Central Sierra Nevada

Problèmes avalancheux

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1–2

  NE winds increased early this morning and are expected to continue through today and tonight.  Wind are expected to be strong to gale force along exposed ridges and peaks.  Blowing snow with new wind slab development is expected to occur in areas with the most available snow for wind transport.  This wind drifted snow should exist near ridgelines, in gullies, and on open slopes exposed to the wind.  Expect to find areas of wind scoured snow surfaces alongside areas of newly formed wind slabs.  Many wind exposed areas will be scoured down to previous firm rain crust. 

  Look for blowing snow, new cornice development,  and wind pillows to identify where new wind slabs may be forming.  Use caution in these areas where unstable snow has developed.    

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpin
  • Limite forestière
  • Sous la limite forestière

  Probabilité

  Possible

  Taille

  1–2

  Loose wet avalanches will become possible as daytime warming occurs.  Above freezing air temperatures with full sunshine will make for another day of spring like conditions.  Steep sun exposed slopes in wind protected areas will be the most likely location for this avalanche problem to occur.  Strong NE winds will limit warming of the snow surface in wind exposed terrain today at the higher elevations.  Roller balls and pinwheels will be early indications of the snow surface warming and loosing strength.  Larger loose wet avalanches could also become possible, especially around rocks, cliff bands, and gully features.

  Use caution on these steep sun exposed slopes as rapid warming occurs today.  Terrain traps and downslope hazards; such as rocks, trees, cliffs, etc, can magnify the consequences of even small avalanches.