Eastside Region

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Very Likely

  Taille

  1.5–3.5

  Very large natural avalanches are expected today in leeward avalanche paths that sit just below ridgelines near and above treeline. With good coverage at lower elevations, these avalanches could run down to valley floors and into low-angle or treed terrain you may typically think of as safe. Even careful route finding will not leave much of a safety margin today, the most straightforward strategy for managing overhead hazards from wind slabs is to avoid travel in avalanche terrain.

  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Very Likely

  Taille

  1–2

  Up to 40 inches of dense snow accumulated in the last 24 hours and another 12+ inches is expected by this evening.  Avalanches breaking within the storm snow could be large enough to bury you deeply. Storm slabs are most likely to release on steeper slopes (greater than 35 degrees) at convex rollovers in the terrain. These avalanches will be most dangerous today on slopes that end in terrain traps.  Avoid flat benches or gully features where snow from slopes and banks above you could pile up and create a deep burial. The best way to manage storm slab hazard today is to stay out of avalanche terrain altogether.

  Beware of roof avalanches in mountain communities above 6500'.

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  3–3.5

  Recent heavy snowfall and wind loading are testing the strength of persistent weak layers at the base of the snowpack. A deep persistent slab is unlikely to be triggered by a person. However, it is possible that natural avalanches will step down, triggering even larger avalanches breaking near the ground. If triggered, deep slabs can propagate around terrain features that would otherwise confine new snow instabilities creating larger-than-expected avalanches. The possibility of these larger avalanches is another good reason to stay out of the run-outs of major avalanche paths.