Boletín de aludes

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
Ver en el mapa

Peligro de aludes

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

Lo esencial

Expect the avalanche danger to rise today as heavy snow and strong winds build slabs of snow. You can easily trigger avalanches on slopes that get about a foot of new snow before the end of the day. Avoid areas where you see smooth, rounded pillows of snow or feel where the snow surface changes from softer to stiffer. You can find safer riding options on lower-angled, wind-sheltered slopes without steep overhead hazards.

Problemas de aludes

  • Wind Slabs

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

    Regardless of where you are, the avalanche danger will increase as the work week begins. The danger is expected to rise earlier in the day on the northern end of the Greys. Fresh wind slabs will form with moderate to strong winds from the southwest. Your terrain of choice may dictate where you find this problem, but assume it will be present at upper and middle elevations and more exposed sections of terrain, rocky features, and saddles. Given the wind, even small amounts of snowfall can start to load areas deeply, and I'd expect slab depths will range from 1+ feet by the evening in some locations. Many smaller avalanches may break easily as new snowfall accumulates on the old snow surface that is now slick or crusted in many spots. Be on the lookout for wind-affected snow on the surface that is stiff or drifted. These slabs may become dense quickly, given the intensity of the wind. Cracking or collapsing are clear signs of instability, so pause to regroup with your partners (or collect your own thoughts), and reassess steep terrain today as the hazard will rapidly increase throughout the day. Sheltered terrain will provide the safest riding. If you travel in avalanche terrain now, cautious route-finding and conservative decision-making are essential.

    Cornice Falls: Observations of cornice failures continue to be reported. Give cornices a very wide buffer zone, and be careful along ridgelines as they can break further back than expected. Falling cornices can impact deeply buried weak layers and trigger large avalanches.

    An old avalanche crown observed from the top of Boulder Ridge.

    Photo: Bridger-Teton Avalanche Center

  • Persistent Slabs

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

    Changing weather means giving slopes with older, weak snow a very wide buffer. Hard slabs 3-5 feet thick overlay weak snow that formed earlier in the season. We expect to see some natural avalanches breaking on deeper weak snow in this zone. Steep, rocky, unsupported, and wind-affected terrain on the north half of the compass remains suspect. Thin spots in the slab (trigger points) are most common in these locations. While it has become unlikely for a human to trigger one of these slabs, larger triggers such as cornice falls, smaller avalanches or even snowmobiles still have the potential to impact weak layers buried deeply in the snowpack.

    The Wyoming Range harbors a weaker and shallower snowpack, making it easier to impact these weak layers. The Snake and Salt River Ranges hold a deeper snowpack, where this is less likely, but remains very possible, particularly with incoming snowfall.

    (2/17/2024)

    A rider trigger avalanche near Sheep Pass. The rider was caught but not buried. 

Avalanche Discussion

Remember the first half of the winter when we had one primary weak layer of snow and knew that each loading event would likely produce large avalanches and dangerous conditions? In many ways, that time was easier than now. More dangerous, sure—but simple and predictable from a forecasting standpoint. But the times are a-changin'.  Our snowpack isn't as hair-trigger but has more complexity based on location. In many ways, this makes it a much less predictable animal. Two things are certain in my mind: the first is that changing weather (especially with wind speeds this high) will make for more hazardous conditions. The other is that I would be shocked not to see avalanches breaking on deeper, old, weak snow in the second avalanche problem above. These avalanches will likely be large, and the feedback will be minimal. They can break even in areas that have seen high traffic. I'm currently avoiding terrain across all the zones where I can find this weaker snow easily—where it is shallower—and terrain that has already avalanched several times this season. Areas that have frequently avalanched have remained shallower, still have weak snow, and are very suspect. 

Realizing that snowpack conditions are exceedingly complex can be relieving in a way. It requires a shift in our approach to the problem—we can simplify the situation by returning to the basics—new snow + wind + weak layers = dangerous conditions. Luckily we also have plenty of tools to combat the complexity. We can read a forecast and gather useful information, look for evidence of the problems in the field, assess and reassess as winds or weather change, and still ride plenty of fun snow this week by choosing terrain wisely. 

Regiones cubiertas