Sunday, January 31, 2016

2016 Avalanche musings (2 of 2)

After some thought, I decided to re-tool this installment of avalanche musings to best address some misconceptions that I have worked through over the years, especially since many are contributing to the current spate of avalanche fatalities and close calls.  When I began backcountry skiing, I was conservative, however I had several major misconceptions about avalanches.  In this last installment of avalanche musings, I will run through a few of my misconceptions in the hopes that others can shortcut them.
  • Misconception #1:  It is OK to assume some risk all of the time
Over the years, most of us have skied a lot of slopes that we thought would "probably" be OK, but weren’t really sure.   Similarly, I bet if you asked most skiers who just got away with skiing a big line with marginal stability, they would give a fairly detailed explanation of why the avalanche danger was high, BUT the temperature was just cool enough, or the slope was just protected enough, or they dug a pit, so it was safe.  As it turns out, this is not really an acceptable approach, and in my opinion, a lot of backcountry skiers push it a little too hard most of the time.   Eleven (1/31 update - I think the January total is up to 16) of them died this month.  Assuming the goal is to never get caught in a big slide over the course of a life time, one must be assuming something very close to zero risk of getting caught on any given day or run.  It is easy to loose perspective, especially when you see other tracks, or are on a familiar slope.  
My bold track on Divide peak with High avalanche danger in 2008.
Routefinding and assessment were meticulous, but in retrospect, 
this was too much risk to assume on a daily basis.

I have found a few big picture reality checks helpful to keep the risk level acceptably low.   First, I try to ski slopes where I anticipate feeling like I made a good decision afterward, not that I just got away with it.  Second, experienced skiers usually have a pretty good idea when stability on any given slope is suspect, so I consider it a red flag If I find myself micro-analyzing a slope, or doing a lot of hemming and hawing.  Some debate happens all of the time and when it does, I will first try to step back and do a big picture check to make sure my line of choice is in the realm of close to zero chance of a dangerous avalanche.  
  • Misconception #2:  Avalanches require a textbook slab and weak layer
After hearing over and over that avalanches are caused by a slab failing on a weak layer, I spent several years skiing sketchy snow, thinking that since there was not a textbook avalanche setup, that I would be OK.  As it turns out, while the ingredients have to align, it can be difficult to know exactly when the snowpack is in perfect is in alignment, and avalanches happen all the time that seem obvious in retrospect, but surprising when they are triggered.  Storm slabs do not have to be a perfect consistency to propogate,  pretty much any old snow surface can act as a weak layer, some weak layers are more reactive and persistent than others, and shear quality in pit tests might not translate well to the slope one is skiing, and with deep instabilities.
I started up this slope near Cliff lake and the snow just felt weird.
Pit results were actually pretty good, but the dense new slab just didn't feel right, so I bailed.
Never mind the fact that I had approached for four hours in near zero temperatures.
Textbook avalanche setup? Nope. Am I glad I turned around? Absolutely.
Did I come back another day and ski it with good stability? Yup.

Along the same lines, I often ran with the assumption that deeper weak layers were less likely to slide than recent storm snow, and as long as the the underlying snow "feels solid", slopes where the new snow danger could be managed were also safe to ski with deep instabilities.  Unfortunately, while triggering a deep instability is often unlikely, the consequences are typically unacceptable, and it is not uncommon for trigger points to exist, except they are in cafeteria tray sized points sprinkled seemingly randomly throughout the mountains.  Pits are quite helpful in determining the depth and structure of deep instabilities, but I would never a use single pit result to justify skiing a slope. The only really good way I have found to deal with deep instabilities is to gather all of the information possible over the course of a season (nature of weak layer, avy forecast discussion, cracking/collapsing, natural and human triggered avalanches, recent snow load and temperature, pits) and keep a wide margin of safety.  This is especially important right now for skiers in more continental snowpacks (i.e. Bozeman and Jackson) with a low risk, high consequence deep instability scenario.  Chances are, experienced skiers in continental snowpacks spent the entire month of January not pushing, except in very isolated cases.
  • Misconception #3 Moderate danger is Low danger
In the past, when the avy danger dropped to Moderate, I would pretty much grab my skis, beeline for something big and steep, and ski it unless a red flag presented itself.  It took a surprisingly long time to really accept that the Moderate rating spans everything from touchy to green light conditions, which is a huge range, and is without a doubt the hardest rating level to make good decisions.  The snow usually feels stable, and big stuff can often be skied perfectly safely.  
Moderate avalanche danger.  We were not confident enough to push into
the steeper starting zones, but skied the lower 2,000 feet of boot top powder with confidence.
When the avalanche danger is Moderate, I have found it especially useful to have a hypothesis going into the day and test it against what I find out there.  My initial guess can range from skepticism (e.g. Moderate, really, I would have guessed Considerable) to something in the middle (e.g. I bet we can go ski the Mega Death slide path today if the top isn’t too wind loaded, let’s go have a look since we can always lap the Minor Death trees instead) to anticipating stable conditions but keeping an eye out for surprises.  Experience and judgement will help a lot in selecting a good initial objective and sussing things out once you get out there. 
Also Moderate danger.  Hanging it out all alone on the
East face of Owen and feeling good about stability. Tetons.
  • Misconception #4: I will be able to handle an avalanche if I get caught
We watch skiers survive avalanches all the time in ski videos.  Similarly, it is common to imagine that in the event of an avalanche, you will do everything right and find a way to ski off the slab or grab a tree, or your partners will not get caught, locate you quickly, dig you out and you will be OK.  
I watched this avalanche splinter and rage through the trees below.
It was humbling to ski next to this debris, thinking about unsurvivable
a ride would have been. Mission Creek, Northern Absorka, Montana
The reality for most of us who have been in even small avalanche is that avalanches are very powerful, and you loose all control almost immediately.  Unless one is able to get off the slab almost immediately, chances are that within a few seconds you will be off your feet, rocketing down the hill really really fast, completely out of control.  You will also have no idea if your partners are caught, or are going to be able to dig you out.  You can not afford to ever be caught in a big avalanche.  
  • Misconception #5:  Avalanches happen to other people
I used to look at statistics and think that getting killed in an avalanche only happened to other people who did stupid things or were unlucky.  Unfortunately, that is simply not the case.  As it turns out, unless one develops a consistent pattern of safe decision making, close calls are likely, and over the course of a lifetime, the threat of being involved in a large avalanche is substantial.  This does not hit home for most people until someone they know dies in the mountains. 
Miss you, Chris.
I remember the phone call in the middle of a work day in June. Chris was missing on Lolo peak.  I walked straight out of the office, grabbed my ski stuff, met a few close friends at the trailhead, and headed out in the middle of a storm to find him.  Tears still well up when I remember skiing down the north side of the peak and seeing two orange ski boots sticking out of the snow.  The hours spent by his side waiting for a helicopter to retrieve his body changed me forever.  Chris lived a fiercely independent life and took risk all the time, but he did not take a lot of risk the day he was killed.  I still struggle with a seeming unshakable conviction that he should not be dead.  But he is.  I no longer assume that I will probably be OK.

Final thoughts
2016 has not been an unusually dangerous year.  Scary deep instabilities on the mend in continental snowpacks, no major deep structural issues but a few weird issues here in Missoula, fire hose of precip in the Flathead, etc.  Pretty much normal.  Within a few weeks, many of us will forget this round of fatalities just like we have in the past, and continue to push.  That will be the time to really keep our guard up.  And for those of us who thrive on skiing big, steep and beautiful mountains, remember there are a lot of days when stability is good.  And there is a lifetime to come back and do it another day.  Be patient, conservative and consistent, and when conditions align, dream big, set an alarm for some ungodly early hour, and go have an adventure.

5 comments:

  1. Thanks for this write up Brian. It is too easy to become overconfident, and start pushing when you shouldn't. Plenty of days when stability is a non-issue.

    ReplyDelete
  2. Thanks Brian. Some of the most thoughtful and intelligent writing I have read on the subject. Thanks for taking the time to put your thoughts on "paper"

    ReplyDelete
  3. Great write up, thanks! I especially like #4 and #5!

    ReplyDelete
  4. Thanks Jason. I am very, very glad to hear you were able to "disprove" my #4 recently. Close calls are scary, and it is crazy to think about your mind switching over to animal instinct, feeling no fear, but instead scraping and clawing just to stay alive. I've been there a few times, and I'm glad to hear you dug in when it counted. Heal up, and be safe out there!

    ReplyDelete
  5. Impressively concise and important words.

    ReplyDelete