Northwest Mountains

Last weekend, there were multiple close calls with human-triggered avalanches and a notable natural avalanche cycle. Don't trust this avalanche problem, it is not your friend, even if it tries to lure you in with a treat. These early season conditions are difficult to manage as many of the slopes that actually have enough snow to ride, are the same potentially dangerous slopes harbering the avalanche problem. You can find less avalanche risk on southerly-facing slopes and terrain below 10,500ft, but it is much more difficult to find enough snow to ride in those areas.

The current weather is allowing the sensitivity of the persistent slab avalanche problem to slowly decrease. The key word there is "slowly". Previous winds have left many slopes with harder and thicker snow surfaces that will be more stubborn to human triggering. While the recent cold weather and clear conditions have the facet machine operating in high gear, with those facets starting to eat away at the slabs in other areas. The avalanche problem is by no means "healing". This is where the concern comes for the potential of backcountry riders beginning to step into bigger terrain features because they are lured in by fewer obvious signs of instability. We are stuck with this classic continental snowpack and this persistent slab avalanche problem. Until we either go into an extended dry period where everything facets away, or we develop a notably deeper snowpack that begins to strengthen. Conditions will get better eventually, we just need to be patient.  🧘‍♀️

Yesterday's forecast discussion is copied below. In summary, it highlights a couple of close calls and the trends coming out of last weekend's avalanche data. 

Over the weekend there were two close calls with human-triggered avalanches. On Purple Ridge in the upper Slate River Valley, a group of skiers remotely triggered a large avalanche from a low-angled slope below. While over the hill in Marble, the fourth skier to enter a slope triggered a large avalanche and became partially buried. That same avalanche further partially buried their two partners that descended before them. We have further documented many natural avalanches that also ran over the weekend. The conundrum of finding enough snow to ski or ride, but not getting caught in an avalanche, is making for difficult conditions to manage.  

Looking at our avalanche database, the vast majority of the avalanche activity has occurred on northerly to easterly-facing slopes, near and above 11,000ft. This terrain is highlighted by the persistent slab avalanche problem. On southerly-facing slopes, we have observed a number of small storm or wind slab avalanches that ran on Saturday during a period of elevated westerly to northerly winds. Observers traveling on southerly-facing slopes yesterday found those previous wind drifts to already be stubborn or unreactive to triggering. If you are traveling on higher southerly-facing slopes today, you can mostly expect normal caution while continuing to manage wind-loaded terrain features for any outliers that could still produce an avalanche. If you are traveling in the highlighted problematic terrain, you can expect to encounter a reactive avalanche problem. 

Of other note is the geographic location where the avalanche activity is occurring. Have a look at the avalanche activity map, under the observations tab. You will notice that the majority of the avalanche activity has occurred in the "snow belt" located in the northwest mountain forecast area. This "snow belt" is where we see the deepest snow accumulations throughout the winter and where we currently have the deepest snow depths now. Less avalanche activity has occurred outside of this area, at lower elevations, and in the southeast mountain forecast area. That lesser amount of avalanche activity is in part due to the shallower snow depths contributing to the avalanche problem being more isolated. While those shallower snow depths are also making travel difficult, so we don't have any data points from areas like Brush Creek and Cement Creek for example.