Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

The potential for unpredictable large avalanches should shape your terrain selection on Sunday. Choose travel routes that avoid overhead hazards such as sagging cornices or blocks of snow primed to fall off rocks and cliffs. If you can avoid these ticking time bombs, you may find generally safe avalanche conditions. 

Avalanche problems

  • Glide Cracks

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    On Saturday, we received reports of multiple recent Glide avalanches due to warm temperatures and sunshine. Some of these slides were able to entrain additional snow or trigger Wet Loose avalanches after falling on the slopes below. Glide avalanches are erratic and very difficult to predict but often occur during periods of warm temperatures, prolonged sunshine, or rain. 

    Temperatures are forecasted to cool and clouds to increase on Sunday, which should diminish the likelihood of these avalanches. However, the threat of some rain overnight Saturday into the morning hours of Sunday could be enough to keep this Glide cycle going. The red flag of multiple recent avalanches tells us that these slopes are ready and waiting, so give slopes where you see large crevasse like cracks in the snow a wide berth. Although the likelihood is low, these avalanches are unpredictable and would be consequential if you happened to be under a slope that releases.

    (4/3/2021) This glide avalanche occurred due to sunshine and warm temperatures on Saturday in the Alpental Valley and approached a common travel route. [Bryant Peak Couloir, E 4800' Photo: Public Observation]

Avalanche Discussion

Saturday ended up being a bit warmer and therefore a bit more active than we had anticipated. We received a report of a Glide avalanche that flushed through the Bryant Peak Couloir in the Alpental Valley. In the same general area, a different public observation relayed that a chunk of ice had fallen from cliffs and started a small Wet Loose slide. Chair Peak also produced some glide avalanches, possibly on both Friday and Saturday. These slides all approached common travel routes and are good examples of the challenges of springtime forecasting.  You may find generally safe avalanche conditions for most of the day or in most locations, but these sporadic slides pose a true hazard and demand you are diligent with your travel routes and observations.

On Sunday, we expect freezing levels to eventually drop toward 3000’ and that should help to stabilize the upper snowpack as it freezes from the top down. Until we reach that point, the possibility for more wet avalanches will remain, largely due to light rain at middle and lower elevations overnight Saturday into the morning hours on Sunday. Avalanches such as wet loose, glide, and cornice failure can’t be ruled out. Avoid traveling on and limiting your exposure traveling below cornices. They are unpredictable and often break back further than expected. At upper elevations, precipitation will be light snow and shouldn’t be enough to drive much of a hazard. That said, keep an eye out for shallow pockets of wind-drifted snow that could sweep you off your feet if you travel to the highest peaks or find yourself in extreme terrain. 

As we continue to make our transition toward a springtime snowpack, remember that conditions can change quickly and may vary greatly depending on aspect or elevation. Below the firm surface crusts expected to develop on most aspects, a layered and cold dry snowpack still exists. As we found out on Saturday, slab avalanches or entrainment of this snow is possible given a large trigger in the correct location. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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