Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

If you’re going to trigger an avalanche, it will probably be in a pocket of wind-drifted snow at upper elevations. Feel for subtle changes in the density of the snow as you travel, or look for areas that appear pillow-like to determine slopes to avoid.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    You may be able to trigger small wind slabs at upper elevations on Wednesday. They could have formed on convex features, the sides of confined chutes, or the leeward side of ridgelines. Although small and isolated, they might be reactive - breaking on a crust or weak snow above it. 

    To complicate matters, there’s a chance they’re hidden below an inch or two of new snow. If so, you’ll need to recognize the terrain where they’re more likely and avoid it. If you notice the density of the snow changing as you travel, you may have stumbled upon one and should retreat.

    (1/1/2024) 

    A  small skier triggered wind slab from New Year's Day. N, 4900ft. HS-ASu-D1-R1-I

Avalanche Discussion

Tuesday yielded snow showers and light to moderate winds at Snoqualmie Pass. Expect a similar pattern to continue through the evening hours and into Wednesday. 

NWAC forecasters in the Alpental Valley found a surface crust at lower elevations, which was mostly breakable. A few inches of light snow sat upon the recently buried 12/30 crust at middle elevations. No new avalanches were spotted, but visibility was poor, preventing travel in the upper elevation band.

Our greatest layer of interest, the 12/22 crust sandwich, will be at the forefront of our minds as this week progresses and hopefully gets snowier. We have been chatting about this interface for about a week in the forecast discussion. You can find it roughly a foot below the surface as a complex of multiple crusts with weak snow in and below it. It continues to produce propagating test results in extended column tests. 

On Saturday, a natural slab avalanche occurred on the north side of Chair Peak, which had a depth that roughly matched that of the 12/22. On Monday, a skier triggered a small wind slab and was carried a short distance - also on the north side of Chair Peak. 

Look out for those open creeks, small bushes, rocks, and holes. They’re still out there, especially at lower elevations where they can impede travel. 

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