Turnagain Pass and Girdwood

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  Recent Avalanches: There was a fatal avalanche accident on the back side of Seattle Ridge in Warmup Bowl on Saturday in which the rider was caught and buried, and did not survive. On Friday, there were at least 4 large human-triggered avalanches on the back side of Seattle Ridge.

  Avalanche conditions remain dangerous in the area, with the most concerning setup right in the middle of our Turnagain Pass forecast area. The main culprit is a layer of surface hoar that is buried 2 to 3' deep. This has been buried for nearly six weeks, and it is continuing to produce large human-triggered avalanches. Most recently these have been happening on slopes with dozens of previous tracks. We have also seen avalanches happen right next to snowpits that don't show any sign for concern.

  In addition to the problematic layer of buried surface hoar, there is also a shallower layer of low-density storm snow from last week that has been slow to heal. This is about a foot deep and should be gaining strength, but may still be a concern today. Given the severity of the buried surface hoar layer, this is more of an afterthought but it is important to keep on your radar.

  This snowpack is challenging to assess and it is very dangerous. This is different from the type of snowpack we are all used to dealing with this late in the season, and it is primed for another accident. If you are getting out in the mountains, the only way to really stay out of trouble is to avoid traveling on or below steep terrain. We've seen several avalanches triggered remotely from low-angle terrain connected to steeper slopes, so be aware of the terrain above you as well as the slopes you are traveling on.

   

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Yesterday's east winds have already started to back down, and should remain light today. However, they were blowing strong enough to move snow for the past 24 hours and some of those most recent wind slabs may remain reactive today. These will be around a foot deep, and are most likely to be found in upper elevations on steep slopes below ridgelines, convex rolls, and steep gullies. You may see signs like shooting cracks or collapsing, or it may be more subtle clues like stiffer snow sitting above softer snow. These relatively smaller avalanches will be big enough to be a concern on their own, but also have the potential to step down to a much larger avalanche described in Problem 1 above.

  Loose Snow Avalanches: Skiers yesterday reported widespread rollerball activity on steeper slopes, indicating the snow on the surface is becoming warm in the heat of the day. Be on the lookout for loose snow avalanches if the sun pokes through the clouds even for a short while. These often release near trees or rocks, or below cornices. They can be particularly dangerous on longer slopes where they can entrain more snow, or if they run into terrain traps like gullies or cliffs.

  Glide Avalanches: We're continuing to see glide avalanche activity across the advisory area. The most recent glide avalanche that we're aware of was on Goat Mtn. in the Crow Creek area on Monday. These avalanches are very large and unpredictable. The best way to manage this problem is to avoid spending time under open glide cracks.