Olympics

Even in low danger, you can trigger avalanches in isolated terrain features. Slab-like snow may bond poorly to a stout crust and winds could form shallow drifts in the lee of ridgelines. If you find evidence for either, steer around steep rollovers and limit your exposure to terrain traps and cliffs where such an avalanche could be problematic.

We expect less than 1" of snow to fall with light snowfall Friday night, followed by mild temperatures Saturday morning, and another period of light snowfall Saturday afternoon. Any snow accumulation should be above around 4000 ft. With this weather forecast, we expect generally safe avalanche conditions. 

At Hurricane Ridge, around 2" of snow that fell Thursday night added to 2" of snow that buried the Early March Crust on 3/1. ONP Rangers found that above-freezing temperatures with partial cloud cover moistened snow surfaces on all aspects. This created a moist, but only slightly cohesive slab within the upside-down snow bonding poorly to the underlying crust. Riding conditions improved as the sticky surface snow consolidated on Friday. Snow surfaces will likely refreeze Friday night to form a breakable crust and challenging riding conditions early Saturday. However, the crust could soften with mild temperatures Saturday morning, re-creating the shallow slab-like conditions observed Friday. If you find upside-down snow near the surface, you can use a Shovel Tilt Test to evaluate this shallow problem. We expect that this layer will only present a problem on steep, unsupported slopes for easier trigger and above rocks, trees, or cliffs where the consequences are higher. Shallow wind slabs should also be limited to isolated areas in the lee of exposed ridgelines. We suspect that higher elevation northerly slopes may harbor dry snow above the Early March crust. Weak snow (facets) have been identified on shaded aspects in nearby zones and may exist in the Olympics. Please submit an observation if you find them.

ONP rangers also observed large rollerballs and very small wet loose avalanche activity within the shallow recent snow on Friday. This activity could renew on Saturday with the sun's energy warming slopes in the morning or rain on snow below 4000 ft in the afternoon. Reducing your exposure to steep slopes above you or terrain traps below you should limit your danger.

If more snow falls than we expect, 6" or more of snow above the Early March Crust should raise your attention that conditions may be more in line with Moderate danger. If you encounter these conditions, steer around unsupported or wind-loaded slopes steeper than 35 degrees.

No slab avalanches have been observed since a major avalanche cycle unfolded over three days ending March 1st when Hurricane Ridge received more than 4 inches of precipitation. In addition to the widespread early March Crust, you can find evidence of a widespread avalanche cycle by noting debris piles covered by 4" of snow. Some shaded slopes produced very large (D2.5-3) slab avalanches. The most notable of these slides occurred in North Bowl (N, 5200’, WS-N-R4-D3-O) where the crown stretches nearly the entire width of the feature. 

2021-22 Forecast Schedule: Avalanchedanger ratings will be issued for the Olympics every Friday through Sunday and during mid-week holidays. During the week when the Hurricane Ridge road is closed, forecast information will be updated daily to include expected conditions and relevant travel advice under the No Rating label.