THIS AVALANCHE FORECAST EXPIRED ON December 10, 2020 @ 6:48 am
Avalanche Forecast published on December 9, 2020 @ 6:48 am
Issued by Steve Reynaud - Tahoe National Forest

Early season conditions with a thin snowpack and numerous obstacles to potentially hit will remain the greatest hazard today.  LOW avalanche danger continues with normal caution advised if traveling in the backcountry.  

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Normal Caution
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  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Caution is advised when traveling in the backcountry due to the thin snowpack and variable snow conditions.  Many obstacles such as rocks, bushes, and small trees are exposed or barely covered under the snow surface presenting the greatest hazard to backcountry users.  Variable snow conditions range from wind scoured surfaces in wind exposed near and above treeline areas, soft unconsolidated snow in wind protected below treeline terrain, and a variety of crusts scattered throughout.  Firm snow surfaces may present falling hazards in exposed areas.

Avalanche activity remains unlikely today. 

recent observations

A mostly supportable snowpack 1-2 ft. deep exists on northerly aspects above 8600 ft. in the Mt. Rose area, above 7000 ft. along the northern Sierra Crest, and above 8000 ft. along the southern Sierra Crest.  Highly variable snow surface conditions exist with wind scoured snow in most near and above treeline areas, soft unconsolidated snow in wind protected below treeline areas, and a variety of surface crusts mixed in.

Most all usable snow exists on northerly aspects, with most southerly aspects having snow melt and loss with large areas of bare ground.

The faceting process has continued throughout this dry period with mostly clear skies, cold long nights, and low sun angles, since our last storm on Nov 18.  This extended dry period has created weak sugary snow that is most prominent just below the surface of our shallow snowpack.  As storms are in the forecast, the concern continues that this weak snow will not be strong enough to support much additional load.  As storms start to load this weak snow, it could potentially become a buried weak layer that could lead to avalanches in the future. 

Weather and CURRENT CONDITIONS
weather summary

Mild weather is expected today with generally light SW winds and sunny skies.  Temperature inversions continue with colder air settling into the valleys and warmer air aloft.  Clouds will increase today and into the weekend as a series of weak weather systems pass by our area.  These storms will start off pretty dry Thursday night, but hopefully will produce light snow over the weekend.  Uncertainty still exists as to exact storm tracks and snowfall amounts.  The weather pattern looks to remain progressive with additional storms possible into next week.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
6am temperature: 35 to 37 deg. F.
Max. temperature: 47 to 51 deg. F.
Average ridgetop wind direction: NE shifting to SW
Average ridgetop wind speed: 15 to 30 mph
Maximum ridgetop wind gust: 41 mph
New snowfall: 0 inches
Total snow depth: 14 to 17 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Mostly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy then becoming sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 45 to 50. deg. F. 23 to 29. deg. F. 39 to 44. deg. F.
Mid Slope Winds: Light winds. Light winds. Light winds becoming southwest around 15 mph with gusts to 35 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Mostly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy then becoming sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 41 to 46. deg. F. 22 to 28. deg. F. 34 to 39. deg. F.
Ridge Top Winds: Southwest around 15 mph with gusts to 25 mph in the morning becoming light. Light winds. Southwest 15 to 25 mph. Gusts up to 35 mph increasing to 55 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
Disclaimer

This avalanche forecast is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This forecast covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This forecast applies only to backcountry areas outside established ski area boundaries. This forecast describes general avalanche conditions and local variations always occur. This forecast expires 24 hours after the posted time unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the avalanche forecast call (530) 587-3558 x258