Bollettino valanghe

Olympics

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Shallow wet avalanches remain possible within saturated surface snow. Use the deth of the saturated snow above a crust to gauge the size of avalanches you might trigger on a steep slope. Old glide cracks serve as a reminder not to linger under these features during periods of warm weather.

Problemi valanghivi

  • Loose Wet

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

    Saturated snow remains above widespread crusts. It will be more consolidated than Friday, but you could still trigger it. Gauge the depth of this layer to determine the potential size of an avalanche in your terrain. If the depth is more than 4", expect the potential for avalanches large enough to injure you. This depth is more likely on the lee side of ridgelines, at upper elevations, and in the southern or eastern Olympics. The other factor to consider is the reactivity of the saturated snow. Push some snow downhill or knock off a small wind lip onto a steep slope and see whether the snow entrains more and runs down the slope. If your tests show destabilized snow surfaces, steer around steep open slopes.

    Example: Wet loose avalanche activity.

    Photo: Sam Clairmont

Avalanche Discussion

Mostly dry, cloudy, and unseasonably mild conditions continue in the Olympics. As a result, dry avalanche concerns are unlikely to be found except above NWAC forecast elevations.

Hurricane Ridge has picked up around 0.75" of water equivalent since the two-week dry spell ended Tuesday evening. The first third of that moisture brought 2-3" of sticky, higher density snow Tuesday night through Wednesday night above 4800 ft. The remainder came as liquid at middle elevations. The remaining saturated surface snow sits above the Late January Interfaces (crusts in the Hurricane Ridge area), formed by over 2 weeks of dry weather. On Thursday, ONP rangers found these crusts to be supportable on the southern half of the compass, but variably supportable where they were decomposing from below on the shaded aspects. Late last week, shaded aspects had 2.5" crusts with decomposing 0.5 mm facets below them. The crusts are sufficiently thick that they are likely to form a new ground for avalanche activity in most of the Olympics.

If you travel to portions of the southern or eastern Olympics, avalanches will be larger and easier to trigger, although the danger is decreasing here as well. The Buckinghorse Snotel at 4500 ft in the Southern Olympics saw an 8" increase in snow depth Wednesday night, followed by 1-2" of liquid precipitation Thursday night through Friday.  If you find more than 6" of wet, sloppy snow above the Late January Interface, avalanches could be larger and more dangerous than forecast.

We're not sure whether recent rainfall has given renewed lubrication to old glide activity. Keep giving brown frowns respect on the slopes below and see some photos in the gallery:

  • A large 1.5-2 meter deep open glide crack was reported on 01/18 on a NE aspect at 5600 ft off the road to obstruction point.
  • A glide crack was observed, in North Bowl just below Sunrise Point on 01/17. The timing of the crack opening remains uncertain.
  • A large glide avalanche was reported on 01/15 on a steep N-NW aspect on the trail to Hurricane Hill (Steep and Icy Path). The exact timing of the avalanche is unknown.

Low snow hazards haven't gone away and the situation is worsening. Conditions are very thin on wide swaths of the compass at lower and even middle elevations. The low tide also limits avalanche activity in very shallow areas.

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