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

The avalanche danger will remain low for a brief period early this morning. As the day warms up, the avalanche danger will quickly rise to MODERATE as loose wet avalanches become possible. Evaluate snow and terrain carefully and move to less steep slopes or slopes with colder more frozen snow once the snow becomes wet and unsupportable. Avoid slopes below large cornices and glide cracks. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Despite above freezing overnight temperatures, mostly clear skies last night should have allowed a thin overnight refreeze in some areas. This refreeze will not last long due to the intense March sunshine and the very warm daytime temperatures. Loose wet avalanches will become possible again today once the refreeze melts. Expect deep wet unsupportable snow on slopes early in the day especially on the sun-exposed E-SE-S-SW-W aspects. Loose wet avalanche activity has the potential to be more widespread and larger today than yesterday on these aspects and could occur on some isolated northerly aspects as well.

    Once the snow becomes wet and unsupportable, it is time to move to a different aspect where colder snow exists or switch activities to avoid the wet snow. 

    In addition to the wet snow potential, large cornices still exist above many slopes and glide cracks have opened on some steep slopes. Numerous cornice collapses have occurred during the warm weather, and some have triggered a loose wet avalanches large enough to bury a person. It is very difficult to predict when these cornice failures will occur or when glide cracks will release as glide avalanches. Due to their size, unpredictability, and serious consequences, it is best to avoid areas below glide cracks and large cornice features during any warm periods.

Avalanche Discussion

Yesterday observations found deep wet unsupportable snow on slopes below 8000 ft. On Mt. Tallac and near Twin Crags. Stepping off one's skis resulting in sinking into wet snow that was mid-shin to knee deep by noon. In the Twin Crags area, ski cuts on steep sun-exposed S facing test slopes at noon also triggered small loose wet sluffs that entrained the top 6 to 8 inches of wet snow. On Mt. Tallac, numerous cornice failures had occurred during this warm spell and one of those along the west ridge of Tallac had triggered a larger loose wet avalanche that likely occurred on March 13, 14, or 15. Above 8000 ft. on Mt. Tallac, mostly supportable spring snow conditions existed on E-SE aspects until about noon.

Regions covered