Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

Rain and snow will fall on a wet snowpack, creating complex and dangerous avalanche conditions. While the most obvious avalanches will be small and will involve wet or new snow, be on the lookout for cornice falls and glide avalanches, which could be big enough to injure or kill you. Give yourself options to travel on lower-angle slopes, and don't linger below cornices and snow-covered rock slabs. 

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    Cornice fall and glide avalanches will be isolated, but they could be very dangerous. They're often big enough to kill a person on their own, and they frequently trigger larger slides on the slopes below.  Minimize your exposure under large, overhung cornices, cliffs holding cornice-like chunks of snow, or other unstable snow features. Ideally, pick a route that avoids crossing under these features. If you must, travel quickly under them, and only stop in locations free of overhead hazards. If you're heading into upper-elevation alpine terrain, use extra caution around craggy features and corniced ridges.

    Smaller wet loose avalanches will be likely at most elevations. If you see recent avalanches, rollerballs, or wet, weak snow that slides easily, move to more frozen or lower-angle slopes. Rain and wet snow falling on an already weak, wet snowpack will increase the avalanche danger.

    (4/6/2025)

    A large, cornice-like chunk of snow fell in closed terrain on the evening of April 5th. Cowboy Mtn, NE, 5,700ft

    Photo: Stevens Pass Patrol

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    You can trigger avalanches in the new and recently fallen snow. This could take the form of typical storm slabs, thicker wind slabs on upper elevations leeward slopes, or even wet avalanches where the snow is moist. Use small test slopes to see how easily the snow slides before committing to larger slopes steeper than 35 degrees. Be ready for changing surface conditions as you move through the terrain and climb in elevation. 

    Up to 7 inches of snow could fall at upper elevations by Monday afternoon. This will land on 4-5 inches of recent snow. At many locations, this storm will be a mix of rain and moist snow. Precipitation started as rain on Sunday. Snow levels will drop into low elevations by Monday. The wind will form deeper drifts at upper elevations. 

    (4/5/2025) Loose wet slides that ran in recent snow on April 5 around 6500ft. This was just to the northeast, near Trinity, in the neighboring East Central zone.

Avalanche Discussion

Stevens Pass Patrol reported natural avalanche activity on Saturday night and Sunday. A large cornice fell and a couple small wet loose avalanches ran naturally on Cowboy Mountain, roughly NE, 5,700ft. On Friday, an NWAC forecaster traveled on sun-exposed slopes in the Skyline Lake area. Steep, southeast slopes below 5,000ft softened by mid-morning and were weak enough to trigger rollerballs by 12p. Some isolated areas near rocks were beginning to get unsupportive for boots. 

There's plenty of older avalanche debris from the late-March (23rd-24th) atmospheric river rain event and subsequent warm-up.  As much as 8" of snow accumulated over the rain crust that eventually froze over the past week. On shaded and upper elevation slopes, you may still find this recent snow. It could be reactive as it warms for the first time.

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