Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Strong SW winds started to pile wind-blown snow onto the downwind side of ridges, in gullies, and on open wind-exposed slopes last night. As the snow and wind continue today, these initially small slabs of wind-drifted snow should increase in size and distribution. Wind slab avalanches may become possible as these slabs grow. Due to the limited snow accumulation, many of these wind slabs should remain small. Still, some could grow large enough to bury or injure a person in areas that get the high end of forecasted snow amounts or where very efficient wind-loading occurs, especially in the southern part of the forecast area along the Sierra Crest.

  Watch for clues that unstable wind slabs might exist, such as recent avalanches, blowing snow, cornices above a slope, drifts or ripples in the snow surface, and other wind-created surface textures. Identifying where unstable wind slabs may exist and skirting those areas can reduce the chances of triggering a wind slab avalanche.

   

  

• 

  Loose Dry

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–1.5

  Temperatures have steadily cooled during this storm, which should have left lighter snow on top of more dense snow. While this may mean the storm snow remains less slabby in sheltered areas, it could still sluff off steep slopes as a loose snow avalanche. Most of these avalanches may remain small since the new snow amounts may remain small, but some could entrain more snow in areas with larger amounts of new snow. Despite the cooler temperatures today, some of these could also have wet snow characteristics if the strong April sun appears.

  Wet or dry loose snow avalanches may not entrain enough snow to bury a person in most places today, but they could still knock a person over or push them off course into higher consequence terrain like cliffy areas or gullies. Pay attention to the terrain around you and avoid areas with terrain traps. Snow and avalanche conditions may change quickly from one lap to another or from one location to another as you move through the backcountry today.