Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

There's a lot of variety in the snowpack throughout the zone, making it hard to nail down exactly where you might find reactive pockets of snow. Paying attention to any changes you feel or see in the snow are some of the most important observations you can do as you travel to help you determine whether a slope might slide. Steer around steep slopes if you feel snow becoming firmer beneath you, or see wind-sculpted features or snow surfaces, as these are strong indicators that you could trigger an avalanche on the slope. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    A backcountry rider was caught and carried in a slab avalanche in the Baker backcountry on Sunday. You can read their observation HERE. We're glad to hear they came out relatively unscathed. Forecaster Lee Lazzarra was out on Sunday and was able to trigger small wind slabs formed in the last few days, mainly around 6 inches deep. He also found stubborn but slightly suspect interfaces a little deeper at around a foot down, underneath Tuesday's snow. This was on shady aspects in above treeline areas. As you gain elevation you're more likely to encounter reactive wind slabs, as temperatures have remained cooler and wind is stronger at higher elevations.

    Search for deposits of snow in gullies, by ridgelines, around rocky outcroppings, or on steep rollovers.  They may be subtle or hard to identify.  Use your senses to feel differences in the snow from one location to the next. Notice any slight variations in the visual appearance of the snow, like maybe a slight pillow, or smoother-looking snow.  On the contrary, the snow may have a patterned appearance. Use small test slopes where you find wind loading to see if stomping on them can trigger a tiny avalanche. If you can cause smaller avalanches on little slopes, expect that you could trigger larger avalanches on similar yet larger slopes nearby.

     

    (12/3/2022) A shooting crack in a wind-loaded pocket. This is a red-flag sign of instability that shouldn't be ignored. Photo: Dallas Glass

Avalanche Discussion

We've received over a foot of low density snow in the last week, meaning there is plenty of snow to blow around and redistribute into reactive drifts. South faces saw plenty of sun over the weekend. Aside from that,  the snow surface and beneath the surface have mainly remained cool, meaning weaknesses could take longer to strengthen. We haven't seen extensive wind or any precipitation in the last 24+ hours, so it may be harder to trigger an avalanche than a couple of days ago. They're still out there though. 

Regarding the sun, we saw clear skies over the weekend, and snow on steep south-facing slopes moistened. Rollerballs and small wet loose avalanches were reported. Crusts are now present on south-facing terrain, and there might be enough sun to soften them again on Monday.

If you get out on Monday, don't hesitate to share information about snow conditions with us by submitting an observation. 

 

Regioni coperte