Central Sierra Nevada

Problèmes avalancheux

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Very Likely

  Taille

  1

  Loose wet avalanches will be very likely on E-SE-S-SW-W aspects at all elevations.  Full sun with intense solar radiation will deteriorate the bonds within our recent storm snow.  Widespread loose wet avalanches are expected to occur throughout the day as rapid warming occurs from direct April sunshine.  These loose wet avalanches could be both natural and human triggered and be large enough to injure or bury a backcountry user. 

  Once a slope receives intense solar radiation, avalanche conditions along with travel conditions will deteriorate quickly.  Terrain traps, such as gullies, could magnify the consequences of even a small loose wet avalanche.  Managing aspects today will be key to finding the best snow and avoiding loose wet avalanches.

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2

  Large wind slabs have formed from the strong to gale force SW winds with our recent storm snow.  Some lingering wind slabs may still exist in steep wind loaded terrain on NW-N-NE-E-SE aspects in near treeline and above treeline terrain.  As the sun comes out today, existing wind slabs may be further weakened by intense solar radiation especially wind slabs that are receiving direct sun on E-SE aspects.

  Avoid steep wind loaded terrain and runout zones below large cornices.

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  2

  In isolated areas, wet slabs could be possible on E-SE-S-SW-W aspects at all elevations.  1 to 2.5' of recent storm snow is sitting on top of a firm rain crust.  As intense solar radiation and rapid warming occurs, the bonds that have formed within the recent storm snow will deteriorate.  Gully features and rock lined terrain may receive more radiation than open slopes.  When the snow surface becomes wet, it is time to leave the area or move to an aspect with colder snow.  Any wet slab avalanche activity could have large consequences.