Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Most slopes hold plenty of soft unconsolidated snow where you may only trigger a small loose sluff. However, in more wind-prone locations, the wind might turn that soft snow into a slightly firmer slab. Blowing snow and small cornices can help you identify which areas you want to avoid.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Observations from the past several days at Crystal Mt, Paradise, and White Pass typically say the same thing, “lots of soft powder.” While many slopes may not hold a significant slab avalanche hazard, the wind can drift snow into slightly firmer layers on exposed features. You might find wind slabs in obvious places like along ridgelines. But, you could also trigger them in confined chutes, on convex rollovers, or along the base of cliffs. Look for clues like blowing snow, textured surfaces, and small drifts to point out which features you want to steer around. 

    The winds in the mountains continue to shift directions. As a result, you might run into wind slabs in areas you don’t normally suspect. This doesn’t seem to be a widespread issue, however, continued snowfall, ample soft snow, and moderate winds keep this problem on our minds.

    (12/13/2021)

    Sharp cornices and smooth snow pillows indicate wind loading on this slope. East Peak, Crystal backcountry. 

    Photo: Robin Pendry

Avalanche Discussion

It’s been a snowy week and another storm should hit the West South zone Wednesday. As the snowfall intensifies and accumulations grow, expect the avalanche danger to slowly rise. Locations near Mt St Helens and Mt Adams could even see more dangerous avalanche hazard by late in the afternoon. 

With all the recent snow, the mountains seemingly transformed overnight into winter. This quick change along with a variable early season snowpack continues to cause us more questions than answers. Storms over the past week resulted in a few avalanches reported in the West South zone, including a fatal accident (see below). The last observed avalanches were reported on Sunday 12/12. As the storm cycle and avalanche activity has slowed, observations continue to find a generally right-side-up snowpack comprised mostly of storm snow layers. One older layer we have our eye on is a thin crust (12/8) about 4-6” above the icy block at the bottom of the snow (Late November crust). Inconsistent test results and a variable distribution around the zone, make this layer hard to nail down. So far, we have not confirmed any avalanches failed at this interface.

With all the recent snow, access into the mountains increased dramatically. Before you step out into larger and less forgiving terrain, consider using small low consequence slopes to gather information and confirm the forecast. Even though it suddenly feels like winter, it’s still early season, and we have limited information about the snowpack across this very large zone. 

Preliminary Report: On Saturday morning, December 11, a party of six backcountry tourers were traveling uphill in a closed section of the Crystal Mountain Ski Area known as Silver Basin. The party triggered a large avalanche on an NE to E facing slope at approximately 6600’. While all members of the party were initially caught, four were fully buried. A nearby party of two witnessed the event and immediately assisted in the rescue. Crystal Mountain Ski Patrol was also notified and responded to the scene. Unfortunately, one of the fully buried victims did not survive. NWAC and Crystal Mountain Ski Patrol will collaborate to conduct an investigation. Our deepest condolences to the family, friends, and community. 

SS-ASu-R3-D2.5-U; Crown Depth: estimated 2’ deep.

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