Seward and Lost Lake

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  Recent Avalanches: Yesterday there were many wet loose avalanches occurring below 3,000' in the Seward area. This included a wet loose avalanche that ran almost to sea level just outside the forecast zone on a south facing slope south of Lowell Point. Earlier last week on Tuesday or Wednesday there was an avalanche on the south side of Mt. Marathon that put 10' of debris in Lowell Canyon. 

  These recent avalanches we are aware of are not the type we are most worried about right now. Our biggest concern is that someone could trigger a large avalanche on a layer of buried surface hoar 2 to 3’ deep that has been responsible for many human-triggered avalanches in Turnagain Pass, including the fatal avalanche that occurred Saturday (see video to the right for a description). There is less avalanche activity in the Seward zone than Turnagain Pass (as far as we know), which could be due to less traffic or it could be that the weak layer isn't as widespread in Seward. Either way we don't trust the snowpack in Seward/Lost Lake yet and we can enjoy the snow on low angle terrain to have a safe day.

  The other thing we have learned about this particular weak layer is that it is unusually difficult to assess. In Turnagain Pass we got stable snowpit results 50 to 100' from where a large avalanche was triggered by a person 2 days later. This means we don't trust our snowpit results and we are relying on the knowledge that this layer exists and has produced large human-triggered avalanches to inform our conservative terrain choices. 

   

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Unlikely

  Size

  1–2

  Winds were strong enough on Saturday evening to make some wind slabs in the upper elevations. Although unlikely, there may be a stubborn one out there that could be triggered in steep terrain. Wind slabs can feel hollow and if you poke them you will find stiff snow over softer snow. An old wind slab may let a person get way out onto a slope before releasing so watch for hazards below and be ready with an escape plan. East wind today is forecast to pick up later this afternoon and will likely create some fresh wind slabs that will become a problem tomorrow. 

  Other hazards today include cornices, which will continue to fail as we head into warm springtime conditions. Give cornices space on the ridgeline and watch for them from below. The glide crack on Mt. Marathon is getting bigger and wrinkling below. Glide avalanches are completely unpredictable and if this glide crack releases the debris would hit the Bench Trail. If you find yourself passing underneath this glide crack make a plan to pass quickly and one at a time or better yet move into the large trees to the east of the trail to avoid this hazard.