Boletín de aludes

Snoqualmie Pass

Northwest Avalanche Center
Ver en el mapa

Peligro de aludes

Fri
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Open full map
Desactualizado: este boletín caducó 4 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

You could find some unstable wind-loaded slopes as you ascend in elevation on Thursday. You should be able to pick out these features near ridgeline or convexities by looking and feeling for changes in the snow surface. If an area looks “fat” or is stiffer than the surrounding snow, consider choosing a different path.

Problemas de aludes

  • Wind Slabs

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

    Continue to keep an eye out for Wind Slabs near ridgelines, on convex features, or near rocky terrain such as the base of cliffs or confined gullies on Thursday. These slabs should be stiffer than the surrounding snow and could even feel hollow in places. Feel for changes in the consistency of the snow as you travel to help you identify the areas we’re concerned about. Wind-loaded features may look “pillow-like” or “fat” compared to the surrounding terrain and you might notice some textured surfaces nearby. If you suspect a slope to be wind-loaded, steer around it by choosing lower-angled terrain.

    (2/15/2023)

    A deep crown was spotted below Bryant Peak and is estimated to be 3+ feet deep in some places.

    Photo: Austin Guyette

Avalanche Discussion

It has been a few days since our last major loading event on Monday, where 1-2 feet of snow fell upon the Pass. This resulted in a few natural avalanche cycles. The first occurred during the height of the storm and many of the slabs are now filled in by storm snow. In the following days, solar input helped snow to shed, spawning loose avalanches that are still visible in the mountains. 

On Wednesday, NWAC forecasters and avalanche professionals in the Alpental Valley found plenty of evidence of wind sculpturing on the surface near ridgelines. Thin Wind Slabs were observed and showed slight cracking on test slopes and during uptrack tests. Slopes that see direct sunshine had a breakable crust in the morning before it broke down in the midday sun and produced another round of Wet Loose avalanches. Shaded slopes continued to hold cold dry storm snow capped by sparkly surface hoar. Expect to encounter similar surface conditions if you venture out on Thursday.

On Thursday, we should find ourselves in a bit of a transition period. Fresh storm snow should continue to settle and stabilize, while sunny weather will start to dissipate. We dropped the Wet Loose problem we’ve been running the past few days during the predominantly pleasant weather. This decision wasn’t made without hesitation, however. Thursday should be the warmest day of the week, but breezier and cloudier. These weather influences combined with the fact that sunny slopes have already had a chance to avalanche the past 2 days led us to drop the problem. 

Any avalanche you do encounter on Thursday should be confined to the recent storm snow above the 2/13 interface. This layer can be found 1-1.5 feet below the surface in most locations and is reportedly well-bonded. That said, avalanche professionals and recreationalists got a glimpse of the crown on Bryant Peak that produced a large debris pile during Monday's cycle. They reported the crown to be approximately 3 feet deep and may have been triggered by a natural cornice fall. If this crown depth is accurate, the question becomes: did it fail on a deeper layer or just a wind-loaded spot?

Regiones cubiertas