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 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering avalanches in previously wind deposited snow near and above treeline are possible. Evaluate wind loaded slopes and when in doubt, stick to slopes less than 30 degrees steep. Cornices at wind exposed ridge tops have the potential to break naturally or under the weight of a person. Wet snow avalanches will be possible at all elevations, especially on slopes in the direct sun as the surface snow becomes wet and slushy. Be cautious on steep slopes that are in the direct sun especially during the warmest time of the day. Small avalanches can still have big consequences in steep terrain and above traps such as cliffs, rocks, and trees. 

 

Problemi valanghivi

  • Cornices

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

    Cornices can weaken during times of warming and direct sun exposure. Don't linger under cornices. Be especially cautious at ridge tops. Observers have been finding cornices to break easily in the last few days. It can be difficult to tell where a cornice is when approaching from behind. Try to get a good vantage point before stepping onto a ridge if you can't see over the other side. Breaking through a cornice can lead to an unexpected fall down the slope below. 

    (3/13/2024)

    Some cornices have broken off already and/or are small like in this picture. There are also some large ones lurking out there. Cornices can be sneaky and hard to see when you are approaching a ridge top.

    Photo: Aaron Hartz

  • Wind Slabs

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

    Existing wind slabs are trending toward being more stubborn to trigger, but it is still possible. This problem is more about the existing wind slabs and I don't expect the wind shift to northerly/easterly winds to move much snow and create new wind slabs due to the mid and upper elevations already being so hammered by the previous winds. As always, observe signs of blowing snow and look for changes. If you see signs of blowing snow moving to west or southwest slopes, use your evaluation skills to look for new wind slabs forming around lee features. 

    Steep, extreme, and unsupported terrain are the suspects where avalanches are more likely to be triggered. Utilize snowpack testing such as hand sheer tests. Look for signs of cracking in the slab, on small safe test slopes, as an inidicator that wind slab avalanches can happen. On a sunny day after the storm, I expect people will be getting into the high country to knock off some lines. It is woth taking the time to do some homework before committing. 

    (3/13/2024)

    Previous wind slab avalanche. Small (D1). Timing and trigger unknown; possibly triggered from a cornice break. East aspect, near treeline. 

    Photo: Aaron Hartz

  • Loose Wet

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

    There will be some variety in this problem through the elevation bands. The upper elevations will remain a little cooler and these will be more promintent around rocks on the steep slopes that can heat up and shed snow and ice causing wet loose avalanches on the slopes below. The low elevations will be warmer and wet loose avalanches may be bigger. Watch for signs like roller balls and the snow surface becoming wet and slushy (to ankle deep or more) as an indicator that wet loose avalanches are possible. Wet loose avalanches will be more of a problem in steeper terrain, think 35 + degrees and on slopes in the direct sun. Use timing and aspect to reduce your exposure to wet avalanches.....i.e. move to slopes that are not in the direct sun.

    Wet slab avalanches are also possible. 

    Archive photo (Aaron Hartz)

    Small wet loose avalanches in steep terrain initiating around rocks heating up in the sun.

Regioni coperte