Bulletin d’avalanche

East Slopes South

Northwest Avalanche Center
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Danger d’avalanche

Mon
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

Warming temperatures will increase the danger on Sunday and will add some uncertainty. Let the upper snowpack guide you: If you find evidence of surface crusts breaking down or wet or sticky snow in wind-sheltered areas, plan to stick to simple or lower-angle terrain.

Problèmes avalancheux

  • Loose Wet

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

    With Sunday's warm-up, we're uncertain how prevalent the avalanches will be. Wet loose avalanches may be isolated at elevations and aspects where the snow surfaces don't warm sufficiently. You can easily manage this uncertainty by looking for signs of instability; Watch for fresh avalanches, rollerballs and moist snow surfaces that slide easily. Direct sunshine on steep SW-S-SE aspects should be your primary concern.

    The breakdown of crusts, rollerballs, or 6" or more of slushy snow are all good indicators that conditions are changing rapidly and to move away from steep slopes. 

    (11/29/2024)

    Small rollerballs releasing from steep rocky terrain.  These may be harbingers of wet loose activity.

    Photo: Dallas Glass

Avalanche Discussion

The warm temperatures and sunshine are starting to increase the potential for cornice fall as a potential trigger of old stubborn wind slabs on shaded aspects or wet loose activity on the slopes below. Give cornices healthy space on ridgelines or the slopes below. A wet loose or cornice-triggered slab avalanche on nearby Mt Rainier illustrates what can happen when the snowpack starts to heat up, unevenly.  A small skier-triggered wind slab on Thursday in the nearby East Central zone highlights the kind of isolated wind slab issues that keep that problem in the forecast. 

The weather relented in the East South nearly a week ago, giving time for consolidation on sun-exposed and weakening of snow surfaces on shaded aspects. How the late November solar radiation + warming react with cold snow surfaces and thin crusts is difficult to predict. Your powers of observations are your best tool to staying safe. If you see something unusual, adjust your travel plans to seek simpler terrain.

It's early season still, and we don’t have a lot of information about the snowpack across the zone. A few excellent observations from the East South emphasize the generally thin and variable early-season snow depths. The last major storm hit the Bumping Lake and Nelson Range areas pretty hard. In these locations, you might find more snow than in the Tieton and Ahtanum Meadows regions. If nearby zones are any clue, the surface snow remains soft and loose on shaded slopes, with friable crusts formed on sun-affected slopes.

Regardless of elevation, numerous obstacles still exist. Rocks, logs, bushes, and creeks all make travel a bit more challenging. Give yourself some extra time to navigate all these potential hazards. This shallow coverage is likely to limit avalanche hazard at lower elevations, but remember that if there's enough snow to ride, there's enough snow to slide.

Régions couvertes