Boletín de aludes

Elkhorns

Wallowa Avalanche Center
Ver en el mapa

Peligro de aludes

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

Lo esencial

Sunshine and warming temperatures will increase the chances of triggering a wet loose avalanche on steep slopes this afternoon.  Avoid steeper slopes in the afternoon as the snow becomes wet and heavy.   At upper elevations, avoid wind-loaded areas as increased wind may deposit snow onto a crust and make wind-drifted slopes sensitive to the weight of a rider.   

This forecast is sponsored by Outlaw Motorsports.

Problemas de aludes

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–1.5

    Wet loose avalanches within last week's storm snow will once again become a concern today as the melt-freeze crust on the surface starts to break down.  Breezy conditions may help to slow this process, but by mid-day start to look for natural roller balls and small wet loose avalanches around rock bands on aspects that the sun directly affects.  Once this occurs, you may be able to trigger wet loose snow in the upper snowpack. 

    While these wet loose avalanches are expected to remain small, getting caught up in one can push you off your feet and carry you over consequential terrain or push you into a terrain trap such as a creek bed or gully.  

    As the snow becomes wet and heavy under your skis or machine, move to lower-angle terrain or shadier aspects.  Stay out from underneath steep slopes that see direct sun in the afternoon.  

    D1 Wet Loose Avalanche on East aspect

    Photo: Caleb Merrill

  • Wind Slabs

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

    Winds are expected to increase throughout the forecast period out of the North.  At upper elevations, wind will move snow from North aspects onto East, South, and West aspects and build a new round of shallow wind slabs.   Any new wind-drifted snow will be deposited onto slopes that likely have a slick melt-freeze crust from overnight freezing temperatures.  

    Wind slabs that formed in the middle of the past week have mostly become unreactive.  However, there could be small lingering pockets of sensitive wind slabs that are hanging out just below corniced ridgelines on NW-N-NE aspects.  

    Be wary of rippled pockets or dunes of snow that are on the downwind side of ridges, below cornices, or cross-loaded on mid-slope convex features.    Find small unconsequential test slopes to ride or walk across to test the sensitivity of wind slabs.  Avoid areas that are wind-loaded in terrain greater than 30 degrees.  

    (3/27/2024)

    The start of the wind loading process.  

    Photo: Caleb Merrill

Avalanche Discussion

Avalanche problems should be manageable today by travelers with good awareness.  Avoid freshly wind-loaded slopes.  Avoid steep sunny slopes when the sun and warmer temperatures start to provide you with clues of wet loose avalanches. 

Set yourself up for success to have a great day in the mountains by using a conservative mindset, making a travel plan with wide margins, and always utilizing safe travel techniques such as only exposing one rider on slopes at a time, keeping eyes on them, and regrouping in zones that limit your exposure.  

The 1-2 feet of new snow that has fallen since last Monday sits above a supportive melt-freeze crust from the mid-month warmup that was buried on 3/22.  Observers are finding this crust to be of varying thickness from 1" to 6" depending on the aspect and elevation.  Some weaker snow has been found around this crust, and we will be keeping an eye on this.  Monitor the new snow and its interaction with the 3/22 melt-freeze crust.  Dig down to the crust and see if the new snow is consolidating into more of a cohesive slab with less dense snow below it.   Step above the skin track and push the new snow downhill to see if it is sliding easily onto your skin track. You can also gain a lot of information about the reactivity of these stiffening slabs by riding across small test slopes that have little to no consequence.  Observers in the Western Wallowas and Elkhorns have found 4-finger hard slabs propagating in Extended Column Tests.  They are failing just above the 3/22 crust.  Check out recent observations from the Elkhorns from the last few days here and here. 

Persistent weak layers: The Needle in the Haystack

While becoming increasingly unlikely, the off-chance of triggering a deeper and more destructive avalanche failing on buried persistent weak layers buried 3-4 feet deep around the 2/1 Rain Crust is not totally off the table.  To hedge your bets against this, avoid shallow snowpack areas, especially around rocky convex rollovers.  Remember what we said earlier in the season?  Don't trust a facet until it is swimming in the river.  

This is a low-likelihood/high-consequence scenario and should be treated with careful consideration.  Before committing to consequential avalanche terrain on the north half of the compass, do your homework to evaluate the snowpack structure.  These deeply buried persistent weak layers will not provide you with obvious clues such as the collapsing or whumphing of the snowpack.  The only way to have greater certainty of whether this problem exists is to dig down to the layer(s) of concern and conduct a snowpack test.  

Cornices this time of year are big and warmer temperatures will continue to make them weaker.  They can break further back than you think.   Give cornices a wide berth, and use clues along the ridgelines such as trees and rocks to make sure you have solid ground below your feet or machine.  

If you are out in the mountains, add value to your avalanche forecast by submitting observations here.  

Regiones cubiertas