East Slopes South

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  2–2.5

  Winds will taper off overnight, but they'll have drifted the new low-density snow into stiff wind slabs where you could trigger an avalanche. Identify wind-loaded features with visual clues like drifts around rocks or trees, cornice formations, and textured surfaces. Avoid steep slopes where you find these stiff, wind-drifted slabs. With 2-3ft of recent snow, these avalanches could easily be large enough to bury, injure, or kill a person. You may also be able to trigger storm slab avalanches on steep, sheltered slopes. These avalanches could also step down to more deeply buried weak layers, become very large, and propagate across terrain features. 

  Look for signs of instability, such as collapsing, cracks that shoot away from you, and recent avalanches. These are all indications that you are likely to trigger an avalanche. At lower elevations with a thinner snowpack, avalanches might be smaller, but they would carry high consequences if you are dragged through terrain still riddled with rocks, stumps, creeks, and other terrain traps.

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2–3

  You could trigger a very large persistent slab avalanche on various layers now buried 2-4 feet deep. These avalanches can propagate widely around terrain features, and you may be able to trigger them from adjacent lower-angle slopes. The best way to manage this avalanche problem is to avoid steep open terrain and slopes connected to steep terrain overhead. Instead, seek out low-angle, simple terrain. Before this week's storm, there were close calls with avalanches on these persistent weak layers. Now, these same layers are buried much deeper and continue to produce avalanches in neighboring zones. 

  Mission Ridge Ski Patrol triggered multiple avalanches that failed on weak, faceted snow over the Solstice Crust, and a backcountry traveler near Lake Wenatchee remotely triggered a small avalanche on a steep convexity on this same layer. White Pass Patrol and Crystal Mountain Patrol also triggered very large avalanches on persistent weak layers on Wednesday and Thursday. Buried surface hoar (1/2) was responsible for two other human-triggered avalanches before this storm. We have yet to hear about more recent avalanches on this layer, but it could still be an issue. With multiple persistent weak layers potentially lurking below the surface, extra caution and wide safety margins in your travel plans are warranted.