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 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Sun and strong temperature inversions will cause upper elevations to warm while lower elevations stay cold.  Anticipate an increase in warming-related avalanches after a long period of Low danger. Don't linger under steep slopes or cliffs where you see bulging or wrinkled-looking snow, glide cracks, or unstable-looking slabs or blocks of snow.

Problemi valanghivi

  • Glide Cracks

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1.5–2.5

    Glide avalanches are not the kind of avalanches people trigger. They occur naturally when the interface between snow and the ground below becomes “slippery”, often during periods of warmer temperatures. Danger from this round of glide avalanches will be greater on slopes below rocky, snow-covered terrain, generally on aspects seeing direct sun. It's less likely, but glide avalanches could release in shaded terrain as well.

    It’s nearly impossible to forecast when they will release, so limiting exposure to the problem is the primary way to reduce risk. Cornices and other delicately perched snow features could also fail during prolonged warming.  Avoid travel - or at least move swiftly -  below rocky terrain where you see glide cracks or other signs of glide.

     

    (1/25/2025)

    This slab on the south side of Herman is a frequent offender when it comes to glide avalanches. The right portion released on Jan 15th or 16th, but there is plenty more to come down here and in other areas with similar terrain.

Avalanche Discussion

Loose wet avalanches should also be on your list of hazards, especially in upper-elevation areas that haven’t yet produced many of them. Avoid travel on or directly below sunny slopes where you see fresh rollerballs, small wet avalanches, or simply find wet mushy snow.

No wind slabs big enough to be considered dangerous were found over the weekend. You may find bigger ones as you climb into exposed, alpine terrain. Keep an eye out for pockets of smooth-looking wind slabs and assess for instability before moving into steep slopes with consequences like rocks, cliffs, or crevasses in the runout below.

Snow surfaces vary widely between slick crust, wind-affected snow, heavily tracked-out slopes, and even some soft snow in shaded and sheltered terrain. Southerly slopes should warm enough over the next few days to produce early-stage corn conditions.  Expect firm crust on these aspects in the morning after clear skies and cooling overnight.

The distribution of weak snow at the surface should shift this week with sunny aspects melting down but shaded slopes preserving surface hoar and faceted snow that has developed over the past few weeks. Plenty of faceted snow can be found below the surface on all aspects, often sandwiched between and around crust layers. 

Regioni coperte