Avalanche forecast

Southern Wallowas

Wallowa Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Riders will easily trigger dry loose avalanches (sluffs) that will run far and fast in terrain greater than 35 degrees.  These avalanches could easily push you into/over terrain traps such as gullies, cliffs, or trees.  They could be large enough to bury you in the wrong location.  With additional snow, wind, and settlement throughout the day- the storm snow may start to form more of a cohesive slab, likely becoming more reactive.  This is more likely to occur at elevations above treeline 

Avalanche problems

  • Loose Dry

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

    Fast moving Dry Loose Avalanches were easily triggered yesterday in terrain 35 degrees or steeper.  Expect to find the same today.  This type of avalanche problem type is predictable.  Manage this problem through your terrain selection.  It will be found on all aspects and elevations in terrain approaching or exceeding 35 degrees.  If you trigger a dry loose avalanche in the wrong location (top of a cliff, above a gully, or in dense trees)- a rider could easily be injured, buried, or killed.   The light density storm snow provides excellent riding on lower angle slopes.  

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    While the chances of triggering a deep persistent slab are becoming increasingly unlikely, we will not turn our backs on the fact that the lower portion of our snowpack structure still is not so great in the Northern Wallowas.  Forecasters found the Solstice Rain Crust about 3 feet from the surface- with very weak sugar snow below.  There is a 2 foot slab of very cohesive snow (Pencil hardness) sitting above the SRC.  This is a double edged sword.  Where the slab is Pencil hard and 2 feet plus thick, forecasters feel that it is helping to keep one from impacting the weak snow below the SRC   We know that slabs of snow vary in thickness and hardness throughout terrain.  If you find an area that has a thinner or softer slab of snow- you will more easily trigger the weak snow near the ground.  This is precisely the scenario that caused a skier to trigger a large deep slab avalanche in McCully Basin on 2/1/21.   Use terrain to your advantage- and if deciding to commit to avalanche prone slopes, try to stick to the meat of the run and stay away from the likely thinner areas on the edges of the terrain.  

    2/12/21 NE Aspect Big Sheep Drainage. Strong upper/Middle Snowpack. Weak Lower Snowpack.

Avalanche Discussion

We really like how this storm has brought us new snow to the area in light waves since Thursday.  The snowpack doesn't like rapid change, and this current storm system has been kind to the snowpack- so far.  The Northern Wallowas have picked up 8" of new snow with .6" of Snow Water Equivelant since Thursday morning.  Temperatures have stayed cold- preserving the excellent riding conditions and delaying the settlement of the snow into a cohesive slab.  As time proceeds, or with the addition of wind and additional snow- a storm slab or wind slab may start to form on exposed upper elevation areas.  Quick hand pits over a variety of aspects and elevations will give you a good idea of how the new storm snow is bonding and whether it is reactive at the old snow interface.  The use of safe test slopes will also give you a great idea of how this snow may be settling into a slab.  If you see shooting cracks, feel the snowpack collapsing, or see recent avalanche activity-  Choose less complex terrain with slopes less than 30 degrees.  

 

 

 

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