Bulletin d’avalanche

Snoqualmie Pass

Northwest Avalanche Center
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Danger d’avalanche

Mon
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

An atmospheric river will drown our weak snowpack with heavy rain Saturday night and Sunday. Throughout this period, several rounds of natural avalanches large enough to bury and kill you are expected. Traveling anywhere an avalanche can start, run, or stop is not recommended.

Problèmes avalancheux

  • Wet Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    2–3

    Large and destructive natural avalanches will occur during this atmospheric river event. If you've skimmed the forecast at any point over the last month, you'll have noticed us talking about persistent weak layers such as the January Drought Layer (JDL), 1/10 complex, and 2/13 interface. This is the time for those layers to fail as wet slabs. Yes - you will see loose and smaller wet slides in the surface snow. However, slopes that have already slid during the onset of this storm could slide again as liquid water works deeper into our weak and dry snowpack, reaching those persistent grains. There will also be cornice collapses and, potentially, glide avalanches. This means that slides could grow very large (D3) and powerful - breaking trees and running toward valley bottoms or openings in the forest. Sunday is not the day to hang out on or below any slope capable of producing an avalanche. Travel corridors you usually think of as "safe" should be suspect. Don't thread the needle - avoid anywhere an avalanche can start, run, or stop.

    (2/22/2025)

    One of multiple natural wet avalanches reported on Saturday at Snoqualmie Pass. This is but a taste of the avalanches yet to come. 

Avalanche Discussion

The main event has arrived at The Pass. Multiple inches of rain are expected to soak our weak snowpack throughout the forecast period, resulting in very dangerous avalanche conditions. Rain will reach the top of the peaks throughout the zone, so there's no escaping it. On Saturday, the initial waves of this atmospheric river resulted in smaller slides in the surface snow. Debris piles large enough to injure or bury you were reported. That was just the beginning. Slides should be larger and more destructive through the evening hours and into Sunday. Wet avalanches are extremely difficult to predict and can occur even after the rain has stopped. So don't tempt fate. Sunday will be a great day to stay home and do mid-winter maintenance on your gear or spend time with your loved ones. Traveling in the mountains is not recommended until this atmospheric river concludes. It's going to be gross outside anyway.

Régions couvertes