Avalanche forecast

East Slopes North

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

In the western part of the zone warming temperatures and sunshine may cause cornices to fail naturally and trigger large and destructive avalanches on the slopes below.  In the eastern part of the zone including low elevations,  shallow slabs may break in surprising ways where denser storm snow overlies a weak base. In all areas, wet snow avalanches are possible on steep sunny slopes (including roofs). 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    Following a significant multi-day storm cycle with few observations, it's essential you use caution near or below large avalanche paths where winds have transported large volumes of snow over the last few days.    With sunshine and milder temperatures (even above treeline) in the forecast, steer clear of slopes with large overhanging cornices.  The chances of you triggering a slab avalanche at upper elevations may be decreasing, but a large natural trigger like cornice fall may unleash a deeper slab.  If you experience shooting cracks or see recent avalanches, these are red flags that conditions are still dangerous and to avoid similar slopes. 

    In the eastern foothills, strong to extreme westerly winds following heavy snow layered over a weak and shallow snowpack.  Whumphing and cracking were reported in the Twisp Valley at low elevations on Saturday and several recent natural slab avalanches were observed over the last few days.  Stick to slopes lower than 30 degrees if you experience sudden collapses while traveling at lower elevations or see avalanches on similar slopes.  Continue to exercise caution around roofs that hold large amounts of snow.  Roof-avalanches continue to be a real hazard along the east slopes of the Cascades following this historic storm. 

    (1/7/2022)

    Intense wind drifting of snow observed in the East Central zone on Friday afternoon. Wind slabs may still be sensitive on Sunday, approach wind loaded terrain with an abundance of caution.    

    Photo: Matt Primomo

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    The East North will be relatively cooler than other zones on Sunday but daytime warming and sunshine will drive the wet loose hazard on steep sunny slopes.  Avalanches can run faster and become larger on steep slopes where recent snow overlies a firm crust. If you see pinwheels, natural loose (point releases or sluffs) wet avalanches or find yourself sinking into the snow surface deeper than your ankle, it's time to seek out lower angle terrain or a different aspect.  Don't let a smaller slide catch you off-guard and slam you into trees or other terrain traps.  Be aware of snow shedding below rock faces and cliff bands that are in the direct sun.   You may find warmer temperatures and an elevated likelihood of loose wet avalanches in the western reach of zone near Washington Pass on Sunday.

    Examples of wet loose avalanches and rollerballs running on steep, sunny slopes. 

Avalanche Discussion

An extensive avalanche cycle occurred over much of the Cascades between Wed night-Friday.  Heavy snowfall along the east slopes of the Cascades caused a widespread avalanche cycle along with avalanches at lower elevations and in sagebrush country.  In the Washington Pass area,  roughtly 3.3 inches of water was recorded over this stretch with 2' of settling storm snow.  Mazama saw 18" over this period.  The storm ended with rapid cooling and extreme westerly winds that transported significant snow at all elevations on Friday.   We're still wrapping our heads around this significant event and you'll need to exercise caution when venturing out into the changed snowscape over the next several days. 

 

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