Summit Lake

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  A layer of buried surface hoar about 1 to 2' deep in the Summit Lake area is still our main concern for causing large human-triggered avalanches. This layer is most concerning above 2000' where the snowpack remains largely dry and the weak layer is preserved upright in many locations. Red flags like shooting cracks or whumphing are clear signs that this layer is a problem where you are traveling. Hand pits and snow pits can also be effective tools for identifying and assessing this layer in Summit Lake, where it is not buried as deeply as Turnagain Pass. 

  Buried surface hoar can cause avalanches on surprisingly low-angle slopes which can easily catch you off guard. We recommend a cautious mindset while dealing with this weak layer. The best way to avoid it is to stick to low-angle terrain and avoid steep slopes overhead. If you venture into steeper terrain you can avoid terrain traps to help minimize the consequences if you trigger an avalanche. Heads up, seeking out sheltered dry snow on northerly aspects could be a likely place to find a problematic slope for this weak layer. 

  

• 

  Glide Cracks

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  A new cycle of glide avalanches started last week throughout the Turangain Pass and Summit Lake forecast areas. These seem to be releasing mostly on solar aspects at mid and lower elevations. These large and destructive avalanches are unpredictable and the best way to manage them is to avoid traveling underneath slopes with glide cracks. 

  Wet Loose Avalanches have been releasing naturally and will be easy to trigger on sunny slopes (east, south, west) as temperatures warm up in the afternoon. Wet loose avalanches are typically small but can be concerning in steep terrain or if they run far down a slope and entrain a lot of wet snow on the surface. Summer trails located underneath large sunny slopes can be impacted by wet loose avalanches running into lower elevations. 

  Cornices naturally start to shed off ridgelines in the spring and can be surprisingly large when they fail. Try to avoid traveling underneath large cornices getting direct sun and give them a wide berth when traveling along ridgelines. 

  Wind slabs might also be forming today at upper elevations where loose snow remains on the surface. Northwest winds will be strongest in typical gap wind areas, like along Turnagain Arm and near Seward. Keep an eye out for active wind transport along ridgelines as a sign that wind slabs are forming. Shooting cracks and hollow-feeling pillows of snow are additional signs to help identify wind slabs.