East Slopes Central

Problemas de aludes

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Possible

  Tamaño

  1

  Scattered windslabs may rest over the most recent (12/21) crust at upper elevations. Slabs will be thickest in higher elevation, wind exposed terrain, and near ridgelines. Look at snow surface texture and feel for stiff snow over weaker snow to identify wind slabs. Use test slopes or snowpack tests to check how well these slabs are bonding. As always, avoid wind loaded slopes steeper than 35 degrees if you find signs of instability such as shooting cracks. You may be most likely to trigger one of these on very steep and unsupported slopes above treeline.

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Unlikely

  Tamaño

  2–3

  Persistent slab avalanches are still on our radar due to a weak layer of sugary snow that sits atop an icy crust from back in early December. This structure is one that is responsible for many avalanche accidents in this area, and continues to warrant respect, even though the chances of initiating a slide have decreased to unlikely. It is the consequences of triggering a slide that are paramount, because it could easily be large enough to bury or kill you. These dangerous and surprising avalanches can catch even the most experienced backcountry travelers. The best way to stay safe is to avoid the type of terrain where you are most likely to trigger one. Keep your distance from slopes 35 degrees and steeper that are open enough and tall enough to produce large avalanches. Watch for obvious signs of instability like recent avalanches, whumphing collapses, or cracks shooting through the snow.

  Look for weak snow just above a thick melt freeze crust roughly 1.5ft to 3ft below the surface, above 5,000ft. We suspect this is more problematic in the northern half of the zone, and closer to the crest where the dry snow exists above these weak layers. The most dangerous slopes will be at the higher elevations, in steep unsupported and rocky terrain. Recent southwest winds may created stiff slabs in some of this terrain. As recently as the 27th observers performed snowpack tests that indicated propagation is still possible with this layer of concern. I found it to 3ft below the surface on an east aspect at 6,600ft in the Near Treeline band near Chickamin Ridge in the Chiwawa Drainage. These layers are not a concern where you find a stout crust near the surface, such as areas further south and at lower elevations.