Bulletin d’avalanche

Snoqualmie Pass

Northwest Avalanche Center
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Danger d’avalanche

Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 6 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

A well-documented weak snowpack structure exists at Snoqualmie Pass. The addition of wind-loading could stress these layers, resulting in unpredictable or widely propagating avalanches. Adjust your mindset and travel plans accordingly to these unique conditions.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    You need to continue to treat all slopes over 30 degrees as suspect. Multiple buried weak layers in the upper snowpack may not provide direct feedback to you as a traveler, but they are there and capable of producing surprising avalanches. In fact, our normal tips and tricks for evaluating stability won't work with this persistent slab problem. Uptrack tests, small test slopes, and even hand pits can't give you a sense for where or how these weak layers will fail. 

    With the addition of wind-loading, slabs will thicken, and our weak layers will be stressed. They could fail naturally or become primed for human-triggers. So yes - you'll want to avoid these wind-loaded areas where it's possible to trigger a wind slab avalanche. But these are the same areas where persistent grains deeper in the snowpack could result in widely breaking or remotely triggered slides.

    Your best management technique will be to avoid all open slopes over 30 degrees. That includes wind-loaded terrain and even large openings in treed areas. 

    (2/24/2026)

    A widely breaking natural avalanche in closed terrain at Crystal Mountain, in the neighboring West South zone. This one broke roughly 800 feet wide and was 2.5 feet deep, failing on the 2/13 surface hoar.

    Photo: Crystal Mountain Pro Patrol

Avalanche Discussion

Friday should be a similar weather day to Thursday, with clouds, light showers, and breezy winds. We'll be on the front end of a slow warming trend, forecast to continue through the weekend. This is expected to add a layer of uncertainty and complexity to an already unsettling time in the mountains. If the sun comes out or temperatures are noticeably warm on Friday, look to the snow surface. If it's getting heavy and moist, natural avalanche activity may be on the rise.

With a documented weak upper snowpack consisting of two persistent weak layers (the 2/13 buried surface hoar and the 2/7 crust/facet combo), any triggered avalanche could result in unpredictable, surprising slides. Managing your typical wet loose or wind slab problems becomes even more harrowing when persistent weak layers lurk below the surface. Although it has been a few days since our last reported persistent avalanche activity at Snoqualmie Pass, that doesn't mean the problem has gone away. In the neighboring West South and Stevens Pass zones, these same layers have been very active this week. The greatest uncertainty surrounding this problem remains the likelihood of triggering. 

Weather inputs, such as warmth or wind, could do the trick. Or maybe a weak point in the snowpack is just waiting for you to find it. Either way, don't try to thread the needle - choose terrain carefully and remember that all steep slopes are currently suspect.

Régions couvertes