Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

You may encounter pockets of wind-deposited snow that are more sensitive. Identifying features such as cornices, rimed trees, and rippled snow surfaces will help you figure out where these areas may be. Stick to lower angle, wind-sheltered slopes if you encounter shooting cracks or collapsing.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1–1.5

    It will be unlikely - but not impossible - to trigger a wind slab avalanche. Deeper slabs could be lingering just below ridgelines or in cross-loaded gullies and couloirs. You might encounter small but more recently developed slabs that formed over surface hoar.  Before committing to a steep slope, check for signs of wind-loading.  Hard, uneven snow surfaces, rapid changes in snow depth, and cornices indicate that terrain has seen previous snow transport. Surface hoar often appears as a thin grey line in a snowpit wall and will not be buried very deep right now so you can easily dig a quick hand pit to check for it. Stomp around on safe test slopes representative of the slope you plan to ski or sled; you have found an unstable slab if you see shooting cracks and collapsing.

    (12/31/2024)

    Cornice fall triggered a small 1ft deep wind slab avalanche in the East South zone recently.

    Photo: Payton Schiff

Avalanche Discussion

Happy New Year!

Widespread surface hoar has been observed throughout the zone recently. We are uncertain about the continued distribution at the moment. A skiff of new snow with generally little wind fell while we passed into 2025 so it could now be buried in many locations. Buried surface hoar is notoriously weak, so my hackles are always raised when I know it might be lurking.

If you've ever found yourself wondering which direction you should look for wind loading if you encounter rippled, uneven snow surfaces, the best way I have found to think about it is that the "pointed" ridges of the ripples "point" towards the prevailing wind direction. It is a similar concept to how riming on trees usually happens on the side of the tree facing the wind.

During periods of low danger, there are still lots of excellent tools at your disposal to reduce your risk in the backcountry. Use your individual or group risk tolerance to dictate how steep of a slope you are willing to expose yourself to. You can default to shorter, planar slopes without convexities or rollovers when risk tolerance is low and practice continued caution in runouts that have exposed hazards and terrain traps. 

The weather will be fairly uneventful on Wednesday night and Thursday, but we will begin to see more activity on Thursday night. Be conscious of buried weak layers and increased avalanche hazard as more snow begins to fall. Help NWAC forecasters reduce uncertainty by submitting an observation!

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