Bollettino valanghe

West Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Several shallow natural and human-triggered avalanches occurred on Saturday. It is likely that you will trigger an avalanche on Sunday, probably shallow but maybe deeper. Steer clear of slopes greater than 35 degrees or ones that end in terrain traps while this sensitive snowpack stabilizes.

Problemi valanghivi

  • Wind Slabs

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

    Wind redistributed snow into reactive pockets on Christmas Day. One observer reported a natural avalanche cycle in the Heather Meadows area of the Baker backcountry. The avalanches were mostly small, however larger ones in higher and more exposed terrain were a very real possibility. You can check out the observation HERE. Another backcountry user reported very touchy conditions, triggering avalanches 20 feet out in front of them consistently, although they were mainly only about 4 inches deep and clearly wind affected. 

    On Sunday, human triggered wind slab avalanches are likely. They will probably remain small, but it is not out of the question that they could break down to the Solstice Crust, now buried about 2 feet deep. Slabs may be subtle and soft, making it challenging to identify wind-loaded areas. Search for the usual clues such as heavier or textured snow, and shooting cracks or whumphing. Stay off these slopes or any other steep ones suspect of wind loading. If you find it at all difficult to identify which slopes are wind-loaded, stick to terrain less than 35 degrees.

  • Storm Slabs

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

    We’ve received several feet of snow in the last 4 days. Even on non wind-loaded slopes you could encounter soft storm slabs. They could  propagate only a short distance, or they may entrain additional soft snow as they descend, acting more like a dry loose avalanche. Regardless of what you want to call them, the end result is the same. They’ll occur on slopes greater than 35 degrees, and will probably remain limited to the top few inches. There is a small chance they could break as deep as the Solstice Crust.

    (12/23/2021)

    Uptrack tests and small slope can help you see how the new snow reacts under your weight. 

    Photo: Shane Robinson

Avalanche Discussion

Over 5 inches of water fell at Heather Meadows since Tuesday. The snowfall amounted to about 47 inches, settling to 31 inches on the total stake. That’s a lot of adjustment! One last wave of snowfall will continue into Saturday night before the tap slowly squeezes shut and temperatures plummet for the next several days. 

This snow came in colder, drier, and lower density than what we’re used to here in the Pacific Northwest. The arctic blast brought snow to lower elevations starting on Christmas Day. Even if you’re only traveling to “lower elevation” areas, expect to find snow. Check out this BLOG I wrote earlier in the year about hiking and snowshoeing in the Cascades. Don’t forget to prepare for snow and cold temperatures no matter what elevation you’re getting out to on Sunday!

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