Avalanche Forecast

A low pressure and frontal system will pass by to the south across Oregon and north California on Wednesday. This system will cause southeast winds in the Olympics and Cascades and will cause some snow mainly in the south Cascades late Wednesday.

Any light snow showers over the Olympics should end Thursday morning with light winds and continued cool temperatures.

New local wind slab is possible on Thursday depending on the local strength of the east to southeast winds on Wednesday. This should be mainly on northeast to southwest aspects near ridges. Older wind slab from the latest storm cycle should have mostly stabilized so the northeast to southwest aspects will be indicated. But watch for firmer wind transported snow on all aspects mainly near and above treeline.

A report from Stevens Pass indicates the December 8th layer is still possibly reactive in the Washington Cascades but we don't have any evidence of a persistent weak layer in the Olympics. This type of layer is less common in the Olympics and it won't be listed here as an avalanche problem. But head for lower angle slopes and ratchet back your plans if you experience collapsing or whoomping or have evidence of this layer such as from snowpits.

Storm slabs from the latest storm cycle should have mostly stabilized in the Olympics by this time.

Loose dry avalanches from snow from the latest storm aren't expected to still be an avalanche problem. But in steep terrain lacking a slab structure continue to watch for small loose dry avalanches near terrain traps like cliff bands where even small avalanches can have big consequences. 

With deep unconsolidated snow in sheltered areas there remains a risk for tree well and snow immersion suffocation. When near trees ride or ski with a partner and keep them in sight at all times!

Even though the lower part of the below treeline band is filling in, watch for early season travel hazards such as barely covered rocks and open creeks.

Weather and Snowpack

Cold and fair weather early last week.

The latest storm cycle began about December 8th starting with a couple day warming trend as southwest flow eroded an Arctic air mass over the Northwest. The warming trend leveled off with temperatures staying well below freezing December 10th and 11th and snowfall tapered off by December 12th. Reports from the rangers and from the NWAC station at Hurricane indicate about 3 feet of snowfall for the 4 days ending Monday morning.

Recent Observations

A regional avalanche cycle was seen December 8th-11th with some avalanches releasing on a December 8th persistent weak layer in the Washington Cascades. There was also a snow immersion fatality at Snoqualmie on December 11th and apparently a snow immersion close call at Stevens on December 10th.

South winds were seen at Hurricane during the storm cycle. These winds should have redistributed snow to N-SE aspects.

The NPS ranger at Hurricane Ridge indicated widespread natural slides had reached the road in many places by Sunday morning, likely releasing overnight during moderate to heavy snowfall.

There is a report via the NWAC Observations tab from Sunday of a triggered slab avalanche on a steep east slope apparently above Lake Angeles.