Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Sun
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

Update: Removed the wet loose problem to reflect the lack of new snow:

There shouldn't be much hazard from any new snow you find. Instead, it's the uncertainty of the much bigger deeper slides that might cause you to avoid large complex avalanche terrain. As the surface crust gets stronger, it will help reduce concerns about these persistent layers. 

Problemi valanghivi

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2–3

    A new crust is growing just below the new snow. As it gets thicker and gains strength, it will help reduce any concerns about avalanches failing on older, deeper layers in the snowpack. The cooling trend on Saturday will help significantly!

    These avalanches are becoming very unlikely. They would likely take a bigger trigger (like another avalanche) or finding a shallow spot in the snowpack. 

    Over the past month, numerous avalanches occurred on well-documented layers of facets on and just above the Early February Crust (4-6 ft down). While unlikely, these avalanches would break widely and be very large. Consider limiting any time you spend on or under large complex avalanche terrain, particularly on more northerly aspects, until this crust has time to develop.

    (3/18/2024)

    A widely breaking avalanche in Mount Rainier National Park. It likely occurred on 3/18 and may have broken on persistent weak layers.

    Smaller wet avalanches can be see in the foreground. 

    Photo: Crystal Mountain Pro Patrol

Avalanche Discussion

A modest storm should bring several inches of snow to the middle and upper elevations around the West South zone on Saturday. However, there won't be enough to really cause any danger.  Cooling temperatures and light winds should allow it to fall right-side-up and bond well to the old surface. At the highest elevations of the zone, you may be able to push a mini avalanche over the firm crust below. 

We’re at the tail end of a prolonged warm spell. An extended wet loose avalanche cycle left piles of debris and frozen rollerballs on and under many slopes regardless of aspect and elevation. This period of hot weather took its toll on the snowpack, particularly at lower elevations and southerly aspects. Tree debris now covers the surface in the forest. Patches of bare ground, open creeks, and plenty of obstacles make it feel more like late spring. 

Recent avalanche activity has been minimal and limited to only a few small wet loose slides in the second half of the work week. 

On Friday, an NWAC forecaster at White Pass found a firm crust above 5800ft. It was nearly 10 inches thick and growing. Lower in the terrain, the crust was still present but weaker and more variable.

Regioni coperte