Boletín de aludes

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Peligro de aludes

Wed
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Desactualizado: este boletín caducó 3 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Expect to find sensitive wind drifts of new snowfall in steep, exposed terrain. These will be most common along higher ridgelines, but look for them on mid-slope terrain features such as ribs, gullies, and below cliff bands. Additionally, layers of weak snow are buried in the upper 2-4' of the snowpack and near the ground in the Wyoming Range. With additional snowfall, triggering an avalanche involving this weak snow is possible, particularly in steep, rocky terrain. Make your terrain selection accordingly and be alert to the consequences of being caught in a slide where you are traveling. You can significantly decrease your likelihood of triggering an avalanche by sticking to lower-angle terrain and avoiding wind-loaded features. 

Problemas de aludes

  • Wind Slabs

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

    Yesterday near Housetop Mountain, we found a variety of conditions ranging from dust-on-crust on the south half of the compass to protected, dry snow on the north half of the compass up to 9,500'. The newest snowfall has fallen on this smorgasbord of surfaces. It will likely move very easily on stout crusts on south aspects, so expect to move a fair amount of loose snow if choosing upper or middle-elevation, south-facing terrain today. Though generally regarded as a "manageable" problem, loose snow can catch you by surprise in steeper terrain.

     I expect wind slabs of fresh snow to be sensitive and mostly isolated to the northern half of the compass at and near ridgelines. In the Tetons, wind-transported snow also collects on aprons and slopes below large cliff bands, so be aware of these features additionally.  No matter the size of the slide, managing travel in wind-loaded terrain is straightforward; avoid slopes where you see or feel obviously wind-affected snow to reduce the chances of triggering avalanches. Look for signs of wind-drifted snow such as pillows, rippled surface textures, or sudden changes in new snow depth. 

    Isolated pockets of older wind slabs beneath the newest snowfall can still be found in steep, exposed terrain in upper elevations. This interface lies 30-40 cm below the snow surface and appears to be a mix of weaker, preserved old snow on the northern half of the compass. The trend with this snow has appeared isolated to specific terrain features and lacks a widespread nature, but you could certainly find this problem, particularly if you don't look for it at all before committing to a slope. Look for this weak snow if venturing into upper-elevation terrain today, particularly if that terrain is north-facing. 

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–2.5
    1. Weak layers that formed during the month of February are now buried ~2' deep. These layers have produced avalanches across most of our forecast area. The pattern of activity outlined by these avalanches points to these layers being most unstable on slopes that face the sun, where they are accompanied by crusts, but they have also produced slides on shaded aspects. 
    2. A pile of large-grained, weak snow exists near the ground in parts of the Wyoming Range. You are more likely to trigger slides on the weak layers higher up in the snowpack, but any slide triggered on this deeply buried weak snow is likely to be unsurvivable.

    As days pass with only small amounts of new snowfall, the snowpack is getting some time to rest, which will gradually decrease the likelihood of triggering an avalanche on these weak layers. However, the possibility of triggering a slide here will be on the table for some time to come. If you choose to enter avalanche terrain, be alert that at least one of these weak layers almost certainly exists in the snowpack underneath you. Even as the danger decreases we continue to advise cautious and conservative terrain selection. Be alert to the consequence of being caught in a large avalanche in the terrain you are recreating in.

    (3/18/2023)

    Recent avalanches and their locations mapped in the Wyoming Range.

Avalanche Discussion

Nine times out of ten, I can recall mishaps in life that have all boiled down to errors in communication. This is all the more true in avalanche country. Communication is a skill that has to be practiced and practiced a lot. We are not objective listeners, and you could park a sideways-sliding semi-truck off Teton Pass in the amount of space some backcountry partners leave open to interpretation. I err on the side of being a chronic questioner because questions can build a knowledge base, enhance our understanding of a problem, and improve situational awareness. Asking questions and requiring communication also makes us vulnerable to the questions and skepticism of others, but it's worth taking that step and building some ask-tell-share protocol into your backcountry travel, whether on foot or track.   

As new snowfall continues to refresh skied-out lines and cool overheating engines, and we continue exploring larger pieces of terrain, remember to keep practicing this skill, both with your partners as well as other parties. Effective communication holds the potential to mitigate nearly every issue we encounter in the backcountry. But don't take it from me, a good additional read as we edge more into an ever-snowier spring: The Ten Common Missteps of Avalanche Professionals. 

Spoiler alert: #1 is a lack of effective communication

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