Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Some areas of unstable wet snow are expected to form today on sun exposed, wind protected slopes. Increased ridgetop winds last night are expected to have blown and drifted recent storm snow into new slabs on downwind terrain. Continue to assess for signs of instability and move cautiously around suspect slopes.

Avalanche problems

  • Loose Wet

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

    Areas of surface wet snow formation are expected today mainly on slopes with both direct sun exposure and protection from the E wind. Maximum daytime air temperatures are expected at 4 to 8 degrees warmer than yesterday.  A continued warming trend with daily increases in air temperature is expected over the next few days. This will allow snow surface melt to spread into the upper elevations and onto northerly aspects.

    The development of roller balls and pinwheels, whether natural or human triggered, indicates that wet loose avalanches are possible. Once signs of wet snow instability develop, you can move to low angle terrain to avoid this avalanche problem. Anticipate that frozen conditions near a wind exposed ridgetop may be significantly more melted a short distance below the ridgetop on a sun exposed slope.

    (4/6/2024)

    On Saturday, skiers triggered these wet snow sluffs on SE aspect terrain near 7,600' around midday. The terrain wasn't quite steep enough to produce wet loose avalanches, but the snowpack was prime to do so. Silver Peak, Pole Creek, CA

    Photo: Sierra Avalanche Center

  • Wind Slabs

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

    Ridgetop winds were strong out of the NE last night and will continue out of the E today. Moderate to large amounts of unconsolidated snow were available on N to NE aspect terrain for scouring and redistribution into new downwind areas. Expect the largest wind slabs to exist in the areas that received the most new snow on Thursday/Friday. This includes the areas around Emerald Bay, Echo Summit, Carson Pass, and Ebbetts Pass. Expect smaller wind slabs in areas that received lesser amounts of recent snowfall.

    You are most likely to encounter an unstable wind slab above about 8,000'. This is where less previous warming occurred and unconsolidated snow was prime for wind transport. Use clues such as visible blowing snow, cracks in the snow surface, newly formed cornices and snow drifts, and/or ripples in the snow surface to identify places where new wind slabs have formed. Move around these areas with caution.

    (4/7/2024) Cracking like this in wind affected snow is a clue to the potential for unstable wind slabs in the area. Red Lake Peak, CA

    Photo: Sierra Avalanche Center

Avalanche Discussion

Air temperatures are going to get quite warm this week, especially from Tuesday to Thursday. Decreasing winds may allow air temperature inversion conditions to develop. This would keep overnight air temperatures above freezing mid-slope and higher on the peaks with below freezing air temperatures limited to areas where cold air settles down near the mountain valley floors. If this occurs, anticipate weaker or at least more superficial overnight refreezes mid-slope and above. With this also comes the increased potential for cornice fall.

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