Bollettino valanghe

Northwest Mountains

Crested Butte Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Wed
Alta quota
1 · Debole
Limite del bosco
1 · Debole
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

On the northern half of the compass, triggering a hard slab that breaks several feet thick has become increasingly rare. The most concerning terrain for finding a surprise avalanche is near and above treeline, where winds have created thin areas and slabs with variable thickness.  Slopes with a deeper, more uniform snowpack offer a lower chance of triggering an avalanche.   You can avoid the problem on southerly aspects, where today's modest warmup should provide nice spring riding conditions and minor wet loose issues.  Wet avalanche concerns increase tomorrow and become more hazardous through the rest of the week (see video).   

Problemi valanghivi

  • Persistent Slabs

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

    Old, hard slabs 2 to 3+ feet thick overlie buried weak layers and are becoming increasingly isolated and 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.  You can reduce your risk by avoiding steep terrain with a thin or variable snowpack, such as rocky areas, rollovers, or places where wind has created uneven slab thickness. Southerly aspects and slopes with consistently deep and uniform snow depths offer safer options.

    The last persistent slab avalanche in the Northwest Mountains ran in late February on Mt. Axtell.  It released below a cornice on a steep face that has avalanched multiple times this winter. 

Avalanche Discussion

Persistent slab issues linger on northerly slopes, typically near and above treeline.  In the Northwest Mountains, triggering a slab that breaks on weak layers several feet deep has become increasingly unlikely.  As you transition from the deeper snowpack to the north and west of Crested Butte into the shallower regions south and east of town,  old slabs are more likely to be triggered.  Slabs are thinner, and weak layers are better developed.  Two recent natural avalanches triggered by wind drifting in the past week provide supporting evidence: one on Mount Whetstone last week and another near Snowmass over the weekend.  Both avalanches occurred in terrain with variable slab thickness due to wind effects.  Steer clear of this type of terrain in both forecast zones to reduce your chances of an avalanche.

A warming trend begins today, with record-setting heat expected later this week. Wet avalanches are expected to become larger and more widespread as the warmup progresses and overnight refreezes worsen.  This video debriefs the situation.  A hard refreeze from the past few days, and temperatures rising into the low 40s, should keep wet avalanches small and limited to a few very steep, rocky slopes today.  The danger starts rising tomorrow, with some uncertainty about how quickly.  We suggest earlier starts and finishes in the coming days, or choosing mellow terrain if you prefer riding in the afternoon slop.   

Regioni coperte