Summit Lake

Problèmes avalancheux

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2–3

  Our week of quiet weather has come to an end, and the first of several rounds of storms has arrived. Strong easterly winds will continue to add stress to multiple buried weak layers in the Summit Lake snowpack through the day. Conditions will become more dangerous once we start seeing heavy precipitation tonight. We're only expecting a trace to 2" snow during the day, with another 3 to 5" likely tonight. Rain levels are low as of this morning, but will likely rise to around 2000' overnight. 

  These deeper weak layers are difficult to assess and have a tendency to produce avalanches even when we are not getting any clear warning signs. What we do know is there are multiple weak layers that seem to be widespread and stubborn above around 2000' in the Summit Lake area. These will become more likely to produce avalanches as they experience more loading over the next few days. You can manage this problem by a very careful snowpack assessment where you are traveling, or you can avoid it entirely by staying away from steep, wind-loaded terrain.

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1–2

  Expect to find sensitive wind slabs forming at and above treeline during the day today, and look for more stable snow in terrain that is protected from the winds. The most problematic terrain features will be steep slopes below ridgelines, convex rolls, and gullies. These should remain on the smaller side (6 to 12") until we start seeing more snow arrive later tonight through tomorrow, but they will become more and more likely as the weather unfolds. In some places this new snow will is burying a fresh round of facets and surface hoar, which may make things a little more reactive.

  You can assess these surface instabilities quickly by looking for stiff snow on the surface. You can evaluate this quickly by stepping off the skin track and poking your pole into the snow or digging a quick hand pit. Small test slopes may be another effective way to collect data. Timing will be important today, and if that next round of stormy weather arrives quicker than expected we need to be ready to change plans and avoid steep terrain entirely. This storm is expected to continue through Tuesday morning, and we could see several feet of snow at upper elevations when all is said and done.