Turnagain Pass

As emphasized above in the bottom line there is a lot of variability with the current snowpack. If you head out today you need to be a bit of a detective and approach avalanche terrain with caution. There is new snow and a recent wind event. There are layers of buried weak snow. Triggering a slab avalanche is possible in steep terrain. The weather forecast for today includes light snowfall and shifting winds.

What you need to keep in mind:

1. A few inches of snow fell last night without much wind. This may have covered up evidence of prior wind effect. It was windy Tuesday night potentially creating wind slabs that may be harder identify today. Pay attention to increasing winds this afternoon as the wind shifts to the northwest. .
2. Snowfall over the past couple of days has favored Girdwood, Portage and Placer so expect slabs to be deeper in these areas.
3. Warm heavier snow has fallen over colder light snow, so small storms slabs may be possible in protected terrain.
4. There are a couple of buried weak layers (facets and surface hoar) in the snowpack. In some locations recent snowpack tests are showing that these persistent layers are still reactive. This indicates that triggering a wind or storm slab avalanche could potentially step down to one of these layers, creating a larger more connected avalanche if you find the wrong spot. In other locations tests are showing signs of becoming less reactive but there is not enough of a definitive pattern to be confident. This uncertainty is makes the whole situation tricky and the snowpack not that trustworthy…
5. Another factor is a buried melt-freeze crust with weak snow above it that goes from sea level to around 1600′ at Turnagain Pass and up to 2000′ in Girdwood and Placer. This combined with a deeper slab on top could make the low and mid elevation steep terrain more suspect.

What to do with all this information if you go out today?

Look for signs of instability like cracking and whumpfing.  Try to figure out if there is wind affected snow and a slab. Is there punchy, hollow-sounding snow? Can you feel really hard snow in wind-loaded area where your skis or track don’t sink in? This could be a hard wind slab over weak snow and could break once you get onto the slope. Don’t forget that weak snow is lurking in the snowpack! Think about the consequences if a slope does slide and as always use good travel protocol. Because of the variability and the buried weak layers approach avalanche terrain with extra skepticism.

Wind effect on Magnum, 2.17.21. What terrain is loaded? Where might there be a slab? 

Buried weak layer in the snowpack on Sunburst 2.17.21.

A buried surface hoar grain from the snowpack at 3150′ on Sunburst, 2.17.21. Photo: Eric Roberts