Lawinenlagebericht

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Mon
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 3 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Avalanche concerns remain primarily in the upper elevations on wind loaded terrain where wind slabs 1-2 feet deep could still be triggered on steep, unsupported slopes especially near cliff features. These slabs along with rapid warming could also stress buried weak layers where the potential exists to trigger a much larger avalanche in areas with a weaker snowpack such as the Wyoming Range. Look to identify areas that have been previously wind loaded and pay attention to warming in the afternoon as avalanche activity on solar aspects will become more reactive.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Significantly moderate to strong S/W winds during and after our last storm system on March 15th created slabs in isolated terrain mainly in the upper elevations. Wind slabs developed 1-2 feet deep could still be reactive as they lie on weak snow surfaces such as crusts and low density snow. With the continued high fluctuations of day to night time temperatures these slabs are becoming more stubborn and difficult to trigger. But these slabs could still be reactive on steep, unsupported slopes near ridgelines or cross loaded features such as cliff bands. Look for these wind slabs especially if venturing into consequential alpine terrain above treeline. Look for obvious signs of previous wind loading such as cornices, rippled surface textures, and stiff slabs above weak surfaces

    Wind slabs, cornices, and loose snow could become more reactive with warm temperatures and increased solar radiation from the sun today. Be aware that cornices can break further than expected and cause unusually large avalanches on buried weak layers. 

    (3/16/2023)

    12-16" soft slab on steep 40 degree slope. Failed on new/old interface on melt freeze crust. 

    Photo: Drinkard

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    Weak layers buried 2-3 feet deep are still haunting the snowpack across all aspects and elevations in areas with a shallower snowpack such as the Wyoming Range(check out the recent reports near Gunsight Pass  and Blind Bull). Drastic differences lie in the snowpack between the Salt, Snake, and Wyoming Ranges. These weak layers are not as concerning in the Snake and Salt River Ranges based on observations in snow pits and overall avalanche activity. The main concern in the Wyoming Range is the Feb 18th layer composed of crusts and facets. The recent warming trend has not been sufficient enough to stabilize this layer. Triggering a large avalanche remains possible on steep slopes over 30°, especially on wind loaded terrain and during rapid warming in the afternoon.

    (3/17/2023)

Avalanche Discussion

Communication

Good morning, today we bring you another day of clear and sunny conditions optimal for venturing into the mountainous backcountry terrain. There has been a shortage of these sunny days this winter, so people are frothing to explore new terrain. Yesterday we saw a decent amount of backcountry enthusiasts stepping out into complex terrain. The main concern continues to be those tricky wind slabs that lie on a variety of weak surfaces, hence the prolonged reactivity of these slabs. We don’t anticipate these becoming a persistent problem as daily fluctuations in temperature really help lock these in place. You could find wind slabs in the places you least likely want, in steep consequential terrain. Remain suspect of wind loaded pockets and test the reactivity with quick stability tests. 

Our attention now shifts to that persistent slab problem in isolated areas of the Greys. This problem could persist for quite some time in the Wyoming Range due to the very poor structure, so continue to practice patience and understand the consequences of triggering one of these large avalanches. 

With an anticipated high number of backcountry users in complex terrain today, make sure to communicate to one another. Strive to avoid incidents involving different groups by talking to other users about where and how they plan to ride a zone or line. I’m sure we’d all love to have these mountains to ourselves, but the reality is we don’t. Practice clear, concise communication with one another as it’s a critical tool you will use and improve upon every single day for backcountry travel and life in general.

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