Turnagain Pass

With good visibility yesterday we were somewhat surprised not to see more wet avalanche activity after the warm and sunny day on Sunday. There were roller balls on many steep southern aspects and a few larger wet loose avalanches on the SW face of Sunburst. The light winds during the day yesterday were definitely helping to keep the snow surface cool and may have been minimizing the effects of sun to create wet avalanche conditions. We did see one new small glide avalanche on a south aspect of Penguin Ridge above Girdwood.

Small glide avalanche that released naturally Monday afternoon. Photo 3.16.24

Winds started to pick up overnight, with averages of 10-15 mph and gusts up to 30 mph out of the east. These winds are expected to persist throughout the day today and then increase overnight tonight. On Wednesday winds are expected to average 30-40 mph with gusts up to 65 mph out of the east. Despite the past few days of sunny and warm weather, there is still plenty of soft snow at upper elevations on northern aspects to form fresh wind slabs. Today these wind slabs will probably be fairly small, ranging from roughly 6-12″ deep. Tomorrow, as the winds become very strong, larger wind slabs are likely to form up to 1-2′ deep in areas where soft dry snow exists on the surface.

Wind slabs tend to form along upper elevation ridgelines, gullies, and convex rollovers. Some good tests to identify wind slabs include using hand pits, jumping on small test slopes, and stepping off the beaten path to feel for hollow, drum like snow surfaces. Shooting cracks or small avalanches on test slopes are strong signs that wind slabs are sensitive to the weight of a skier or rider in your area.

At lower elevations temperatures stayed pretty warm last night, with lows in the mid 30s F and cloudy skies this morning. Depending on when those clouds moved into the area and how much of a re-freeze the wet snow on the surface got last night wet avalanche conditions could develop later in the day. The cloud cover should help block out the sun somewhat today, but wet loose avalanches may still be possible below treeline. Keep an eye out for wet snow on the surface, and if you are sinking in more than ankle depth it is best to avoid steep terrain where wet avalanches could start.

A few recent glide avalanches have also be observed in Turnagain Pass and Girdwood over the past few days. Glide avalanches can release spontaneously and cause very large and destructive avalanches. If you see a glide crack on the slope above you it is best to avoid spending time underneath.

Recent wet loose avalanches on the SW aspect of Sunburst that look like they were skier triggered on Sunday late in the day. Photo 3.16.24

It’s been four days since the last human triggered avalanche occurred on a buried weak layer of surface hoar and facets about 1-2′ deep. We saw a lot of tracks on steep terrain in Turnagain Pass yesterday with no signs of slab avalanches being triggered. This is an encouraging sign, but it doesn’t necessarily mean that we are out of the woods yet. Persistent weak layers can lie dormant for extended periods and then become active again if they are loaded with new snow or wind. The chances of triggering an avalanche on a buried weak layer seems low right now, but it would not be impossible. To evaluate whether buried weak layers are an issue where you are travelling you can always dig down a couple feet and test the snowpack using stability tests like a compression test or extended column test.