Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Avalanches are likely as snowfall continues over the next few days.  Expect snow to shed on steep slopes, especially where wind drifts the snow into deeper deposits. Travel on slopes less than 35 degrees as the snowpack adjusts to the added load of new snow.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    You can trigger large avalanches within new snow above the December 9 crust.  There is a weakness between these most recent two  snow layers from around December 12, about 6 inches above the crust. The snow has not bonded well at this interface, and surface hoar from Saturday may have survived the recent sunshine and wind in that same location. It could be buried in isolated areas under the new snow on treeless slopes  at mid elevations on east, north and west aspects. It is unclear at this time how widespread the surface hoar may be, so stay off suspect slopes. 

    Expect more slab development at higher elevations, as the wind will play a role in redistributing the new snow into thicker more reactive deposits on leeward slopes.  As you travel observe wind shifting the snow across slopes. Feel for changes underfoot as the snow transitions from light and fluffy to firmer and breaking with cracks around you.  With snowfall continuing throughout the day Wednesday, stick to slopes less than 35 degrees.

    Slab avalanches are likely on steep slopes.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Small loose dry avalanches, or sluffs, will occur during this period of snowfall.  You’ll see them on slopes steeper than 35 degrees where loose low density snow is on the surface. They should be confined to about the top 6 inches of snow.  Some will fail naturally, but they will likely be triggered by you or a partner if you are on a steep slope.  

    Loose dry avalanches commonly run from steep areas in new snow layers.

Avalanche Discussion

Snowfall will continue through Wednesday, so the avalanche danger will increase throughout the day. Wet loose avalanches may occur below treeline or where you find moist snow surfaces up to 4000ft. Be aware that even small avalanches could be a problem if they push you into trees, rocks or gullies.

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.

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