Turnagain Pass

Placer Valley: A snowmachine triggered an avalanche at low elevation near the approach to Squirrel Flats (photo below). The avalanche was about 6-12″ deep, 75′ wide, and ran for about 100′.

Crescent Lake: A snowmachine triggered a small wind slab avalanche near Crescent lake.

Snowmachine-triggered avalanche near the Squirrel Flats uptrack. Photo: Travis Smith. 02.13.2021.

With moderate winds yesterday evening through this morning, it remains possible to trigger an avalanche 1-2’ deep in steep, wind-loaded terrain. Winds began picking up late yesterday, blowing 10-15 mph out of the east with gusts above 30 mph near ridgetops, and we are expecting to see sustained winds of 15-30 mph through most of the day. Today we will be dealing with several generations of wind slabs. The slabs that have formed since last night, and continue to develop during the day, will be the most sensitive and may be up to a foot thick. But there are also persistent weak layers of buried surface hoar and near-surface facets buried up to 2’ deep that may still be reactive to human triggers, where they are capped by new or old wind slabs. While these buried weak layers are slowly gaining strength with time, we still cannot rule them out.

For today, safe travel will mean staying diligent in identifying and avoiding steep, wind-loaded terrain. You can recognize fresh wind slabs where there is stiff snow at the surface, which may feel punchy or sound hollow. They may also have a smooth, rounded appearance that looks different from adjacent terrain. In some areas, older wind slabs may be covered by a few inches of light snow, which will make them a little bit harder to identify. If you notice any cracks shooting out from your snowmachine, skis, or snowboard, it is a sure sign that the snow beneath you is capable of producing an avalanche. The same can be said if you experience a collapse, or whumpf. You can often expect to see wind loading below cornices and ridgelines, in cross-loaded gullies, or below convexities.

Sluffs: There is (hopefully) still some terrain in our area that has remained sheltered from recent wind events. We have been getting reports of folks triggering dry loose avalanches (sluffs) in steep terrain with loose snow at the surface. Be aware of these, as they can become dangerous if they carry you down steep slopes and into terrain traps.

Cornices: With another windy day today, our large cornices will continue to get bigger. If you are traveling along ridges be sure to give them plenty of space, and minimize the amount of time you spend traveling below them.

Wind textures along the ridgeline of Pete’s North at about 2750′. 02.13.2021. Photo: CNFAIC

Glide cracks have opened up throughout the area. These avalanches are unpredictable and they are large since they involve the entire season’s snowpack. Avoid spending any time on or below slopes with glide cracks, as they can release unexpectedly. If you see any new glide activity, please let us know here.