Bollettino valanghe

Olympics

Northwest Avalanche Center
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Limite del bosco
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Sotto il limite
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In sintesi

Cold temperatures and plenty of low density snow to blow around will keep you on your toes near and above treeline.  Assume you can still trigger a slab avalanche on steep open slopes where you find recently drifted snow.  At lower elevations, take care on very steep slopes where a fast-running sluff could knock you into trees, rocks or other terrain traps.  

Problemi valanghivi

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–1.5

    Due to cold temperatures and additional light snow, you're likely to trigger or see natural loose dry avalanches in very steep and non-wind affected terrain.  Take stock of the terrain where you could trigger a fast running loose dry avalanche or sluff, and avoid slopes where you could be pushed into a terrain trap like trees or over a cliff band.  

     

    (1/28/2021) Small Loose Dry Avalanches can run fast and catch you off guard on steep slopes. Photo: Sam Luthy

  • Wind Slabs

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

    Human triggered slab avalanches were reported in the Hurricane Ridge area just below ridgelines on different aspects Thursday (E-SE) and Friday (N-NE) as shifting winds redistributed the recent snow. The wind slab problem will be slow to heal over the next few days with very cold temperatures expected.

    Travel cautiously along ridgelines, looking for wind-textured snow surfaces, and identifying areas where deeper drifts have formed.  Steer around steep open slopes below ridgelines where you can still trigger a wind slab avalanche.  If you observe shooting cracks or feel hollow or punchy snow, choose simpler terrain.  Fresh cornices have formed so give them a wide berth while traveling along ridgelines. 

    (12/24/2021)

    Human triggered slab avalanche on Sunrise Face, just outside of the Hurricane Ridge ski area.  N/NE aspect. 

    Photo: NPS

Avalanche Discussion

The recent storm cycle came to an end on Friday, dropping about over 2' of fresh snow this week with a cooling trend. Soft wind slab avalanches were reported both Thursday and Friday in the Hurricane Ridge area.  On Thursday, NPS and NWAC observers found sensitive wind slabs up to 16" deep that were easy to trigger below ridgelines.  Small loose dry avalanches, or sluffs, released in steep terrain along the Hurricane ridge road as the snow continued to pile up.  The Dec 21 (solstice crust) can be found about 2' down, with a thicker melt-freeze crust from Dec 19 several inches below it.  Observers identified weak snow grains (facets) below the 12/21 crust.  While snow pit tests did not indicate avalanches are likely to propagate on this layer,  remember we have a limited sample size for a large backcountry.  Observe, test, and consider your terrain choice before jumping onto big open slopes over the holiday weekend.  And please share your observations with us and your backcountry community, we love concise observations along with photos. 

Merry Christmas and Happy Holidays from the NWAC team and stay warm over the next week! 

2021-22 Forecast Schedule: Avalanche danger ratings will be issued for the Olympics every Friday through Sunday and during mid-week holidays. During the week when the Hurricane Ridge road is closed, forecast information will be updated daily to include expected conditions and relevant travel advice under the No Rating label.

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