Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You can still trigger large avalanches in wind drifted snow, primarily on convex features steeper than 35 degrees near and above treeline. Use visual clues to identify and avoid wind loaded slopes, and seek out lower-angled and wind-sheltered terrain to reduce your risk. An active weather pattern will resume Tuesday night, bringing rising avalanche danger. 

Problemi valanghivi

  • Wind Slabs

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

    Areas of wind drifted snow will become more sensitive to triggers as you climb up in elevation. The most dangerous conditions will exist in leeward terrain near and above 5000ft. Be especially cautious of convexities, gullies, areas around rocky outcrops, and slopes below cornices. Slabs could break 1-2ft feet thick within new and wind drifted snow since Christmas, or deeper and wider on the slick 12/21 crust below. Feel for sudden changes in snow surface texture and hardness as good indicators of the wind slab presence. Previously wind drifted slabs may lurk underneath the most recent few inches of low-density snow making them more challenging to identify. Ease into terrain slowly and carefully evaluate the snowpack as you travel. When in doubt, default to lower angled terrain. 

    (12/28/20) One of many large human-triggered avalanches (north, 5000ft) on Shuksan Arm in the West North Zone that occurred Monday. Photo: Adam U

Avalanche Discussion

Several human-triggered avalanches (D2) were reported in the adjacent West North Zone over the past few days including an incident on Monday where a snowboarder was caught, carried, partially buried, and swiftly dug out by their partners. Fortunately, the snowboarder was uninjured. Recent avalanches occurred in northerly terrain above 5000ft on convex slopes steeper than 35 degrees. A few remotely triggered avalanches were reported in similar terrain since Christmas, and some recent avalanches had impressive propagation breaking several hundred feet wide. In some instances, avalanches also occurred on slopes with previous tracks, with the second or third rider triggering the slide. Very few recent natural slab avalanches have been reported. With sunshine on Monday, wet loose activity was small but widespread on sun-exposed slopes. All the recent avalanche activity is bull's eye data the snowpack is adjusting to the recent storm snow and still needs time to stabilize. Uncertainty exists regarding the extent of weak snow associated with the 12/21 crust and the 12/25 new/old snow interface. Dig down 2-3ft to carefully assess these layers looking for sudden or propagating fractures in snowpack tests before committing to steeper terrain.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte