Bollettino valanghe

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
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Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Large variability in new snow across the zone will create dangerous avalanche conditions in the upper elevations in areas such as the southern portion of the zone which received higher amounts of new snow recently. Strong, gusty SW winds will form slabs that will be most sensitive during active loading of new snow and stress weak layers buried 2-3 feet deep. Identify and avoid heavily wind loaded slopes while choosing conservative terrain to manage the uncertainty of the persistent slab problem.

Avalanche danger will increase throughout the day with continued snow and  sustained 20-30 mph winds.

Problemi valanghivi

  • Wind Slabs

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

    New snow combined with strong, gusty W/SW winds will form sensitive slabs. Slabs depths will range 1-3 feet. Shifting winds of strong intensity will transport snow across a large array of aspects in both the middle and upper elevations. Watch for increases in reactivity throughout the day even in unsuspecting terrain. The key takeaway today is to monitor these changing conditions and use heightened caution in areas with higher amounts of new snow. Avoid wind loaded slopes by looking for terrain with rippled textures, stiffened surfaces, drifts and cracking. 

    Storm slabs will be reactive in areas with higher amounts of new snow on steep slopes near or over 35°.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    The March 20th interface is now buried 2-3 feet deep above a stout slab. Active loading of new snow with heavy wind transport will add stress and increase the chance of triggering a large avalanche. This layer is composed of facets/crusts on solar aspects and small preserved facets on northerly aspects protected by the sun. The sensitivity and distribution of this layer is hard to gauge due to the varying slab depths, recent temperature fluctuations, and differing characteristics across slope aspects. Remote triggering could occur from gentler slopes above, below, or adjacent to steep slopes. Wind loaded terrain will have the highest likelihood of finding reactivity. Long story short: persistent slab avalanches are unpredictable, so careful snowpack evaluation is required. 

    In areas with a weaker snowpack, such as the southern portion of the Wyoming Range, deeper weak layers still remain a concern. Triggering a wind slab or persistent slab on the March 20th interface could step down to these layers resulting in a large to very large avalanche. 

    (3/28/2023)

    The third rider near or on slope triggered 1' thick soft slab from the diagonal track on the right. The slab slid on a slick crust with small facets on it that was buried March 20.

    Photo: Frank Carus

Avalanche Discussion

April Fools’

Tricky avalanche conditions will exist today as snowfall amounts have varied across the Teton and Greys forecast zones, while Togwotee sustained more consistency. I’m sure a lot of us have been looking forward to those sunny spring days, but that will certainly not be the case today as you’ll find stormy conditions with continued snowfall and harsh winds. The challenge will be choosing terrain and evaluating avalanche conditions based on what you see out there. The consistent problem will be strong winds creating sensitive wind slabs. The more uncertain problem will be the unpredictable nature of persistent slabs. The easiest option to manage this problem is to simply stay humble, choose the conservative terrain, and wait for conditions to stabilize before riding those steep, challenging zones. Don’t be fooled by this complex snowpack even though it’s April.

Regioni coperte