Bulletin d’avalanche

Tetons

Bridger-Teton Avalanche Center
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Danger d’avalanche

Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 7 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Yesterday's storm system brought 10 to 16 inches of snow with 1 to 1.5 inches of moisture to the mountains. Last night the Wyoming Department of Transportation triggered an avalanche in Glory Bowl that ran to the roadway. The new snow and strong winds have created dangerous conditions at the mid and upper elevations. Large to very large slab avalanches could be triggered by the weight of a single person. These slabs lie on persistent weak layers that formed earlier in the season and cannot be trusted. These dangerous slabs could be triggered on slopes that have been previously crossed by skiers, snowboarders or snowmobilers. Safe travel will require excellent terrain evaluation skills, restraint and a knowledge of the distribution of buried persistent weak layers. Avalanches are unlikely at the lower elevations.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3

    At the mid and upper elevations the new snow and strong winds have increased the load on weak faceted snow layers that persist near the base of the snowpack. In steep terrain humans could trigger dangerous slab avalanches up to four feet in depth. Yesterday's load has greatly increased the consequences of being caught in one of these large slab avalanches. Understanding and identifying where the old weak snow is present is essential in avoiding this hazard.

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2

    At the higher elevations strong southwest to northwest winds have created dense wind slabs on leeward aspects. These fresh surface slabs could be triggered by skiers or riders in steep wind loaded avalanche starting zones. These slab are one to two feet deep and could easily step down to faceted snow layers at the base of the snowpack and become a large and dangerous persistent slab avalanche.

Avalanche Discussion

Cloud cover is to increase overnight and skies are to be overcast on Tuesday morning. During the afternoon skies are to be mostly cloudy. Temperatures in the mountains are to be near ten degrees in the morning, rising into the low twenties in the afternoon. On summits west winds are to have averages between ten and fifteen miles per hour. The general avalanche hazard will remain Considerable. Above 8500 feet, dangerous avalanche conditions continue. Persistent weak snow layers that were covered in late November could be triggered by presence of a single person, even after a slope has been tracked several times. These conditions exist mostly on slopes with a northerly component in aspect although in higher terrain weak snow can be found on more aspects, therefore snowpack evaluation is warranted in all steep terrain. These slabs could have depths of one two four feet. Recent snow and strong winds have further loaded this weakness and conditions remain sensitive.

Régions couvertes