Bulletin d’avalanche

Tetons

Bridger-Teton Avalanche Center
Voir sur la carte

Danger d’avalanche

Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
Open full map
Périmé — ce bulletin a expiré 11 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Snow throughout the week and southwest to northwest winds have formed wind slabs at all elevations. These slabs could be triggered by backcountry skiers or riders this morning and will increase in both size and sensitivity as they are further loaded by new snow and west winds today. Above 7500 feet, weak snow persists in the snowpack. Although there has not been recent activity involving this deep layer, failure of large dangerous avalanches remains possible, especially given the amount of loading expected over the next several days. Conservative decision making and cautious route taking are essential today.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    Soft wind slabs that lie at all elevations will be additionally loaded today. At higher elevations, they lay upon harder snow surfaces and could have depths to three feet. At low elevations they lie upon faceted snow and could release to 12 inch depths. Watch out for steep terrain with obvious areas of wind loading. Several of these wind slabs have been reported in recent days on varying aspects and elevations.

  • Deep Persistent Slabs

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

    Above 7500 feet, hard slabs with depths to five feet lie upon persistent weak layers of faceted snow. Although these slabs have become less likely to trigger, the chance remains for them to be initiated by larger loads such as groups or from a wind slab being triggered and causing a secondary failure.

Avalanche Discussion

A Winter Weather Advisory has been issued for Western Wyoming by the National Weather Service. Overnight, the mountains could receive an additional five to ten inches of new snow with the Tetons seeing highest amounts. Nighttime lows in the mountains will be around ten degrees before rising to near 20 during the day. Westerly ridgetop winds will increase to 25 to 35 miles per hour overnight before relaxing during the morning hours as snowfall intensities decrease.The general avalanche hazard is expected to be Considerable on Sunday. If snowfall amounts or wind speeds are significantly higher than forecasted, the hazard could increase to High. Two avalanche problems will confront skier and riders on Sunday. Wind slabs, with depths of one to three feet, are likely to be triggered by backcountry travelers and could release naturally. The second threat is either deep persistent slab in the Tetons and Greys River area or persistent slab in Togwotee Pass forecast zone. If triggered, these slabs will result in high consequences and could be up to six feet deep in the Tetons, four feet in the Togwotee Pass area and five feet in the Greys River forecast zone. Large triggers, such as groups of people, may be needed to trigger one of these slides, particularly in the Tetons where the persistent weak layers are the deepest and most difficult to impact. The release of a wind slab could also step down to these basal facets. A conservative approach to both terrain selection and decision making will be essential for safe travel on Sunday.

Régions couvertes