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May, 12, 2014, Cascades, Consolidation

  • avajane
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11 years 9 months ago #133045 by avajane
As it's that time of year, I'd like to see how different people feel about and define late spring/summer consolidation. Over the years I've spent lots of time skiing sunny,warm snow at this time of the year. I've also seen some of the worst slides of my life in May/June. About 5 years ago I saw a picture of the WHOLE Northside of the Flute/lesser Flute area down to the ground. One long fracture line about 500 feet above tree line, encompassing terrain that I had been skiing since November. The same thing happened that year in Jersey Cream Bowl shortly after the lifts had closed on a hot, spring day. How do you best guard against this? (I'll try to find the pictures)

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  • avajane
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11 years 9 months ago - 11 years 9 months ago #133048 by avajane
Replied by avajane on topic Re: May, 12, 2014, Cascades, Consolidation
Flute late spring avalanche (after lifts had closed at Whistler but while Blackcomb was still open.) 2008

www.whistlersnowreport.com/wp-content/ga...y/2008-may/Flute.jpg
Last edit: 11 years 9 months ago by avajane.

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  • peteyboy
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11 years 9 months ago #133057 by peteyboy
Replied by peteyboy on topic Re: May, 12, 2014, Cascades, Consolidation
Then there's the Grouse Creek wipeout here on Baker a few years ago.
People far more knowledgeable than I have commented here on depth of overnight freezing. There seems to be, to be close to truly free from the risk of the not-super-likely and not-very-predictable catastrophic spring slide, a need to have overnight freezes of adequate depth at some point during the spring period of liquid water percolation down into the pack. I find it very difficult to know what is enough to go anywhere we want afterward. The periods of high probability of upper layer failure are easy (like recently). The security of safety from deep failure to me is not.

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  • pipedream
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11 years 9 months ago #133068 by pipedream
Replied by pipedream on topic Re: May, 12, 2014, Cascades, Consolidation
To me it seems to come down to how well the snowpack is draining. If water melting at the surface is able to run to the ground, then it's relatively straightforward to grasp the risk of climax slides and where they're likely to occur (typically on smooth, sloped rock such as the entirety of the terrain out the lower gate at Alpental). If that water isn't percolating fully through the snowpack, it may be lubricating a buried weak layer which dramatically increases the risk of wet slab avalanches. Those are the kind that terrify me - loose wet slides are predictable and while not entirely avoidable, usually manageable with ski cutting and smart terrain selection. Wet slabs can release above you and bring an incredibly massive amount of snow down in a much quicker fashion than a wet loose slide.

That said, a wet loose slide can entrain a large amount of snow and run for a very long distance. You need to be aware of those below you as well as attentive to any terrain traps when the risk of wet loose avalanches is present.

How can you determine how well the snowpack is draining? That I don't have a great answer for as digging a snowpit to the ground is exhausting and time-consuming at this point in the year.

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11 years 9 months ago #133069 by pipedream
Replied by pipedream on topic Re: May, 12, 2014, Cascades, Consolidation

Flute late spring avalanche (after lifts had closed at Whistler but while Blackcomb was still open.) 2008

www.whistlersnowreport.com/wp-content/ga...y/2008-may/Flute.jpg


Better link w/ more photos: www.whistlersnowreport.com/photo-gallery/2008-2/may

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  • avajane
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11 years 9 months ago #133087 by avajane
Replied by avajane on topic Re: May, 12, 2014, Cascades, Consolidation
The heavenly basin shots show how skier compaction doesn't help when things go to the ground. I've talked to Blackcomb Patrol about their spring time decision making and a lot has to do with overnight crust recovery. If there is no crust formed they are more apt to close the alpine early.  I guess timing is critically important

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