Bulletin d’avalanche

Snake River Range

Bridger-Teton Avalanche Center
Voir sur la carte

Danger d’avalanche

Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
1 · Faible
Open full map
Périmé — ce bulletin a expiré 8 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

One to two feet of snow has fallen on hard and slick snow surfaces at the mid and high elevations since Tuesday.  This snowfall was accompanied by strong winds and has created dangerous avalanche conditions. Additional snowfall today will further increase the size and likelihood of triggering slab avalanches. Avoid all steep terrain, especially in areas that have undergone obvious wind loading.  Also watch for shooting cracks as that will be an indication of unstable snow.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–2.5

    The heavy snow that has fallen over the last few days has been accompanied by strong to very strong winds.  These winds have ranged from the southwest to northwest and have impacted avalanche conditions on all aspects. The old snow surface is uniquely hard, slick and can found on all aspects. Today skiers and riders can easily trigger soft or hard slab avalanches that fail on the December 10th crust or on density breaks within the recent snow.  An additional 1 to 2 feet of snow that is expected today could bring maximum slab depths to four feet by this evening.  Stay away from steep terrain that has wind loaded or wind pressed snow. Be attentive to the fact that wind slabs can be supportive and hide the buried instabilities.  

    The old weak snow buried in early November is not expected to be active at this time and will continue to be monitored. 

    Note the unusual loading pattern on the slope in the foreground. This photo was taken last week after a very strong wind event.

Avalanche Discussion

In the Snake's , approximately 16-20 inches of snow has fallen since Tuesday containing 2-3 inches of moisture.  The winds have been extreme with gusts on Rendezvous mountain to 68 mph in the last 24 hours and gusts on Mount Coffin to 144 the day before (prior to that instrument failing). The underlying hard slick surface were formed from the last storm that ended with rain to 9000 feet and a rime crust above that elevation. Warm and sunny conditions kept the surface particularly slick. Fortunately this week's moisture started with fairly warm temperatures during the evening when the snow surface was still warm on many aspects, allowing for some bonding to occur at the old snow/new snow interface.  This bonding is by no means strong and slabs will become increasingly sensitive as they are loaded by the additional foot or two of snow that is expected today.   Avalanches at low elevations are unlikely today due to low snow depths. 

Régions couvertes