Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

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

Skies should start to clear Monday after a mostly snowy and windy weekend at Snoqualmie Pass. If you’re heading to the mountains, be on the lookout for unstable piles of wind-drifted snow where you have a higher chance of triggering an avalanche. Closer to the trailhead, you could encounter difficult travel conditions with plenty of early-season hazards to avoid.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    The most likely location for you to trigger an avalanche on Monday will be in wind-loaded terrain at mid to upper elevations. Some of these slabs may be hidden under a few inches of fresh snow from Sunday night, making it harder for you to identify them. Feel for changes in the snow as you travel with your snowmobile, feet, or poles. If you encounter stiffer snow, you could be in wind-loaded terrain. If they’re on the surface, visual clues like small drifts behind objects or textured snow surfaces can key you into wind-loaded areas to avoid. Take extra care when traveling near ridgelines or rocky features such as confined chutes or the base of cliffs. These are terrain features where Wind Slabs often develop.

    (11/27/2022)

    Actively blowing snow, textured surfaces, and fresh drifts behind natural objects are all signs there could be fresh Wind Slabs near by. [Example from 11/27 in the neighboring West South zone]

    Photo: Andy Harrington

Avalanche Discussion

Sunday’s storm delivered over an inch of water to much of the Snoqualmie Pass zone. As is often the case, the amount of new snowfall varied due to fluctuating freezing levels. At the lowest elevations, much of the precipitation was rain before temperatures cooled and dropped a couple of inches of snow. At upper elevations, however, cold temperatures accompanied by moderate to strong winds resulted in about a foot of new snow. This helped to further the divide of snow depths between lower and upper elevations. 

Sunday night, we expect to squeeze out a bit more snow at all elevations as chilly temperatures take hold on the zone. Despite this, you may find that there is marginal white stuff when you step out of your car at the trailhead, resulting in minimal avalanche hazard. As you ascend in elevation, a more wintery world will greet you with a colder and more layered wintertime snowpack. Since it is early season and access to these upper elevations is difficult, information is still sparse. Be sure to take the time to look in the snow for potential instabilities before committing to terrain. 

Regardless of your elevation and the cold stormy weather, we are still building our snowpack and early-season hazards exist. Many natural obstacles such as open creeks, stumps, rocks, or bushes are currently on or near the surface. There’s a long season ahead, so try to temper your excitement and travel cautiously.

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