going to think that he (she?) can get away with it for many many reasons, which are the same reasons that we draft that age group to go to war for us. They don't individually learn restraint vicariously until someone/ thing very close to them impacts their life. So in my mind the whole "Project Zero" or "Backcountry Zero" is a farce. And I teach avalanche education for a living.... with a dark mindset, honestly.

  23. #48
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    ^^^ Thanks for writing what I was thinking.

  24. #49
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    Quote Originally Posted by homemadesalsa View Post
    I tried the book and it was too dense for my ADD brain. Here's a good summary: http://www.nytimes.com/2011/11/27/bo...ok-review.html....They don't individually learn restraint vicariously until someone/ thing very close to them impacts their life. So in my mind the whole "Project Zero" or "Backcountry Zero" is a farce. And I teach avalanche education for a living.... with a dark mindset, honestly.
    Yep, +3

    That's a great book too btw.

    I wasn't in this party, but knew the deceased and one other member in the group. This had the most profound effect on my decisions with both snow and terrain assessment as well as choosing appropriate touring partners.
    https://utahavalanchecenter.org/avalanches/18137

    RIP ALX88!

  25. #50
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    Quote Originally Posted by covert View Post
    The Sheep Creek incident is fascinating to me because it seems to be a bit of an outlier in terms of the information available to those involved.

    http://www.americanavalancheassociat...3_Feb_2014.pdf

    Normally, message fatigue and uncertainty are really big issues with DPS problems. In the Sheep Creek incident, the forecasts were kinda shouting that uncertainty was decreasing and the likelihood of triggering a deep slab avalanche was increasing. I think it's rare to have that kind of in your face beta for that kind of problem.

    But I don't have the old forecasts at hand, so I may be wrong.
    IMO at Sheep Creek multiple things broke down for that group resulting in a total collapse of protocol and judgement. Not paying attention to the potential for DPS was part of it but also terrain management and travel protocol were absent. If they would have either traveled one at a time or used effective terrain management all or most of them would have been alive today. I have skied at and around LL pass a hundred times and never have gone into this area - terrain trap.

    So IMO to say that lack of paying attention to DPS slide potential is only a smaller part of the story there.



    Overall for education skiers on deep instabilities - more and more detailed stories about deep slab incidents are a great way. Videos, text, 1st hand presentations, etc. to get the message across that this is real and as an olderish school skier I remember the days when Avy materials and Avalanche courses included the pictures of the badly mangled avalanche victims. I know that now adays no-one wants to show pictures of the dead, but it sure was effective in locking into my brain the real consequences of getting the decisions around avalanches wrong. There is so much positive feedback on social media and the Ski Porn world showing how awesome the skiing is but it very little gets put in front of kids to counter balance that, other than the random name on a newsite or internet forums. Why do we only make the first responder deal with the ugly reality of the results of poor decisions. If you're picking up a book on avalanches to learn or taking a class, you should be ready to see the ice mask on the dead guy or the twisted into abnormal form of the lower body of a victim with skis still attached. Those are the chips that are on the table, the players should know what the result may very well be. That teaches respect of DPS.

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