Bollettino valanghe

Tetons

Bridger-Teton Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
Open full map
Non aggiornato — questo bollettino è scaduto 11 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Four to five feet of snow has fallen over the last week. Snowfall has and continues to be accompanied by strong southwest to northwest winds. Wind slabs could be easily triggered by riders or skiers at all elevations and all aspects. Natural avalanche activity is also likely above 9000 feet today. Once triggered these slabs could cause the failure of persistent deep slabs that lie upon weak snow near the base of the snowpack. Yesterday a snowboarder died in large avalanche with a two foot crown on the Pyramid which is located just to the south of Jensen Canyon. Travel above 9000 feet is not recommended today and cautious route finding and decision making is essential. Known avalanche paths and their run out zones should simply be avoided and safer, low angle, conservative terrain should be the focus of any backcountry travelers.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Skiers and riders could easily trigger new and recently developed soft wind slabs on all aspects and elevations. At the higher elevations, these slabs could have depths of one to three feet and fail on old hard surfaces or density breaks within the recent snowfall. At the lower elevations, they lie upon faceted snow and could release up to 18 inches deep. Beware of known starting zones, or any steep terrain with obvious areas of wind loading. The sensitivity of these slabs will increase today as strong winds veer to the northwest this afternoon.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Above 7,500 feet, hard slabs with depths to six feet lie upon persistent weak layers of faceted snow. Since Wednesday night, over four inches of snow water equivalent have been added to the snowpack. Large triggers, such as groups of people or the release of a wind slab, may be needed to trigger one of these slides although in isolated areas a single person could cause their failure. If triggered, these slabs will carry high consequences. Yesterdays slides on the Pyramid and in Horseshoe bowl likely failed on this layer although slab depths were lower given both paths had large releases in late December.

Avalanche Discussion

Periods of light snow or flurries are possible in the mountains this evening as the system moves to the east. By morning valley fog is expected on the east side of the Tetons and in Star valley. Mostly clear skies are expected above the low cloud layer although some mountain top clouds could linger. Temperatures are to rise from the teens to the mid to upper twenties. Northwest winds are to have ten to twenty mile per hour averages overnight. The general avalanche hazard is expected to be Considerable in the Teton and Southwest trails areas and Moderate in the Togwotee Pass area where significantly less snow has fallen during the past week. Winds slabs will still be easily triggered in steep wind loaded terrain with depths to three feet at higher elevations. The chance also continues for large dangerous avalanches to occur above 7500 feet where weak snow persists at the base of the snowpack. Large triggers such as the triggering of a surface avalanche are the most likely events to cause their failure. In areas where that weakness is less buried these slabs will be easier to trigger. A cautious approach is needed when dealing with rapid loading events such as has occurred over the last seven days.

Regioni coperte