Turnagain Pass Avalanche Forecast

The last known avalanche observations were natural wind slabs that occurred during last weekend’s outflow wind event on 11/25 to 11/26.

Lingering wind slabs that formed during yesterday’s NW outflow wind event are the primary concern for today. Those wind slabs likely formed up to 1′ deep on top of weak faceted surface snow, which can cause them to remain reactive for longer than normal. They are most likely to be found along upper elevation ridgelines, on convex features, and in cross loaded gullies. Keeping a close eye on the surface conditions around you and stepping out of the skin track to feel for stiff and hollow feeling wind transported snow is a good way to identify wind slabs in the terrain.

In addition to wind slabs, the surface snow has been loosing strength over the past week and turning into facets under the clear skies. We have observed some large skier triggered loose snow avalanches (aka sluffs) that could knock a person off balance in steeper terrain. Heads up to try and manage sluff by stopping and letting it go by you or skiing across the fall line to allow it to run beside you.

Mixture of weak surface snow (surface hoar and surface facets) that could be buried by a wind slab after yesterdays outflow wind event. Photo 11.30.22

A layer of faceted snow on the ground at upper elevations continues to be on our radar, despite being over two weeks since the last avalanche activity on this layer. This persistent weak layer could produce avalanches 2-4′ deep, but it is currently unlikely for a person to trigger an avalanche on this layer. Part of the reason we are still concerned about this layer is that the snowpack depth at upper elevations remains thin and variable, with only 1-3′ of total snow depth in many areas. That means it would be relatively easy to find a spot where the weight of a person could initiate a failure on this persistent weak layer.

The other main reason is that we still don’t have a lot of information about the snowpack structure and general conditions from the higher alpine elevations of the forecast region. Some of our observations over the past week have indicated that this layer is gaining strength and others indicate that it is well preserved and just waiting for a new snow load to potentially become active again. We are seeking more information from high alpine areas to help fill our knowledge gaps, so please submit an observation if you are able to look for this layer at the base of the snowpack above 3000′!