Avalanche forecast

West Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The frequency of large and very large dangerous avalanches is slowly decreasing, but temperatures haven't cooled enough for us to let our guard down. Avalanches remain possible, even if they are a little less likely than previous days. Consider continuing to avoid terrain beneath corniced slopes or rocky steeps and glide cracks with large snow deposits still intact until temperatures further cool. 

Avalanche problems

  • Glide Cracks

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

    Limit your exposure to steep terrain and the lower angle slopes beneath them, especially where you see cracks or wrinkles in the snow that indicate where the entire snowpack is slipping on a smooth ground surface. These are the conditions when very large avalanches may occur. Blocks of melting snow clinging to rock faces are also a red flag.

    After days of hot weather, we suspect most avalanches have already happened.  However, glide activity lingers even as temperatures begin to cool, since water may still be percolating down through the snowpack. While many slopes have shed wet snow, natural loose snow avalanches can still be triggered by cornice fall or snow shedding from rocks and cliffs.

    Example photo: Glide cracks and avalanches seen in the Del Campo area of  the Mountain Loop Highway in a previous year. Don't travel beneath cracks like these.  Photo: Irene Henninger

  • Cornices

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

    Infrequent large cornices failures have been reported in neighboring zones. We suspect large cornices are peeling off all over the West Central zone as well, and some are triggering large, unsurvivable avalanches on the steep slopes beneath.

    The slight cooling may slow activity a bit, but not by enough to make us feel good about traveling beneath cornices yet. Identification and travel advice for this problem is simple - don’t travel under cornices until there is a significant drop in temperatures for a few days. Stay well away from steep slopes below cornices as well.

    (3/16/2024)

    A suspected cornice fall on Mt Pilchuck caused this slab avalanche sometime near the start of the warming event. 

    Photo: Irene Henninger

Avalanche Discussion

Freezing levels are cooling a bit for Wednesday. and there's a small uptick in southwesterly wind. For the first time in days, we can expect some cloud cover. There are a lot of variables so we're not quite sure how conditions will change, but we expect snow to be different than the previous days when we had clear skies. Northerly aspects may moisten more than they have previously, and you may see more avalanche activity on those slopes.  Surfaces will probably be stickier.  Temperatures are still warm enough that we don't particularly expect a surface crust to persist for the day, but who knows? 

It's unlikely you would find a slab of dry snow in which to trigger an avalanche except for at the highest elevations. If you do make it to the alpine, lookout for pockets of wind slab in steep terrain, especially on slopes with consequences like cliffs or rocks in the runout below. 

Hikers the last several days at Heather Lake and Lake 22 on the Mtn Loop Highway have been reporting constant rumblings from large avalanches higher up on Mt Pilchuck, likely from large cornice falls and subsequent avalanches. The steep, cliffy terrain on the backside of the lakes constantly rained down small loose avalanches during the warming period as well- good examples of where not to be (the backside of the lakes) during the warmup. 

If you're out in the snow, share your observations with us and your local backcountry community. This is even more valuable now that we're getting into the spring and folks are getting out on mountaineering and more distant objectives in the longer daylight hours. Sharing details from areas that are less frequently traveled are even more valuable to help keep the community informed. 

Regions covered