Boletín de aludes

West Slopes South

Northwest Avalanche Center
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Peligro de aludes

Tue
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó 5 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

A fresh shot of wind and additional light snow will keep the stakes raised at upper elevations Monday.  Continue to avoid big open slopes capable of producing large avalanches, sticking to lower angle and less wind affected terrain. 

Preliminary Report: On Saturday morning, December 11th, an avalanche fatality occurred in the Silver Basin area of Crystal Mountain Ski Resort. See the forecast discussion below for additional details.

Problemas de aludes

  • Storm Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    New snow and wind continue to drive the hazard in the West South.  Shifting winds will easily transport recent low density snow overnight through Monday.  Recent storm instabilities from this weekend are healing with time but cold temperatures and suspect layers in the upper snowpack mean you need to tread carefully as you climb into more exposed and consequential terrain. Slab avalanches are more likely to break near the surface, but there's a crust/weak snow interface (Dec 8th) that may have been the culprit from Saturday's fatal avalanche in the Crystal area that's now several feet down.  Poor visibility, stormy conditions, and a building snowpack have limited direct observations this weekend.  We have more uncertainty than usual coming out of this storm cycle, so take a cautious approach when planning your day.   

     

    (12/11/2021)

    Multiple avalanches were observed in the Crystal Mountain backcountry on 12/11. These slides occurred on multiple aspects and are a red-flag sign of instability.

Avalanche Discussion

On Sunday, snow continued to pile up slowly but consistently in the form of showers. The few observations that did trickle in detailed the new snow that was less cohesive and reactive to ski tests or from avalanche mitigation than earlier in the storm.  In neighboring zones with a similar story,  shallow storm slabs (less than 1 ft) were more widespread and easy to trigger.  All areas in the West South zone have received notable precipitation since 12/8 as a significant storm cycle dropped 3-4+ feet of new snow as we more than doubled the depth of our early season snowpack. The tragic incident near Crystal Mountain helps illustrate that although it is early season and snow depths are still building, many slopes have now reached the threshold where they can kill you.  Take the time to investigate the snowpack and let us know what you see out there by submitting an observation.  You'll find the stout Late November Crust several feet down in all areas now (see photos).  While all this snow is welcome for base building, you'll still find some early-season travel hazards below treeline in some areas.  Use care around open creeks and recently buried rocks and stumps. 

Preliminary Accident 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 N to E facing slope at approximately 6500’. While all members of the party were initially caught, four were partially or 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.

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