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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Highlights

You're most likely to trigger and get caught in wind slab avalanches in the new snow, which may be a few inches or up to a foot deep. Search for wind-drifted, stiffer snow and avoid these deposits on steep slopes. Intense sunlight may cause wet loose avalanches on sunny slopes despite the cooler temperatures. 

Avalanche problems

  • Wind Slabs

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

    Steep, wind-loaded slopes are where you're most likely to trigger an avalanche on Tuesday. You may see subtly textured surfaces, larger wind features, or the slabs may be hidden beneath a smoother, non wind-affected layer. Reactive layers could be shallow, only a few inches thick, but they may have formed into drifts a foot or deeper. There's a small chance that non wind-loaded slopes could still avalanche with a human trigger, so start small before venturing out onto large slopes. Most storm instabilities are relatively shallow, so using test slopes or hand pits may work well for evaluating the bond above the crust or in the new snow layers. Expect drifts to be larger and more reactive as you gain elevation. If you see long, shooting cracks running from your feet or sled, this is an obvious clue to avoid nearby steeps. Steer around wind-loaded slopes greater than 35 degrees on Tuesday

    We are still concerned about a subtle weak layer near a crust, buried about 2-4 feet deep. Infrequent avalanches have occurred on this layer, in wind-loaded terrain near and above treeline. Most avalanches failing on this layer happened Wednesday, 2/8, but an avalanche was reported late in the day Saturday in Canyon Creek, remotely triggered by a snowmobile. The large avalanche occurred on a 5400' north-facing slope, and was 2 feet deep. This layer may be more prevalent in Canyon Creek. It is very difficult to determine whether a slope has this weak layer, so even if you dig you may not find obvious clues as to whether the layer of concern is present on the slope. If you head out into this terrain, you are simply assuming a larger risk. 

    A small wind slab failing on a test slope. This is a good indicator for larger avalanches on bigger slopes. Wind slabs like this could fail on steep slopes with a human-trigger on Tuesday. 

    Photo: Irene Henninger

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    The sun will be shining in full force on Tuesday. Temperatures will remain cool, but we expect small wet loose avalanches to occur on steep sunny slopes. Wet avalanche activity will likely shift during the day from easterly to south, and finishing on westerly slopes. You might end up only seeing rollerballs, or subtle moistening on snow surfaces. Evaluate the snow surfaces as you travel, and if snow starts getting sticky and heavy, and rollerballs are running in abundance, keep in mind that wet loose avalanches in the previously dry low-density snow could follow. Start shifting your travel plans away from steep slopes on those aspects when indicators of wet loose avalanches start happening. 

    Dry loose avalanches could also run on steep, non wind-affected slopes. They could run naturally in very steep shady areas, or as the sun first hits some sunny slopes. As you enter a steep slope you may trigger a small sluff, or dry loose avalanche.

    Small wet loose avalanches triggered by snow shedding from trees higher on the slope. This could be very similar to what you may see on Tuesday. 

    Photo: Julz Holder - Grounding Truth

Avalanche Discussion

Avalanche activity on Monday was mainly limited to the new snow layers above the crust which formed at the start of the storm. The crust, from a wet, wintery mix before transitioning to snow, is present up to around 5000 - 5500ft. The Heather Meadows weather station at Mt Baker received 1.5" of water with this last storm, but many other locations may have received less than an inch of water. Over half of the water fell as rain below 4000ft, but at higher elevations the snow totals that came out of this storm should be much higher. Depending on where you are in the zone, the avalanche forecast could vary based on how much snow the area received. 

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