Central Sierra Nevada

Problemi valanghivi

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Possible

  Dimensione

  1–2

  Cool NE winds will work to keep the snow surfaces frozen today while the strong March sun and daytime highs above freezing work to melt the snow surfaces. Whether or not wet snow instabilities form on a slope will depend on which of these has more of an influence. In upper elevation areas exposed to the cool NE winds, less warming will occur and wet snow instabilities should remain limited. In lower elevation areas with less NE wind and warmer temperatures, more warming will mean wet snow instabilities like pinwheels, rollerballs, or sluffs of loose wet snow may be possible. 

  Pay attention to the weather and snow conditions as you travel and be willing to change plans as conditions change. If you are in a sunny area and start to see signs of wet snow like rollerballs, pinwheels, or wet sticky snow, move to a colder aspect where the snow remains cold and dry or switch to lower angle slopes.

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alta quota
  • Limite del bosco
  • Sotto il limite del bosco

  Probabilità

  Unlikely

  Dimensione

  1–2

  Some hard slabs of wind drifted snow still linger on slopes loaded by the intense NE winds. Triggering one of these hard wind slabs has become unlikely in most places. Still, some instability is not impossible on an isolated terrain feature, especially where the hard slab is thinner or in more complex terrain like couloirs, hanging snowfields, cliffy areas, unsupported slopes, and steep convex rollovers. These hard slabs mostly formed on the NW-W-SW-S-SE aspects in near and above treeline terrain.

  Smooth areas of drifted snow, firm hollow-sounding snow, ripples on the snow surface, and other wind-created features can all help identify where these hard wind slabs may exist.