"Armchair" touring on a considerable day (12/4/16)

I'm hoping one of the smarter people in the room read and review "The Undoing Project" by Michael Lewis.

I'd like to try an experiment here.

Who can look at the forecast and conditions on the days in question and write a few sentences about the physical processes going on during the storm, during the wind, and in the snowpack. If a little prodding would help, here are some questions:

What is the name for the type of snowpack instability we're discussing here?
What are some key facts about this type of instability?
Was it a cold storm? What are the implications of this?
Was it a warm storm? What are the implications of this?
Did the amount of water vapor and/or temperature change during the storm?
How would you figure this out?
What might it tell you?
What about crystal forms and layers?
Did anyone use hand pits to check density? If so, what would you want to see?
Was it windy?
Where was it windy?
How can you look for signs of wind transported snow without looking at the snowpack itself?
Does wind promote instability? If so, how?
Do cold temperatures promote instability? If so, how?
Do warm temperatures promote instability? If so, how?
What was the run list?
What runs were red?
What runs were yellow?
What runs were green?
How many people used a written trip plan?
How many people are religious about using a written trip plan.

These are the things I think about on a considerable day with lots of storm snow. I personally felt like avalanche danger was moderate in most places with a fairly uniform distribution of high avalanche danger on steeper slopes regardless of aspect.

Note that I would think about all these things, along with other things, and I'd have a written trip plan with two alternates.

Always good to see a CookieMonster post.

I like TAY because you can actually have a discussion.

I ski BC in considerable danger all the time. I live in Colorado, which absolutely has a more challenging snowpack (our danger can last ALL WINTER LONG, not just days after the storm).

How do these two statements jive and I'm still alive to write this?

For me it really is terrain knowledge and terrain choice. I wouldn't go out of my way to ski unknown terrain in considerable (or Moderate for that matter if the objective is wild), or ski anything that would slide, so mellow runs in the trees is usually where I'm at on a considerable day. Low danger is when you test those new ideas and new areas.

Yeah, it gets "boring" year after year skiing the same ol' mellow spots in untracked snow....but I'm still alive! Wait, did I just say skiing untracked powder was boring? Shame, shame, powder snobbery: it's a Colorado thing.

I was part of the platinum peak tr linked above.


I'm not an avy expert by any means but this is what our groups decision making was.

We went up there aware of the nwac forecast and assessed as we went with the plan to find some trees or  lower angle slopes to ski if things were uncomfortable.  I did several quick arm pits along the skin track and the snow was not cohesive at all.  It just fell apart when you pushed on it.  We had also noted the natural sluffs on very steep terrain across the basin but there was no propagation to them.

There was essentially no evidence of wind effects more than a few turns down from the ridge where it wasn't as steep and we were skiing the windward slope of the mountain.  Sluffing was the main concern.  Finally a couple of people had already skied the slope we went down.  So with all off that info we all felt fine but tried to maintain proper spacing as much as was practical.    On my first steep run my sluff did run on the steepest part but didn't expand our accelerate too much.  (Before that we went a few hundred feet down the backside of the hill on low angled terrain but it was to deep and not steep enough to really be able to ski.)

I hesitate to call the small side in the pictures a slab.  My wife essentially did a ski cut on the small roll and a 15'x15' area kind of started moving all at once but only released from under the ski cut.