San Francisco Peaks / Kachina Peaks Wilderness

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Likely

  Taille

  1–2

  Strong southwest winds have created wind slabs on leeward slopes and terrain features. Winds are forecasted to continue for the next several days and will continue to redistribute the snow. Anticipate wind slabs avalanches to be likely for the foreseeable future with continued winds and additional snowfall over the next few days. Avoid wind-loaded, rounded, pillowed, rippled or corniced slopes, as these may have new sensitive wind slabs.

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2–3

  New wind slabs may be large enough to re-energize the dormant persistent weak layer of basal facets. Human-triggered wind slab avalanches may have enough force to step down, creating propagating failures in the weak layer of basal facets. If so, the avalanches may become very large. The basal facets and depth hoar have been documented on northerly and northeasterly slopes between 11,000' and 11,800.  Over the last few weeks, this weak layer has become less reactive as it has been buried deeper with strong slabs above it, providing additional support. We have not had any recent persistent slab avalanches; however, this week's snowfall could reenergize this problem.

  The best way to manage the risk from persistent slab avalanches is to make conservative terrain choices and avoid slopes with this suspected problem.