Crystal South Backcountry 12/16/08

[AlpineK]

This is kind of a TR and kind of a cautionary tale.

 

Jeff H and I were looking to get some turns in on the 16th. After looking at the Avy forecast we decided the most prudent thing to do would be to find some tree skiing. The Crystal backcountry seemed like a good bet since I knew there was fun tree skiing there and as a bonus the ski area didn't have the SBC open to the regular masses.

 

Anyhow we started skinning up the Quicksilver lift at about 8:30 AM. Going through the resort went smoothly.

 

 

After passing the top of Chair 4 we decided to take a direct line staying on the ridge crest in between Silver Basin and Avalanche Basin. Things were going just fine till we got near mid height on our route. At that point we had to do a short crossing in a more open area to get back to trees. While ascending we noticed the distinct icy base to the snow pack. Jeff made it 98% of the way through the open section when a medium sized chunk of the slope cut loose. I was a little below Jeff, so I became involved in the slide. The whole slide wasn't that big so the worst thing that happened to me was I got buried up to my knees and dusted with snow.

 

 

Close up view of the slide

 

 

Wider view of the slope. We were trying to stay to the left edge of the open area.

 

After that I skinned the now safe avy debris and made it up to Jeff's high point. We decided that further upward progress was a bad idea, so we went into downhill mode and had a nice run on the new avy debris then some nice tree skiing. We skied down to Silver Creek and took a look back up.

 

 

The biggest opening in the center is where the slide happened. We got forced out of the trees to the left.

 

 

Here's a wider angle where you can see the cool but much scarier

slopes to the left side.

 

After that we followed the cat track back to the top of Chair 4 then cut left to the top of the run known as Boondoggel. The run was fenced off so we got a nice uncut powder run back to the lower cat track.

 

Despite the scary bit this is the best skiing I've had yet this winter. we just need a warm spell with 14 grand freezing levels for a couple days and the slopes will be safer.

[counterfeitfake]

I was up there that day with a big Mounties' avalanche class. We had dug a rutschblock and it failed on 2, but there was a fair amount of uncertainty about how we should interpret this- the failure was just the 6 or 8 inches of unconsolidated soft upper snow sliding over the hard rain crust below. Once that had sloughed off we got back on the block and wailed on it, and could not get that to fail. One of the instructors said he would probably still be willing to ski a slope under these conditions, since the unstable layer was so unconsolidated, and our tests didn't show failures propagating anywhere. He thought an avalanche would be mostly a point-release type of situation, and without a lot of momentum. Sounds like your experience sort of backs that up?

[ilookeddown]

Glad everyone is OK. Found the same conditions on the 15th in the Snoqualime Pass area.

[hefeweizen]

I was up there that day with a big Mounties' avalanche class. We had dug a rutschblock and it failed on 2, but there was a fair amount of uncertainty about how we should interpret this- the failure was just the 6 or 8 inches of unconsolidated soft upper snow sliding over the hard rain crust below. Once that had sloughed off we got back on the block and wailed on it, and could not get that to fail. One of the instructors said he would probably still be willing to ski a slope under these conditions, since the unstable layer was so unconsolidated, and our tests didn't show failures propagating anywhere. He thought an avalanche would be mostly a point-release type of situation, and without a lot of momentum. Sounds like your experience sort of backs that up?

 

Actually, Feck's experience contradicts what the instructor said. The slide they triggered was a soft slab, not a point release, which indicates cohesion in the new snow and stored energy (i.e. propagation). They must have been at a terrain feature that gets wind loaded juuust right to encounter those conditions on Sunday. I was at Stevens skiing all over doing hill setup for unopened terrain and we found almost no slab quality to the new snow. However, since then, the additional snow and wind have changed conditions somewhat.

[Hugh Conway]

I was at Stevens skiing all over doing hill setup for unopened terrain and we found almost no slab quality to the new snow.

 

"almost no"? not sure I'd agree. I noticed small slab behavior at several Stevens spots sunday (open and closed terrain) None of the accumulation since the rain even 2 weeks ago has bonded well to ice/rain crust. On Saturday noticed several larger slabs at baker. How cohesive the slab above that is a function of wind/snow loading but I'd be careful anywhere until that layer disappears - especially with the increased accumulation forecast over the next couple days.

[AlpineK]

It was a slab not a point release. We were both on the left had edge of the slide. Basically the original layer put down starting in October warmed up then refroze forming an icy sliding layer.

 

I'm glad we were sticking to mostly tree skiing on Sunday. In the end it ended up being an interesting diversion and a good reminder to stay away from the the cool big slopes in the area. Small open areas are dangerous enough.

 

What the Cascades needs now is a period of warming weather to get the two layers to bond to each other. Until then don't go out planning on ripping up the gnar gnar.

[counterfeitfake]

Learning this stuff is difficult, there seem to be so few signs that lead to a clear-cut "yes" or "no". We saw a bunch of people up there that day on terrain that looked a lot sketchier than what you were doing. Glad nothing bad happened.

[Argus]

Get used to it. I see people doing stupid shit all the time. I'm suprised our # of avalanche incidents aren't higher.