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

Watch for changing conditions throughout the day as wind and sun affect the recent storm snow. Steer around large rollovers and steep wind-loaded slopes, especially at upper elevations. Bring a cautious mindset and gather information before committing to consequential routes.

Avalanche problems

  • Storm Slabs

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

    Human-triggered avalanches are still possible on slopes 35 degrees and steeper. The potential for deeper and larger avalanches exists at upper elevations and in wind-loaded areas. Conditions are variable and recent storm snow accumulated on a wide variety of snow surfaces that may include crusts, facets, surface hoar, and settled snow. This may cause the snow to respond very differently from one slope to the next. You could see avalanches fail easily if they occur over weak persistent grains. Use hand pits, column tests, and small slopes to assess the recent snow. If you find recent avalanches, cracking, collapsing, or sudden or propagating fractures in tests, choose simple, lower angled terrain. Continue to make assessments throughout the day as you change aspects and elevations.

    (3/23/2021) This large slab avalanche failed within recent snow about 10 inches deep in the Canyon Creek area on Tuesday. Unknown trigger.

  • Loose Wet

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

    Although cloudy skies look to significantly limit solar radiation, the strong March sun could play a factor on Friday. Be heads up if the sun comes out for any prolonged period of time. Cold, dry snow surfaces could rapidly lose strength and loose wet avalanches could even grow large on steep, E-S-W facing slopes. In areas sheltered from wind and sun, loose dry avalanches are possible as well and could run far and fast downslope. Stay off steep sun-exposed slopes, especially as temperatures warm in the afternoon. Watch for snow shedding from trees and rocks, wet sticky snow surfaces, or fresh pinwheels and rollerballs as signs you may be able to trigger wet loose avalanches on nearby slopes.

Avalanche Discussion

Snow totals from the 3/18-24 storms range from 2-3+ feet throughout the West North Zone. Several natural and triggered slab avalanches occurred recently on various storm interfaces. Observers in the Twin Sisters Range on Thursday reported two very large natural avalanches that ran sometime during the past 48 hours. There were also a few close calls on Shuksan Arm on Tuesday, including a snowboarder-triggered avalanche that resulted in a partial burial (see media gallery). 

Another day of mostly dry, cloudy weather will continue to give recent storm snow time to settle and gain strength. Variability in snow and avalanche conditions throughout the zone adds uncertainty. Ease into terrain slowly and gather information along the way. Be ready to make assessments as you travel as what you find on one slope may be different from the next. 

Sadly, a fatality occurred in the Lake Tahoe area in California on Saturday when a snowmobiler stepped too close to the edge of a cornice and it broke on them. You can read the report HERE. Stay far away from the edge of cornices and the slopes beneath them as they continue to grow larger. Glide cracks are also widening, and despite cooler temperatures, exercise caution by avoiding or limiting your time beneath them.

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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