Salmon River Mountains

Lawinenprobleme

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  Yesterday, wet loose avalanches were reported on steep slopes. These avalanches are likely again today, especially below 7,000, where temperatures have remained warm, or on steep slopes on the south half of the compass (E-S-W). Wet, loose avalanches begin at a point, usually the base of a warm rock or tree, and fan out, picking up snow as they move. They are most problematic in confined terrain or on steep slopes, where they can accumulate large amounts of snow. Rollerballs, or small snowballs peeling off steep terrain, can be a helpful clue that the snow surface is weakening and that wet slides may occur. These avalanches can gouge deeper into the snowpack, triggering a larger avalanche.

  CORNICES

  Overnight temperatures are staying above freezing. Give all cornices a wide margin, and be careful along ridgelines as they can break further back than expected. Limit exposure under or adjacent to them. With warm overnight temperatures and more direct March sunshine, a cornice fall is currently one of the more likely ways to trigger a larger avalanche. 

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Unlikely

  Größe

  1–1.5

  Look for clues of wind-affected snow, such as drifts, dunes, pillows, and freshly built cornices. Watch for signs of instability such as shooting cracks from your skis, board, or sled. If you're observing signs of a wind slab, find another aspect away from wind-drifted snow. Strong winds and local terrain features can alter the prevailing wind direction. This recent observation from Lick Creek documents a wind-slab avalanche on a cross-loaded slope. Pay attention to cross-loading and wind-loading on unsuspecting slopes. 

  ADDITIONAL DISCUSSION: Triggering a large persistent slab avalanche is unlikely. Weak snow sits about 2–3 feet deep (1.5–2 feet deep around West Mountain). This layer is responsible for many large avalanches in February, mainly on wind-loaded terrain that faces NW–NE–E above 7,500 feet.