Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Rain and freezing rain left the snowpack at the Pass as a wet sloppy mess. You could continue to see large natural avalanches even after the showers taper. Pay attention to what’s above you, and limit any time you spend on or under steep slopes.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Natural wet avalanche activity should be a full notch less on Sunday than Saturday and Saturday night. However, water will continue to make its way through the snowpack and could result in a few delayed natural avalanches. You could see wet slabs, cornice collapses, glides, and wet loose slides gouging into older snow. The bigger avalanches will likely result from some blob of snow falling off of rocks or a smaller slide, causing a failure deeper in the snowpack. 

    Even though the likelihood of wet avalanches should decrease throughout the day, the uncertainty and consequences remain. Look for routes that help minimize or even eliminate any time you spend underneath steep open slopes. 

    With such a wet upper snowpack, you may still trigger avalanches in steep terrain. These will likely be thick heavy wet loose slides, but they could also step down into one of the bigger and scarier avalanches mentioned above.

    Example: Wet avalanches like these could continue on Sunday. Photo: Dallas Glass

Avalanche Discussion

By the end of Sunday, the Pass could be looking at ~3 inches of rain from this atmospheric river (AR). Even as the fire hose turns off, the wet problems won’t stop on a dime. On Saturday, freezing rain formed an ice crust on many mid-elevation slopes. This likely limited the avalanche activity in these areas. In many ways, that makes Saturday night and Sunday slightly scarier. As that layer melts and water percolates into the snowpack, it could prolong the wet avalanche cycle. 

Natural avalanche activity will be most likely during and just after periods of heavier rainfall. With some pretty potent showers expected Saturday night, that could mean a natural avalanche cycle that lingers into the morning hours. 

Prior to this AR, the surface around the pass began to slowly transition to wet snow during the mild and damp period last week. A few natural and triggered wet loose slides occurred. However, below this wetter surface, the snowpack remained cold, dry, and layer, particularly at middle and upper elevations. You could still see nearly every crust and interface all the way back to mid-December (Solstice Crusts). This abrupt transition with rain impacting these older dry snow layers is tricky. It’s hard to say exactly if or when the snowpack will reach its breaking point.

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