Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

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

Yet another day of warm temperatures, periods of sunshine, and poor overnight freezes will prolong this spring shed-cycle and wet snow avalanche concerns. During times like this snow can simply fall down. Don’t linger underneath rocky complex terrain especially when you see looming cornices.

Avalanche problems

  • Loose Wet

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

    The upper snowpack around the Pass is wet and weak from four days of above freezing temperatures. Punchy snow maybe knee to even thigh deep. While this isn’t the kind of set-up where you’re likely to trigger loose wet avalanches on every slope, any steep area where you find wet snow deeper than your ankle should be suspect. If the snow starts to move, it could easily entrain deeper layers, grow larger, and will be difficult to escape. This will be very different from loose wet slides we often deal with mid-winter. Some recent avalanches even gouged into older snow. With sunshine expected Tuesday, slopes receiving direct sun could be more dangerous.

    While they may be hard to classify, spring-shed avalanches go right along with this weather pattern. They could include cornice collapses, glide avalanches, wet slabs, or blocks of snow falling from rocky terrain. It's very hard to predict exactly when these avalanches will occur and they likely won’t give much warning. So, the best thing you can do is pay attention to the terrain above you. Don’t linger underneath cornices, glide cracks, or steep rocky slopes.

    (3/28/2022) Several large loose wet avalanches and cornice falls in the Thunder Creek drainage. Don't linger under overhead hazards like this during warm and/or sunny weather. Photo: Dallas Glass

Avalanche Discussion

Monday will be the fourth night in a row without a solid freeze at Snoqualmie Pass. That means you could encounter wet snow issues right off the bat in the morning and starting early may not significantly reduce the hazard. While a thin breakable crust might form overnight, this should quickly soften with the warm and sunny weather. The longer we go without a solid freeze the more our uncertainty grows about the potential size and likelihood of these spring avalanches. Debris piles littering many tracks and runouts tell the story of nearly a week of warm weather. Tuesday’s continued warm weather could produce the most avalanche activity yet. 

On Monday, NWAC forecasters traveled through several drainages near and below treeline to take stock of this spring transition. Numerous natural loose wet, cornice, and glide avalanches were observed up to size D2. It's hard to tell exactly when each individual slide occurred, but many covered recent tracks. Even still, there is plenty of snow waiting to come down. Much of the upper snowpack fully transitioned to spring-like snow (melt forms) over the past week. This includes shaded north-facing terrain. We still have some uncertainty about the 3/8 facets and Early March Crust, especially on higher northerly aspects and in the easter portion of the zone. Despite the lack of avalanche activity on this layer at the Pass, it's hard to say how it might respond to this prolonged warm weather or a large cornice trigger impacting the slope. 

Below treeline the snowpack continues to melt, exposing obstacles, creeks, and bare ground. Fortunately, at these lower elevations, the snowpack has been through a lot and isn’t likely to produce a sizable avalanche.

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