Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Friday should be a transition day, both in terms of weather and avalanches.  A bit more sunshine and warming should lead to an increased chance of wet loose avalanches, especially on very steep sunny slopes or anywhere you find wet punchy snow.  Slab avalanches are still possible, especially on very steep unsupported slopes or where winds have drifted snow onto steep lee slopes at higher elevations. 

Avalanche problems

  • Storm Slabs

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

    The chances of triggering a wind or storm slab avalanche should decrease as we move away from significant new loading and wind.  You may still trigger a storm slab avalanche within recent storm layers on very steep unsupported slopes or convex rollovers.  Deeper, stiffer slabs are possible on steep lee slopes at upper elevations where moderate winds have moved snow consistently over the last 2 days.  Any avalanche would be deeper and more consequential if it breaks down to underlying crust below the most recent storm snow. 

    Track variations in snow depth and stiffness as you gain elevation and change aspects. You can easily compare new snow depths by feeling for a crust below the new snow. Use a ski pole handle or even just dig down with your hand to find the crust.  Using tests on small slopes can help you gauge how well the new snow has bonded.   

    (4/12/2023)

    A crust is visible in the bed surface of this slab avalanche. This is similar to the layering currently found at the new-old snow interface down 1-2'.

    Photo: NWAC Public Obs

  • Loose Wet

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

    It's springtime, so even on a cool day with a mix of sun, clouds, and showers we can't ignore the effects of daytime warming on the snowpack.  Conditions can change rapidly in the spring; slopes that are cold and stable in the morning may be wet and heavy in the afternoon.  Natural wet loose avalanches may occur on steep slopes below rocky terrain during sunbreaks. 

    If you see signs of pinwheels, rollerballs or natural wet loose avalanches, avoid very steep terrain features and pivot to cooler slopes and simpler terrain.  Most avalanches will be small, but you don't want to get flushed into a creek hole or through rocks or dense trees. While some low-elevation terrain does not have the consistent snow cover to allow for avalanches, enough places do that it should still be on your radar. Wet loose avalanches may run further and grow larger than you where the snowfall from the last few days sits over a firm crust. 

    (3/8/2024)

    Fresh rollerballs are an initial sign the snow surface is warming.

    Photo: Julz Holder - Grounding Truth

Avalanche Discussion

Slab avalanches up to 1' deep were reported in the Baker backcountry on Thursday.  Winds were still moving snow along ridgelines on Thursday but the weather was tamer after a strong spring storm impacted the area Wednesday.  Heavy snowfall and gusty winds brought over a 1' of snow to the Baker area with drifts over 2’ on lee slopes.  Shallow storm slabs were easy to trigger mid-day Wednesday. The storm snow has layered over a firm crust 1-2' down from the surface (see profiles below).   

Be ready for rapid changes in weather and snow stability as we head into the heart of spring. Strong storms can give way to sun and microwave-like warming in a matter of minutes - and then turn back to snow showers by the afternoon. Dry snow avalanche problems can quickly turn into wet snow avalanche problems, or you might see both at the same time on slopes with different aspects. Low elevations have less snow than average after repeated rain and warming events throughout the winter. On the other hand, some are venturing into less traveled areas by capitalizing on easy access that is more on par with April or May.

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