Bulletin d’avalanche

Snoqualmie Pass

Northwest Avalanche Center
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Danger d’avalanche

Wed
Alpin
2 · Modéré
Limite forestière
1 · Faible
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

It's looking like a messy weather day at Snoqualmie Pass on Tuesday. Snow, rain, freezing rain, and gusty winds are all on the table. Any avalanche activity should be confined to wind-exposed or rain-soaked slopes.

Problèmes avalancheux

  • Wind Slabs

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

    You might find fresh snow drifting into shallow slabs above the rain/snow line. Look for actively blowing snow or pillow-like drifts to identify wind-loaded features to avoid. These slabs should be small but could be sensitive and break easily on top of the firm crust we have developed in recent days. Convex slopes, rocky features such as cliffs and chutes, or leeward ridgelines are the most likely locations to find these unstable pockets.

    (2/7/2023)

    Example: A shallow wind slab that formed at the base of rocks near ridgeline.

    Photo: Alpental Pro Patrol

Avalanche Discussion

After several days of unseasonably warm temperatures, winter is trying to make a comeback at Snoqualmie Pass. This isn’t much of a storm, but it should provide a quick shot of precipitation, resulting in a few inches of snow at upper elevations. At middle and lower elevations, expect periods of snow, freezing rain, and eventually all rain. By day’s end, rain could creep up toward ridgelines as the storm finishes warm.

After a few atmospheric rivers followed by warm temperatures to start the season, the snowpack should be well suited to handle additional liquid input. That said, you could see some rollerballs, small pushalanches, or, in isolated locations, a rogue shedding avalanche. Be leery of traveling under blocks of snow clinging to rocky ledges during periods of rain. They could release without warning.

Any new snow is expected to bond fairly well to the wet and warm surface, creating a new interface. Avalanche activity below this layer should be minimal to non-existent unless there is enough rain to break down the crust and get to drier snow below. 

Unfortunately, this storm will likely only exasperate our early-season coverage and travel hazards. Gushing creeks, exposed boulders and logs, holes, and variable surfaces have littered the landscape and provided challenges over the past week for backcountry travelers.

Régions couvertes