Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Gale force NE winds have deposited slabs of wind-blown snow on the downwind side of exposed terrain features like ridges, gullies, and open slopes. Most of these wind slabs will exist in areas near and above treeline, but a few may lurk below treeline since the winds have been so strong. Expect less blowing snow today due to decreasing NE winds and the fact that much of the soft snow has already moved. Triggering a wind slab avalanche remains possible today. These stiff wind slabs often break after someone gets onto the slab and has already committed to a slope. Today's strong sunshine could make triggering one of these wind slabs easier on sunny slopes.

  Recent avalanches, snow surface cracking, blowing snow, newly formed cornices, piles of drifted snow, and snow surface texture can all help identify where unstable wind slabs may exist. These clues can also indicate where wind-hammered snow lurks. Traveling in areas sheltered from the wind can reduce the chance of triggering a wind slab and increase your chances of finding softer, less variable snow.

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Due to the strong March sun and warmer daytime temperatures, wet loose avalanches could become possible in some places today. Most should remain small. Still, long, steep slopes could produce wet, loose avalanches large enough to cause problems for people, and terrain traps like gullies or cliffs could magnify the consequences of small avalanches. Exposed rocks and trees can soak up the sun and accelerate wet snow formation near them.  Sunny wind-sheltered slopes at lower elevations will experience the most warming today. Continued NE winds may help keep windward aspects cooler, especially at higher elevations.

  Sinking into boot-top deep wet snow, roller balls, and pinwheels can indicate that enough wet snow exists that wet loose avalanches may soon become possible. Moving to a different aspect where the snow remains colder or simply recreating on lower angle slopes without steep sunny slopes above can help reduce the chances of encountering a wet loose avalanche.