Avalanche forecast

Stevens Pass

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

New snow and wind will build fresh, shallow slabs at upper elevations. Be cautious near ridge crests and convex rollovers. Stay alert as you transition into wind-affected terrain, and continue to give cornices a wide berth. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Precipitation and increasing southerly winds will arrive Thursday night as temperatures continue to cool off. Expect the bulk of snowfall overnight with a lull during the day Friday. Shallow slabs of wind drifted snow will form on a variety of old snow surfaces and could be reactive to the weight of a person on slopes greater than 35 degrees. Approach leeward terrain above 5000ft cautiously and look and feel for sudden changes in snow surface texture and hardness. Seek out small slopes to test the new snow, and keep an eye out for recent avalanches, cracking, and collapsing. You can avoid the problem by sticking to wind-sheltered terrain or lower angled slopes.  

    (3/8/2021) Example photo of a small natural wind slab on Wright Mountain in the Snoqualmie Pass Zone. The slab broke near the base of cliffs and the cornice above serves as an indicator of the wind-loaded slope below. [Photo: Trevor Kostanich]

Avalanche Discussion

The storm will ramp up Thursday evening and periods of light snowfall will continue through the weekend. New snow and wind will drive avalanche concerns at upper elevations, while the hazard will remain limited below treeline. In addition to slabs of wind drifted snow, keep cornices in mind as these already large features will continue to grow the next few days. They could drop onto slopes below acting as huge triggers. Stand back from cornices along ridgelines and minimize overhead exposure to these features. Several large glide cracks and a few glide avalanches were observed recently as well. These avalanches are difficult to predict, but if you notice crevasse-like cracks in the snowpack, avoid these slopes and areas below. 

While deep persistent slab avalanches are dormant and unlikely, the snowpack structure can still be found in the zone. The mid-January crust-facet layer is now 8-9 feet below the surface and shows signs of strengthening. The last known deep slab avalanche in this zone was on March 1, and one was suspected in the West South zone on March 3. Major warming events later in spring and summer could trigger further rounds of avalanches on this 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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