Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

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

Saturday’s warm and sunny weather will make for an inviting day in the mountains but could cause the snow to fall down. Pay attention to what’s above you and limit the time you spend underneath steep snow slopes, rocky terrain, and looming cornices.  Rollerballs, fan-shaped debris, and snow shedding from trees will let you know the surface is becoming wet and unstable.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    While Snoqualmie Pass received snow continually throughout the week, periods of sunshine and warmer temperatures helped this loose wet cycle come in trickles rather than a wave. So, while Saturday will be quite warm and sunny, and we expect you’ll see natural loose wet slides, they should be generally small and only involve the most recent snow. A good freeze and new surface crust will help delay this hazard in the morning, but as the snow softens, begin to anticipate loose wet slides. That may happen faster on the steep sunny slopes above you than it does in the cooler shaded valleys. Watch for rollerballs, fan-shaped debris, and snow shedding from trees to help indicate when the snow is becoming wet and unstable. Then limit the amount of time you spend on and under similar terrain.

    While loose wet avalanches may be the most common issue, this warm and sunny period could cause the mountains to start to “shed.” Blocks of snow may fall from rocky terrain, cornices could collapse, and loose slides might gouge into deeper layers. We think these hazards will be more common on Sunday, but you could see an isolated case on Saturday. Pay attention to the terrain above you and don’t linger under large rocky slopes or looming cornices.

    (4/22/2022)

    Rollerballs and snow falling from rocky faces indicate loose wet avalanches are becoming more likely. 

    Photo: Erin Addison

Avalanche Discussion

Saturday looks like a gorgeous spring day, and with the fresh snow from this week, the mountains will seem quite inviting. Even though we aren’t forecasting a widespread avalanche cycle, we are still talking about natural avalanches. If you start to see larger and/or more widespread avalanching than predicted, get out of their way. Seek out routes well away from large steep slopes. 

On Friday Alpental ski patrol and backcountry travelers reported both natural and human-triggered rollerballs. Some of these were quite large. However, loose wet avalanches were less common and remained small. The warm snow surface from Friday will likely form a new crust overnight and could make for tricky travel Saturday morning. 

It has been a snowy week at the Pass. Mid and upper elevations received 6-12 inches of snow in a series of small storms since Monday 4/18. This adds to the upper snowpack above the very widespread and prominent 4/8 crust that is typically found 2-3 ft below the surface. While we aren’t expecting avalanches that deep on Saturday, we are watching all of these layers carefully during this warmer weather. If the mountains start to shed, they could involve snow all the way down to this older crust.

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