Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

A foot and a half of snow fell Wednesday and there is uncertainty as to how quickly this new layer will settle, so travel with the expectation that it's likely you could trigger a large avalanche especially on steep, wind-loaded slopes.  Pay attention to long shooting cracks and stiffer, thicker-feeling and looking snow deposits as indicators to avoid steep areas. We'll probably see the sun Thursday and wet loose avalanches could run on steep, south-facing slopes, which you should consider steering around when you notice rollerballs running coming down in these spots. 

Avalanche problems

  • Wind Slabs

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

    A large, natural slab avalanche which propagated surprisingly far, occurred naturally on The Arm in the Baker backcountry on Wednesday. We don't have any information aside from the photo, but considering how wide it ran, there may have been a buried persistent weak layer, just above the MLK crust, that it could have failed on. This is an important factor to consider looking into your day on Thursday, as avalanches could surprise you with how large, wide, and reactive they are, although at this time we really don't know much about it. If a weak layer is present, it's most likely on the northerly half of the compass at upper elevations. 

    Snowfall quickly stopped in the afternoon and we don't expect we'll see as many natural avalanches on Thursday. We suspect this new snow will settle and gain strength relatively quickly. However, in wind-loaded locations, it is still likely that you could trigger a large, destructive slab avalanche that could bury, injure or kill you. Taking into account the large natural avalanche which naturally occurred during the storm, and that we just got a foot and a half of snow with limited information, it'd be best to wait at least a day before testing high-consequence steep terrain. 

    Search for thicker, wind-affected slabs to avoid, which you're most likely to find beneath ridgelines, around rocky outcroppings, on steep rollovers, and in gullies. If you see wind actively moving snow on a slope, pay attention to where it's landing and if it's on a steep slope, steer around it. Long, shooting cracks from your feet are indicators of weakness in the snow, in addition to whumphs, and it's best to avoid nearby steep slopes if you encounter these signs of instability. Slabs you trigger could fail as deep as the new snow layer, or possibly deeper depending on the size of the drift or any additional underlying weaknesses. When in doubt, steer around slopes greater than 35 degrees on Thursday, especially where wind-loaded. 

     

    (1/18/2023)

    A D2 (large) slab avalanche which occurred naturally, during the day Wednesday on The Arm in the Baker backcountry. N, 5100'. SS-N-D2-I

    Photo: Mt Baker Snow Safety

     

  • Loose Wet

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

    It's a surprise to say that we'll probably see the sun on Thursday. Wet loose avalanches could run in the new snow layer. Wet avalanches could be a foot or more in depth depending on how much sun and warming we get. You'll probably see indicators on these steep, south-facing slopes first, like rollerballs coming down. Snow might get sticky, or gloppy. When this starts happening, pay attention to where you currently are, and where you're going. You may need to start thinking about avoiding the steep south-facing slopes, or beneath those slopes as well, if an abundance of rollerballs are coming down, and continued warming may lead to natural wet loose avalanches. 

    (1/1/2023)

    Rollerballs or pinwheels, your first indicator that the snow is getting moist and if the sun and warming keeps up, wet loose avalanches could follow. 

    Photo: Irene Henninger

Avalanche Discussion

On upper elevation shady slopes you may be able to trigger shallow dry loose avalanches. Pay attention to triggering them if you're entering steep terrain. THIS observation does a good job of painting the picture of the stormy conditions on Wednesday. We still have a lot of uncertainty about conditions and avalanches as we enter this period of high pressure.  The Heather Meadows weather station at Mt Baker recorded 1.5" of water during the storm, and about 1 1/2 ft of snow. Other areas in the zone may have seen less new snow. We broke 100" yet again on the total snow stake. There's been a surprising amount of warm/wet cycles with a few feet of snow between to break them up. There are old, large debris piles now hidden under about 2 feet of snow. Gaping holes from creeks or rocky areas are still a concern that it's important to focus on during your travels to make sure they don't swallow you up. 

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