Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

Dangerous avalanche conditions exist after a storm produces around a foot of snow on Sunday night that will slow as the day progresses. Avoid all steep slopes, as it's likely that you can trigger large, surprising avalanches that can kill you. If the sun shines, expect rollerballs and small wet avalanches running on steep slopes facing the sun. 

Avalanche problems

  • Storm Slabs

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

    We're getting a rapid load of snow that will result in dangerous avalanche conditions on Monday. Avoid all steep slopes, and if you experience whumphing or natural avalanches, take another step back and avoid traveling beneath large avalanche paths as well. There could be a natural cycle early in the morning, before stability slowly improves during the day as precipitation rates decrease. 

    There were reports on Sunday of failures occurring with heavier new snow over softer snow, and in some cases, weak grains, within the top 6 inches to foot of the snowpack in the Baker backcountry. With the added load of 6 inches to a foot of new snow, depending on where you are in the zone, expect more failures in these new layers. Especially in wind-drifted areas, avalanches will be more reactive and could be well over two feet deep. 

    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 Monday. Photo: Colin Wiseman Photo: Colin Wiseman

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    If the sun pokes out, which it may do in the afternoon, it could initiate a flurry of rollerballs, and possibly some small wet loose avalanches. Expect to encounter this on steep slopes facing the sun if we see the sun. Then take actions like shifting aspects or moving away from the bottom of these paths to avoid getting caught in one of these small wet slides or masses of snails rapidly running downhill. 

    Example photo: Wet loose avalanches often initiate where snow sheds off rocks and trees onto the slope below. Note that there are both small rollerballs and wet loose avalanches in this image. This is very similar to what you might see on Monday is the sun pops out. 

    Photo: Zack McGill - Cascade Mtn Ascents

Avalanche Discussion

A professional in the Swift Creek area of the Baker backcountry, a sheltered, lower-elevation gully, found persistent, weak grains and experienced easy planar releases at the new/old interface about 6 inches deep. This occurred on test slopes, kick turn cuts, hand shears, and shovel tilt tests, and influenced them to avoid avalanche terrain. There may be similar weaknesses in other areas like this in the zone, which may be more alarming and will require taking a further step back with the additional snow load. 

Many of us haven't been finding such sensitive weaknesses, mainly in higher, more exposed areas, including my visits to Canyon Creek (observation) and Cascade Pass (observation) in the last few days, plus what others have been finding in higher locations in the Baker backcountry, which is mainly new wind and storm slab concerns (observation) (observation). It's not out of the question, however, that given the unusually light, low-density snow and the possibility of weak layers forming in recent weeks and now getting a heavier load on top, that you could trigger a larger avalanche than expected, or it could surprise you by propagating much further than you think it might. Monday isn't a good time to test your luck on steep slopes. 

Depending on where you were in the zone, 3-6+ inches of snow fell on Sunday, although in most areas this was highly wind-affected. There will be another 6 inches to a foot overnight, and a few more inches will fall Monday morning before precipitation amounts back off a little for the next few days. 

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