February 24, 2013 Heather Ridge Avalanche

Hey Will, glad your alive and I truely hope your injuries aren't too serious. Excellent write up! I read through it twice, and I think you hit all the points very well. The biggest thing that stands out for me is relying on a pit, that as you said only conveys conditions at the that point. I was at Stevens in-bounds with my kids both Sat. & Sun. Sat. the winds was really blowing out of the west, and the top of the backside ridge was heavily wind loaded. I wasn't concerned skiing it as it was well ski cut. I did get a piece of untracked snow about 8' x 16' to easily go with a ski kick just below the ridge. Once down from the ridge a 100', it was fairly well bonded - wind loading. Wind loading is very varible between locations.

I really commend for you for writing this up. As Marcus said, it is a lot a small judgement errors that contribute to these types of incidents, errors that anyone of could easily make. Thanks for your honest account to really drive the lessons home to all of us out here.

Heal up fast!

Glad you're OK Will!  Hope the knee doesn't keep you from skiing for too long!

Thanks for having the courage of honesty, your observations, and writing up the report.

some observations (prompted by your report, but more generally applicable in terms of stability assessment):
R&R - - Ridge lines command Respect. or for that matter, any feature with increased wind and weather exposure (leeward side especially).
Like you said, that first picture tells a story (of recent weather behaviour).
With increased settlement and bonding (depending on conditions) your line may have skied great a day later... which adds an element of time, along with weather and terrain features.  I also think that Mowgli's assessment of "micro-topographic spatial heterogeneity" in the thread where your incident is first mentioned is spot on.  How the complexities of terrain in combination with weather phenomena (wind channeling or sheltering, variability of potential running surface, solar and fog effects, etc.) can make all the difference.

I was telling Charlie and Susan the other day about a tour we did on Presidents Day recently and coming back and reading one of Silas' Snoqualmie Pass reports (N. aspect 5200'-4200' skied great with 12" of fluff; SE had less snow with crust... etc. [details not verbatim but you get the picture] )  and thinking hmmmm, we were in the Snoqualmie Pass vicinity that very same day and yet at least half of our experience was diametrically opposed to what Silas was reporting in terms of aspect and elevation. We found that the N. was crusty and the SE skied great at similiar elevations...
Two truths, but without the specifics of terrain.

In terms of condition reporting nothing (or nobody) can fully report what one will find, not NWAC or NWS.  Conditions can only ever be generally predicted or hinted at--providing a good starting point for every backcountry skiers best friend: real time vigilance and attentiveness to the terrain and conditions one happens to be in.  Especially in the Cascades with its plethora of micro-topographic spatial heterogeneity.

For me each trip is a learning experience.  The other day I was poking around in some wind slab feeling the very visceral difference in density to the surrounding fluffier snow and it made me wonder: how does this happen?  in fact I voiced that to my partner and together we came up with a very visual scenario of wind buffeted six-sided snowflakes being pulverized into less than six-sided entities: decreasing the amount of air in the snowpack and significantly increasing its density, i.e. increasing its weight and impact on any lower layer.
Suddenly 'wind slab' had a story, it's own narrative and life, a story of crippled snowflakes bonding together...
Sure there's probably a more scientific version in a book somewhere, but for me it doesn't become real until my body and imagination are directly engaged with the elements.  Being in the place that will allow me to try and trace that snowflakes path...

Of course none of this addresses lapses in judgement...  which we're all prone to and which seem to be the crux of all avi reports.
Maybe we can learn something from sharing--so thanks for sharing Will!

Great write-up, thanks for sharing Will. Good observations on the need to be cautious about using pit info to tell you how things will be up higher, just below and on the lee side of cornices - that strikes me as a very key point in your writeup (along with choosing a line based on fun versus safety, though this is of course ALWAYS an interesting question of balance and if you swing too far the other way you will never get any turns...).

Regarding navigation, even w/o a GPS, I presume that if you'd had a map/compass handy you could have figured out that you weren't looking down at the slope you thought you were before starting the first run - you'd presumably have had to go past your desired saddle to be facing in the direction that you faced when you started that run. While hardly foolproof, a little map/compass check can be very helpful in nasty weather for sanity checking your assumptions. Just a thought...

Thanks for the write up and glad you are only tweaked a bit. You seem to be aware of the snowpack analysis issues. Folks often fall into the trap of "...well, that last run skied just great, no signs of instability, so lets move over (or up) there".

The plan discussed in the parking lot should be adhered to, unless there is a good reason for changing. Everyone is excited to get out and ski, and it can seem anal to just have a tailgate meeting and say - here's the plan - are we ok with this?

This workshop is tomorrow. I'm going. Don't know what is the ticket availability:
www.nwac.us/media/uploads/pdfs/GoingDeep...ion%20_4_2.28.13.pdf

Good job on the self-rescue.

Third - not properly assessing the dangers of the slope we were on.  The second pit I dug showed good stability, and indeed at that point on the slope it was quite stable.  However, up higher along the ridgeline there were fresh cornices and obviously the wind had been moving a lot of snow up there.  We didn’t reassess conditions when we got to the top despite the evidence of a lot of transport and possible slab formation staring us in the face (see the picture of the group standing on the ridgeline).

This is what stands out to me the most. A re-assurance to continue to look for instability even over a short distance.
This correlates to micro-climates that exist in terrain and storm cycles can affect the snowpack in a very small localized spot.

I appreciate your posting this story, excellent write up.