Northwest Mountains

Carefully assess the snowpack before riding on slopes steeper than 30 degrees.  On the northern half of the compass, it is possible to trigger a large avalanche that breaks several feet thick on weak layers near the ground.  Recently wind-loaded terrain is most suspect.  The safest riding is on wind sheltered, southerly aspects or slopes that avalanched last week.  

Avalanche activity has taken a sharp downturn and the danger has slowly trended down to Moderate over the past week.  In part, that is because of the extensive natural cycle on December 10th that significantly reduced the distribution of persistent slabs.  In part, that is because we have noted a very gradual decrease in the sensitivity of the problem.   However, we are still getting daily reports of large collapses: a clear sign of unstable snow (Example A, B, C).  Problems are out there, but they are becoming harder to find.  With higher quality snow right now on the more troublesome side of the compass, we know people will be drawn to those shady aspects.  This video highlights some strategies for reducing your risk if you are traveling in persistent slab territory.  Slopes that avalanched sometime during the big storm are a safer alternative than slopes where the entire season's snowpack remains intact still.  If you have uncertainty in your snowpack assessments, choose terrain with gentler consequences - terrain where you won't get beaten up by trees or buried deeply in a gulley or bench.  Some of the terrain I'm most worried about this weekend is the sparse glades where you might stumble into an intact, unstable pocket that drags you into trees.  The other worrisome slopes are in the alpine, where wind loading this past week has continued to stress the snowpack, and where evidence of previous avalanche activity is largely erased now.  The snowpack is more variable above treeline and harder to assess.  Don't forget the golden rule of avalanche safety: You can always default to slopes less than 30 degrees free from connected overhead hazards to have a safe day.  

Following the extreme wind event on Wednesday, we have had limited opportunities to get feedback from alpine terrain.  Our initial assessments suggest that wind slab formation wasn't as widespread as expected.  We did see some natural wind slabs release, but winds may have been too strong to effectively cause widespread wind slab formation in start zones. You can find lobes of dense wind slabs out there, and they are becoming harder to trigger.   Following a statewide trend, we've pulled the wind slab problem off the list, but it is still prudent to be cautious of any hard, thick drifts you encounter at higher elevations, regardless of what aspect you are on.  Slabs may be lurking lower on the slope, or in cross-loaded gullies.