Bollettino valanghe

Gunnison

Crested Butte Avalanche Center
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Pericolo valanghe

Wed
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

Heightened avalanche danger exists on two types of specific terrain. Strong northerly winds have formed wind slabs on the lee sides of ridgelines and cross-loaded terrain features, and steep slopes on the northern half of the compass have a loose snow avalanche problem. If you have uncertainty about the avalanche conditions, then terrain selection is the answer. Consider avoiding those wind-loaded terrain features, and decreasing your slope angles to manage the loose snow avalanche problem. That should help set you up for an easy day enjoying the snow. A hot drink and a few extra jackets would be a good idea too.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Strong northerly winds have formed wind slabs on the lee sides of ridgelines and cross-loaded terrain features. In some areas, these slabs are forming over a notably weak interface after a prolonged dry spell before the last storm. In some cases, these slabs will also be hard. Even if the avalanche size is small, a 4-inch hard slab can be enough to take you off your feet and push you into more hazardous terrain. The wind has also blown through some lower-elevation open valleys, which can build wind slabs in uncommon locations.

    This slab avalanche was human-triggered on Saturday, and though it didn't run far, it propagated widely on the old weak snowpack. 

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    The snow that accumulated last weekend is adding volume to the loose snow avalanche problem that we have been dealing with for the last week. In many areas, these sluffs are small and relatively easy to manage. In some areas, these sluffs can entrain enough volume to become large and difficult to manage. This avalanche problem will be the largest on northerly facing terrain, primarily below 11,500ft. In some areas that have an entirely weak snowpack, a triggered sluff can entrain that entire snowpack. You can manage the problem by riding off the fall line or pulling out of the way to let your sluffs go past you. You can avoid the problem by riding on lower slope angles less than about 35 degrees. 

    Dry Loose avalanches start from a point, before growing in size. Don't be that tree and move to the side. In sustained steep terrain, this problem may grow large and become difficult to manage. 

    Photo: Zach Guy

Avalanche Discussion

The wind has driven the most recent round of slab avalanche activity. Peak instability likely occurred on Monday when the majority of the snow available for transport was first loaded onto lee terrain features. Northerly wind speeds increased overnight, however there was less snow available for continued transport. We have seen multiple strong northerly wind events this winter, and not a whole lot of accumulating snow between each event. In the alpine, the old snow surface is fairly hardened from those past wind events. Near treeline elevations likely have the most snow available for transport, and the old snow surface has more notable weak layers. 

Visibility was a bit limited by the weather yesterday, but we still received a number of observations about current conditions. Backcountry travelers triggered wind slabs, and natural avalanches occurred. The recorded avalanche size has remained small so far. Those observations can be viewed here. The smaller size was again due to the amount of snow that was available for transport. The potential avalanche size will increase where there is more snow available for transport. Again, this could be the near treeline elevation ban, areas with a big fetch, or in the parts of the Ruby Range that received a foot of new snow last weekend. 

Once new snow starts accumulating later today, the avalanche danger will again be on the rise. If the snow forecasts verify, we are looking at an exciting week ahead, and a busy week of documenting avalanches. 

Regioni coperte