Central Sierra Nevada

Avalanche problems

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1

  Clear skies and near-freezing temperatures during the night have left firm snow surfaces and a thick layer of refrozen snow on many slopes this morning. Cooler temperatures and increased wind should help slow down the melting that occurs today. As a result, the window for supportable snow will last longer. Still, it is May, and cooler weather means daytime highs in the 50's above 7000 ft. and long hours of intense sunshine on all aspects so the supportable snow is unlikely to last all day. By this afternoon the overnight refreeze should melt away exposing deep wet snow on some slopes and loose wet avalanches will become possible on steep slopes. 

  Expect soft wet snow to form on E-SE-S aspects first and move to all other aspects as the day warms up. Once the snow starts getting wet and deep, it is time to avoid avalanche terrain by recreating on lower angle terrain without steep slopes above.

• 

  Glide Cracks

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1

  Falling cornices still represent a potential problem. Large pieces could break off of these overhanging waves of snow as they melt. These blocks of snow could injure a person and may entrain more wet snow or trigger a loose wet avalanche when they impact the slopes below them.

  Cornices often break farther back from their edges than expected or at unexpected times. Staying far away from the edges of cornices and not traveling underneath cornices can help avoid this problem.