Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
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Pericolo valanghe

Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

We are in the middle of a major winter storm that will drop over 60 cm. of snow.  Avalanche danger is rising throughout the weekend as more snow falls.  Be particularly careful on East facing slopes above treeline where you could trigger a large Wind Slab avalanche.

Problemi valanghivi

  • Wind Slabs

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

    Heavy snowfall and moderate windspeeds  mean that Wind Slabs will be our number one problem going into Sunday.  The wind has been blowing from the West and Southwest throughout the storm which means that the most dangerous slopes will be steep East faces above treeline.  Wind Slabs could be larger than we are used to, so don't get caught in a trap of familiarity.  As we may see a break in the storm tomorrow, I'll use conservative terrain management (start on low angle slopes) if I venture above the treeline.

  • Storm Slabs

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

    Heavy snowfall can lead to a Storm Slab avalanche character.  Evaluate the cohesiveness of the surface snow, as well as how well it is "bonding" to older layers.  Today at Todd ridge I found very heavy, slabby snow that overlaid weaker snow from Friday.  This is the time to use hand shears, test slopes, and shovel tilt tests to see if there is slab potential.

    (12/11/2021)

    Cohesive Surface Snow

    Photo: Gabriel Coler

  • Loose Dry

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

    The forecast is for cooling temperatures during the remainder of the storm.  This will hopefully contribute to a "right-side-up" snowpack where we'll see Loose Dry avalanches in steeper terrain rather than the more dangerous Storm Slabs.  When Loose Dry avalanches are your problem, avoid terrain that collects your sluff like gullies and other terrain traps (particularly right now when there are so many tree and rock hazards out there).

Avalanche Discussion

In open areas today observers were seeing between 20 and 40 cm. of new snow.  This overlays anywhere from 20 cm. of old snow to bare ground.  The overall height of snow appears to be 50-65 cm.  It is pretty surreal to be skiing deep pow and also be terrified of all the obstacles out there.  Be careful!  At Todd Ridge today on East facing open glades the newest snow was very cohesive and overlaid weak snow from yesterday or earlier in the storm.  While there was no avalanche activity observed I expect that is largely due to the combination of scary early season conditions and stormy weather limiting backcountry travel a bit.

Regioni coperte