THIS AVALANCHE FORECAST EXPIRED ON December 1, 2019 @ 6:59 am
Avalanche Forecast published on November 30, 2019 @ 6:59 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

Lingering wind slabs will keep the avalanche danger at MODERATE in near and above treeline terrain today. As the next winter storm starts to impact the region tonight, expect the avalanche danger to rise quickly. In addition to the avalanche concerns, the thin snowpack presents hazards in the form of numerous exposed and barely covered obstacles. 

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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Some instability could linger in near and above treeline terrain where slabs of wind drifted snow exist. Triggering an avalanche involving one of these wind slabs remains possible on wind-loaded aspects. Most of these avalanches would remain small (D1) but some could involve enough snow to bury or injure a person (D2). Regardless of the size, any avalanche could have consequences since collisions with barely covered or exposed rocks, stumps, and other obstacles would be inevitable.

Use clues like drifted snow, cornices above slopes, blowing snow, and other wind created surface textures to help identify where unstable wind slabs may still linger. While the snowpack may be the "best it has been in months" as one observer put it, it is still shallow and many equipment and body wrecking obstacles exist. "Going big" right now isn't worth the rest of the season on the couch. Lower angle slopes may provide more supportable coverage and easier speed management to help mitigate some of the early season hazards and any lingering avalanche concerns. 

recent observations
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* A 1 to 2.5 ft. deep snowpack exists over most of the forecast area with a high degree of variability in coverage. 

* Some wind slab avalanches have been reported along the Sierra Crest and the Mt. Rose area in the last few days. People have also reported some human-triggered shooting cracks in wind-loaded areas. 

* Backcountry travelers in the Mt. Rose area continue to report localized whumpfing in sheltered areas. A group of skiers triggered a small pocket of unstable snow near some rocks on Prolateriate, but it was not large enough to cause problems.

Weather and CURRENT CONDITIONS
weather summary

The lull in the weather should come to an end this afternoon as a strong winter storm moves into the area. The forecast calls for snowfall to start late this afternoon with up to 10 inches tonight and 6 to 15 inches tomorrow. Precipitation should continue through Monday with storm totals reaching 1-4 ft of heavy snow accumulation by midday Monday. The S and SW winds will also increase as this storm moves in. This system should bring warmer air and rising snow levels with it. By Monday snow levels may climb into the 7000 ft range bringing a chance for some rain on snow in some places and heavy wet snow in higher elevations. This system has a high degree of uncertainty and variability concerning actual snow levels, the timing of warming, and snowfall amounts. Check-in with the Reno NWS for the lastest weather forecast.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 8 to 12 deg. F.
Max. temperature: 12 to 18 deg. F.
Average ridgetop wind direction: Southwest and South
Average ridgetop wind speed: 20 to 30 mph
Maximum ridgetop wind gust: 62 mph
New snowfall: Trace to 1 inches
Total snow depth: 14 to 27 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Cloudy. Chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 25%. Cloudy. Snow likely in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 95%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%.
Temperatures: 26 to 31 deg. F. 23 to 28 deg. F. 30 to 35 deg. F.
Mid Slope Winds: Light winds. South 15 to 20 mph. Gusts up to 25 mph increasing to 45 mph after midnight. South 15 to 25 mph with gusts to 40 mph.
Expected snowfall: up to an inch late in the day. | SWE = less than 0.10 inch. 80% probability of 3 to 7 inches. 20% probability of 7 to 10 inches. | SWE = 0.50-0.75 inch. 80% probability of 6 to 10 inches. 20% probability of 10 to 15 inches. | SWE = up to 1.40 inches.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Cloudy. Chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 30%. Cloudy. Snow likely in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 95%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%.
Temperatures: 24 to 29 deg. F. 21 to 26 deg. F. 27 to 32 deg. F.
Ridge Top Winds: South 15 to 25 mph. South 20 to 30 mph with gusts to 45 mph increasing to 30 to 40 mph with gusts to 60 mph after midnight. South 20 to 35 mph with gusts to 50 mph.
Expected snowfall: up to an inch late in the day. | SWE = less than 0.10 inch. 80% probability of 6 to 10 inches. 20% probability of 10 to 14 inches. | SWE = 0.55-0.80 inch. 80% probability of 8 to 15 inches. 20% probability of 15 to 20 inches. | SWE = 1.10-1.60 inches.
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