Lawinenlagebericht

Stevens Pass

Northwest Avalanche Center
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Lawinengefahr

Wed
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

A welcome dump of 1-2 feet of snow with winds created dangerous avalanche conditions. You could easily trigger large avalanches where the wind drifted snow into thick slabs. Avoid steep slopes with deep drifts below ridgelines and the base of cliffs. At upper elevations, avalanches could be very large and break widely across terrain. 

  

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    The snow is piling up, and strong winds are drifting it into large wind slabs, particularly at upper elevations, where avalanches could step down to more deeply buried weak layers. Wind slabs are most likely on steep slopes below corniced ridgelines, the base of cliffs, and in confined gullies. Steer clear of steep, open, wind-drifted terrain at upper elevations. Instead, seek out sheltered low-angle slopes to enjoy the return of winter. 

    You can use clues such as snow surface texture or actively blowing snow to help identify wind loaded terrain. Long, shooting cracks on test slopes or natural avalanches are key warning signs to avoid steep slopes.  

    (3/13/2025)

    Wind-loaded test slopes that produce cracks and mini avalanches are a red flag for unstable conditions. (4300ft) 

    Photo: Katie Warren

  • Loose Dry

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–1.5

    With fresh, cold, dry snow piling up, dry loose avalanches in steep terrain will be easy to trigger. While these avalanches are more predictable than slabs, they can still push you into cliffs and trees or bury your partners below. Use caution on steep slopes and practice good terrain management by staying out from under where your partners are traveling above. 

    With cooling temperatures, storm slab instabilities have been isolated. But you could find small pockets on steep features where you could trigger a small storm slab. Quick hand pits and test slopes are a great way to assess the reactivity of new storm snow. Cracking or hand pits where snow slides easily as a cohesive block are signs to steer to lower-angle terrain. 

    (3/9/2026)

    A loose-dry avalanche triggered on Monday at Stevens Pass. You can see the grooves the sluffs cut out. This slide ran a long way in this steep gully. 

    Photo: Irene Henninger

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    We have limited information from upper elevations, but we can't rule out very large, deadly, persistent slab avalanches. They could be big enough to destroy a car and can break widely across terrain features. Avoid steep open terrain at upper elevations, especially slopes with deep wind drifts. It's worth not lingering beneath any of these slopes, as there is still potential for natural avalanches.

    This remains a high-consequence problem. The same wind loading that's creating avalanche problems in the new snow is also stressing older weak layers. With these deeper weak layers, you may or may not receive warning signs such as collapsing or cracking. The most suspect slopes are above 5,800ft where the snowpack has remained mostly dry and lacking new crusts. You can find layers of facets and buried surface hoar just above a couple of crusts about 1.5-2.5 feet (50-80cm) below the surface.  The only way to manage this problem is to avoid these suspect slopes. 

    (2/28/2026)

    Multiple widely breaking avalanches (up to D2.5) on the southeast aspect of the South Peak of Rock Mtn. SE-S, 5,800ft-6,600ft

    Photo: Josh Hirshberg

Avalanche Discussion

It's the winter storm we've been waiting all winter for! Stevens Pass picked up between 1.5-2" of snow, and more is on the way for Monday night. The moderate winds will continue to drift snow around, particularly in more exposed locations at upper elevations. For all the new snow, avalanche activity on Monday was mostly small loose avalanches and small, isolated slabs. However, in exposed locations where the wind has more effect, we have a lot of uncertainty. So it's essential to stick to a conservative mindset, ease into terrain, and actively look for signs signaling unstable snow. 

 On Saturday, an NWAC forecaster in the Skyline area reported a moist upper snowpack. At 5,300ft, NW water had reached and weakened the mid-February weak layers (2/13 surface hoar and 2/18 facets) and underlying crusts. We expect the cold temperatures to freeze these wet layers, making them less of a concern. However, at upper elevations, the snowpack likely stayed mostly dry, and we have limited information. We suspect these weak layers are still active, and this ongoing storm is the first true test.  Just 10 days ago, a much smaller storm drove a cycle of widely breaking D2-2.5-sized avalanches. Natural and human-triggered avalanches occurred on leeward and sun-exposed slopes following a major westerly wind event. Given the ongoing loading, avalanches on these weak layers could become more likely as the week progresses. Things could get particularly spicy looking at the warming temperatures and significant precipitation for Wednesday. 

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