Turnagain Pass

The peak of the NW outflow wind event occurred yesterday and although significant wind transport was seen in many areas, there were only a handful of small wind slab avalanches observed. All of these occurred in the upper elevations (no photos). That said, there were likely more that went unnoticed and/or were blown in quickly with the winds.

Wind transport off Tincan Proper yesterday seen from Eddies Ridge. Note the direction, southerly winds loading northerly aspects along Tincan. This is an example of terrain channeled winds as the main wind direction was almost 180 degrees different – from the northwest. 11.26.22 Andy Moderow. 

Triggering a wind slab avalanche will again be the main avalanche issue for today. Although the NW winds are slowing down currently, they could still be strong enough in some areas to continue transporting snow. Today’s ridgetop forecast is for 10-20mph NW winds gusting near 30mph. Either way, much of the terrain above the trees has seen a good degree of wind effect. Wind slabs are likely up to a foot thick at the mid elevations and could be in the 2′ range up higher.

For those headed out hunting for soft snow, watching the surface texture and signs of wind loading will be key. Winds are likely to have loaded unusual aspects due to terrain channeling, an example seen in the photo above. Along with looking out for smooth rounded pillow features, be sure to feel for stiffer snow over softer snow and watch for cracks that shoot out from you. How touchy these wind slabs are has yet to really be determined. They may be stubborn enough to allow a person onto them before releasing. Additionally, there is a layer of surface hoar from last week that was buried 4-6″ on Thanksgiving night that could keep slabs from bonding, or maybe not. These are questions we’ll be trying to answer the next few days and something for all of us to keep in mind. Quick hand pits are another tool to use to see how easy a wind slab wants to pop out.

Small pocket of a wind slab that Andrew triggered yesterday on a test slope at Eddies. A good example of what might be found today at the mid elevations and above. 11.26.22.

Another photo from Eddies yesterday of a skin track that was not only blown in, but loaded with a pillow of snow. Photo by Andy Moderow, 11.26.22.

At the high elevations, above 3,000′, we continue to track the weak October snow that sits right at the base of the snowpack. How likely this layer is to produce an avalanche is the main question for anyone headed to the higher peaks during this clear sky period. As we gather more information, we’ll be looking to see if the winds were able to overload it anywhere and create an avalanche breaking near the ground. We can’t rule this layer out as it has shown to react in some pit tests recently and facets are notoriously tricky. What we can do is remember it is there, take routes with minimal exposure, dig a pit and look for it, feel for any whumpfing, and simply be suspect, it is early season after all and there are a lot of unknowns.