Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Wind slab avalanches are likely on steep mid to upper elevation slopes in wind loaded pockets of snow. These slabs may be easy to trigger, so travel carefully and avoid wind drifted areas on slopes steeper than 35 degrees. Be wary of icy surfaces beneath the new snow which could make a good sliding surface for avalanches, or a difficult surface for travelling on, especially at lower elevations. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    You will find wind slabs 6-18+ inches deep that you can trigger an avalanche in on Wednesday. These slabs developed with the strong winds that began Tuesday. Expect to find slabs lee to the south and east, but you might find them on other aspects as well. Loading from this wind direction is not common, so you may find deposits in unusual locations and further downslope than you might normally look. Search for them around features such as in gullies or near outcroppings, and along ridges and subridges. Snow may appear smooth and pillowlike, or textured. Expect the snow to feel stiffer, or hollow. Avoid slopes steeper than 35 degrees where you notice any of these snow characteristics.

    Watch out for wind slab avalanches like these on Wednesday.

Avalanche Discussion

An observer in the Heliotrope Ridge area saw avalanches and other signs of instability like cracking on Tuesday.  You can read his report here. Since then winds will have increased, loading more snow onto leeward slopes and continuing with this avalanche problem. 

The 6+ inches of snow we’ve received in the last few days is a welcome addition to our mostly firm preexisting snowpack. Backcountry users noted remarkably improved snow conditions on Tuesday. You will still notice the old snow layer, especially at lower elevations where a solid or punchy crust was previously at the surface. You may find icy patches at upper elevations where wind stripped the snow away, especially on south aspects.  Use caution, as these icy surfaces are potentially dangerous for travel, and they also make a good bed surface for avalanches to slide on. 

On the northern half of the compass you might find a weak layer of snow just under the snow that started on Sunday.  These aspects are probably where snow will be loading, and if these weak layers are present slabs may fail easily on the weak layer.  

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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