Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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In sintesi

You can still trigger avalanches on recently wind affected slopes steeper than 35 degrees. We still have uncertainty about the potential for deeper and more powerful avalanches following a week-long storm cycle in parts of the zone. Give the snowpack more time to settle and avoid consequential terrain capable of producing larger avalanches for another day. 

Problemi valanghivi

  • Wind Slabs

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

    Wind slab avalanches are possible on Wednesday. Numerous natural and human triggered avalanches occurred in the last week in neighboring zones. Most recent avalanches occurred on interfaces in the recent snow, 1-2 feet down and predominantly on wind loaded features.  

    On Wednesday ease into terrain slowly. Expect most wind slabs to be in shallow pockets of Monday night's redistributed snow.  If you see recent avalanches or experience shooting cracks and collapses, seek out supported and lower-angled slopes. Use small slope tests and hand pits to observe the recent snow and determine which layers are most sensitive to triggers. Steer around slopes below cornices and use extra caution near steep wind loaded terrain.

    A recent slab avalanche

  • Loose Wet

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

    Wet loose avalanches are possible on south facing terrain Wednesday as afternoon freezing levels rise to 6500ft and higher.  Avalanches will mostly occur within the fresh snow that fell on Monday evening.  As snow surfaces moisten on sunny slopes make plans to shift around the compass to shady aspects. Alternatively if plans keep you on sunny aspects start early and get off steep slopes by the time they moisten midday. Rollerballs and pinwheels are the first indicators of surface layers losing strength, and start retreating when you see them coming down.

    Rollerballs are good indicators that loose wet avalanches may follow Photo: Pete Durr

Avalanche Discussion

In nearby zones (Stevens Pass, East North/Central) weak persistent grains formed and were buried over a week ago. Some uncertainty exists surrounding this potential layer in the West Central. If you dig a snow profile, look for weak snow above the prominent 12/09 crust buried 3-4ft deep. If you travel at mid and upper elevations where this layer may still exist, consider limiting your exposure to large avalanche terrain until we know more.

The storm ended Monday night, with 7+ inches of water in the last week amounting to at least 3 feet of snow on top of the 12/9 crust. This much change requires time for the snowpack to settle and stabilize. We’ve seen a lot of avalanches in the last week. There are very few observations in the alpine due to the intense weather, limiting our knowledge of recent avalanches. If you do get out, let us know what the snow and avalanche conditions were like by submitting an observation.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte