Bulletin d’avalanche

West Slopes South

Northwest Avalanche Center
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Danger d’avalanche

Thu
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Périmé — ce bulletin a expiré 5 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Wednesday might be the most dangerous day of the week. More rain will continue to erode the upper snowpack, potentially resulting in very large and dangerous avalanches. Choose travel routes that limit your time spent on or below large open slopes.

Problèmes avalancheux

  • Wet Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1.5–2.5

    We're entering the timeframe when wet avalanches are expected to become more sporadic but potentially much larger. So we're switching up the problem from wet loose to wet slab for Wednesday to help drive home the point that deeper, larger, and more dangerous avalanches could occur as rain continues to soak our snowpack.

    You will likely still see some wet loose out there, starting at a point and gaining mass as they move downhill. Whether slab or loose, either avalanche type has the potential to travel long distances and gouge down into last week's storm snow, creating dense, powerful, and difficult to escape avalanches.

    You won't be able to predict when these slides will occur. Your best bet will be to limit the amount of time you spend below large open slopes, sagging cornices, or rocky ledges with snow clinging to them. This includes being aware of terrain far above you and limiting your exposure to terrain traps.

    (3/16/2026)

    A small, but powerful, wet loose slide that started at a point near a tree. The snow was saturated and gouged down into older snow layers, exposing rock as it descended. It crossed a common travel route for both skiers and snowshoers.

    Photo: Andy Harrington

Avalanche Discussion

Wednesday will be the third day in a row with rain falling on what was once a cold, dry snowpack. Rainier continues to lead the way with the most recorded rain during this event. The southern volcanoes have largely avoided the deluge, so you may want to check out the Mount Hood forecast for a better sense of conditions in the southern half of the zone.

On the ground observations remain limited, but the Crystal Mountain Pro Patrol let us know about a handful of new wet loose slides on Tuesday. They also let us know that water is working its way deeper into the snowpack. 

The deeper percolation could lead to wet slab activity in the days to come. We have two layers at the base of last week's storm snow: the 3/12 interface and the 3/8 crust. They were several feet deep when the storm began, but we've already lost a significant amount of snow depth in the last two days of rain. 

With Tuesday night into Wednesday morning expected to be the biggest shot of rain for the duration of this week-long event, it's not a stretch to think that those deeper, scarier slides could start to be a problem. They're nearly impossible to predict with accuracy and are isolated by nature, but if you happen to be around when one occurs, it will likely have devastating consequences. As a precautionary measure, you may want to consider avoiding all avalanche terrain - anywhere an avalanche can start, run, or stop.

Régions couvertes