Bollettino valanghe

Olympics

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Early season conditions returned following a major rain event this week. A weak system will build shallow slabs that could take you for a ride in the lee of ridgelines. Steer around wind-loaded start zones where you find lens-shaped snow deposits or evidence of recent wind loading.

Problemi valanghivi

  • Wind Slabs

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

    Cooler temperatures and fresh snowfall will enable a round of moderate winds early Thursday to form fresh slabs that you can trigger near and above treeline. These slabs should be proximal to wind-exposed ridgelines and alpine terrain. In these areas, you can trigger a small slab on slopes 35 degrees or steeper. These will be more likely to harm you above a ravine-like terrain trap. Keep in mind that any avalanche has an added risk of trauma associated with a return to low snow / early-season conditions following the Christmas rain event.

    (12/17/2020) These wind slabs formed Wednesday and fresh wind slabs will form anew on Friday. Photo: Sam Luthy

Avalanche Discussion

We're expecting you'll find 2-5" of dry snow that has fallen since Tuesday, sitting above a refreezing rain crust. A big reset of the snowpack occurred when 4.50" of precipitation fell from 12/24 through 12/27. Unfortunately, almost all of that water fell as rain, with breezy south winds eating back the snowpack.  The cold and layered snowpack is gone (or mostly gone, see pit photo below).  Professionals found evidence of several glide avalanches that occurred earlier in the storm cycle.

Several excellent public observations add to document documentation from Hurricane Ridge depicting the return to early season conditions on the typically drier eastern and northern sides of the Olympics. Snow bridges have collapsed and creeks have opened, and you might find holes where you don't expect, making travel significantly more difficult. If you find areas of unconsolidated snow, reduce your exposure to the problem. More wind-exposed ridgelines have also melted out and plenty of early-season hazards have returned to the region. We'll need significantly more snow before travel drastically improves. 

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