Avalanche forecast

Central Cascades

Central Oregon Avalanche Center
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Avalanche danger

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

For Sunday, human triggered avalanches will be likely. Look for wind drifted snow near and above treeline on northerly, easterly and southerly slopes. Storm slabs will also be possible near and below treeline on all aspects. And lastly, we have weak layers buried deep in our snowpack. Although unlikely to trigger, an avalanche in these deep layers would be very large. If you see signs of unstable snow and/or are in doubt, stick to slopes lower than 30 degrees. 

Avalanche problems

  • Wind Slabs

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

    With 8-12" of snow forecasted for Sunday, human triggered avalanches will be likely. These slabs will form near and above treeline on northwest, north, northeast, east and southeast slopes.  Wind slabs generally form near ridgelines and areas that catch snow. You might also find wind slabs anywhere the wind can freely blow snow (i.e burn forest zones).  Wind slabs will continue to grow throughout the day as more snow falls. Remeber that the wind can transport new snow 3-5x deeper.

    Look for clues of wind slabs such as pillow-like features, drifts of snow, textured snow surface and hollow sounding snow. Ease into terrain and use safe indicator slopes to check for instabilties. If you see recent avalanches and/or cracking in the snow, move to lower angle terrain. 

    (2/24/2023)

    Archive photo of shooting crack in snow.

    Photo: Elliot Reed

  • Storm Slabs

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

    This avalanche problem will depend on how much new snow we recieve. If we receive 8" or more, storm slabs will become possible on all aspects near and below treeline. Storm slabs generally form in wind protected areas and are easier to trigger on steep convexed slopes. When traveling, continue to assess the depth of new snow, and look for clues of storm slabs such as cracking and/or recent avalanches. Using small convexed indicator slopes is a great way to assess for instabilities. Avoid terrain traps that would make the outcome of a small avalanche worse (cliffs, gulley, trees). The good news about this avalanche problem is that it usually goes away after a day or two as the snow stabilizes.

    (1/13/2024)

    Archive photo of storm slab

    Photo: Elliott Reed

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1.5–3

    Although this avalanche problem is unlikely, consequences of triggering a deep persistent slab would be catastrophic. These persistent weak layers are buried deep in our snowpack (around 200cm). The last observed avalanche on this layer was this last Monday (1/14) in the alpine. This is a tricky avalanche problem, as we usually do not receive feedback such as cracking or whumpfing. The best technique is to give yourself a larger margain of safety by avoiding large, unsupported slopes and shallow rocky areas. 

Avalanche Discussion

Weather models have been showing different snow totals and temperatures for Sunday. If the temperature starts to rise above freezing and/or it starts raining,  be on the lookout for unstable snow, specifically wet loose activity. If you start to see the snow surface loose cohesion, observe pinwheels and/or see recent wet loose activity, move to lower angle terrain.

 

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