Bulletin d’avalanche

Snoqualmie Pass

Northwest Avalanche Center
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Danger d’avalanche

Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Happy holidays from the NWAC Team!

Ongoing light snow and moderate wind are forming slabs on exposed slopes near and below ridgelines, where triggering a slab avalanche is possible. Keep an eye out for blowing snow, uneven surfaces, and chalky wind drifts, and consider steering clear of steep terrain where these signs are present. With a major storm arriving Wednesday night, be mindful of shifting conditions and aim to wrap up your day and reach the trailhead well before dark.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Any potential wind slab avalanches will likely result from Wednesday’s new snowfall. While limited snow totals and light to moderate winds suggest these avalanches should be isolated and small, they could carry consequences if they sweep you into a terrain trap. Prime locations to look for wind slabs are below ridgelines, cliffs, and in steep gullies.

    If visibility is good, you may be able to observe these slabs developing in real time. Wind slabs are most prone to triggering during and shortly after they form, so pay attention to exposed ridgelines, and if you see blowing snow, steer clear of steep, lee-facing slopes that are actively loading.

    Soft slabs formed by lighter wind may just feel like powder under your feet/sled, making them harder to identify. While shooting cracks are clear signs of instability, you may not experience any cracking on Wednesday. Small test slopes and hand pits can help you assess reactivity, but the safest approach is to avoid wind-loaded areas entirely if you see signs of active snow transport. In zones with heavier snowfall or stronger winds, anticipate more sensitive slabs and a heightened avalanche risk.

    (12/26/2023)

    Actively blowing snow and fresh crowns from wind slabs.

    Photo: Andy Harrington

Avalanche Discussion

Tuesday’s new snow earned the monikers of cream cheese, peanut butter, thick, and schmoo. Higher elevations received about 5” of accumulation, while lower and mid-elevations saw just 1-2”. This limited dense snow, combined with warm temperatures, likely minimized new slab formation and helped stabilize older wind slabs. Summit at Snoqualmie Pro Patrol observed no signs of instability and well-bonded snow to the crusts below.

Wednesday will see light to moderate precipitation and increasing winds ahead of a powerful winter storm set to impact the Cascades. Feet of snow are expected by the end of the week and avalanche danger will spike on Wednesday night as the snow starts to stack up. While the brunt of the storm will arrive after dark, travel and avalanche conditions could worsen as early as Wednesday afternoon. Stay flexible with your plans, aim to be near your exit well before dark, and adjust if heavy snowfall begins earlier than anticipated.

Travel below 4000’ remains a slog. Plan for extra time to navigate these challenges safely.

If you’re heading out on Wednesday, we’d love to hear from you—send us an observation! 

Régions couvertes