Avalanche forecast

Central Cascades

Central Oregon Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanches that were associated with our latest snowfall will mostly be a thing of the past.  While triggering an avalanche on the weak layers deep in our snowpack continues to be unlikely, any resulting avalanche would be catastrophic.  The Moderate avalanche danger for Saturday reflects the need to identify and avoid steep, shallow and unsupported slopes that may provide a trigger point for these deeper layers.

Avalanche problems

  • Deep Persistent Slabs

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

    Very large avalanches on peristent weak layers have occurred within the past week.  Deep Persistent Slabs are a difficult avalanche character to work with because they don't provide us with much feedback.  We don't expect to see the widespread activity, collapsing, or whumphing that we associate with Persistent Slabs.  Similarly, frequent digging to assess these weak layers is prohibited by their depth.  The best strategy for Deep Persistent Slabs is to increase your margin of safety.  Specifically avoid travel on unsupported, shallow slopes.  I find myself avoiding big, steep slopes in general when I have increased uncertainty.

     

Avalanche Discussion

Our most recent storm snow from Tuesday through Thursday produced a fairly widespread avalanche cycle of Storm Slabs, Wind Slabs, and finally as the snow turned to rain on Thursday evening, Wet Slabs and Wet Loose avalanches.  Most instabilities associated with that new snow have likely run their course by now.  That recent snow had fallen on surface hoar, but I was unable to find reactive burried surface hoar in the upper snowpack today.  I don't anticipate that enough new snow will fall on Saturday to create new avalanche problems.

Observers are working hard to continually assess our Deep Peristent Slab character by digging deep profiles and probing to find old faceted layers.

Regions covered