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

LOW avalanche danger exists this morning, but MODERATE avalanche danger will form on sun-exposed E-SE-S-SW-W aspects steeper than 35 degrees at all elevations as last night's refreeze melts. Loose wet avalanches will become possible due to daytime warming today. Enough warming may also occur on the low elevation NW-N-NE aspects for some loose wet activity as well. Some loose wet snow avalanches could entrain enough snow to pose a threat to backcountry travelers especially in areas where terrain traps exist.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Increased winds should slow some of the melting that occurs today, but they will not cause enough cooling to prevent the strong March sunshine and warm daytime temperatures from forming a deep layer of wet snow on sun-exposed slopes today. Loose wet avalanches involving this wet snow will become possible once last night's refreeze melts. Most of the loose wet instabilities that do occur should consist of small roller balls, pinwheels, and point releases, but some larger loose wet avalanches that entrain enough snow to cause problems for backcountry travelers could still occur. Slopes steeper than 35 degrees on sun-exposed E-SE-S-SW-W aspects at all elevations will hold the best potential for loose wet activity since they should experience the most warming, but some of the lower elevation NW-N-NE aspects could also see enough sun for some wet snow issues to form.

    Sinking into wet snow above your boot tops and small surface instabilities like roller balls, pinwheels, or point releases can provide clues that enough wet snow has formed for loose wet avalanches to become an issue. Once deep wet snow exists on a slope, changing aspects to find more frozen slopes or moving onto lower angle slopes off and away from slopes 35 degrees or steeper represent wise choices. Terrain traps like gullies, creeks, and cliffs can greatly increase the risk of any size loose wet avalanches.

Avalanche Discussion

Yesterday human triggered roller balls, point releases, and pinwheels up to 4 ft. in diameter started to occur on E-SE-S facing slopes below 8000 ft. on Caslte Peak (Donner Summit area) by 11 am and on low elevation road cuts between Truckee and Carson Pass by 9 am. Deep wet snow and smaller loose wet instabilities also existed on many of the upper elevation sun-exposed E-SE-S-SW slopes by noon on Castle Peak and on Meiss Ridge (north of Carson Pass).  Some of the more exposed and previously wind scoured or wind packed slopes on these aspects held less deep, wet, almost corn snow on top of mostly supportable melt freeze crusts. Observations on the north aspects in both of these areas showed wind scoured surfaces near the ridgelines and cold soft snow below the ridgelines at the upper elevations. Below about 8600 ft. in the Miess area, the snow on the north aspects became wet and sticky.

Regions covered