Avalanche forecast

Olympics

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Low-density continues to pile up without fully allowing wind-stiffened snow layers time to heal.  Additional snowfall and northeast winds will easily transport low-density snow, creating fresh slabs on atypical aspects.  At lower elevations, make a plan before entering slopes approaching 40 degrees where a fast-running sluff could knock you into trees, rocks or other terrain traps.  

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    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. NE winds will also build shallow slabs on more southerly and westerly aspects which may sit on previously wind-scoured crusts or old snow interfaces. 

    Given the complexity of the wind loading patterns, both sides of a ridge may harbor wind slabs. If you're unsure which slopes may have wind deposits where you can trigger an avalanche, you can travel safely along ridgelines or retreat to below treeline terrain. But take care to 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

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    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.  Anticipate terrain features approaching 40 degrees 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

Avalanche Discussion

A 5-day storm cycle at Hurricane Ridge has delivered over 2' of fresh snow this week with a cooling trend. Temperatures ended the day around 14F at Hurricane Ridge on Christmas Day with light low-density continuing to pile up and 56" of snow on the ground. Even light winds may have been enough to drift fresh slabs given the low density of the snow. With additional snow piling up and the potential for heavier Fraser River upslope snowfall in some areas and down to the lowlands, there is some uncertainty in the forecast. Heavier than anticipated snowfall could create a storm slab in areas where 8" or more of fresh snow falls within 24 hours. However, in most areas we expect that wind transport and wind-stiffened snow will be the key ingredient for slab avalanches.

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 just over 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. 

Some of the coldest temperatures of the year continue to spill into the region. Wind chills will be below zero in exposed terrain. Make sure you are prepared for the conditions and think through the consequences of any accident leading to extended exposure in backcountry terrain.

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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