Avalanche Forecast

Another Pacific frontal system, in the long series of recent storms, is moving into the Olympics Tuesday afternoon. This next system will cause renewed light to moderate snow and light to moderate westerly winds later Tuesday and Tuesday night. This should begin to build new areas of wind slab on lee slopes below ridges and create some isolated storm slabs.

Dangerous avalanche conditions should persist Wednesday, especially in the near and above treeline zones. 

Expected avalanches should remain within the near surface storm related weak layers. Watch for evidence of wind deposited snow or pillows. Test for inverted of strong over weak storm snow and give cornices a wide margin. 

In addition, recent strong winds above tree line have scoured much of the snow from exposed slopes, leaving exposed rock and vegetation. Terrain anchors are still causing anchoring at the lowest elevations, but less and less with every storm passage!

A series of cool storms has deposited increasing storm snow at relatively low freezing levels since early December. The last rain event occurred to the Hurricane Ridge elevation on December 17th. Over the past five days Hurricane Ridge has received about 3 feet of snow as of Tuesday morning. 

No observations have been received since the weekend.

NWAC pro observer, Matt Schonwald and an NPS ranger traveled extensively Friday around Hurricane Ridge testing the recent storm snow. As of Monday morning, Dec. 21, the Hurricane Ridge study plot had a snow depth of 5 feet! From observations last Friday, about 5500 feet the December 9 crust was buried about 1.5-2 feet and now is likely another foot or more down. 

The snowpack in the Hurricane Ridge area was mostly unconsolidated low density surface snow with a gradually increasing density down to the well bonded crust, a very good profile as of late last week. No slab character was noted in the upper snowpack during testing. Only isolated wind slabs were noted with no releases. Extensive cornices were noted on north to northeast sides of ridges. Skiing was very good.

The most recent snow over the past few days has fallen at very cool and even temperatures and without significant winds.

The main avalanche problem in the Hurricane Ridge area remains surface snow problems, most notably wind slabs and possible storm slabs. The most likely aspects of wind slab formation, should be N-SE facing, however, they may exist on a variety of aspects near ridges. Large cornices were also noted in observations last weekend.