Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

On Wednesday, the snowpack will still be capable of producing wet avalanches as it adjusts to the recent rain. Consider taking a more conservative approach to your travel plans than you typically might at Moderate danger. Recent avalanches and rollerballs, or large crevasse-like cracks in the snow are all indicators that you should put plenty of space between yourself and features over 35 degrees.

Avalanche problems

  • Glide Cracks

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

    The snowpack around the Pass just received significant liquid water that produced a widespread wet avalanche cycle. As the rain tapers and temperatures start to cool, the number of avalanches should decrease. However, the threat of Glide avalanches will remain as water continues to work its way through the snow. These avalanches are almost impossible to predict and can release long after the rain has stopped. Other wet avalanches such as loose or slab might also occur but could be more stubborn to trigger. That said, with so much heavy rain-soaked snow, any triggered avalanche could grow large enough to bury and kill you. In the case of Glides, they could grow very large and destructive given the right piece of terrain. You should limit the amount of time you spend in the runout zone of large avalanche paths and give slopes that contain crevasse-like cracks a wide berth as you travel. 

    (3/1/2022)

    Chair/Bryant Peak avalanches hit the lake and rolled up the knob on the other side. A popular lunch spot.

    Photo: Andy Harrington

Avalanche Discussion

The water numbers since Saturday night at the Pass are staggering. We have received over 9” of precipitation during that time frame, the majority of which has been rain. High freezing levels resulted in liquid water likely reaching peaks and ridgelines to thoroughly soak our once dry wintertime snowpack. On Tuesday, NWAC forecasters slogged up the Alpental Valley to Source Lake to take a look for recent avalanches. There were large debris piles on many slopes along the way, and upon arriving at the lake, they found that large-very large avalanches had come down from both Bryant Peak and Chair Peak. The debris from these avalanches overran Source Lake and traveled halfway up a knob on the far side that is a popular lunch spot for skiers and snowshoers. Remarkably, this is the 1 year anniversary to the day of this terrain producing a similar avalanche in 2021. 

Unsurprisingly, the snowpack was observed to be moist and heavy but draining well at lower elevations. This leads us to believe that the likelihood of human-triggered avalanches is decreasing. As temperatures start to cool and snow flurries return to upper elevations, the snowpack should slowly start to stabilize from the top down. That said, plenty of uncertainty exists about upper elevations, and conditions around the zone are still in a state of flux as our snowpack adjusts to the recent rain. You may want to consider shaping your travel plans as if you were traveling at Considerable danger. You also need to realize that the landscape has changed drastically since you last were in the mountains. Creeks and streams are swollen with water and could be impassible. In some low elevation areas, there could be bare ground showing where snow existed just a few days ago. If temperatures cool enough, surfaces should freeze and make for dangerous slippery conditions. 

We still don’t know the full extent of what happened during this atmospheric river event, but would love to hear from you if you spot recent avalanches during your travels. You can help us track this cycle by submitting a public observation.

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