Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 7 years ago.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

Highlights

MODERATE avalanche danger at all elevations today as rapid warming of recent new snow creates loose wet avalanches.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Rapid warming of new snow from the past 36 hours will allow for loose wet avalanche activity to occur today in sun exposed areas at all elevations. Avalanche activity will likely be both natural and human triggered today. While loose wet avalanche activity may be fairly widespread today in steep terrain, avalanche size is expected at D1 to D1.5. An isolated size D2 avalanche is not impossible on slopes where long vertical runs are possible. With the increasingly higher sun angle of spring, increasing amounts of loose wet instability are expected on NW-N-NE aspects in addition to the expected instability on the usual E-SE-S-SW-W aspects.

    Consequences from a small size D1 avalanche will come from secondary terrain hazards. This means being pushed into rocks, trees, over cliffs, or into terrain traps by what would otherwise be an inconsequential avalanche in simpler terrain. Rollerballs and pinwheels will be the indicators that loose wet instability is present. Use low angle slopes to reduce the hazard as needed. Plan appropriately for the timing of travel in sun exposed avalanche terrain and exit steep terrain before daytime warming creates problematic instability.

Avalanche Discussion

* Reports were received yesterday of two size D1 to D1.5 wind slab avalanches that were skier/snowboarder triggered near treeline on NE to E aspect terrain on Red Lake Peak (Carson Pass area) and on Incline Lake Peak (Mount Rose area). Crowns were reported at 2 to 5 inches deep, but up to 150' wide.

* Thinning cloud cover was observed around midday yesterday in the Donner Summit area with a sun crust observed to form quickly up to at least 8,100' on Andesite Peak.

* Bonding strength of the most recent storm snow to the melt-freeze crust below it was reported to vary from weak to strong yesterday at various locations around the forecast area.

Regions covered