Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
View on map

Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 7 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

MODERATE avalanche danger continues near treeline and above treeline due to the possibility of encountering unstable wind slabs. Below treeline avalanche danger is LOW.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Ridgetop winds continue to shift back and forth between SW and NE. Problematic wind slabs have been observed on all aspects in near treeline and above treeline areas. Wind slab avalanches have occurred each of the past three days. The possibility of encountering an unstable wind slab continues today on any aspect in near treeline to above treeline terrain. Sensitivity to triggering may be stubborn.  Avalanche size up to D2 is expected.

    Due to the recent wind shifts, expect to encounter wind slabs on a variety of aspects while moving through terrain. Evaluate near treeline and above treeline terrain slope by slope for clues indicating the presence or absence of wind slabs. Unless a slope has been heavily wind scoured, anticipate that a problematic wind slab is present. If in doubt, opt for the more conservative terrain choices of your travel plan. Softer, less dense snow with less avalanche hazard exists on sun and wind protected slopes below treeline.

Avalanche Discussion

* Wind slab avalanches size D1 to D2 have occurred each of the past three days in near to above treeline areas. A small (size D1) wind slab avalanche was intentionally human triggered by cornice fall yesterday morning on a NE aspect in above treeline terrain on Anderson Peak (Upper Cold Stream area).

* NE winds were observed to create periods of moderate to intense blowing snow yesterday morning in some near treeline and above treeline areas.

* Buried surface hoar has been reported 1 to 2 feet below the snow surface in the Ebbetts Pass and the Spooner/Kingsbury areas.

* No signs of problematic instability have been reported from wind protected areas below treeline over the past few days.

* Snow surface warming has created thin surface crust in many sun exposed areas.

Some very minor amounts of snow surface warming may occur today in sun exposed areas at low to mid elevations. The approaching cold front is expected to limit snow surface warming this afternoon and keep a loose wet avalanche problem from forming today.

Regions covered