Northwest Mountains

The mild weather this past week has resulted in a downturn in avalanche activity as the upper snowpack has gained strength and can now better support light loads like a human. While the likelihood of triggering an avalanche has decreased, the weak layers buried 2 to 4 feet deep are still very capable of producing a large and deadly avalanche. Yesterday, 2 large avalanches were explosively triggered near Irwin, as the most recent reminder of our current predicament. Obvious signs of instability have become rare, and the poor snowpack structure will not be revealed unless you dig into the snowpack. Careful evaluation is required to identify the specific terrain of concern. More likely areas to trigger an avalanche are where the snowpack depth becomes variable in wind-affected terrain or thins near rock outcrops for example. 

The avalanche danger has dropped one rating level. If you are an active backcountry rider, don't be so naive as to look at this change, as your callout to start pushing your terrain choices. If you keep pushing and find the wrong spot at the wrong time, the potential avalanche size could be deadly. 

The drop in the danger rating reflects how current conditions are changing. The potential avalanche size remains large to very large and better fits a CONSIDERABLE danger rating. The travel advice and likelihood for avalanches better fit a MODERATE danger rating, as the areas for triggering an avalanche become more specifically located, natural avalanches are unlikely, and human-triggered avalanches remain possible. This is a classic Colorado setup. You can get away with riding a lot of terrain, but if you find the wrong slope or the wrong trigger point, the resulting avalanche could easily kill you. Don't gamble with those stakes. If you are in avalanche terrain, gather information about the snowpack and terrain characteristics. If you can't make a confident decision about the likelihood of triggering an avalanche in that area, reduce your slope angles and look for simpler terrain choices. The snow is riding fast, so even the low-angle slopes are shredding. There have been a significant number of avalanches over the last several weeks. So in some areas, the current avalanche problem has been removed. Be mindful of potential hangfire lingering in that terrain or right next door. You will need to have a keen eye and an informed knowledge of the avalanche history to identify this terrain. If you don't know what a trigger point is, click the link and get informed. You will continue seeing this term used in upcoming forecasts. The upper snowpack is strong, and it often does a good job supporting the weight of a human. This makes it more difficult to affect the weak layer below, collapsing the snowpack, and triggering an avalanche. Those more likely trigger points will occur where that strong upper snowpack, or slab, is thin and your weight can more easily affect the weak layer below. While this classically occurs near things like rock outcrops, we are observing the most reactive snowpack in wind-affected terrain with variable snow depths. A collapsing snowpack and shooting cracks are obvious signs that you have found a reactive avalanche problem, but you will not see those obvious warning signs if you are traveling in areas that have a strong slab over the buried weak layer.