Central Sierra Nevada

Problemas de aludes

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Possible

  Tamaño

  1–2

  As winds increase this afternoon, some blowing snow may pile up on the leeward sides of ridges and create small wind slabs at the upper elevations where some soft snow still lingers. Signs of instability on older wind slabs have decreased over the last few days, but some may remain unstable, especially in gullies or in complex or extreme terrain. Today's warmer weather and intense sunshine will weaken wind slabs on slopes that get direct sun, like cross-loaded SE aspects. This warmth and sun could also weaken the massive cornices lurking along many ridgelines and cause them to fail. Falling cornices or wind slabs could involve enough snow to bury or injure a person. 

  Watch out for slopes with cornices above them and slopes where blowing snow has piled up.

  

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta montaña
  • Límite del bosque
  • Bajo el límite del bosque

  Probabilidad

  Possible

  Tamaño

  1–2

  Warmer weather and intense April sunshine should provide enough warming for areas of unstable wet snow to form on sunny slopes. Wet snow instabilities will start as rollerballs and pinwheels. They could progress to sluffs of wet loose snow large enough to cause problems for backcountry travelers. The largest wet loose avalanches would occur on long slopes steeper than about 35° since these avalanches entrain more wet snow as they slide downhill. Sunny E-SE-S-SW-W aspects will experience the most warming, but smaller amounts of wet snow could form on NE and NW aspects due to the high sun angles this time of year. 

  Once rollerballs and pinwheels start occurring, the snow is wet enough to slide downhill. Consider moving to slopes less steep than 35 ° or to different aspects where the snow has not warmed to reduce the risk of encountering a wet loose avalanche.