Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

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

MODERATE avalanche danger at all elevations is expected today for the vast majority of the forecast area. Isolated, highly localized areas could have greater danger. Wind slab, loose wet, and storm slab avalanche problems are expected today. Identify suspect slopes and avoid areas of concern.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Continued periods of wind and snowfall will build additional winds slabs on top of those that formed yesterday. The vast majority of wind slabs are expected to form near treeline and above treeline on NW-N-NE-E-SE aspects today. Wind slabs could form in isolated areas on S-SW-W aspects as well. Some wind slabs could become increasingly unstable today if sun breaks cause rapid warming of newly formed wind slabs.

    Avoid steep slopes where wind drifted snow is accumulating, slopes below cornice features, and steep slopes with recently formed wind pillows.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Periods of rapid warming could occur today during sun breaks between convective showers. Natural and human triggered loose wet avalanches could occur on all aspects at all elevations. The spring sun angle is getting high enough to affect NW-N-NE aspects, not just the E-SE-S-SW-W aspects.

    Avoid travel on or below steep slopes where roller ball activity is occurring.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    For most areas today that receive the expected 1 to 4 inches of new snowfall, problematic storm slabs are unlikely. Any areas the receive the upper end forecast numbers of 5 to 10 inches of new snow could develop problematic storm slabs. These would be found in wind protected areas near treeline and below treeline on all aspects. Similar to the today's wind slabs, newly formed storm slabs could becoming increasingly unstable if subject to rapid warming during sun breaks.

    Look for snow surface cracking while making fresh tracks either uphill or downhill in wind protected areas. Avoid steep slopes in areas where snow surface cracking is occurring.  

Avalanche Discussion

Observations made yesterday on Tamarack Peak (Mount Rose area) revealed accumulating new snow above 8,500' during the morning hours with wind slabs forming near and above treeline. Skier triggered cracking of wind slabs on wind loaded test slopes was very minor. Visibility was too poor to see any signs of natural avalanche activity. Convective snow showers during the afternoon added additional snowfall at lower elevations around much of the forecast area.

Regions covered