Boletín de aludes

West Slopes South

Northwest Avalanche Center
Ver en el mapa

Peligro de aludes

Thu
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
2 · Moderado
Open full map
Desactualizado: este boletín caducó 2 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Stormy weather will increase the chance of avalanches throughout the day. Slides will be the largest and most likely in wind loaded terrain and on the volcanoes. Steer away from steep open slopes once you find more than about 6-8 inches of new snow.

Problemas de aludes

  • Storm Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    In some parts of the zone, there might not be much, if any, new storm slabs to start the day. However, as snow continues to fall, slabs will grow and become more widespread. Different areas will see danger develop at different times and in slightly different ways. 

    Wind drifted slopes will be dangerous first with slightly deeper slabs. Fortunately, blowing snow should make them easy to spot and avoid. In terrain near Crystal and White Pass, the hazard may stay confined to these wind affected slopes. 

    Once you find more than 6-8 inches of new snow, you see avalanche issues on any steep open slope. This could happen early in the day near Mt Saint Helen and Rainier. When this occurs, steer away from all steep open terrain. Some of these slabs may trigger easily over a firm crust (southerly aspects) or old settled powder (shaded terrain).

    (2/18/2025)

    This natural slab avalanche was spotted Tuesday near White Pass ski area. NE, 6600ft. 

    Photo: White Pass Ski Patrol

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–2.5

    A large rumbling whumpf reported by two long time avalanche professionals on Monday is the snowpack reminding us not to write these older layers off. The January Drought Layer (JDL) and 1/10 facets have a well-documented history of avalanches, collapses, and snowpack tests. Sure, they’ve been more quiet lately, but if you dig they are still there and largely unchanged. 

    You can add the 2/13 interface to the list. While avalanches on this layer have been less common in the West South, a natural avalanche likely occurred on it Tuesday near White Pass. This interface is often a crust on southerly aspects and possible surface hoar or rimed grains on shaded slopes. 

    This isn’t an easy problem to assess. You have to dig. Unfortunately, a single snowpack test doesn’t say much against the volumes of evidence of instability. Be very leery of complex slopes containing rocks, rollovers, cliffs, and other natural trigger points. 

    (2/15/2025) Photo: Joe Dellaporta

Avalanche Discussion

Another storm, another round of new snow problems, another interface to track. This new snow will burry the 2/18 interface; a crust on sunny slopes and settled powder in shaded terrain. We expect most of the recent storm layers to be well settled. If an avalanche breaks into older snow it will likely be all the way back to the 2/13, JDL, or 1/10 layers. 

This next round of storms will once again add more weight to these older weak layers. We haven’t really seen the scales tip, but Monday’s whumpf has our attention. Predicting how much load is needed to make these layers fail is nearly impossible, but this storm certainly moves us in that direction. 

At lower elevations, you’ll find wet heavy snow. Don’t be surprised if you can push a wet loose slide in very steep terrain. These shouldn’t pose much risk, just don’t let one carry you into a creek or over a cliff.

Regiones cubiertas