Bollettino valanghe

Olympics

Northwest Avalanche Center
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In sintesi

A significant storm buffeted the Olympics, creating wind slabs that are most likely to be large and reactive at upper elevations. Identify and avoid steep slopes where you find fresh, sharp cornices or cracking of the snow surfaces. Travel safely along ridgelines, on wind-scoured slopes, or anywhere you find less than 6" of snow above the most recent crust.

Problemi valanghivi

  • Wind Slabs

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    • Limite del bosco
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    Probabilità
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    Dimensione
    1–2

    Strong winds transported significant snowfall at elevations above the highest rain/snow line on Saturday. Use your pole to keep tabs on a thin, refreezing rain crust. At lower elevations, wind-blown deposits greater than 6" deep atop the crust layer, may produce small avalanches in cross-loaded gullies or in deposits below ridgelines.   However, conditions become more dangerous once you no longer feel this crust. At this point, dial back your terrain selection and avoid all potentially wind-loaded slopes steeper than 35 degrees. Cracking beneath your feet, firm or punchy snow layers, or recent fresh cornices all point toward danger on the slopes nearby. 

    Example: Cracking beneath your feet.

    Photo: Katie Warren

Avalanche Discussion

A powerful storm brought 5" of snow before snow levels rose to at least 5200 ft Saturday morning during a period of horizontal light rain, and then descended to 3300 ft by 2:30 PM as additional snow accumulated. This should produce a melt-freeze crust in many locations with snow and mostly shallow wind slabs on top. We don't know whether the rain extended to ridgecrest or whether all surfaces have been wetted. 

On Thursday, NWAC Observer Sam Luthy and NPS staff found wind rolls,  new cornices, and stripped windward surfaces all along ridgelines.   Directly below lee ridgelines, 6-8" of denser wind-affected snow could be found.  No new avalanches were observed in the Maggie's area. 

Total snow depth above 4500 ft in sheltered areas remains relatively unchanged around 3' (1m).  The landscape has filled in nicely at mid and upper elevations, but we aren't close to mid-winter depths. Keep an eye out for sharks lurking not too far below the snow surface at lower elevations (rocks, logs, etc).  Observers are tracking a weak snow (facet) crust combination about 3' down on northerly aspects near treeline in the Hurricane Ridge area.  No known avalanches have been reported on this layer, but it's worth keeping an eye on as we give the snowpack time to adjust after a significant winter storm.  At the bottom of the snowpack, you can find a thick crust from late November. 

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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