Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Natural and human-triggered wind slabs were observed on Tuesday near the crest. With an uptick in winds and another couple of inches of snow on the way, expect this problem to continue. Winds should be strongest near the crest, while precipitation favors the volcanoes. 

Problemi valanghivi

  • Wind Slabs

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

    The most likely location for you to find consequential avalanches will be in wind-loaded terrain. Look for fresh cornices, drifts behind objects, or textured surfaces to help determine which way the wind was blowing and thus wind-loaded slopes. Wind slabs often appear as pillow-like drifts that look “fat”. They like to form near ridgelines, at the base of rocks or cliffs, or in confined chutes. If you notice cracking of the surface or blocks of snow failing during upslope tests, avoid wind-loaded features over 35 degrees.

    (12/26/2023)

    Two wind slab avalanches on the same ridgeline. One occurred naturally while the other was intentionally triggered by Crystal Mountain Pro Patrol by kicking a cornice. [N-SS-D1-R1-U and ASc-SS-D1-R1-U]

    Photo: Andy Harrington

Avalanche Discussion

An NWAC forecaster, along with others traveling in the Crystal backcountry on Tuesday, identified multiple natural wind slabs and one intentionally triggered slab by Crystal Mountain Pro Patrol. These slabs all occurred just below ridgelines, and blowing snow was occasionally observed near their locations. 

Anywhere from 2-6 inches of dry snow was found above a mostly supportable crust. A thin wind skin capped the new snow in exposed areas at upper elevations. Lower down, evidence of rain and freezing rain was evident below a dusting of new snow. No observations were received from elsewhere in the zone.

Wednesday should be the windiest day of the week, particularly near the crest. A quick shot of precipitation is expected to deliver an inch or two of new snow and some drizzle at lower elevations once again. Precipitation amounts favor the volcanoes as well as slightly higher freezing levels. Keep an eye on how the weather is unfolding near you. Anywhere you experience rain on dry snow, put wet avalanches on your radar on slopes over 35 degrees.

Despite some new snow and a more winter-like feel at upper elevations, natural hazards remain the story in many areas. Take care to avoid open creeks and holes or exposed rocks and logs while traveling in the mountains. 

Regioni coperte