Avalanche Forecast

Archived

Feb 6th, 2015–Feb 7th, 2015

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Olympics.

Heightened avalanche danger will be limited to above treeline in the Olympics on Friday.

Detailed Forecast

The next system in SW flow aloft should bring moderate amounts of precipitation to the Olympics on Saturday with snow levels oscillating around 5000-5500 feet. This may build some shallow storm and wind slab on lee aspects above treeline. Only storm slab will be identified as a problem, but it is mostly likely on lee aspects. The snowpack near and below treeline is spotty and does not generally pose an avalanche threat.

Snowpack Discussion

The small amount of new snow received this week at Hurricane Ridge has been washed away by heavy rains Thursday and Friday.

The latest observations from Hurricane are from January 25th by pro-observer Katy Reid. She made a trip out to Mt. Angeles to one of the few above treeline areas accessible from Hurricane Ridge. She found snowdepths averaging 40-80 cm on N slopes with a few drifts above 1 meter. Snow cover was patchy only a few hundred feet below the ridge even on N facing slopes. This snow was well bonded consisting of melt forms and crusts and did not pose an avalanche problem.

There is currently not enough snow near and below treeline at Hurricane to cause avalanche danger.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.