Lawinenlagebericht

Salt River and Wyoming Ranges

Bridger-Teton Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Wed
Hochgebirge
4 · Gross
Waldgrenze
3 · Erheblich
Unterhalb
3 · Erheblich
Open full map
Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

The combination of recent snow and wind are creating dangerous avalanche conditions at all elevations, but especially on wind-affected slopes above 9,000'. You could trigger avalanches involving just the recent storm snow or a very large avalanche that fails on weak layers deep in the snowpack. Human-triggered avalanches are most likely in recently wind-loaded terrain but are also possible in areas more sheltered from the wind. 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    1–2

    Over two feet of snow has fallen in portions of this zone over the past 48 hours. New snow and moderate winds out of the west will form fresh soft slabs 2-3+ feet deep in exposed, mainly mid and upper-elevation terrain. While there is some uncertainty surrounding the persistent slab problem (see below), the wind slab problem is cut-and-dry: new snow + wind = dangerous avalanche conditions. The new snow is low density and will be easily transported by today's moderate to strong westerly winds. Expect to find touchy wind slabs, especially in the upper-elevation terrain of the Salt and on exposed middle and lower-elevation slopes.  These wind slabs will be dangerous on their own and will also add more weight to the persistent weak layers described below. Avoid any slope where you find evidence of fresh wind drifting.

    A small wind slab that was tiggered yesterday during a period of increased wind. Expect similar, but potentially larger, avalanches in wind loaded terrain today.

  • Persistent Slabs

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

    A thin layer of weak snow was buried on February 6th. Avalanches breaking 2-4 feet deep on this weak layer are possible today in steep terrain as new snow and wind stress the snowpack. This problem is most pronounced on the north half of the compass above 7,500’ on both sheltered and exposed slopes. Avalanches involving this layer also have the potential to propagate long distances across slopes, making escape difficult. These avalanches may be triggered without any signs of instability and could occur after multiple riders put tracks on a slope.

    Riding low-angle terrain and managing the new snow avalanche problem should be enough to avoid deeper avalanches. However, given the consequences of being caught in a slab at these depths, it is essential to build in extra margin around avalanche terrain today.

Avalanche Discussion

  1. We'll likely see some mid-storm instabilities or slides breaking on different storm snow interfaces. These slides will be on the smaller side (especially where less snow has fallen), and these issues will be short-lived.
  2. Triggering a larger avalanche will be possible on weak layers in the top portion of the snowpack that formed in early February. These newer layers are largely "unproven," making predicting their behavior with the forecasted snowfall more difficult. These layers will trend more stubborn as they get buried deeper. They include a widespread rain crust, and small facets were buried on February 6th and now lie 2-4 feet below the surface. While there has been little activity reported on these layers in this zone, it is worth noting that avalanches involving these interfaces have been triggered by people every day since they were buried in neighboring zones. Snowpits show that the recipe for these avalanches exists in the Salts and Wyoming Ranges. These layers should be considered guilty until proven innocent. Most activity observed on this layer has been in very steep (>35°) and cliffy terrain above 9,000’ that faces north through east. Keep the potential for deeper avalanches on your radar today as there will be little warning before triggering one of these slides.

     

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