West Slopes South

As we transition out of a major storm cycle into nicer weather, human triggered avalanches will continue to be of concern on Wednesday. Avoid wind-drifted piles of snow where avalanches could be triggered more easily. If you feel the snow getting wet and sticky from the sun, head for shadier slopes. 

It was nice to wake up to some snow on Tuesday morning after a weekend that saw areas of the West South get close to 5” of rain. Most NWAC weather stations recorded between 4-7” of new snow that was accompanied by some gusty winds. This snow is helping us to change our focus toward new snow avalanche problems and away from the wet and wild weekend which saw widespread Wet Slab avalanche activity throughout the zone. Although no longer our main focus, this past weekend is not something to be put out of your mind completely. We just received a pretty ridiculous amount of water in a fairly short time period, and as mentioned above, saw a lot of avalanches, so it’s worth revisiting quickly. We have been concerned about weak snow (12/13) sitting a few inches above a prominent crust (12/9) throughout the zone. Prior to Saturday night, this weak snow was buried as deep as 3 feet. Sunday morning brought word from Crystal Mountain Pro Patrol of multiple crowns in the Crystal Mountain backcountry, with slides estimated up to size D2. Sunday and Monday, NWAC observers and forecasters were able to confirm a widespread avalanche cycle at Paradise with over 20 avalanches counted within a relatively small geographic area and with poor visibility. The largest slide appeared to approach size D3 and had close to a 3-foot crown. On Tuesday, White Pass Pro Patrol was able to get visibility into the surrounding mountains and confirmed that there were multiple large avalanches that had occurred in the Goat Rocks Wilderness. What this tells me is that the snowpack had a weak structure and we certainly put enough load on it to test that structure, with the result being lots of avalanches large enough to bury or kill you. Does this mean that this layer is now played out and we can take it off our radar? I wouldn’t go that far quite yet, but avalanches appear to be trending toward unlikely.

As we move through the holiday week and into some nicer weather, we anticipate a busy few days in the backcountry. Before heading into consequential terrain, think about what we do and do not know about the snowpack structure and this previous storm. Take some time and do a little digging where you are looking to recreate to determine if the 12/13 layer is still present or if there are any interstorm layers that are reactive to your weight. The likelihood for natural avalanches is decreasing, but conditions could still be ripe for human triggered avalanches to occur, particularly if you find yourself in terrain that did not slide during the previous cycle or has been recently affected by the wind. When in doubt, dial back your terrain choices.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.