Turnagain Pass and Girdwood

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Recent Avalanches: Yesterday, a human triggered dry loose avalanche in Todd's Bowl stepped down to a deeper weak layer. Fortunately no one was caught. Over the past two days multiple avalanches were reported in Portage and Whittier at low and upper elevations. We suspect they were around 1’ deep, failing at the new/old snow interface and likely occurred in the afternoon when warm temperatures peaked. We have limited information on natural avalanches that released around Seattle Ridge and Lynx Creek. 

  Avalanche conditions are becoming more complex. There are multiple weak layers responsible for the avalanches that occurred yesterday. In Turnagain Pass one of these layers will be more concerning on wind loaded slopes where storm snow has blown into wind slabs around 1’ deep. We are also looking out for weak layers buried around 2’ deep that are capable of producing a large avalanche. Yesterday, there was a report of a loose snow avalanche that triggered a deeper avalanche in Todd’s Bowl. This is a possible scenario where dry loose on shady aspects or wet loose on sun aspects have the potential to trigger a deeper avalanche with higher consequences. 

  Portage and Placer Valley received around 12” of snow earlier this week which was enough to assist in multiple natural avalanches over the past 2 days. These avalanches are telling us that this problem could occur on most aspects and all elevations. As stated above, deeper weak layers in these places and in the Girdwood Valley are still possible where the snowpack is more dangerous. 

  Be aware that each of these areas in the Turnagain Pass zone have similar and unique avalanche problems. Portage, Placer Valley, and Girdwood Valley are places where it will be more likely to trigger an avalanche. If you plan to head out it could serve you well to look at the recent observations for the area you intend to go. Snow tests may be unreliable especially if sluffing snow triggers a deeper avalanche. Manage sluff and look for safe spots that are out of the path of a potential avalanche. Only expose one person at a time in avalanche terrain. Safe travel protocols and conservative decision making will lower the risk of getting caught in an avalanche. You can avoid these problems by choosing lower angle slopes

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Temperatures look to warm up in the afternoon which will increase the chance of wet avalanches. Clouds are expected to increase through the day which could shade sunny slopes or trap heat from the sun. Regardless, if the air starts to feel hot and the snow becomes wet and heavy your best bet is to head to shadier slopes (north aspects). These have the potential to gain momentum and carry a lot of snow and you into trees or terrain traps.  

  We are close to the time where warm temperatures and a saturated snowpack will begin to release wet slab avalanches. This problem is also more likely in the afternoon and can be managed by moving to shadier slopes or staying in upper elevations where it is colder.