Boletín de aludes

Elkhorns

Wallowa Avalanche Center
Ver en el mapa

Peligro de aludes

Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Open full map
Desactualizado: este boletín caducó 3 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

It will be possible to trigger an avalanche today as winds pick up and transport snow onto the leeward side of ridgelines and cross-load mid-slope terrain features.  It is still possible to trigger a deeper and more destructive avalanche in persistent weak layers buried 2-6' deep in the snowpack.  To avoid avalanches, steer clear of terrain steeper than 30 degrees, wind-loaded slopes, and areas that harbor a shallow snowpack (less than 3 feet).  

This forecast is sponsored by The Wallowa County Gamblers Snowmobile Club.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–2

    Increasing winds today out of the Southeast through South through Southwest will blow surface snow onto leeward slopes and crossload mid-slope terrain features.  These wind slab avalanches could break up to 12-16" deep.

    Look for clues of windslab development such as cornices along ridgelines, a rippled texture on the snow surface, and a stiff feel to the snow under your machine or boards.  

    Guides from Wallowa Alpine Huts yesterday were in the higher reaches of the alpine terrain in the Norway Basin area and found shallow and soft wind slabs that were isolated to the upper ridgelines.  They remained small and were sometimes reactive to ski cuts.  This will change today, and wind slabs will become deeper and more sensitive to the weight of a rider.  (see below for a photo of some scouring and crossloading on Red Mountain yesterday.)

    Avoid terrain that has recently been wind-loaded.  

    (1/11/2024)

    Rippled snow texture and cracking are clues to windslab development.

    Photo: Caleb Merrill

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–3

    Reports from the field indicate the persistent weak layers in the snowpack are becoming less reactive. They are also getting more deeply buried. This is good for the overall stability.  The reality of the mountain snowpack is that it is not completely uniform.  There are plenty of areas in the Elkhorns and Southern Wallowas that have over 7 feet of snow, and the snowpack is carrying our weight quite well over deeper weak layers.  In areas that have been stripped by the wind and have a shallower snowpack, it is still possible to trigger a persistent slab avalanche.  Check out the snowpack structure from Sarah Jakober's observation on Wednesday in the Elkhorns...it looks a bit unstable!  

    Avoid thin, rocky, and steep areas to avoid triggering a persistent slab avalanche. 

    Through your travels in the mountains today, use your probe to track the depth of the snowpack.  This is a low-likelihood, high-consequence problem.  An avalanche failing on deeply buried weak layers would likely be unsurvivable.  

    The persistent slab problem is a tricky one to manage, and snowpack tests are becoming more inconsistent.  Forecaster Victor McNeil and Eagle Cap Mountain Guides in the Western Wallowas yesterday found a mix of results in their snowpack tests, with propagation still occurring on sugar snow 3 feet deep in extended column tests in zones that had about 4 feet of total snow.  If you don't feel confident assessing the persistent avalanche problem, just keep your slope angles to less than 30 degrees.  

    (2/7/2024)

    Snowpit Graph form the Elkhorns 2/7

    Sarah Jakober

Avalanche Discussion

12"-16" of new snow sits above the Late January Rain Crust that was buried on February 1st.  Observers in the field have been finding that this snow is right-side up, meaning it is more dense near the crust and lighter (less dense) near the surface of the snow.  It seems to be well bonded to the Rain Crust in most locations. 

As time progresses, the light new snow will settle into more of a slab and could become a bit more reactive.  This will be accelerated by an increase in winds today. 

On North aspects that may be sheltered from the wind, it will remain possible to see or trigger some small dry loose avalanches.  On middle and lower elevation solar aspects that are sheltered from the wind, you may continue to see some minor wet loose avalanches as these slopes catch direct sun and warmer temperatures this afternoon. 

Be observant of how today's weather is affecting the snowpack.  Look for clues of wind loading (see above), use small inconsequential test slopes to test the reactivity of wind slabs, dry loose, and wet loose avalanches (this afternoon).  Dig down to the rain crust with your hand and get curious about how well the new snow has bonded to the Rain Crust.  

If you haven't checked out some of the recent observations from the Southern Wallowas and Elkhorns, you can find them here.  

WAC Executive Director/Forecaster, Victor McNeil wrote this excellent Conditions Blog. It provides a great summary of conditions in January and what that means for the snowpack now in February.

Keep the observations coming!  Let us know what you are seeing in your travels by submitting an observation here.  

Regiones cubiertas