Olympics

We're coming out of a significant rain event in the Olympics. Rapid changes to the snowpack in the past 36 hours add to our uncertainty. Wet slabs, wet loose, glide, and cornice fall avalanches may be less likely as temperatures cool, but their large size encourages you to reduce your exposure to steep, open terrain features.

1.37" of snow water equivalent fell at Hurricane Ridge from Monday evening through Wednesday morning which comes after several inches of snow fell Monday morning. With temperatures in the low-to-mid 30s throughout, the majority of this fell as rain. You'll need to adopt an assessment mind set as you head out on Thursday. We don't know how quickly the rain has drained the snowpack. Snowfall and cooling temperatures will be slow to impact the water that has already entered the snowpack. Wet avalanche problems will be low probability, but high consequence as these avalanches could be large or very large. Wet slabs may be the most dangerous if water pools on a crust. These avalanches can propagate widely across a slope and sometimes release well below typical avalanche start zones. You'll need to assess this possibility by digging into the snow and observing whether water has pooled above any crusts. Wet loose avalanches entrain wet surface snow and grow in size as they accelerate downslope where you have more than 6" of slushy snow. Glide avalanches can occur on any steep bedrock slab and will release the entire 5 ft deep Hurricane Ridge snowpack. Lastly, cornices are more likely to fail as warm temperatures make them soft and heavy. Several inches of wet snow may fall at upper elevations overnight into Thursday morning. Winds could form shallow slabs on lee slopes. While you can steer around a small wind slab on steep wind-loaded rollovers at upper elevations, the same cannot be said for wet snow problems. To minimize your risk of serious consequence, you'll need to evaluate each potential problem before exposing yourself to larger open slopes steeper than 35 degrees.

Hurricane Ridge picked up nearly 3 feet of snow since the start of the year, but was spared relative to the snowpocalypse that the Cascades experienced 1/5-1/7.  The snowpack has consolidated 1.5 ft since it reached a depth of 6 ft on 1/6. Much of that consolidation has occurred within the last 36 hours. This rapid change should give us additional pause.

On Saturday (1/8), NPS rangers and observers noted that S-SW aspects along ridgelines were largely stripped of snow and had a semi-breakable crust.  On northerly aspects and away from wind effect, the storm snow was largely right side up.  Natural cornice fall triggered at least two large wind slab avalanches between Friday afternoon and Saturday afternoon in the Hurricane Ridge area.   On Sunday, ONP Rangers noted several natural loose wet avalanches on steep sunny slopes. 

2021-22 Forecast Schedule: Avalanche danger 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.