Strong winds this past week have created stiff Wind Slabs above treeline. The Wind Slabs are showing strength but can propagate long distances resulting in large avalanches. Human-triggered avalanches are unlikely but would be high consequence. Wind Slab avalanches can be remotely triggered by collapsing a weak layer in a thin part of the snowpack. Be aware of what the snow you are on is connected to, especially as you approach slopes from the bottom. New snow is showing up today so I'd anticipate elevated avalanche hazard with it's arrival.
Wind Slabs will be found near ridges on Leeward slopes. Be aware of wind loaded slopes over 35 degrees. Most of the wind loading you'll encounter will be on SE-E-NE-N slopes.
Wind etching on the ridge and wind loading lower on the slope.
A storm is showing up today. Expect to see new snow today and tonight. The avalanche danger will increase today with the arrival of new snow. The firm snow currently on the surface could act as a good sliding surface for the new snow.
The new snow will be falling on a firm surface which will make a good sliding surface for new snow.
I was surprised to see such a dramatic transition in backcountry conditions yesterday. Our days of bottomless powder are over for now. The powder has been replaced with firm wind-packed snow above treeline and a rain crust at lower elevations below treeline (below 3900’).
Yesterday, Brian Hilland and I took the sleds from the Pack River up the Jeru Road with a plan to head to Fault Lake. But, we were turned around by momma and baby moose! They didn’t want to move or let us by, so we backed off, changed our plan and gave them some space. Instead, we went up the ridge south of Young’s Creek. We snowmobiled to about 5500’ and then skied the rest of the way up the ridge to 6200’.
Below treeline, there was a prominent but unsupportable rain crust on the surface. The rain crust is acting like a cap to the lower snowpack and keeping the snow underneath it cold and relatively soft. I’m curious what will happen to this snowpack when it is buried in the future. Currently, it’s a bit challenging to travel in with skis or snowmobiles due to the breakable crust on the top. Also, we did notice surface hoar growing in the treeline area. It's worth noting with the arrival of new snow. More than likely, it'll get buried and be a problem down the road.
At treeline and above, the rain crust disappeared and was replaced by a supportable wind slab making it much easier to travel. We kept a close eye on the steep, wind loaded areas and avoided them. There’s a feel of a ‘sleeping giant’ in those areas. As we approached the ridge, we encountered a lot of snow transport from strong SW winds.
Once we got to the windy ridge, we quickly ripped skins and descended via a north-facing bowl, being sure to manage our slope angle to stay away from avalanche terrain. We saw a bunch of new snowmobile and ski tracks in the steep terrain, but it wasn’t enough for us to feel okay with it. I was happy with our call. We were able to ski a fun descent and keep it safe…win, win!
Thanks you Brian and Micah from Selkirk Powder for all of your helpful observations!
