Avalanche forecast

Central Cascades

Central Oregon Avalanche Center
View on map

Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

For Sunday, human triggered avalanches will be likely in wind drifted snow near and above treeline on north, northeast, east and south aspects. We also have weak layers within our snowpack that will be possible to trigger due to added stress from recent  snowfall. These layers have been found near and above treeline  primarily on northern and easterly slopes. Look for clues of instability such as shooting cracks, whumpfing and/or recent avalanches. If in doubt move to slopes lower than 30 degrees. 

Avalanche problems

  • Wind Slabs

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

    On Saturday I found reactive wind slabs in the Tumalo bowl and on nearby indicator slopes. With more snow in the forecast and plently of snow available for transport, wind slabs will continue to build on Sunday.

    Wind slabs will likely be found on N, NE, E, SE and S aspects. These will primarily be near and above treeline on leeward aspects and features that collect snow. You might also find wind slabs in lower elevation, open zones such as burn areas. Look for clues of wind slabs such as wind drifted snow, pillow-like features, textured snow surface, cracking, and recent avalanches. If you encounter these signs and/or you are in doubt, move to slopes lower than 30 degrees. 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    We have been tracking a few different persistent weak layer within our snowpack. These weak layers have been spotty and not found everywhere. On Tumalo, I was able to find buried surface hoar down 30-35cm and more weak snow down 55cm. These were found on north and northeast aspects near the summit. There are also a variety of crust layers within our snowpack that have been showing signs of weak snow forming. 

    We have not seen any avalanches on these layers yet. However, with added stress from new snow, it might be possible for a human to trigger these layers. It is best to dig into the snowpack and look for these weak layers. Performing a compression test and an extended column test are great tools for finding and assessing weak snow. Other signs of unstable snow are experiencing a whumpf or collapsing. Persistent slabs can create larger avalanches than expected. If in doubt avoid being on or under slopes over 30 degrees. 

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    On Sunday, I found plenty of cold, unconsolidated snow. With continued cold temperatures, dry loose avalanches will be possible. These will likely be on the smaller side; however, be cautious in and near terrain traps. Getting knocked off your feet near a cliff, trees, or water source could make the outcome of a small avalanche far worse. These avalanches often occur in steeper terrain and start directly underneath the rider and fan out as the surface snow "entrains" more snow as the avalanche descends down the slope.  

     

Avalanche Discussion

Our local terrain has received about 6-10" of new snow. Higher elevation zones have remained cold which has helped the new snow to remain unconsolidated. Lower elevation areas, such as Santiam Pass, are expected to see warmers temps.  This might lead to heavy/dense snow sitting on weaker/colder snow. As always, be mindful if you find slab formation, cracking, and/or recent avalanches in the snowpack.

Regions covered