Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  The variable winds of the last few days have come into alignment and gained strength. Expect strong to gale-force NE winds along the ridges. These winds will move soft snow away from slopes loaded by the SW winds during the last storm and deposit it in new places today. These new slabs of wind-blown snow may not bond to the old snow surfaces, making triggering a wind slab avalanche possible today. Even though very little new snow exists, plenty of soft snow lingers from the last storm. As a result, some of the wind slabs grow large enough to cause problems for people. These wind slabs will exist on the downwind side of ridges, gullies, and wind-exposed terrain features, but due to the NE wind, the downwind side will be different from where wind slabs normally form during storms.  

  Look for blowing snow, new cornice formation, wind pillows, and wind-created textures on the snow surface to help identify where new wind slabs are forming. Recent avalanche activity and cracking in wind-blown snow provide clear signs that the wind slabs are unstable. The strong NE winds will also scour most of the snow away from some slopes and expose firm rain crusts. Terrain sheltered from the wind can help reduce your exposure to wind slabs and firm crusts. Some sheltered terrain may also still hold soft, non-wind-affected snow.