San Francisco Peaks / Kachina Peaks Wilderness

Lawinenprobleme

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  Near and above treeline, expect continued development of wind slabs on leeward slopes and terrain features. Avoid wind-loaded, rounded, pillowed, rippled or corniced slopes, as these may have new sensitive wind slabs. Yesterday (Sunday), generally, west and southwest winds loaded leeward slopes for most of the day. Expect these loaded and cross-loaded slopes to be reactive, especially as additional snow falls over the next 12 hours with continued winds. Last night, 6" (15 cm) of new snow was reported by Snowbowl at 10,800 feet. 

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Unlikely

  Größe

  2–3

  The likelihood of a single backcountry traveler triggering an avalanche in deeply buried persistent weak-layers is probably unlikely; however, the consequences will be high, with avalanches breaking wider, deeper, running further than expected, and possibly destroying trees that are 30-40 years old. However, it is possible for a traveler to trigger a wind slab avalanche that then steps down, triggering a deep persistent slab avalanche that is larger and probably unsurvivable. 

  North, northeast, and northwest slopes near and above treeline should be considered highly suspect and avoided, or travelled on with the utmost care and consideration. You are most likely to trigger these avalanches in areas with a shallower snowpack (< 1 meter) where the traveler's weight can initiate propagation on the weak layer.

  So far this season, four known natural persistent slab avalanches have occurred on ~northern and northeasterly slopes, with starting zones between ~11,000' and ~11,800'. 

  Sometime around January 16, an approximately 1.5m thick (possibly thicker) hard slab avalanche occurred in the Silverton Avalanche Path, a northeasterly slope of Fremont. See photo, and get more information here. Additionally, evidence of a second avalanche from the same storm cycle was reported in Jay's Slide (~northerly aspect). See photo. Both of these avalanches presummably failed in depth hoar near the ground, similar to the HS-N-R3-D3-O avalanche on Fremont, during the New Year’s storm cycle.