Avalanche forecast

Blues

Wallowa Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Winds out of the Northwest and Southwest have loaded new snow onto leeward aspects and cross-loaded mid-slope terrain features.  To reduce your chance of triggering an avalanche today, avoid wind-loaded start zones.  Persistent slab avalanches remain possible where buried surface hoar exists now 2-3 feet from the surface.  Determine whether this persistent weak layer is present in the terrain before committing to riding any slope greater than 30 degrees. 

This forecast is sponsored by CB Construction. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3

    A layer of buried surface hoar that is now buried 2-3 feet was reactive to remote triggering last week.  I dug a snowpit on an East aspect at 5200' in the southern Blues yesterday and found a reactive layer of buried surface hoar 2 feet down.  It propagated in my Extended Column Test on the 20th hit.  As these layers of surface hoar become more deeply buried, they can be difficult to see in your snowpit wall, so it is recommended to conduct a shovel shear test and/or extended column test to see if there are any failures on this layer.  If you need to brush up on your snowpack test skills, here is a great resource.  If not confident in your snowpack assessment skills, there will be plenty of great riding in the Blue Mountains in terrain less than 30 degrees.

    (2/16/2023)

    East Aspect 5200'.  ECTP20 (2 feet down) on Buried Surface Hoar

    Photo: cm

  • Wind Slabs

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

    The Blue Mountains picked up the lion's share of Monday and Tuesday's snow.  Winds out of the Northwest and Southwest have likely loaded the new snow onto leeward aspects and cross-loaded mid-slope terrain features.  Look for patterns of wind loading and clues to wind-loaded slopes as you travel through the mountains today.  Visual clues include rounded and smooth-looking deposits of snow.  Look for corniced ridgelines and windward areas that are stripped of new snow.  Avoid traveling in wind-loaded start zones to reduce your risk of triggering a wind slab.  

    (2/14/2023)

    Active wind loading during Monday's storm 

    Photo: cm

Avalanche Discussion

Monday and Tuesday's storm brought 1-2 feet of new snow to the Blues, with the Northern Blues receiving the higher end.  The Milkshakes snotel recorded just over 2" of snow water equivalent which should have been a good test for persistent weak layers in the snowpack.  There is a great observation from Tuesday near Spout Springs that can be found here.

Yesterday in my travels in the Southeastern Blues, I noted buried surface hoar 2 feet from the snow surface, large surface hoar on the surface of the snow, and 1 natural avalanche that likely ran during the storm on Tuesday.  You can read more in my observation here.  

Recent observations from Spout Springs did not find the buried surface hoar, but you can read Sarah's observation that has details on the snowpack structure here.

In addition to the above primary avalanche problems, expect to see some small Loose Dry avalanches on protected shady aspects in terrain steeper than 35 degrees.  On more solar aspects, with temperatures rising to near freezing today, we could also see small Loose Wet avalanches.  The warning signs of these will be pinwheels and rollerballs as the surface snow on solar aspects loses cohesion.  With both of these avalanche problems, avoid riding terrain that is above terrain traps such as gullies, cliffs, or dense trees.  

Thank you for your recent observations...you are adding valuable information to our forecasts.  Keep 'em comin'! 

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