Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Fri
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

On Thursday triggering an avalanche will be likely in wind deposited snow on lee terrain features near and above treeline on west, north, and easterly facing slopes. As new snow stacks up, triggering an avalanche in the new storm snow layer will also be possible. Use low angle slopes to evalute snow conditions before committing to steep terrain and if you observe signs of unstable snow such as cracking, previous avalanches, or if you have uncertainty in the stabilty of the snowpack, stay on low angle terrain less than 30 degrees steep.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5

    Over the next 24 hours the wind will shift around the southerly directions and wind transported snow will load a variety of aspects ranging from west, north, east and southeast. Wind slab avalanches will range from small to large. Wind slabs are most reactive to triggering when they are fresh.

    Use visual clues to identify where wind slabs have formed and are building below ridge tops, peaks, and around features that catch blowing snow from cross slope winds. Monitor the depth of wind deposited snow. As the new snow stacks up and wind slabs become deeper, resulting avalanches can become larger.

    On Wednesday small skier triggered wind slab avalanches were observed near and above treeline on northerly aspects. 

     

    (3/8/2023)

    Small skier triggered wind slab on a north facing slope above treeline on Wednesday near Broken Hand.

    Photo: Gabe Coler

  • Storm Slabs

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

    This problem will depend on how much snow falls on Thursday. As new storm snow stacks up 8 inches or more be catious on steep, convex, and unsupported slopes. 

    There can be a fine line between storm slabs and wind slabs in some locations. Monitor the depth of new storm snow and in places where wind drifted snow is adding to the new snow accumulation. Evaluate the new storm layer for heavier over lighter snow that will make storm slabs more likely.

    Use small test slopes to evaluate storm slabs before travelling on steep and committing slopes.

    Where the surface snow is lacking cohesion, small dry loose avalanches may be possible in steep terrain. 

     

  • Cornices

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

    Cornices have been building at ridge tops and with more snow and wind on the way they will continue to build. Fresh cornices can be fragile,  break easily, and can trigger slides on the slope below. Be cautious when approaching ridge tops where cornices may be lurking over lee slopes. Stepping out onto a cornice could result in a break and an air drop onto the slope below. 

Avalanche Discussion

Triggering an avalanche can result in more consequences in certain terrain. Be especially cautious where an avalanche can result in a long ride down a steep slope and/or above terrain traps such as cliffs, rocks, trees, or gully features.

In central Oregon, we have many areas where forest fires, beetle kills, and other factors have thinned out forests. Use your judgement when evaluating 'near treeline' terrain....places with sparse or dead trees and clearings do not block the wind and can be subject to blowing snow and wind slab avalanches (see picture below). 

You cannot control the snowpack, but you can choose terrain. Anytime you have uncertainty, move to lower angle slopes less than 30 degrees.

Regioni coperte