Central Sierra Nevada

Avalanche problems

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1

  Lingering wind slabs continue to exist on NW-N-NE-E-SE aspects in near and above treeline terrain.  These wind slabs remain reactive to triggering with wind slab avalanches up to size D2 occurring recently.  Yesterday, winds shifted from the SW to the NE and have been moderate in speed.  Wind transport along with new wind slab development will continue on SE-S-SW-W-NW aspects in wind exposed near and above treeline terrain.  Rapid warming today may weaken existing wind slabs and cornices. 

  Blowing snow, snow surface clues, and new cornice development should help to identify where new wind slabs are located.  Large cornices exist throughout the forecast region and represent potential overhead hazards.  Make a trip plan to avoid these specific areas.

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1

  Gradual warming with the possibility of sunny skies today will allow loose wet instabilities to form on E-SE-S-SW-W aspects.  Depending on the amount of solar radiation occurring at your location, this rapid warming could start by mid to late morning.  Most instabilities should be in the form of roller balls and pinwheels and be relatively small in size.  Larger loose wet avalanches that involve all of the recent storm snow could occur in some areas that experience more warming.

  Small roller balls, sticky snow, and deteriorating snow conditions will all indicate that the snow surface is warming and starting to loose strength.  Change aspects or avoid avalanche terrain that is experiencing rapid warming conditions.