Valanga

Kendall Peak

Andy HarringtonSnoqualmie Pass
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Quick report

I took all the off-duty NWAC kids out for a walk in the trees today to do some terrain familiarization and get a sense of how our stormy week was shaping up. Travel was much better than expected, and we were on skis from car to car, with only a few tricky creeks to navigate. The snow was deep and soft, with a big mix of rimed precipitation particles/graupel. More than once, a stumble knocked over someone in our party who had some difficulty getting back up with all the low-density snow near the surface. Near the top of the slide path, open areas showed a hint of wind effect on the surface. We started to get blocks of soft snow to fail during uptrack tests and quick handpits, even with minimal wind observed in this area.

Uptrack tests and hand pits produced very soft slabs in the upper snowpack that failed on a density break.

Weather

We were in and out of snow showers most of the morning, some of which were rimed. Very little wind was observed except in open areas at the top of Kendall Trees.

Snowpack

The upper snowpack contains multiple density breaks from this week's storm parade. The most notable of which is a layer of graupel roughly a foot below the surface. It failed repeatedly in small and large column tests, but did not propagate in ECTs. It was also easy to find and fail during quick handpits. Unlike most graupel layers, I found this in almost every location I checked, which is a bit uncommon. 

Lastly, there is an interface 3cm above the 1/3 crust that failed during deep tap tests but not during standardized tests starting at the surface. This layer was identified earlier this week, and it surprised me slightly that I still got results on it. Again, no propagation, but it's there. It appears to consist of stellar arms, although grain ID can be tricky when it's nuking outside.

HS in the meadow at the top of Kendall Trees was 145cm, with the 1/3 crust down 73cm.

Avalanche

We observed a singular D1 natural avalanche at the base of the waterfall cliffs. We also observed snow actively shedding from cliffs and steep, unsupported slopes.