Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
No rating
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Highlights

Triggering an avalanche in the upper elevations will be likely today on steep wind loaded slopes.  Early season snow coverage is low.  Triggering an avalanche today may result in serious injury due to the presence of rocks and bare ground just below the surface.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Storm totals over the last 24 hours range from 5-13” in the Tetons.  Winds have been light to moderate out of the southwest.  This new snow is sitting on a wide variety of surfaces.  Crusts, old stiff wind slabs, facets, surface hoar and bare ground are all possible interfaces with the new snow.  Because of this variability, it will be important to be suspicious of all slopes today.  Approach terrain with caution and assume the worst.  Triggering an avalanche at the old snow/new snow interface may be easy where it sits on a crust/facet combo and difficult on the ground.  Triggering will also be more likely on wind loaded slopes. Expect slabs to be in the 1-2 foot range.  The consequences of taking a ride could be high due to low overall snow coverage.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Dry early season conditions have allowed for weak layers to form where old snow exists.  A storm over the Thanksgiving holiday deposited new snow that was then redistributed by strong easterly winds.  This has resulted in a set up of stiff wind slabs 2-3 feet thick sitting on weak snow.  While triggering is becoming less likely, it is still possible to encounter this problem in steep mid and upper elevation terrain.  This problem will be difficult to detect, as new snow has now covered up these old hard slabs.  Approach terrain with caution.  Getting caught in an avalanche on old snow holds the potential for serious injury due to generally low snow coverage.

Avalanche Discussion

An extended dry period for the month of November was interrupted by two storms.  In between storms two main processes occurred. On north facing sheltered slopes in the mid and upper elevations, snow has been faceting and growing surface hoar.  On solar aspects snow has been gradually disappearing.  Throw into the mix a significant east wind event after the Thanksgiving day storm and the result is a mixed bag of possible interfaces with this new snow.

A high degree of uncertainty exists due to both the snowpack variability and minimal observations from the field. Keeping this variability and uncertainty in mind, take the time to slow down and evaluate the snowpack before committing to terrain.  Informal tests such as pole probing and hand pits are quick and easy ways to assess the snow while traveling.  Getting out the shovel and digging down can help to take a closer look at the snowpack in more detail in specific locations. Whatever information you gather about the snow, please share your observations by clicking here. The best way to improve our understanding  of the snowpack is to share info with each other.

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