East Slopes Central

Problemi valanghivi

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Likely

  Dimensione

  1–2

  Storm slab avalanches will be the largest and most dangerous near and above treeline. You could trigger avalanches within the new snow or at the interface of old and new snow. If you find snow that slides easily, stick to lower-angle slopes under 35 degrees. Avoid traveling on convex roll-overs and steep, unsupported slopes. Use extra caution in and around terrain traps, where any avalanche could have serious consequences. Use extra caution in and around terrain traps, where any avalanche could have serious consequences. Use test slopes or snowpack tests to check how well these slabs are bonding.

  A total of 1-1.5 feet of snow could accumulate by midday Thursday near the Cascade crest. In the Wenatchee Mountains, concerns for avalanches will be only where you find freshly drifted snow. Throughout the zone, a key element will be warming temperatures Wednesday night into Thursday which could add necessary cohesion to the recent snow. At the lowest elevations, you may encounter heavier, moist snow and possibly small wet avalanches. Above treeline, you may encounter subtle drifting and stiffer, wind-affected snow. Cracking in the snow, sculpted drifts, and stiff feeling snow are all indicators. Avoid leeward wind-loaded slopes over 35 degrees. 

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Possible

  Dimensione

  2

  Persistent slab avalanches are still on our radar due to a new load of snow and a weak layer of sugary snow that sits atop an icy crust from back in early December. This structure is similar to that involved in past avalanche accidents in this area and continues to warrant respect. The consequences of triggering avalanches are serious as they could easily 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 create 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. We 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.