Bollettino valanghe

Southeast Mountains

Crested Butte Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 5 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Extreme winds and a dusting of new snow could form isolated drifts in unusual locations.  Carefully read the snow surface to identify hard wind deposits and steer around them to manage the hazard.  On the northern half of the compass, triggering an avalanche on weak layers deeper in the snowpack remains possible.  Consider choosing smaller terrain features with clean runouts to reduce the consequences of a surprise avalanche.  A simpler and more effective strategy is to select slopes with conservative slope angles.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–2.5

    Old, hard slabs 1.5 to 3+ feet thick overlie buried weak layers and are typically difficult to trigger. Without obvious warning signs, avalanches are most likely triggered where the slab is thinner and easier to impact the weak layer below. The most fragile layers are buried in the middle and lower portions of the snowpack on the north side of the compass. Persistent slab avalanches are dangerous in size; they can propagate widely and be remotely triggered from adjacent low-angle terrain.  The most reliable way to manage this problem is to choose conservative slope angles or travel on southerly aspects, where the snowpack structure has become stronger and more spring-like. On northerly aspects, avoid steep terrain with a thin or variable snowpack, such as rocky areas, rollovers, or places where winds have created uneven slab thickness.

    This avalanche on Mt Whetstone is an example of terrain to avoid, with a thick slab transitioning to thin trigger points around its boundaries. Photo: Kelly Jensen

Avalanche Discussion

The disturbance rolling through Colorado delivered a lot more wind than snow and cold temperatures.  It's difficult to know how much snow accumulated, but an inch or two is a good bet.  Isolated slabs may form across the landscape from the extreme winds.  Gusts have commonly exceeded 60 mph, with a few gusts above 100 mph.  The distribution will likely be isolated across the landscape and small in size.  Drifts may form in uncommon places, so keep a watchful eye on concave features and behind windbreaks like trees, ribs, or ridges.

The cooler temperatures will cut off the threat of wet avalanche activity.  Unfortunately, southerly aspects have been a go-to terrain choice for many folks thanks to quality riding conditions and a low threat of slab avalanches.  Expect to find most terrain features locked up on Sunday, with little hope of softening due to cold temperatures and strong winds.

On the northern half of the compass, there is a lingering threat of slab avalanches breaking a week layers 1 - 3 feet deep.  The likelihood of triggering a persistent slab avalanche has slowly decreased over the past few weeks of relatively warm and benign weather.  Although the probability continues to decrease, you can't rule out triggering a dangerous avalanche.  This natural avalanche on Mount Whetstone likely ran early this week during a period of wind drifting.  Poor structure and a recent large natural avalanche support the MODERATE danger rating in the Southeast forecast zone.  Slabs are often thinner and weak layers better developed in the Southeast Mountains.  In the Northwest Mountains, the danger rating has dropped to LOW; however, poor snowpack structure exists on many northerly-facing slopes around the range.  This poor structure keeps the unlikely threat alive in the Northwest Mountains.

Regioni coperte