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Out of date — this forecast expired 6 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

The snow has ended, but this may not be our normal post storm powder day. Unstable snow could linger longer than normal on some slopes, and natural avalanches may run if the sun comes out. Ease into the terrain slowly, using plenty of small and low consequence slopes to gain information. 

Avalanche problems

  • Storm Slabs

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

    It just snowed a lot in the West North zone! Most locations received 2-2.5ft (the majority of that falling on Monday). All this new snow will need time to heal. 

    As the storm snow settles, often avalanches become localized to very steep slopes, convex rollovers, and wind loaded areas. Seeking out lower angled, more planar, and/or sheltered terrain can reduce the chance of triggering a slide. Expect avalanches to be larger and much harder to manage in wind loaded areas. Firm wind slabs may be difficult to assess and often surprise travelers. 

    That all feels very common; what’s not normal is the potential for weak layers lurking in the upper snowpack and the base of the new snow. These grains have been reported in higher terrain and sheltered drainages. So far, there haven’t been any confirmed avalanches on these layers in the West North. If these grains come into play, slabs may break widely, release lower on the slope, or even fail remotely.

    Example photo: A snowboarder-triggered avalanche on Shuksan Arm (NE, 5400ft). The avalanche broke 80-100ft wide and 1-2ft deep. It's likely that you can trigger an avalanche like this if you venture into steep terrain on Tuesday. Photo: Colin Wiseman Photo: Colin Wiseman

  • Loose Wet

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

    This is an “if-then” avalanche problem. IF the sun comes out, THEN expect natural wet loose avalanches from steep sunny terrain. With all the recent snow, anything that gets rolling could grow large and dangerous. Think about this when planning your day, and make sure you have a route back to the car that avoids traveling on or under steep sunny slopes. Fortunately, this one is easy to monitor. Pay attention to the sky. If you grab the sunnies, the snowpack is probably feeling the sun too. New rollerballs are a great indicator that the snow is becoming wet and unstable. 

    Example: Natural wet avalanches like this could release if the sun comes out on Tuesday. 

Avalanche Discussion

Monday’s storm exceeded expectations. Most of the zone added 1-2 feet to their storm totals! Reports from the Heather Meadows area were of light, fluffy powder. Most avalanche activity was localized to wind loaded terrain. 

The forecast for Tuesday is a bit tricky. It could stay cloudy. However, if the sun comes out, conditions could change quickly. Sometimes, even how the storm snow reacts may shift throughout the day with just a touch of sunshine and settlement. 

Avalanche professionals this week reported several weak layers below the recent snow, including sugary facets, surface hoar, and stellars, often prompting them to dial back their terrain choices. We haven’t confirmed any avalanches on these layers in the West North zones, but other parts of the region are dealing with persistent slab issues. Unfortunately, with these layers buried a couple of feet down, small test slopes may not tell you what you want to know. You might have to dig and look carefully.

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