Bollettino valanghe

Gunnison

Crested Butte Avalanche Center
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Pericolo valanghe

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

In sintesi

A 6-day string of human-triggered avalanches highlights the dangerous avalanche conditions.  Today, continued snowfall and wind-loading keep the snowpack near its breaking point and possibly produce a few natural avalanches.  You will likely trigger a slab avalanche on many drifted and sheltered slopes.  Avalanches can be triggered from below and adjacent to steep slopes.  You can reduce your risk of avalanches through conservative terrain selection (slope angles 30 degrees or less), avoid travel directly below steep terrain, or find less risky snowpacks on sheltered, low-elevation southerly slopes.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Soft slabs averaging 1 to 2 feet thick in sheltered terrain and larger in wind-loaded terrain will be most sensitive to triggers where they formed over fragile facets, collapsible crusts, or surface hoar layers on west, north, and east aspects.  Slab behavior is becoming more challenging as slabs stiffen and thicken, with dozens of recent remote triggers and slabs propagating wider across terrain features.  Human-triggered avalanches continue to occur each day and point to a sensitive snowpack.  The obvious risk management strategy is to choose low-angled terrain without steep slopes above.

    This large avalanche was remotely triggered from the ridge above Red Coon Bowl, 12/31. 

  • Wind Slabs

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

    Snowfall Wednesday night and Thursday may fuel another round of Wind Slab formation on the east half of the compass.  Wind direction began from the southwest last night and will likely shift to the west and northwest throughout the day.  Fresh slabs may form throughout the day and increase in size on leeward terrain features.  Steer away from terrain features where you see evidence of drifting or feel stiffer surface snow.  The most suspect aspects are highlighted above, but you could encounter fresh drifts on more windward slopes.  Many aspects and elevations highlighted overlap with the Persistent Slab problem and are best avoided as an avalanche in the recently drifted snow could step down, creating a large, dangerous avalanche.

    An example of a slab avalanche that broke below a leeward ridgeline from last weekend.

Avalanche Discussion

Let's look at the numbers: Six consecutive days of human-triggered avalanches, 164 recorded avalanches, 59 large avalanches documented, 24 observations with overt signs of instability, and three fatal avalanche accidents across the western US. These numbers are a product of a slow to moderate loading event over the last 11 days. With each additional snowfall, the snowpack clings precariously near its breaking point, and potential avalanche size creeps larger and larger.

Continued snowfall and wind maintain the trend and make human-triggered avalanches likely and natural avalanches possible on most slopes facing west through north through east, and some drifted southerly facing terrain.  Careful route finding and conservative terrain selection are your best risk reduction strategies.  The snowpack structure is very poor on most slopes, with low-elevation southerly terrain being the exception.  Skillful snowpack assessment is required if you attempt to play on steep, sunny features in sheltered areas.

Low-angled terrain offers great riding conditions with far less risk. However, it can be challenging to get stuck in an entrenchment mindset. Enjoy the fresh snow, and know that avalanche conditions will improve eventually, but not anytime soon.

Regioni coperte