Turnagain Pass

Triggering a wind slab today in steep leeward terrain is possible today. Winds over the past few days have deposited additional snow, continuing to cross load and top load terrain features. Look for pillowed snow, listen for hollow sounds and pay attention to stiff snow under your skis, snowboards or snowmachines. Investigate if the stiff snow is overlaying soft snow. Watch for shooting cracks and remember even a small pocket of wind slab in steep terrain can have high consequences. Wind slabs are notorious for letting you travel out onto them and then breaking above you. Evaluate carefully before committing to steep terrain from above or below.

****In some parts of the advisory area 5-7′ of settled and wind effected storm snow is sitting on a layer of old faceted snow on top of the Thanksgiving Rain Crust. This still needs to be a consideration as you travel into the backcountry today. This Deep Slab concern is a low probability, very high consequence set-up.  As always it is important to use safe travel practices: ride slopes one at a time, have an escape route planned, regroup and/or park in safe areas and watch your travel partners. Do not overload slopes with multiple skiers, boarders or snowmachines. 

Wind transporting snow on Turnagain Pass. 

Very large cornice features have formed throughout the region as a result of a two-week storm that deposited ~9’ of snow and was accompanied by very high winds. Cornices have the potential to fall naturally or be triggered by the weight of a person or machine and can be very dangerous. Travel under or on them should be avoided. They have the tendency to break farther back from the ridge than expected and can trigger an avalanche on the slope below by adding a lot of weight quickly. As you approach ridgelines and the entrances to backcountry bowls make sure you aren’t accidently traveling on overhanging snow. A snowmachine took a dip into the cornice crack near the top of the Seattle Creek uptrack.

A large crack was found on the Magnum ridge above the cornice.

Glide cracks are continuing to appear throughout Turnagain Pass. They may lead to Glide Avalanches which are incredibly difficult to predict and will be deep and destructive if they do release. Travel under glide cracks should be avoided. In addition the cracks can be quite deep and falling into one could be very hazardous. They are sometimes mistaken for old avalanche crowns. The characteristic “brown frown” shape can help you identify the glide cracks in the terrain. 

Glide cracks on Seattle Ridge just north of the common uptrack.