Galena Summit & Eastern Mtns

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1–2

  On Tuesday, skiers triggered wind slab avalanches in the northern and southern Sawtooths while entering steep, exposed terrain. 

  Yesterday, the wind shifted to the WNW and NW, causing cornice failure and small natural and human-triggered avalanches along wind-exposed ridgelines. Although active wind loading should subside, triggering one of these slabs remains possible today in upper and some middle elevation locations. Some slabs overlie crusts and/or thin layers of weak, faceted snow, where they could be easily triggered and break wider than expected. 

  • Look for shooting cracks, smooth dunes, textured snow surfaces, or cornices. 
  • Feel for changing surface conditions as you enter more wind-exposed terrain. Wind slabs will feel firmer than snow in sheltered locations. 

  You can reduce your odds of triggering a wind slab by moving to lower-angle terrain sheltered from the wind.

  Additional Discussion: Natural and human-triggered loose snow avalanches are possible in steep terrain. Although likely to be small, these slides can sweep you off your feet or trigger larger slab avalanches as they move downslope. Rollerballs or small herds of snowballs moving downslope indicate that the snow is warming up, and loose avalanches may follow. 

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Unlikely

  Taille

  1.5–2.5

  While unlikely, we can't write off triggering large avalanches in middle and upper elevation terrain. Unfortunately, you probably won't receive any obvious signs of instability before triggering one of these lingering monsters. We are most concerned with a layer of weak facets found near the ground on middle and upper elevation slopes, especially those facing away from the sun.

  Triggering a slide on this layer is most likely in rocky, heavily wind-affected areas where the snowpack depth is variable, and in more sheltered terrain where the snowpack is around 3 feet deep.