Bollettino valanghe

Soldier & Wood River Valley Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering large avalanches that break widely remains a disconcerting possibility here. Slides that break in the upper 1-2 foot of the snowpack will be smaller, but easier to trigger. Much larger avalanches failing on weak snow near the base of the snowpack will be harder to trigger, but hard to survive if you do. Smaller, wet snow avalanches may occur on steep, rocky slopes where the snow is being melted by the sun. 

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–3

    Triggering large to very large avalanches here is a disconcerting possibility. These will come in two flavors:

    • Weak snow from December forms the base of the snowpack and has produced dozens of avalanches large enough to turn your car into scrap metal. A very dense slab rests uncomfortably on top of this weak snow. This slab makes triggering one of these avalanches much more difficult, but the resulting slide would be destructive and likely unsurvivable. The first sign of instability on this weak layer will be the very large avalanche you trigger. The most likely terrain for making one of these beasts is steep, rocky, wind-affected terrain where the snowpack has thinner spots that give you access to the weak layer. 
    • Several weak layers exist in the upper 12-18 inches of the snowpack. These layers are highly variable. On some slopes they are well bonded, while on others they are producing large avalanches. You may find good stability on one slope and then trigger an avalanche when you change to a nearby slope. Cracks shooting out from your skis or machine are a clear sign you've found an unstable slab. The human-triggered slides that have failed on this layer have involved crust+facet combinations and have been triggered from a distance (remotely). 

    Persistent Slab avalanches behave in ways that catch experienced users off guard. You can trigger them from flat or low-angle terrain long distances away from steep slopes, and they can break far above you. Dozens of skiers or riders can ski/cross/highmark large slopes before a very avalanche releases. 

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Today will be a few degrees warmer than yesterday and somewhat windier. Wet snow issues should remain relatively small and predictable. Sunny slopes start the day capped with a stout crust that will break down as the sun goes to work warming and melting the snow. If you are finding stacks of wet snow on the surface, these types of slides are coming onto the menu.

    Even small slides can knock you off your feet and send you down through unpleasant terrain. Natural and triggered slides will travel quickly downslope on buried crusts. These types of slides can also serve as triggers for the larger avalanches failing on layers of weak snow described above.

Avalanche Discussion

The meaning of MODERATE

The Avalanche Danger Scale is an imperfect tool. This is particularly apparent during periods of decreasing danger with widespread persistent slab problems. We find ourselves in this exact situation today. The likelihood of triggering very large avalanches is gradually decreasing following major loading events earlier this month. As this likelihood drops, the Avalanche Danger drops with it. The important thing to remember here is that decreasing danger is very different than a lack of danger. 

As we choose to enter avalanche terrain with widespread buried weak layers, we are choosing to accept the outcome of those choices. If we're lucky, we can enter big, steep avalanche terrain, get tons of snow in our faces, and return home to tell our friends about it. If we aren't so lucky, we trigger an avalanche that can wipe our house off its foundation. We can stack the odds in our favor by avoiding the type of terrain where triggering a large persistent avalanche is most likely:  big, alpine terrain that is steep, rocky, wind-swept and peppered with rocks. Here, the snowpack has a lot more trigger points where we can access the weak layers underneath the very dense slabs. 

The goal of an avalanche forecast is to give you the information you need to travel how you want to travel in the mountains. What you do with that information is completely up to you. If you are entering avalanche terrain today, be aware that the possibility of triggering large, unsurvivable avalanches is on the table. 

Regioni coperte