Central Sierra Nevada

Avalanche problems

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  1–2

  The combination of snowfall rates around 2 to 3 inches per hour today and warming air temperatures are expected to rapidly create upside-down layering within today's new snow. Storm slab avalanches are very likely today in wind protected areas below treeline. Avalanche size will quickly increase as the morning progresses.

  If traveling non-avalanche terrain today, pay close attention to slope angles. Keep travel limited to slopes that are well below the 30 degree slope angle threshold for avalanche terrain and without steeper connected terrain above or to the side.

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  In isolated areas along the eastern side of the forecast area, there remains relatively weak, faceted (sugary) snow in the lower portion of the snowpack. This storm may deposit enough new snow load to the eastern side of the forecast area to cause failure of this old snow near the base of the snowpack. Any deep persistent slab avalanches that occur have the potential to be long running, large, and destructive.

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  1.5–3

  High intensity snowfall combined with SW wind will rapidly load new snow onto the downwind side of ridgetops and into gully features. New wind slabs will form on top of existing wind slabs that were reactive yesterday. Some avalanches could become fairly large over the next 24 hours, potentially depositing debris down near the valley floor.

  If traveling non-avalanche terrain today, expect poor visibility. Plan your method for avoiding exposure to avalanche terrain above you when you cannot see it.