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Thread: Avalanche question

  1. #1
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    Avalanche question

    So I have been doing work with beacons and gaining avi knowledge since I was pretty young. My dad being a ski patroller made sure that my brother and I knew as much as possible so I am not ignorant on the subject.

    But as I have become a better skier and wanting to push my skiing I am finding that with steeper lines I dont know what to take into consideration.
    So I guess my question is on lines that are 45-50 degrees, how do you take into consideration the avalanche danger? I mean you cant exactly get out on your line and dig a pit which is what I am used to doing. So say the avi danger is moderate , how does that effect slopes of 40/45 +? Does that mean it is more dangerous, than say a 35 degree slope.

    So I guess my main question could be if you have moderate, or any level of avi danger, how does that effect lines that are already high risk because of the pitch?

  2. #2
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    You know, there's a whole forum devoted to this stuff.

    Edit: Nice move.

  3. #3
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    My advice to you is to sign up for some Avalanche courses that include 'on the snow' instruction that teaches you how to dig pits, read snow, properly use your beacon, safe snow travel, avoiding danger zones etc.........

  4. #4
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    Quote Originally Posted by geomorph View Post
    You know, there's a whole forum devoted to this stuff.
    And.......moved there. KC- PM me if this gives you heartburn.

    You'll get the same feedback you would have in ski/snowboard, while leaving that forum more open for the legendary TR's from, say, Tahoe.

    and x2 on skier666's advice. A good Avi 1 course will dive in to this exact question, and be on the snow so you take away real and practical skills. You'll find it's almost always 'case by case', i.e. that same pitch might be fine on a south facing slope but ready to rip on an NE aspect, etc. It's great you're asking yourself these questions though.
    Something about the wrinkle in your forehead tells me there's a fit about to get thrown
    And I never hear a single word you say when you tell me not to have my fun
    It's the same old shit that I ain't gonna take off anyone.
    and I never had a shortage of people tryin' to warn me about the dangers I pose to myself.

    Patterson Hood of the DBT's

  5. #5
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    Quote Originally Posted by skier666 View Post
    My advice to you is to sign up for some Avalanche courses that include 'on the snow' instruction that teaches you how to dig pits, read snow, properly use your beacon, safe snow travel, avoiding danger zones etc.........
    Uhm, thats great, but I have done that. I started digging pits and doing courses when I was ten years old. I also got my first beacon when I was 9. That was 15 years ago. However since then my skiing, has pushed way further than even 5 years ago. And the only advice I can get regarding 45-50 degree lines is that they are too dangerous. Tell that jermemy jones.
    BTW thanks for the advice.

  6. #6
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    Guess we posted on top of each other.

    Have you progressed up the training ladder? Until you've taken and passed the Level 3, you still have lots to learn. I've only taken Level 1, so may well know less than you. But that kind of knowledge, imho, or another 24 years of observation and experience, is what you're going to need to make good calls on that steep of terrain.
    Something about the wrinkle in your forehead tells me there's a fit about to get thrown
    And I never hear a single word you say when you tell me not to have my fun
    It's the same old shit that I ain't gonna take off anyone.
    and I never had a shortage of people tryin' to warn me about the dangers I pose to myself.

    Patterson Hood of the DBT's

  7. #7
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    Quote Originally Posted by Tye 1on View Post
    And.......moved there. KC- PM me if this gives you heartburn.

    You'll get the same feedback you would have in ski/snowboard, while leaving that forum more open for the legendary TR's from, say, Tahoe.

    and x2 on skier666's advice. A good Avi 1 course will dive in to this exact question, and be on the snow so you take away real and practical skills. You'll find it's almost always 'case by case', i.e. that same pitch might be fine on a south facing slope but ready to rip on an NE aspect, etc. It's great you're asking yourself these questions though.
    Yeah. I do want to take some courses/possibly go to guide school. JP said its the best thing hes ever done. I would like some thoughts though since there are a few nasty spine lines I want to film this weekend after the storm lifts here in Tahoe. So taking a course may take care of my questions for the future, but not by the weekend.

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    See if you can figure out what your avalanche "problem" is. If you are dealing with a persistent weak layer (buried surface hoar) or a deep slab (depth hoar) or hard slab problem, then it is going to be a problem for a long time, or at least til it is buried a solid meter (meaning consistent slab depth with no weak thin spots).

    If you are dealing more with wind slab or new snow issues, especially in your generally maritime pack, then your problem will dissipate sooner.

    If you haven't already, start tracking your weather and snow structure on some kind of spreadsheet. See if your weak layers from last week/ month are still producing avalanches. Try to create your own "roses" (see UAC or CAIC forecasts for that, and I think your Sierra Avalanche Center forecast has them too). If so, then are they natural or skier triggered?

    That is the kind of thing that we don't see behind the scenes in the TGR movies. Go look at Jim Conway's tutorials on this site somewhere (somebody here- please chime in). You are asking yourself "nowcasting" questions like "how much force made this weak layer fail yesterday, before it (choose one or more) warmed up, snowed an inch of water, blew like stink.

    That's what we cover in level 3 and a good level 2, making you take the basics from level 1 and learn the exceptions, the science, and translate them into action.

    Does that help?
    Last edited by homemadesalsa; 01-21-2010 at 12:53 PM. Reason: because SAC is not SAC in this case

  9. #9
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    I always thought that lines steeper than 45 degrees went down in danger from those below. I thought it was due to increased down hill pressure not allowing for weakly bonded snow.

    That being said I choose to leave the death defying runs for controlled areas.

    Does Jermey Jones have a level 3 certification, or does he just keep cheating death? I've always wondered that.

  10. #10
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    inthemtns: I don't know what Jeremy Jones' education is, but he often has guides forecasting and advising him.

    OP: your question is actually always a toughy. I'd echo some of what HMS said. To get more to your particular point, how do you judge that steeper slope that you cannot get onto for a pit? That 45 or 50 deg couloir or just over a cornice? There is some degree of guestimation involved. This is where HMS's points come in. If you are aware of the local snowpack's structure on that aspect and elevation as a generalized notion (spacial variability between and within slopes always applies). Add in your recent weather history and observe local terrain features and snow surface features to see how heat and wind have been playing. Form a range of possibilities in your mind of what the snowpack may look like. If you can find a representative slope to confirm this hypothesis with, that's great. IF YOU CAN'T you really have to decide how certain you are that your "nowcast" is right and whether you are willing to risk being wrong.

    What can you say about the risk of the steeper line versus a less steep line? We are all familiar with this graph:



    But let us consider it more deeply as it is misleading at first glance:
    1. There are just plain more slopes that are less steep, especially in certain climates.
    2. The distribution of frequency by bed surface angle varies by snow climate and avalanche type (slab versus wet, maritime versus continental).
    3. The influences on these steeper slopes varies by area. For example, in Colorado, most of the steepest lines are in couloirs and are subject to wind sheltering, cross loading, solar shading, and direct/indirect solar affects like horizontal TG and rapid melting much more than open faces. (obviously this affects other skiing safety factors in addition to avalanche danger)
    4. Additionally, many avalanches still occur on these steeper slopes, but they are more prone to naturals during a storm cycle because of our friend gravity.

    More to the point of #4, particularly gravity, what the graph is trying to say is that slope angles in a certain range are more prone, other variable aside, to accumulation significant amounts of snow before breaking mechanical equilibrium (avalanching) versus constantly sloughing (steeper) or not having strength overcome by strain (lower angles).

    So could a 50 deg slope be safer avalanche wise than a 40 deg slope? The answer is sometimes in some ways. You have to figure it out case by case.

    Lastly, you must consider whether your line, which inevitably decreases in pitch at some point, will present you with more avalanche danger as you descend onto lower angle areas that may be holding more "pregnant" snow.

    In the most extreme cases and with proper training and experience, one could do a belayed analysis of an otherwise inexaminable slope... but that is for the rarer circumstance.

    I won't get to specific for you because I don't know you and I don't really know Tahoeland.
    Last edited by Summit; 04-21-2010 at 09:16 PM.
    Quote Originally Posted by blurred
    skiing is hiking all day so that you can ski on shitty gear for 5 minutes.

  11. #11
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    I ski those kind of slopes fairly often throughout the winter in a maritime snowpack. I pay close attention to the weather especially temperature. I dig pits on those type of slopes. Do not understand why you cannot. If you are not going to dig a pit on the slope I would dig on another represenative slope. If you see something you do not like in your pit or get moderate results on your tests it is a good indecation that what you saw in your pit could become problematic on a steeper slope. We were just in CA skiing. we had skied the Pinner the day before and were going to ski the Crescent on Roundtop that day. My kids were pushing for it. Our tests showed moderate results. However our pit profile showed a weak layer of rounding fascets on an icy bed surface overlayed with a soft slab. I saw the presence of a slab and a bed surface as a double negative and decided not to ski the line. No problem on a lower angle but could become a problem as conditions change higher up and the angle increases. Also I had never been here before so had no idea of the history of the line or the weather that created these conditions. Interesting later while searching I found the Sierra avalanche center site. They were calling conditions low that day and had a test pit on Elephant's Back. Totally different aspect and angle.
    I type to slow looks like all the experts weighed in. HMS has a good post. Blow off the cornice advice. In my opinion cornice cutting is alot easier said than done.
    off your knees Louie

  12. #12
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    Quote Originally Posted by homemadesalsa View Post
    See if you can figure out what your avalanche "problem" is. If you are dealing with a persistent weak layer (buried surface hoar) or a deep slab (depth hoar) or hard slab problem, then it is going to be a problem for a long time, or at least til it is buried a solid meter (meaning consistent slab depth with no weak thin spots).

    If you are dealing more with wind slab or new snow issues, especially in your generally maritime pack, then your problem will dissipate sooner.

    If you haven't already, start tracking your weather and snow structure on some kind of spreadsheet. See if your weak layers from last week/ month are still producing avalanches. Try to create your own "roses" (see UAC or CAIC forecasts for that, and I think your Sierra Avalanche Center forecast has them too). If so, then are they natural or skier triggered?

    That is the kind of thing that we don't see behind the scenes in the TGR movies. Go look at Jim Conway's tutorials on this site somewhere (somebody here- please chime in). You are asking yourself "nowcasting" questions like "how much force made this weak layer fail yesterday, before it (choose one or more) warmed up, snowed an inch of water, blew like stink.

    That's what we cover in level 3 and a good level 2, making you take the basics from level 1 and learn the exceptions, the science, and translate them into action.

    Does that help?
    Yeah I would say so. Its good to have someone echo what Im thinking. I have been on the Sierra avalanche centers site and I went out at the beginning of the storm and checked the snow and temps.

    The issue is high winds. The storm started out with rain/wet snow that turned to snow which actually bonded better than I thought. Then the wind came and loaded the hell out of the N/NE/NW slopes. So it has created a wind slab that will be about 30 inches deep as of now , but more snow is coming. There is a weak layer that is lower but is beginning to bond better and better each day eliminating the crust layer that is about 4-5 feet down.

    The other issue with digging a pit, in response to the other posts is that the line I want to get done is a spine line that sits on top of a cliff. The top of the spine is about 100 feet up, super exposed, and as the spine works down the cliff it stops at about 30. So my issue is how do I dig a pit on top of a line that only forms, or holds snow maybe once every 5 years. The last time this line was doable was 6 years ago. To be honest if Im going to go and dig a pit on a line like that I would feel more comfortable getting in and just skiing the line. I would probably dig on a slope facing the same direction, and dig on say 40 degrees and then take and educated guess on what will happen with a steeper line.

    Thoughts?

  13. #13
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    Quote Originally Posted by Summit View Post
    inthemtns: I don't know what Jeremy Jones' education is, but he often has guides forecasting and advising him.

    OP: your question is actually always a toughy. I'd echo some of what HMS said. To get more to your particular point, how do you judge that steeper slope that you cannot get onto for a pit? That 45 or 50 deg couloir or just over a cornice? There is some degree of guestimation involved. This is where HMS's points come in. If you are aware of the local snowpack's structure on that aspect and elevation as a generalized notion (spacial variability between and within slopes always applies). Add in your recent weather history and observe local terrain features and snow surface features to see how heat and wind have been playing. Form a range of possibilities in your mind of what the snowpack may look like. If you can find a representative slope to confirm this hypothesis with, that's great. IF YOU CAN'T you really have to decide how certain you are that your "nowcast" is right and whether you are willing to risk being wrong.

    What can you say about the risk of the steeper line versus a less steep line? We are all familiar with this graph:



    But let us consider it more deeply as it is misleading at first glance:
    1. There are just plain more slopes that are less steep, especially in certain climates.
    2. The distribution of frequency by bed surface angle varies by snow climate and avalanche type (slab versus wet, maritime versus continental).
    3. The influences on these steeper slopes varies by area. For example, in Colorado, most of the steepest lines are in couloirs and are subject to wind sheltering, cross loading, solar shading, and direct/indirect solar affects like horizontal TG and rapid melting much more than open faces. (obviously this affects other skiing safety factors in addition to avalanche danger)
    4. Additionally, many avalanches still occur on these steeper slopes, but they are more prone to naturals during a storm cycle because of our friend gravity.

    More to the point of #4, particularly gravity, what the graph is trying to say is that slope angles in a certain are more prone, other variable aside, to accumulation significant amounts of snow before breaking mechanical equilibrium (avalanching) versus constantly sloughing (steeper) or not having strength overcome by strain (lower angles).

    So could a 50 deg slope be safer avalanche wise than a 40 deg slope? The answer is sometimes in some ways. You have to figure it out case by case.

    Lastly, you must consider whether your line, which inevitably decreases in pitch at some point, will present you with more avalanche danger as you descend onto lower angle areas that may be holding more "pregnant" snow.

    In the most extreme cases and with proper training and experience, one could do a belayed analysis of an otherwise inexaminable slope... but that is for the rarer circumstance.

    I won't get to specific for you because I don't know you and I don't really know Tahoeland.
    Yeah Tahoeland can be pretty fickle and hard to read. The other reason Im a bit puzzled is that I never really have gotten to do much on spine lines.

    The particular lines that Im trying to get this weekend are spine lines. I have to admit I really dont know much about riding bigger spines. I do feel somewhat safe in the fact that if it does slide I will be at the high point on the spine. The bad part is if I do get taken for a ride its like a 70-100 foot drop off the side so I want to make sure I know whats going on.

    Also as you said about the pregnant snow at the end of the line, I am a bit worried about that although the runnout is about 20-25 degrees and pretty short. So if the bottom were to rip out and Im on my feet Ill have a ton of speed coming off the end to make it out left to trees.

    With the way that snow typically fills in what would you say the danger on spines is to say a couloir? Or a regular line that say has scattered trees but for the most part open, considering they have the same windloading, snow depths, strong and weak layer, etc.?

  14. #14
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    I'm going to read between the lines of your post and provide some additional information that you may or may not find useful. Your question(s) underline a very common, and often unacknowleged, source concern for anyone in the backcountry:

    Even after observing the terrain, snowpack, and weather, how do I manage the remaining uncertainty?

    1. To maintain awareness:

    You can combine information from the public avalanche bulletin with your own observations of the local terrain, snowpack, and weather. Experience and knowledge play a very important role here, and it sounds like you're already doing this to some degree.

    You discuss having obtained a significant amount of knowledge from your father. This is definitely very useful, but regardless of the source of our training, each of us must eventually learn how to *apply* that knowledge in the field.

    HomeMadeSalsa's advice is excellent - you should definitely pay very close attention to the professional-level tips/tricks and thinking frames included in her post.

    2. To manage uncertainty:

    The first step is to consciously acknowledge uncertainty. I find it helps to say it aloud: "What is my uncertainty?" Then you must identify the sources of uncertainty and determine if your uncertainty can be reduced by seeking additional information. Many times, you will not be able to reduce your uncertainty by seeking out additional information. This is exactly when a lot of mistakes get made in the backcountry. Many classic mistakes, such as trying to "outsmart" the snowpack, are simply ill-advised reactions to high uncertainty.

    High uncertainty is a sign that you lack the information, for whatever reasons, to make sound judgments about risk. A highly uncertain mind is a great breeding ground for human factors, half-truths, unscientific speculation, and other dangerous biases.

    Therefore, even if you are meticulous about maintaining awareness through careful and objective observations of the terrain, snowpack, and weather, you should take an immediate step back if you feel "highly uncertain" prior to decision-making. The correct reaction to high uncertainty is to dial back your expectations.

    3. Caveat:

    While important, awareness and uncertainty are just two parts of the multi-faceted discipline of backcountry avalanche forecasting. There are other elements and relying solely on awareness and uncertainty will eventually lead to mistakes. In my opinion, and it is just my *opinion*, the bare minimum framework for backcountry avalanche forecasting considers all of the following:

    Goal, People, Awareness, Uncertainty

  15. #15
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    OK, I'm going to keep this comment short because I don't have a lot of experience on spines since we don't have that many here (continental pack doesn't hold snow to them so well and what does often rots/blows away), but you have to think about spines having multiple aspects and consider the different solar and wind effects they have received vis a vis the rest of the face.

    Often, you can get strong or week wind deposits on these spines, particularly when they are sticking out far, and they can have significantly different strata than the rest of a face. Still, having a general idea of the stratification, distribution, and strength of the pack on ALL aspects at that elevation can be useful: If one is worried about deeper instabilities, I'd stay off them, particularly a high consequence line. I don't know your skiing ability or how you feel about slough management, but that's something you have to worry about in a loose snow environment on a line like that, but even a shallow slab will just ride you right off the edge.

    As I'm sure you realize, the consequences of being wrong on a line like yours are extremely high if you misjudge your exposure.

    To answer your other question, if I'm ok skiing a 45-50deg line, I'm very much not worried about triggering something on a 20-25deg section of the line. I may still be worried about the part of the line that's 30-45 though, in which case I'm likely staying away.

    I don't know if that ramble was useful...
    Last edited by Summit; 01-21-2010 at 02:54 PM.
    Quote Originally Posted by blurred
    skiing is hiking all day so that you can ski on shitty gear for 5 minutes.

  16. #16
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    Cookiemonster's post is most excellent
    Quote Originally Posted by blurred
    skiing is hiking all day so that you can ski on shitty gear for 5 minutes.

  17. #17
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    Actually this is something where a lot of AST courses won't help. Skiing steep lines involves a bit more then just avalanche hazard.

    Context is steep slopes in Southwest BC and the interior BC and a coastal or inter-mountain snowpack

    Preference is to climb them so I know what kind of pack Im skiing

    Usually that means its pretty stable in which case avalanche hazard isn't the primary concern. To assess that I track weather, conditions etc. It's not particularly hard to do when I'm fortunate to live there.

    If I don't get a chance to climb the slope (approach might be hard, too much snow - ie skiing down steeps with good pow!!!) then I'll ski a lot of slopes with similar aspect close to that area. Again I'm fortunate to live here so I don't have to rush it. I have lots of ski time, lots of faces and lines from which to pick and lots of choices. So I can pick and choose conditions. I'll chop cornices if I have them or just ski cut the hell out of convexities (a poor 2nd choice to chopping cornices)

    This is disjointed and rambling but hope it helps.

  18. #18
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    Just saw the bit about spines. They're fun but tought to manage. Most of us aren't radgnar enough to manage sluffs and slabs by skiing the spines fast enough to outrun danger.

    Look on them as gigantic ski cuts and pillows. Know how you can treat a pillow drop series ending as benches as basically ski-cutting convexity after convexity without ridiculously dangerous consequences? Treat the spines the same way but with a lot more respect since hte consequence of getting it wrong are a binary outcome - ie you get it right - great ski down. Get it wrong and serious injury or death.

    Can't say much about these spines because this kind of advice ends up being hopelessly generic.

    Quote Originally Posted by KC_Deane View Post
    The particular lines that Im trying to get this weekend are spine lines. I have to admit I really dont know much about riding bigger spines. I do feel somewhat safe in the fact that if it does slide I will be at the high point on the spine. The bad part is if I do get taken for a ride its like a 70-100 foot drop off the side so I want to make sure I know whats going on.

    Also as you said about the pregnant snow at the end of the line, I am a bit worried about that although the runnout is about 20-25 degrees and pretty short. So if the bottom were to rip out and Im on my feet Ill have a ton of speed coming off the end to make it out left to trees.

    With the way that snow typically fills in what would you say the danger on spines is to say a couloir? Or a regular line that say has scattered trees but for the most part open, considering they have the same windloading, snow depths, strong and weak layer, etc.?

  19. #19
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    Quote Originally Posted by Tye 1on View Post
    Guess we posted on top of each other.

    Have you progressed up the training ladder? Until you've taken and passed the Level 3, you still have lots to learn.
    After completing a level three course, most people realize that they don't know squat. I think almost all level three grads will agree with me on this one. All of the top dogs in the avy game are always talking about how little they know.

    Quote Originally Posted by homemadesalsa View Post
    See if you can figure out what your avalanche "problem" is. If you are dealing with a persistent weak layer (buried surface hoar) or a deep slab (depth hoar) or hard slab problem, then it is going to be a problem for a long time, or at least til it is buried a solid meter (meaning consistent slab depth with no weak thin spots).

    If you are dealing more with wind slab or new snow issues, especially in your generally maritime pack, then your problem will dissipate sooner.

    If you haven't already, start tracking your weather and snow structure on some kind of spreadsheet. See if your weak layers from last week/ month are still producing avalanches. Try to create your own "roses" (see UAC or CAIC forecasts for that, and I think your Sierra Avalanche Center forecast has them too). If so, then are they natural or skier triggered?
    HMS is spot on by stating that knowing what kind of weak layer you're dealing with is paramount. I can't say for sure, but I would guess that there is probably not any surface hoar forming on a 45+ degree slope. In AK, I often find surface hoar above convex rollovers, but it doesn't seem to be present on the steepest slopes. It has been hypothesized that the direction of the longwave radiation from such slopes isn't conducive towards forming surface hoar. This phenomenon is something I'm hoping to quantify this upcoming heli-skiing season and in the new cold labs here at MSU.

    KC, I think you related that the storm started off as rain on snow, but later switched to snow. This can often lead to faceting around the melt layer that doesn't really seem to reach it's most active state with respect to avalanches until at least a few days after the snow falls. Getting a buttload of snow on top of the weak layer should help with stability though in the long run.

    Quote Originally Posted by KC_Deane View Post
    Yeah Tahoeland can be pretty fickle and hard to read. The other reason Im a bit puzzled is that I never really have gotten to do much on spine lines.

    The particular lines that Im trying to get this weekend are spine lines. I have to admit I really dont know much about riding bigger spines. I do feel somewhat safe in the fact that if it does slide I will be at the high point on the spine. The bad part is if I do get taken for a ride its like a 70-100 foot drop off the side so I want to make sure I know whats going on.

    Also as you said about the pregnant snow at the end of the line, I am a bit worried about that although the runnout is about 20-25 degrees and pretty short. So if the bottom were to rip out and Im on my feet Ill have a ton of speed coming off the end to make it out left to trees.

    With the way that snow typically fills in what would you say the danger on spines is to say a couloir? Or a regular line that say has scattered trees but for the most part open, considering they have the same windloading, snow depths, strong and weak layer, etc.?
    KC, do you have a pic of the line? It would be a lot easier to dissect your objective with a visual. It sounds like you are asking yourself the right question though, which is, "What is going to happen if I get caught?"

    I don't have the time to try and give a thorough answer on the last part about comparing coolies and spines, but I can say that generally if a steep spine pops, the slabs are often shallow and relatively small. You might also have somewhere to go. If a couloir rips, you are probably gonna get flushed.

    Be careful not to consider anything in the avalanche game as, "typical" or "regular." There has been a lot of research completed which illustrates that many avalanche accidents, especially involving professional avalanche workers, occur when "irregular" events occur (i.e. the slope loads from the W 90% of the time, but someone got spanked when it loaded from the S).

    Good luck!

  20. #20
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    Good data from everyone.

    One mistake that you want to avoid is searching for reasons that it's okay to ski your line of choice. This is a classic beginner mistake, and not only is it a great example of "playing the game backwards", this type of approach represents a dangerous form of bias in and of itself.

    Choose a line that is appropriate for the current conditions, and if you lack the skills to determine whether or not conditions are safe for your line of choice, then choose lines that are well inside your backcountry avalanche forecasting ability.

    Given that you have 15 years of experience digging pits and, I assume, 15 years of experience interpreting the results of snowpack tests, along with 15 years of experience operating an avalanche beacon, your apparent inability to grasp the basic elements of snow safety is somewhat surprising.

    You might benefit from an honest self-evaluation of your skills. I know I certainly did.

  21. #21
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    Quote Originally Posted by stalefish3169 View Post
    After completing a level three course, most people realize that they don't know squat. I think almost all level three grads will agree with me on this one. All of the top dogs in the avy game are always talking about how little they know.


    HMS is spot on by stating that knowing what kind of weak layer you're dealing with is paramount. I can't say for sure, but I would guess that there is probably not any surface hoar forming on a 45+ degree slope. In AK, I often find surface hoar above convex rollovers, but it doesn't seem to be present on the steepest slopes. It has been hypothesized that the direction of the longwave radiation from such slopes isn't conducive towards forming surface hoar. This phenomenon is something I'm hoping to quantify this upcoming heli-skiing season and in the new cold labs here at MSU.

    KC, I think you related that the storm started off as rain on snow, but later switched to snow. This can often lead to faceting around the melt layer that doesn't really seem to reach it's most active state with respect to avalanches until at least a few days after the snow falls. Getting a buttload of snow on top of the weak layer should help with stability though in the long run.



    KC, do you have a pic of the line? It would be a lot easier to dissect your objective with a visual. It sounds like you are asking yourself the right question though, which is, "What is going to happen if I get caught?"

    I don't have the time to try and give a thorough answer on the last part about comparing coolies and spines, but I can say that generally if a steep spine pops, the slabs are often shallow and relatively small. You might also have somewhere to go. If a couloir rips, you are probably gonna get flushed.

    Be careful not to consider anything in the avalanche game as, "typical" or "regular." There has been a lot of research completed which illustrates that many avalanche accidents, especially involving professional avalanche workers, occur when "irregular" events occur (i.e. the slope loads from the W 90% of the time, but someone got spanked when it loaded from the S).

    Good luck!
    Actually i dont have a picture of it. but it is the same spine that is at 0:40 sec
    [ame="http://www.youtube.com/watch?v=-f28BWdZxgg"]YouTube- Paradox - Standard Films - OFFICIAL Snowboarding Trailer[/ame]

    The spine is not as filled in as it is in the video. You can see the exposure, and if you look skiers left there is a chute, and right now that chute is barely filled in at best, and instead of a run out its like a 20 foot mandatory at the end.

    And thanks for all the help. It has actually helped my confidence a bit, I realize that I do have a lot to learn but at least I know that I am looking at the right variables and weighing them.

    I do know if something were to let loose that a big fall.

  22. #22
    Join Date
    Nov 2009
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    Quote Originally Posted by CookieMonster View Post
    Good data from everyone.

    One mistake that you want to avoid is searching for reasons that it's okay to ski your line of choice. This is a classic beginner mistake, and not only is it a great example of "playing the game backwards", this type of approach represents a dangerous form of bias in and of itself.

    Choose a line that is appropriate for the current conditions, and if you lack the skills to determine whether or not conditions are safe for your line of choice, then choose lines that are well inside your backcountry avalanche forecasting ability.

    Given that you have 15 years of experience digging pits and, I assume, 15 years of experience interpreting the results of snowpack tests, along with 15 years of experience operating an avalanche beacon, your apparent inability to grasp the basic elements of snow safety is somewhat surprising.

    You might benefit from an honest self-evaluation of your skills. I know I certainly did.
    I understand where you are coming from. I know that if someone had years of experience and they didnt know I would think they are probably full of shit.

    The deal is Ive never dealt with lines that are this steep, and have never dealt with spines. above I posted a vid with one of the lines I want to get done. Ive never dealt with something this long. If it were a regular line on the side of a slope. I would look at the avi report before going out, I would have known what the layers are, then upon getting out there ,dig a pit to the side of my line, do a few tests, and determine the safety of the snow pack. From there I would ski, or find something else to do.

    The other thing is when your working with lines from 25-35/40ish max, which is what I have dealt with and received most of my knowledge on. Thats the reason I am guessing myself. also just in order to be safe.

  23. #23
    Join Date
    Feb 2005
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    North Vancouver/Whistler
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    14,442
    i see the problem but don't have a good solution. You're not likely to be able to climb that one. Its steep enough for a slab avalanche but not so steep that most of the snow would have sluffed away. Interesting project though

  24. #24
    Join Date
    Dec 2008
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    Quote Originally Posted by KC_Deane View Post
    Actually i dont have a picture of it. but it is the same spine that is at 0:40 sec
    YouTube- Paradox - Standard Films - OFFICIAL Snowboarding Trailer

    The spine is not as filled in as it is in the video. You can see the exposure, and if you look skiers left there is a chute, and right now that chute is barely filled in at best, and instead of a run out its like a 20 foot mandatory at the end.

    And thanks for all the help. It has actually helped my confidence a bit, I realize that I do have a lot to learn but at least I know that I am looking at the right variables and weighing them.

    I do know if something were to let loose that a big fall.
    Keep in mind the guy in the video is Jeremy Jones, and he mentions he waited a long time for it to fill in correctly. This is what the snowpack looked like that year:

    You're not there yet. One big storm an epic winter does not make. I think your main concern right now is hitting rocks and falling off the cliff!

  25. #25
    Join Date
    Nov 2009
    Location
    Reno, NV
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    120
    Quote Originally Posted by stalefish3169 View Post
    Keep in mind the guy in the video is Jeremy Jones, and he mentions he waited a long time for it to fill in correctly. This is what the snowpack looked like that year:

    You're not there yet. One big storm an epic winter does not make. I think your main concern right now is hitting rocks and falling off the cliff!
    Yeah I def have taken both of those into consideration. That line is weird. Just like he waited ive waited 5 years, looking at it every year and for some reason its filled in right now. And Im pretty sure that it was actually the winter of 2005.

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