Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Relentless east winds will continue to drift snow into deeper drifts. If you see shooting cracks or textured surfaces, you've likely found wind-loaded terrain and should change course. Slabs could exist on features or aspects where you're not used to finding them.

Problemi valanghivi

  • Wind Slabs

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

    Our multi-day east wind event will peak on Friday night. These cold and strong winds have transported snow and created irregular loading patterns since Wednesday. Look for wind slabs on leeward slopes, convex features, or near rocky terrain. They're likely on different aspects than you’re used to. They could also be further down in the terrain due to cross-loading. You can use small test slopes or uptrack tests to determine how sensitive they are to your weight as a traveler. Look for actively blowing snow, new cornices, textured surfaces, or fresh drifts to help identify wind-loaded features to avoid.

    (2/16/2024)

    An unintentionally skier-triggered wind slab in a confined rocky chute. Note the textured surface up against the rock wall.

Avalanche Discussion

Wednesday night's storm dropped roughly 3-6 inches of low-density snow at the Pass proper, creating the 1/14 interface. Since then, east winds have been ripping through Snoqualmie Pass and accelerating into the western foothills. Alpental Pro Patrol, avalanche professionals, and backcountry travelers have all reported significant wind transport in recent days. This has created irregular and atypical loading patterns in the terrain. Some areas have been scoured down to a hard crust, while others contain drifts, textured surfaces, or hard wind-effected snow.  We'll hit the peak of this prolonged east wind event on Friday night. Multiple skier-triggered wind slabs were reported in rocky chutes on Friday. 

Snow depths over the Early February Crust (EFC) will vary based on aspect, elevation, and exposure to wind. Expect to find more snow over the EFC on wind-protected shaded aspects. On slopes that often receive direct sunshine, you'll find a series of crusts possibly interspersed with weak grains. The 1/14 interface may contain buried surface hoar in wind-sheltered areas. NWAC forecasters found facets sitting above the EFC earlier this week. Investigate all the snow above the EFC for potential failures before committing to a slope. Where they exist, those weak grains could cause avalanches to break widely or in surprising ways.

The new snow helped to mask some of our low-elevation travel hazards, but open holes/creeks, exposed rocks/bushes, and frozen avalanche debris still exist. You may see wind effect in this elevation band, but likely not avalanches large enough to be consequential. 

Regioni coperte