Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Warm temperatures and sunny skies make wet loose avalanches likely on Thursday. Switch to a shady or lower-angle slope if you see fresh avalanches, rollerballs, pinwheels, or sink in past your boot tops into wet or moist snow. Avalanches will be most likely on steep sunlit slopes, but at the lower elevations they could also occur in the shade.  

Problemi valanghivi

  • Loose Wet

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

    Wet loose avalanches will be sensitive to human triggers on Thursday and will likely release naturally. On slopes that saw sun on Wednesday, a surface crust will need to break down before this problem develops. However, some east-facing slopes and many west-facing slopes may not have a crust at all, allowing wet loose avalanches to initiate quickly once the sun hits. While most avalanches should remain small, an isolated large wet loose slide is possible, especially on slopes that lacked a crust and in the low-elevations. Stay aware of what’s above you, as snow may shed off rocky faces before the surface you’re on shows signs of moistening. Additionally, wet loose avalanches could trigger deeper slab avalanches.

    Below the recent storm snow, much of the upper snowpack is still sopping wet. Continued warming will add more meltwater to an already saturated snowpack, keeping glide and wet slab avalanches on the radar, even if they remain unlikely. Avoid lingering below glide cracks, and think twice before committing to a steep, sunlit slope if you see signs of wet snow on the surface.

    Finally, cornices are large and could fail during this warming trend. Stand far back and ensure you are on solid ground.

    (2/26/2025)

    A wet loose avalanche at the low elevations in the Alpental Valley on Wednesday. The deepest and largest wet loose slides were observed down low where very little new snow rests on a soaking wet upper snowpack. 

    Photo: Josh Lipkowitz

  • Wind Slabs

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

    You may be able to trigger a wind slab in steep and complex terrain, especially where slopes are confined and/or unsupported. Think rocky faces, tops of couloirs and chutes, on a rollover, and below cliff bands. Identify wind slabs by looking for textured surfaces, dunes, or pillow-like deposits. It's hard to safely assess representative snow from an adjacent slope when you are considering a piece of complex terrain, so consider the consequences before committing. Lingering slabs could be hard, many feet deep, and may let you well out onto the slope before breaking above you. Heed them if you see them, but don’t expect to find obvious signs of instability like shooting cracks. Better riding and safer conditions can be found on non-wind loaded slopes.

    (1/1/2025)

    A wind slab avalanche triggered earlier in the season in confined terrain. Ligering slab instabilities will likely migrate into more extreme confined and unsupported terrain on Thursday.

     Photo: Ryan Stoddard

Avalanche Discussion

NWAC forecasters found minimal signs of fresh avalanche activity from the storm that subsided Tuesday night. They observed variable cloud cover, which will leave variable surface conditions for Thursday. Lower elevations had a few inches of snow over a breakable crust, but above about 4500ft there was 14-16” of dry and very dense storm which skied quite nicely on shaded slopes. No obvious signs of dry slab instability were observed. Wet loose activity was isolated and was most significant in size and distribution at the lower elevations, where far less new snow rests atop a very saturated snowpack, allowing avalanches to gouge deep and gain more mass. Crusts are forming in the wet snow, but they will take some time to harden and freeze.

Expect a bump in the warming on Thursday with little help from the breeze except at the highest elevations. Use your senses and give a wide berth when things start to get wet. 

Regioni coperte