Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

While isolated pockets of unstable wind-drifted snow may still exist, a warmer and sunnier day on Wednesday means wet avalanches will be the more likely problem. Avoid lingering beneath steep rocks that may shed snow from above, and move to shady slopes if the snow feels wet and heavy.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    We've slowly turned the thermostat up over the past few days, along with decreasing cloud cover. Wednesday might be the warmest and sunniest day yet, so wet avalanches on steep terrain in the sun will be increasingly likely as the afternoon progresses. Variable surfaces, including crusts and stiff wind-affected snow, will likely limit the size of these avalanches. However, steep rocks or cliffs could shed heavy chunks of snow from above, so don't pause below these overhead hazards for long. If you begin to see rollerballs, trees, and rocks shedding snow, or the snow becomes sticky and wet, consider moving to shady slopes or dialing down your slope angles. 

    (12/28/2023)

    Rollerballs are a good indicator of the increasing likelihood of wet loose avalanches.

    Photo: Matt Primomo

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Wind slabs are becoming more difficult to trigger this far out from the storm. However, in isolated areas, there is still a chance of getting surprised by triggering a wind slab that rests over weak snow. The most likely place to get caught in a wind slab is at upper elevations, in very steep unsupported terrain, or confined rocky chutes. This is also the same terrain where a small avalanche could have high consequences, so consider this potential before stepping out into more complex, aggressive terrain. 

    (1/13/2025)

    Stability test results produced unstable results on weak snow below a stiff 1ft thick wind slab on Monday, Jan 13th.

    Photo: Julz Holder - Grounding Truth

Avalanche Discussion

Wednesday will be slightly warmer and likely much sunnier than Tuesday. However, the snowpack has already had a few warm days with broken sunshine, which formed thin melt-freeze crusts on the surface. These crusts must break down before wet avalanches are possible, so expect this problem to increase throughout the day. Lower elevations will be slower to warm up, as the inversion may also take some time to mix out. 

On Monday, an NWAC forecaster reported weakening snow surfaces that produced dry, loose avalanches in steep terrain. This problem could become more widespread with chilly, clear nights and sunny days. Be aware of your partner, and avoid sluffing them out on steep slopes. 

NWAC Forecasters traveled to Icicle Creek and Salmon La Sac over the weekend to investigate the presence of wind slabs and recent weak interfaces of surface hoar and faceted snow. We both found signs of wind loading at all elevations, but signs of instability didn't appear until above 5000ft. The overlaying slabs were small but wanted to slide on slick crusts or weak, faceted snow. Observations indicate that wind slabs are becoming less reactive and likely fairly isolated to very steep, confined alpine features.

At lower elevations, crusts and refrozen chunder any avalanche concerns. Instead, the challenging travel is a hazard in itself. In sheltered terrain we found isolated surface hoar and more widespread faceted grains on 1/10 interface, while this is a layer to track moving forward, there currently isn't enough cohesive snow over this layer for avalanche concerns. 

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