Boletín de aludes

Snoqualmie Pass

Northwest Avalanche Center
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Peligro de aludes

Tue
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 8 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

The snow continues to stack up, and coverage is improving. However, early-season conditions still limit access to the higher terrain. With so little information about the new snow, be suspicious of any steep open slope. This is especially true at higher elevations and in wind loaded areas.

Problemas de aludes

  • Storm Slabs

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

    We don’t know much about the recent storm snow. What does seem clear is there’s probably somewhere around 20 inches over a firm crust at middle and upper elevations. One way to address this uncertainty is to question every steep open slope. Make sure to check all the recent snow, all the way down to the crust. If your feet, hands, or sled aren’t touching it, you aren’t getting the full picture. 

    Ultimately, you’re looking for strong (slab) over weak snow. If your uptrack tests, small slopes, or hand pits produce cracks or blocks, then you’ve found the issue. Slabs could fail on interstorm layers or at the base of all the new snow. These potential avalanches would be most likely to fail on convex rollovers or unsupported slopes. If it just sluffs off or is right-side-up, you’re likely dealing with loose snow issues, which might simply mean fun powder!

    Even if you don’t find slabs in sheltered areas, winds may have drifted the snow on more exposed slopes. Drifts, textured surfaces, and wind lips all point toward possible slabs. These may be most pronounced in the tops of chutes and along the base of cliffs. 

    (12/20/2025) This uptrack test produced a significant result on Saturday. Note how the crack moves out head of the traveler. 

Avalanche Discussion

Monday should provide another break in the stormy weather, but not before the Pass picks up another 4-6 inches of snow Sunday evening. This continues an impressive stretch of snowpack building storms. That said, it’s still pretty thin out there, especially down low. For those willing to fight their way through the creeks, trees, logs, and brush, snow depths do improve. Where’s the magic line? Hard to say. 

The snowpack seems to consist of three main parts: the recent snow over the 12/18 crust, a mid pack of drier snow, and the lower atmospheric river ‘snow’ from earlier in December. This last layer is probably absent in the lower elevations and possibly on some mid-elevation slopes. On Thursday, 12/18, rain, sleet, and freezing rain reached high into the mountains, creating a firm and slick crust. It's the new snow above this prominent marker that we’re still concerned about. 

With such a shallow snowpack persistent at all elevations, there are plenty of obstacles to hit of you do happen to get surprised by an avalanche. Even a small slide could take you for a nasty ride. 

The weather over the past few weeks has been extraordinary, with torrential rains, extreme winds, flooding, and landslides. Many communities are dealing with damage to homes, infrastructure, and businesses, stretching resources thin. These events have limited access to the mountains for all of us. State and local resources are working diligently to reduce the worst of these impacts. We can help by being respectful of local communities, obeying road closures, and heeding ski area uphill travel policies.

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