Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

UPDATE: Increased avalanche danger to high at middle and upper elevations to reflect higher anticipated rainfall totals on Satruday.

The mountains are in for a big change as rain reaches well above ridgetops, creating very dangerous conditions. Natural wet avalanches of every type and size could occur, including very large deadly slides. Stay off of and out from under any steep open slope. 

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1.5–2.5

    You’ll certainly see wet loose avalanches, but as water percolates deeper into the snowpack, conditions should get much scarier. Wet slabs, glides, cornice collapses, and wet loose slides gouging into older snow layers will likely occur. The tricky part is the timing. Weather forecasts this morning (1/27) show considerably more rain than previously anticipated. However, there is still plenty of uncertainty. 

    Very large natural avalanches are most likely during periods of heavier rain, but could occur at any moment. This is a good time to just give the mountains time and space to deal with the major shift to rain on dry snow. Avoid places where avalanches start, run, and stop. 

    Example: (1/15/2023) A very large wet slab avalanche on the W Face of Kendall. W, 5600ft, WS-N-D2.5-R2-U, likely from the 1/12-13 cycle. Photo: Dallas Glass

Avalanche Discussion

The old adage, “Big changes mean big problems,” has been ringing in our heads all day. This is certainly a big change for the snowpack as we move from mild and wet to hot and soaked. We anticipate very dangerous conditions on Saturday, but there’s a chance things won't be that bad if the rain backs off. 

The real concern is that despite the relatively warm temperatures of the past week, only the upper few inches of snow transitioned to the added heat. Below the surface, the snowpack remains very cold, dry, and layered. This includes several older crust layers and lingering facets. These go all the way back to the Solstice Matrix 4-6ft below the surface. If some of these deeper layers wake up… look out! 

On Friday, avalanche professionals reported breakable crusts, wet sticky snow, rollerballs, and a few very small wet loose avalanches. The crust was often weak and breakable below about 4800ft. Runnels in the snow surface showed the upper snowpack became wet during the recent mild weather. Below the crusty wet surface, the snowpack still remained cold, dry, and layered particularly at middle and upper elevations.

Regions covered