Boletín de aludes

Snoqualmie Pass

Northwest Avalanche Center
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Peligro de aludes

Wed
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó 6 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Recent snowfall and multiple buried weak layers in the snowpack will continue to create dangerous avalanche conditions on Tuesday. All steep slopes are suspect; consider sticking to simple, lower-angle terrain.

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    Persistent slab activity will continue on Tuesday, with the recent snow straining the upper snowpack. Snoqualmie Pass picked up 6-11" of snow in the past 24 hours, depending on elevation. All this new snow is stacked on top of the well-documented and recently reactive 2/13 and 2/7 interfaces. Activity on these weak layers was minimal on Monday, but that doesn’t mean the problem has disappeared or that we’re in the clear. These layers may simply be more difficult to trigger right now. Regardless, buried weak layers are still present in the snowpack and deserve careful consideration.

    Long shooting cracks, audible collapsing underfoot, and recent avalanche activity are all good indicators of an unstable snowpack. If triggered, these avalanches could break multiple feet deep and be large enough to bury/kill you. This setup is tricky, and you're better off not testing your luck. Avoid traveling on large, steep slopes, especially in areas of recent wind loading.

    (2/21/2026)

    An unintentionally triggered, widely propagating avalanche from 2/21. N, 5500ft.  Its unconfirmed, but this slide may have failed on older persistent grains. 

    Photo: NWAC

Avalanche Discussion

Snoqualmie Pass received up to 11 inches of snow at the upper elevations from Sunday night into Monday. The lower elevations saw closer to 6 inches due to the warmer temperatures. A couple of avalanches were spotted high in the Alpental Valley, but no other avalanches were seen. Observers reported generally good travel, with light reactivity on density changes within the new snow. No reactivity was reported on the 2/13 and 2/7 interfaces.

A few more inches of snow are expected through Tuesday, with generally cooler temperatures and light winds. The 2/7 and 2/13 interfaces remain the primary concerns in the upper snowpack, with the 2/13 layer composed of preserved surface hoar and the 2/7 layer consisting of facets and surface hoar. The 2/13 interface may now be buried 2+ feet below the surface, and even deeper in wind-loaded terrain. These weak layers are most prominent on north-facing slopes, but have been identified in some form on all aspects.

It's nice to see the dense new snow improving coverage around the Pass, but improvement is relative! It's still very thin out there, with abundant creeks, logs, trees, and rocks across all elevation bands. Under the tree canopy, there may only be a few inches on the ground. Take it slow, and plan a little extra time for your travels.

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