Avalanche Forecast

Archived

Feb 1st, 2015–Feb 2nd, 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.

Shallow storm slabs are possible on lee northerly terrain above treeline Monday.

Detailed Forecast

An incoming frontal system will bring light rain and snow to the Olympics on Monday. Snow levels should fluctuate around 5000 feet. New snow may bond poorly to surface crusts on northerly aspects above treeline, allowing shallow storm slabs to develop.

The increasing avalanche danger Monday will be relegated to aspects and elevations with existing snow cover.

Snowpack Discussion

Mainly mild and sunny weather last week continued to deplete the Olympics meager snowpack. A frontal system on Sunday brought some light rain and snow to the Hurricane Ridge area.

There is currently not enough snow near and below treeline to present any avalanche danger.

On Jan 25th, pro-observer Katy Reid ventured out toward Mt. Angeles to observe one of the few above treeline areas accessible from Hurricane Ridge. She found snowdepths averaging 40-80 cm on N aspects with a few drifts above 1 meter. Snow cover was patchy only a few hundred feet below the ridge even on N slopes. This snow was well bonded consisting of melt forms and crusts and did not pose an avalanche problem.

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.