Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
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Pericolo valanghe

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

In sintesi

Triggering avalanches in recent storm snow and wind drifted snow are possible. Most avalanches will be small, but slopes that have accumulated wind drifted snow can produce larger avalanches. North and northeast slopes are harboring weak snow that can make avalanches more likely. The key is monitoring the dept of recent snow above the crust....10 + inches of snow above the crust can start to pack a punch, especially in steep/extreme terrain.

Problemi valanghivi

  • Wind Slabs

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

    Lets give this one a little more time. On Wednesday, I found wind slabs to be stubborn to trigger near treeline but it was still possible. I used some small, steep, convex test slopes and definitely got some action, but avalanches were small and took some work to make them go. Remember, the forecast zone is a big area and there can be a lot of variability in conditions. In some terrain, burried surface hoar and faceted snow above the melt freeze crust can add to the likelihood of wind slab avalanches initiating and running....this is probably more the case in north and northeast facing terrain. The melt freeze crust underneath the recent storm snow/wind loaded snow is a great bench mark to reference how deep wind drifts have become. Monitor the depth of wind slabs with your ski pole. Deeper drifts can result in larger avalanches.

    (2/7/2024)

    I found triggering wind slabs to be stubborn on Wednesday, but were possible. This picture is from a small test slope on a north facing aspect near treeline.  The slope was small, thereforethe avalanche was small. 

    Photo: Aaron Hartz

  • Storm Slabs

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

    This one has quite a bit of variability associated with it. In some areas the recent snow is sticking to the crust really well and storm slabs are not a problem. In other areas weak snow above the crust will allow for small storm slab avalanches. Observers have been finding buried surface hoar and faceted snow above the crust that will make triggering storm slab avalanches more likely. This is probably more the case on northern and northeast aspects. Hand sheer tests and digging quick pits can help to identify where weak snow is still lurking above the last melt freeze crust. Utilizing small test slopes such as small steep rolls with little consequence can offer up good information. Look for cracking in the slab and small avalanches on test slopes to indicate storm slabs are possible. With 6-10" of storm snow above the melt freeze crust, storm slabs will be on the small side.

Avalanche Discussion

Most avalanches on Thursday will be small. Large avalanches will be possible in isolated pockets of terrain where wind accumulated snow is deep over buried surface hoar or faceted snow. Be aware of the terrain below you. Terrain traps such as cliffs, trees, rocks, and even long sustained steep slopes can increase the consequence of getting caught in an avalanche. 

Regioni coperte