Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Higher storm totals and strong winds should create more dangerous avalanche conditions across the zone. Expect the hazard to increase as you ascend with larger and more easily triggered avalanches. Steer around steep slopes with firm pillow-like drifts.

Problemi valanghivi

  • Wind Slabs

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

    Strong winds Thursday night should easily turn the new soft snow into a fresh batch of wind slabs. You may encounter pockets of firmer wind-drifted snow along ridges and near exposed rocky features. While wind-loaded pockets won’t be everywhere at middle elevations, expect them to become more pronounced and widespread the higher you travel. 

    Fortunately, they should be easy to spot. Look for sharp drifts, textured surfaces, scoured slopes, and small cornices to all point toward wind-loaded slopes. These clues also give you an indication of local wind patterns that loaded different aspects. 

    While some avalanches could be more than a foot thick, even a small slide might seriously injure you. Plenty of exposed rocks and trees could turn even the smallest ride ugly. 

    Outside of wind-exposed areas, cooling temperatures and decreasing snowfall rates should help limit slab development. We expect more of a right-side-up snowpack. This could lead to a few small loose dry avalanches in very steep terrain.

    (4/13/2023) Example: These wind slab clues helped us determine the local wind patterns and potentially wind-loaded slopes. Photo: Dallas Glass

Avalanche Discussion

After a warm, rainy start to the week, winter returned to the West South area! As of Thursday afternoon, snow totals around the zone ranged from 8 to 12 inches. By Friday, you could find closer to 15 to 18 inches at mid and upper elevations. With the peak of the storm overnight, expect the most dangerous conditions in the morning. By the afternoon, the sun may even make an appearance. Given the time of year and late hour of the day, it shouldn't have much effect. 

On Thursday, avalanche professionals in the Crystal area reported minimal wind drifting, typically isolated to ridgelines. The only new avalanche noted was a small natural loose dry slide on Threeway Peak. Similar conditions near White Pass also showed some minor drifting in exposed areas. 

Of course, all this new snow sits atop of the wet, older snowpack. Observers noted a good bond but also added the interface (12/6) was still wet and weak. As it freezes, the crust should become more pronounced. 

A pair of heavy rain events earlier this week took a toll on the snowpack. Many locations lost 50% of their snow depths Sunday-Tuesday. You may even see old wet avalanche debris from this cycle covered by the new snow. It left us with a mess. Roaring creeks, shallowly buried rocks, numerous trees, and open holes could make travel tricky, especially at lower elevations.

Regioni coperte