Turnagain Pass Avalanche Forecast

After a surprise mostly sunny day yesterday, clouds are forecast to move in today ahead of the next series of stormy weather. Easterly ridgetop winds are already rising this morning and should be blowing 15-25mph with gusts in the 30’s by later this afternoon. Snowfall should begin this evening with 2-3″ possible by tomorrow morning (to sea level!) and another 2-3″ through the day tomorrow. Another, more powerful, system looks to arrive tomorrow night.

With a generally stable snowpack now, the main avalanche concern moving forward will be associated with today’s increasing winds. There is not much snow to transport so any wind slabs that are able to form will most likely be small and in the high elevations. Once the snow starts falling, wind slabs will get a bit larger. There is a new crop of surface hoar that has been forming over the past few days. We saw this on all aspects and elevations on Seattle Ridge yesterday, even on the ridgelines above 3,000′. It has also been reported region-wide by others over the weekend. It is a fairly small layer (2-5mm feathers) but sitting on hard surfaces in many places. Until proven otherwise, we have to assume any new snow or wind slab sitting on this layer won’t bond quickly in the coming days.

For today, paying attention to changing conditions will be important. If you are in an area the wind isn’t transporting snow, the danger will remain LOW. Normal caution avalanche issues will still be present however. These are cornice falls, dry sluffs on steep slopes, and lingering wind slabs in steep rocky terrain. As always, good habits, such as giving cornices a wide berth and being suspect of old wind slabs in steep exposed zones are good practices.

A new batch of surface hoar with some small near surface facets were found on old wind crusts and melt freeze crusts. Sorry – the camera really wanted to focus on John Sykes riding instead of the surface hoar… This photo is from the Seattle Creek drainage yesterday 3.1.22.

Surface hoar was also found on very hard snow that exists along the highly wind affected Seattle Ridge. 3.1.22. *Big shoutout to Alaska Mining and Diving Supply and BRP/SkiDoo for providing the avalanche center with a new ‘loaner’ snowmachine each season, which gets us into these motorized zones!*

On the far north and south corners of the forecast zone, and to the south in Summit Lake, we are keeping track of old faceted layers that sit near crusts from Halloween and New Year’s. Although these layers are unlikely for a person to trigger, they could become active again with the next strong storm. The system coming in on Friday may not be strong enough to overload these layers, yet this is something we will be watching. In case you missed it yesterday, take a look at this report from Summit Lake that is outside of the advisory area – HERE.

Another additional concern are glide cracks.  A few more glide cracks have been noticed around the region. Be sure to keep an eye out for them and limit time under them. They can release unpredictably into a glide avalanche at anytime.

Glide crack, looking west from the Seattle Ridge weather station in the small drainage between 1st and 2nd Bowl. The crack looks to have stopped opening due to the old snow still covering up the ground. 3.1.22.