Summit Lake

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  1–2

  Strong east winds gusting 50+ mph will continue to create wind slabs 1 to 2’ thick on any slopes exposed to the wind. Slopes protected from the wind are also capable of storm snow avalanches as anywhere from 1 to 2’ of storm snow may have fallen above 2,500’. Both of these avalanches could be easy for a human to trigger. These are dangerous avalanche conditions where the safest option would be to avoid traveling in avalanche terrain.

  Strong winds peaked across all of the forecast zones yesterday with winds on Sunburst gusting from 60 to 119 mph for most of the day. Today’s weather could see more than 5” of new snow in Summit Lake with 50+ mph winds to transport it. East winds are forecast to increase throughout the day creating larger wind slabs that will be easier for a human to trigger. Triggering storm slab avalanches and dry loose avalanches are also likely in mid to upper elevations where all slopes have seen large amounts of snow fall. Both wind slab and storm slab avalanches may release naturally, or by a cornice triggering an avalanche above you. These will be large enough to bury a person. 

  We are all itching to get out and ride some powder. Traveling in the backcountry today during a storm is much more challenging than on calmer days. It may be harder to see wind loaded slopes or feel stiff snow underneath you. Clues such as shooting cracks may be harder to see or feel. The easiest place to trigger an avalanche will likely be on steep wind loaded slopes. The safest option today is to avoid traveling in or above avalanche terrain. If you do choose to get on steeper slopes, carefully assess the snow, look for clues of instability such as recent avalanche activity, and shooting cracks, and travel from safe zone to safe zone. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  2–3

  Rain, snow and wind has placed a lot of stress on weak snow buried near the ground. This will make triggering this layer likely as the storm continues today. The safest option is to avoid traveling on steep slopes until the storm passes.

  Last week's storm event produced large avalanches in Summit Lake that ran to valley bottoms. These avalanches likely failed on faceted snow near the ground. The storm yesterday released a few avalanches on slopes at higher elevations that ran to valley bottoms. As the storm continues today, traveling on steep slopes at any elevation seems risky. In upper elevations wind and snow will be loading start zones, areas where avalanches tend to start. At mid elevations the snow has not frozen hard in almost a week. Eventually all this rain will find weak layers of snow and flow along it decreasing the snowpack's strength. Until the snow has a chance to refreeze and adjust to all this new snow the best option is to avoid riding or traveling in or above avalanche terrain. Carefully assess the snow, look for recent avalanche activity, and travel from safe zone to safe zone if you do get out today.

  

• 

  Glide Cracks

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  These wet and warm conditions seem to increase glide avalanche activity. Each day we are hearing of or seeing new glide cracks releasing into large avalanches. In Turnagain, glide avalanches are releasing on all slopes at all elevations. Try to minimize or avoid spending time under these brown cracks as they can be large and destructive.