Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

The combination of strong winds and new snow last night is expected to have drifted and deposited snow into cohesive slabs on the downwind side of ridges and into gully features. Clearing skies and above freezing air temperatures are expected to create areas of wet snow instability as the day progresses. Move cautiously around slopes below cornice features and near areas where roller balls and pinwheels are occurring. A period of HIGH avalanche danger is expected tonight into tomorrow.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Strong to gale force winds out of the S to SW occurred over the past 24 hours. Areas of drifting snow were observed yesterday before the new snowfall occurred. A couple of shallow skier triggered wind slabs were reported yesterday from Relay Peak, NV. New snow amounts of 2 to 7 inches combined with wind last night created new wind slabs for today. Rapid warming may make wind slabs easier to trigger today, especially on E-SE aspects.

    Use clues such as recent avalanches, blowing snow, cornice formations, snow drifts, and snow surface texture to identify areas of potentially unstable wind slabs. The downwind side of ridges and within gully features are the most common locations for wind slabs to exist. Move around these areas with caution.

    Wind slabs will further increase in size tonight into tomorrow with a natural avalanche cycle likely during that time.

    (2/15/2024)

    Natural cornice collapse and wind slab avalanche near Frog Lake Cliffs, Donner Summit area. Photo: Public

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Cloud cover cleared out last night. Sunny skies are expected this morning. Air temperatures are forecast to warm above freezing for most locations today below about 9,000' or so. A wet loose avalanche problem is expected to develop across E-SE-S-SW-W aspects as the morning progresses. Areas around exposed rocks and trees will warm the fastest, with natural roller balls expected as new snow melts and falls off of rocks and trees. Instability will spread to other sun exposed slopes as the day progresses.

    Roller balls and pinwheels are indicators that the surface snow is losing strength and wet loose avalanches are possible. For today, the largest wet loose avalanches are expecetd on sun exposed slopes with long sections of sustained slope angle 35 degrees and steeper.

    Rising snow levels tonight are expected to create wet loose avalanches on all aspects below about 8,000' as rain falls on recent new snow.

    (2/11/2024)

    Roller balls off of rocks and trees during rapid warming on ESE aspect terrain. Incline Peak, NV

    Photo: Sierra Avalanche Center

Avalanche Discussion

The storm starting tonight and lasting into Wednesday has the potential to load inches of snow water equivalent (SWE) / multiple feet of snow onto the existing snowpack.  Concern lingers for an isolated deep slab avalanche to occur during or immediately after the storm. The slopes of concern are on the eastern side of the forecast area in NW-N-NE aspect terrain above about 8,500' where some locations still hold weak snow in the bottom two to three feet of the snowpack.

Regions covered