Northwest Mountains

The string of human-triggered avalanches has extended into the 12th day, with a couple of remotely triggered avalanches occurring yesterday and a rider getting caught and carried. The evidence is overwhelming that the avalanche conditions remain dangerous across many slopes, primarily facing west to north to east. Muddying the waters is a strengthening snowpack, interspersing itself into some of those same areas. So don't be surprised if you observe no signs of instability and then suddenly bump into a more reactive snowpack. Conservitive terrain selection is recommended to manage these complicated and dangerous avalanche conditions. Safer travel can be found on wind-protected southerly aspects, and as a bonus the consistent light snowfall has created good riding quality in many of those areas.

I believe we are in record-setting territory with the string of human-triggered avalanches that have occurred every day for the last 12 days. The majority of those avalanches have thankfully been remotely triggered, with the avalanches occurring a safe distance away. However, more recently, we have started to see some close calls occurring. Like this rider cutting out of an avalanche in the Kebler Pass area and this rider getting caught and carried on Mt Axtell. 

Obvious signs of instability and direct feedback from the persistent slab avalanche problem have disappeared in some areas. When this occurs, it is easy to begin stepping out into more aggressive terrain choices, and that's not necessarily wrong to do. However, avalanche conditions are complicated right now, even for the most experienced individuals. Terrain features with a comparatively stronger snowpack are butting right up next to other terrain features with a dangerous and reactive snowpack. Identifying one from the other is no easy task.

The main characteristics leading to the persistent slab avalanche problem being reactive on one terrain feature rather than another are the total snow depth and the history of avalanche activity on that slope. Where the snow depth is greater than 120cm, it is slowly gaining a little strength, and the avalanche problem is becoming more stubborn to trigger. Where the total snow depth is around 50cm to 100cm, it is more commonly reactive. These two setups can live right next to each other. There are 637 avalanches in our database from this winter, and all that avalanche activity has made for highly variable snow depths through the terrain. So you can't reliably measure the snow depth in one area and expect it to be the same on another terrain feature right next door. 

On a different note, the wind slab avalanche problem was removed from the problem list after the last couple of days with light winds. If you are getting up into the alpine today, keep in mind that we did have a northwest wind event last weekend that formed thicker slabs on the lee sides of terrain features at upper elevations. If you are traveling on bigger alpine terrain features, normal caution should involve keeping an eye out for any lingering wind slabs.