Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Potentially sunny and windy weather could lead to a few pockets of unstable snow. Since we expect any avalanche to be generally small, pay close attention to the consequences of each slope. Don’t let a small slide push you over a cliff or into a deep creek.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    There’s plenty of loose snow to blow around as NW winds increase on Saturday. Small shallow wind slabs could form throughout the day. Look for blowing snow, textured surfaces, and small sharp drifts to point toward pillow-like slabs. 

    While these wind-loaded pockets should be relatively small, they could fail easily on the underlying soft snow. Don’t let them catch you off guard in steep rocky terrain where they could take you for a rough ride.

    (2/18/2023)

    Example: Signs of wind loading to look for Saturday.

    Photo: Dallas Glass

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    This wet loose problem is a bit of an “if, then” statement. Cloud forecasting is tricky, but if the sun comes out on Saturday, then you’ll probably see rollerballs and a few natural wet loose avalanches. With several inches of recent snow over a firm crust, these slides could run easily downslope, entrain additional snow, and grow larger. 

    If you start to see snow shedding out of trees or off of rocks, the sun is beginning to warm the snow. This shedding often leads to rollerballs and eventually small wet loose slides. 

    Pay attention to the terrain above you. Rocky cliffs may bask in the sun while you continue to shiver in the shade. We expect clouds to increase in the afternoon, which might put an end to any wet loose issues.

    (2/7/2024)

    You could see wet loose slides like these originating on steep rocky slopes.  

    Photo: Jonathan Spitzer

Avalanche Discussion

Saturday looks like a pretty nice day in the mountains. While not a massively impactful weather day, moderate winds and periods of sunshine should be enough to slightly increase the avalanche danger over the conditions we experienced all week. However, if the Pass stays socked in by clouds, conditions may not become quite as dangerous as expected. 

It may not seem like we’ve gotten much snow lately, but inch by inch, very weak storms added to the snowpack. Lower in the terrain, only 2-4 inches (5-10cm) of snow sits above the Early February Crust (EFC). However, as you move higher, you’ll find 8-12 inches (20-30cm) above ~4500ft. This snow is generally right-side-up and unconsolidated. 

The stout and thick EFC gave us essentially “new ground.” While we can still see many of the weak layers from December, we aren’t currently worried about avalanches failing on any layers below the foot plus thick crust. 

This week’s snow greatly improved travel conditions, particularly on lower-angled terrain. Unfortunately, it wasn’t enough to undo the damage of the last atmospheric river. Steep slopes remain slick and firm. Open creeks, holes, glide cracks, and piles of frozen avalanche debris continue to pose real travel challenges.

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