Bollettino valanghe

West Slopes South

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The West South should see windy and snowy weather start to subside on Monday. If you’re going to trigger an avalanche, it will likely be in wind-loaded terrain. Look for these slabs to be lingering near rocky features or convex rollovers.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Wind Slabs that formed over the weekend may still need some time to heal. Look for these slabs near ridgelines, the base of cliffs, in confined gullies, or on convex features. These slabs were formed by atypical east winds, so they could exist on different features or aspects than you are used to. Look for large “pillow-like” piles of snow, fresh drifts behind objects, or small freshly built cornices to help you identify where wind-loading has occurred.

    (12/3/2022)

    This skier-triggered slab near Paradise caught and carried an individual for a short distance on 12/3. No burial or injuries were reported.

    Photo: Sarah Ehm

Avalanche Discussion

Sunday was a bit more stormy than expected around much of the West South, with moderate to strong east winds, plus a few inches of snow. It’s been a similar story much of the last week -  snow and wind have impacted the zone since 11/27. And we may not be quite done yet. A few more inches could fall tonight, with greater accumulations possible on the volcanoes. The good news is that those cold east winds should diminish with the flow switching back to westerly and the stormy weather should start to let up on Monday. 

Those winds certainly did some damage to the snowpack around the West South over the weekend, however. Professional and public observations from the weekend indicate plenty of wind-affected snow and multiple Wind Slab avalanches were triggered. In a few cases, people were caught and carried by small slabs. Luckily, no one was injured in one of these slides as far as we know. 

The lower snowpack around in the West South consists of various crusts and mostly rounding grains. There have been reports of weak snow near these crusts both in the West South and some adjacent zones. Some larger slides triggered by Crystal Mountain Pro Patrol may have failed on weaker snow near a crust. The take-home point is that we have a large zone and the season is still young. We are in the process of collecting information, but there are many areas of the zone we have not yet visited. Take a moment and make your own observation wherever you are recreating to help inform your terrain selection. 

When choosing terrain, think about the consequences of being caught, even in a small slide. While this week’s stormy weather has helped our snowpack grow, there are still plenty of bushes, stumps, creeks, and open holes. These natural hazards could make what you might consider a somewhat insignificant mid-winter avalanche more costly.

Regioni coperte