Turnagain Pass

Yesterday was the second day since the surface hoar was buried on November 17th that we haven’t received any reports of human triggered slab avalanches in Turnagain Pass. With time this layer of buried surface hoar is becoming more stubborn and less reactive but this also means the slab has the potential to fracture once well onto the slope. This layer hasn’t gone away and still needs to be a major factor in slope choice. Remember buried surface hoar is persistent weak layer and human triggered avalanches are still possible. Observations around Turnagain pass continue to show that this layer is widespread throughout the terrain. Dozens of human triggered and remote triggered avalanches have occurred since November 17th on the popular slopes of Tincan, Sunburst, and Magnum. These avalanches have been small to medium in size; just large enough to bury a person or seriously injure you in a ride. Larger and/or steeper, more wind-loaded slopes that haven’t been ridden still have potential to avalanche and could have high consequences because of this weak layer. This is important to keep in mind today and throughout the weekend with more snow heading our way. Today new snow and wind increasing late in the afternoon may cause the danger level to rise. Pay attention to changing conditions, additional load will only make the consequences even larger. Be on the lookout for obvious signs of instability like blowing snow, shooting cracks and whumphing sounds.  In addition new snow and wind will be loading weak surface snow (new layer of surface hoar and near surface facets) that has developed over the past few cold clear days and may be reactive at this interface as well.

With the holiday weekend there could be more people heading into the backcountry. Be extra aware of other groups above and below you and only expose one person on a slope at a time.

National Avalanche Center Danger Scale tutorial: HERE.

Buried surface hoar found easily in a snow pit on Tincan yesterday at 2700′. Photo: Andy Moderow  

There were two glide avalanches reported on November 23rd and other glide cracks have been observed around Turnagain and Summit area. If you see a glide crack give these a wide berth, minimize time spent underneath, and remember these are totally unpredictable. They are not triggered by humans and are the entire snowpack releasing. These will also be hard to see when covered up by new snow and wind loading. 

Glide crack opening on the face of Common Bowl on Tincan. Photo: Andy Moderow