Avalanche Forecast

Gradual cooling is underway as of Wednesday afternoon in the Olympics as a cooler trough approaches. Light to moderate showers at further lowering snow levels are expected Wednesday night and early Thursday.

Cool air should be over the area by Thursday with only scattered light showers expected as high pressure rebuilds over the area.

This weather will allow the previously wet snow pack to begin re-freezing and strengthening, causing an overall decreasing trend in the avalanche danger. 

We have already experienced a region-wide avalanche cycle, such that the overall likelihood of wet snow avalanches has diminished. However, destructive wet slab avalanches are still being reported in isolated areas in the Cascades as of Wednesday. Realize that wet snow avalanches, specifically wet slab avalanches, are very hard to predict and demand an extra amount of caution when engaging with avalanche terrain.

The cooling trend through Thursday will lower the overall danger as surface snow begins to form a crust and liquid water continues to drain.  

With that said, there remains a possibility of further wet slab avalanches, especially on unsupported slopes with a rock face bed surface.  These types of avalanches are highly unpredictable and not necessarily tied to peak warming or rainfall. Besides their huge destructive potential, wet slab avalanches often surprise backcountry travelers when they run further than expected. 

Cornices have been weakened and prone to failure due to rain and mild temperatures. Very large cornices have been reported in many areas and have been involved in recent accidents and close calls. A cornice failure could trigger a large and destructive wet slab avalanche.

If you manage to venture into the above treeline zone Thursday, expect new or previous wind slab mainly on NW-SE aspects due to recent SW-W winds. Continue to watch for firmer wind transported snow on all aspects, especially in areas of complex terrain.

Weather and Snowpack

The first week or so of March was very cool and snowy. It looks like Hurricane had about 40-50 inches of snowfall during this period.

A strong frontal system brought increasing precipitation and winds along with a warming trend to the Olympics and Cascades on Thursday 3/9. On Thursday night rain fell  up to about 5000-5500 feet in the Olympics. Natural and skier triggered avalanches were reported on Friday 3/10. 

Moist W-SW flow and a stalled frontal boundary have produced periods of moderate to occasionally heavy rainfall at most locations throughout the Olympics and the west slopes of the Cascades on Monday through Tuesday. Only light precipitation has fallen in the Hurricane Ridge area Wednesday between disturbances. 

Recent Observations

The Hurricane NPS rangers reported that a snowboarder triggered a large cornice release on Friday 3/10 which in turn triggered a very large slab avalanche on the locally named Pit Bull path (NE aspect at about 5000 ft). NWAC is working on a blog post featuring photos of this avalanche incident. We hope to post online in the next few days. 

A loose wet avalanche near the summit of Mt. Angeles in turn triggered a large slab avalanche on S-SE slopes at about 6000 ft. Other loose wet avalanches from S-SE slopes crossed the main road below the level of Hurricane Ridge on Thursday 3/9 or Friday 3/10. 

Goat Creek avalanche where it crossed the road at about 3500 ft. Avalanche occurred 3/9 and the photo was taken 3/10. Photo by Dave Turner.