Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

The fluffy surface snow is covering up buried weak layers that could produce a dangerous avalanche. You are not likely to hear, see, or feel any signs of instability, but the potential for avalanches exists regardless of what you experience on your tour. The only sure way to stay safe is to avoid steep and consequential open slopes that face east, west, or north.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2

    A 1.5-3.5 foot slab rests over weak layers formed in January. This setup resulted in multiple avalanches and whumpfs (would-be avalanches if the slope was steeper) last week. Recent snowpack tests continue to produce failing test scores. Though these layers are variable in their distribution and sensitivity over the landscape, they are generally capable of producing avalanches on shaded slopes at all elevations. 

    While the likelihood of triggering a persistent slab avalanche has decreased, the consequence remains unchanged. You can't dig and assess your way out of this problem. Though you may not hear a collapse, observe an unstable test result, or see any avalanches, the body of evidence over the past week strongly suggests that this problem may be lurking on the slope in question. The only way to navigate this is through disciplined terrain choice. Plan a route in forested or low-angle terrain and avoid steep and sustained open slopes on the northern half of the compass.

    If you should decide to venture onto open, steeper shaded slopes, choose planar and supported terrain with clean runouts, avoid rocky outcrops, and only expose one person at a time. 

Avalanche Discussion

The problem persists. We have been tracking the 1/10 complex (facets and crusts) and the January Drought Layer (JDL - facets or facets and crusts) and over the past week plus we have seen avalanches, whumpfs, and unstable snowpack tests on these layers. In addition, a snow professional noted a recent avalanche on Chair Peak that may have failed on the PWL. We know you want this problem to disappear. So do we, but the snowpack doesn't care. Don't let your guard down and remember that low-angle and forested slopes are holding fantastic snow right now.

We realize some folks have and may continue to venture into steeper shaded terrain. Consider that areas around rocks and trees could be trigger points where a thinner slab sits over the weak layer. Things are uncertain, the weak structure persists, and there may be some "sweet spots" out there where you could trigger a large and consequential slide. 

A few other things to keep in mind. While storm slabs from the weekend's snow should mostly settle out by Monday, there is a chance for some fresh slab formation with increasing easterly winds. Look for blowing snow and textured surfaces, and steer clear of slopes where you see those signs. In addition, some solar-induced loose avalanches could shed from steep slopes and rocky features facing the sun. These point releases should be relatively small but could become a problem if they knock you off your feet in the wrong spot. 

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