Central Sierra Nevada
Avalanche danger
Highlights
Increased amounts of snow surface melt are expected today on sun exposed slopes with the potential to allow for some rollerballs or even a small wet loose avalanche (wet snow sluff). The snowpack is in good condition to handle warming today keeping larger avalanches unlikely at this time. Anticipate how down slope hazards such as rocks and cliffs could magnify the consequences of being pushed off line by an otherwise minor snow surface instability.
Avalanche Discussion
Conditions are lining up for increased amounts of surface wet snow formation today. Decreasing winds, above freezing air temperatures at elevation this morning under inversion conditions, and forecast maximum daytime air temperatures in the 40s for the 7,000' to 9,000' range are all contributing factors. The existing snowpack in sun exposed areas has been through numerous melt-freeze cycles over the past several weeks which is expected to keep larger avalanches from occurring today. Minor snow surface instabilities such as roller balls may be more of an issue today on slopes with less direct sun exposure than what has occurred during warmer days in the past few weeks. On slopes with direct sun exposure, there may be enough surface wet snow formation today for some small wet loose avalanches (wet snow sluffs ) especially around exposed rock where additional heating and melt occurs.
The consequences of being pushed off line by an otherwise minor and inconsequential wet snow surface instability change dramatically if pushed into rocks or over a cliff. Make terrain choices today with this in mind. Surface wet snow ankle deep or more, rollerballs, or any small wet loose avalanches are indications that it is time to back off to less consequential terrain without downslope hazards.
Recent Observations:
- Variable snow surface conditions exist across the forecast area. Expect to encounter firm ice, shallow unconsolidated snow, wind-packed surfaces, wind-scoured surfaces, breakable crusts, and spring-like melt/freeze snow.
- Some faceting has occurred in the upper snowpack in most areas on northerly aspects. Otherwise, the existing snowpack is well consolidated.
- Total snowpack height at the Snotel automated sensor sites in the 8,200' to 8,700' elevation range has decreased 25 to 34 inches since December 28th, mostly due to settlement.