Avalanche forecast

Olympics

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

There is minimal dry snow available for transport and avalanche danger at middle elevations, but you're likely to find enough for shallow slabs at upper elevations. Probe as you ascend, anticipating 6" slabs on lee slopes once you find more than a few inches of snow on the crust. These slabs will be more likely to harm you in extreme or cliffy terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Most wind slabs will be relegated to upper elevation terrain. Ascend with caution, probing the snow for the snow depth as you ascend. Once you find typical snow depths in the 2-3" range, anticipate shallow slabs in the immediate lee of ridgelines. Steer around steep slopes under fresh, sharp cornices or where lense-shaped pillows lie. Note the bond of the new snow to the underlying crust interfaces. If test slopes fracture more widely than you expect, shallow slabs will be more difficult to manage. Pay particular attention above cliffs, or funnel-like terrain traps where a small avalanche could bury you. Cracking snow surfaces lets you know that a slab may want to propagate on the crust.

    Example: Shooting cracks in wind drifted snow. 

    Photo: Joe Dellaporta

Avalanche Discussion

Saturday should be a cool and pleasant day with decreasing light to occasionally moderate winds and partly cloudy skies. We don't expect more than snow flurries at Hurricane Ridge, but there could be some minimal snow transport.

A sharp frontal system brought a brief period of heavier precipitation Friday morning.  Most of the 0.25" of snow water equivalent fell at temperatures between 34 and 32F as rain at Hurricane Ridge proper. Thus,  we have a new 1/10 crust up to 5500 or 6000 ft with a skiff to a few inches of snow on top. At higher elevations, you might find that the snow fell directly on older firm crusts on S and W aspects or a trap crust (breakable crust with low density snow below it, overlying a firm crust) on N and E aspects. In areas where the trap crust is preserved it could help a shallow slab propagate. We expect you could find this structure on N and E aspects above 6000 ft, so evaluate test slopes carefully if you ascend to these elevations.

On Thursday, ONP Rangers traveled in the Hurricane Hill area of Hurricane Ridge. With temperatures rising to 49F(!), melt-freeze (corn) conditions developed on aspects directly facing the sun. The ONP Rangers also investigated several other weaknesses in the snowpack. They found two layers that sheared off with a shovel (around 14 and 22 inches down, respectively), but these layers did not fail in compression tests. The snow overlying the solstice crust failed progressively on hard taps 30" down at a grain size interface. This layer is not believed to be of concern at this time.

Ample snow cover makes for easier travel above 4000', however near this elevation, holes, creeks, and other obstacles quickly impede easy navigation. 

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