THIS AVALANCHE FORECAST EXPIRED ON April 5, 2020 @ 6:58 am
Avalanche Forecast published on April 4, 2020 @ 6:58 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

Cold windy weather and limited new snow this afternoon should keep avalanche activity unlikely today. As more snow and wind impact the region tonight and tomorrow, the avalanche danger will increase dramatically. Today, icy slopes, breakable crusts, and generally challenging snow conditions will present other hazards for people like long sliding uncontrollable falls. Travel cautiously 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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    Very Likely
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Observations this week have shown a trend of increasing strength in the snowpack. As the snowpack has gained strength, recreation conditions have also deteriorated. The strong April sun has left firm icy surfaces on many exposed slopes. In some more sheltered places, breakable crusts exist. Traveling on slopes safely in these firm and challenging conditions requires proper equipment and skills. While sliding snow may be unlikely, long, out-of-control, sliding falls are not. Very low angle slopes or flat meadows can prevent falls from gaining momentum and may provide decent recreation opportunities. 

As new snow starts to cover these icy surfaces this afternoon expect "dust on crust" conditions to form on some slopes. The avalanche danger will also start to increase. Wind slabs and storm slabs will start to form and continue to grow in size and extent tonight and tomorrow. By tomorrow expect avalanche activity on steep slopes at all elevations.

recent observations
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Yesterday widespread firm icy conditions existed on exposed slopes in the Carson Pass, Donner Summit, and Yuba Pass areas. In some more sheltered places, variable breakable crusts existed on some northerly aspects. By mid-day lower angle sun-exposed E and SE facing slopes did soften a bit. Other slopes remained firm.

Snowpit data from areas on Lincoln Ridge showed significant improvement over data gathered in the same area on 3/31. While the buried surface hoar was there, it was no longer reactive.

Snowmobilers reported recent cornice failures on Basin Peak. 

Weather and CURRENT CONDITIONS
weather summary

Strong SW winds and some cloud cover have started to push into the region ahead of a series of winter storms. The first of these storms should arrive this afternoon with increased SW winds and a few inches of snow. Snow and wind will continue through the night. The forecast calls for the second stronger system to impact the forecast area Sunday through Monday with continuous moderate to heavy snowfall and gale force SW winds. Currently, the NWS predicts 1 to 2 ft of new snow above 7000 ft with 6 to 12 inches at Lake level by midday Monday. Check in with the Reno NWS for more details. 

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 22 to 28 deg. F.
Max. temperature: 34 to 42 deg. F.
Average ridgetop wind direction: SW
Average ridgetop wind speed: 25 to 35 mph
Maximum ridgetop wind gust: 58 mph
New snowfall: 0 inches
Total snow depth: 54 to 77 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Partly cloudy then becoming mostly cloudy. Slight chance of snow in the morning, then snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 70%. Mostly cloudy. Snow likely. Snow levels below 7000 feet. Chance of precipitation is 70%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 95%.
Temperatures: 35 to 41 deg. F. 25 to 30 deg. F. 32 to 37 deg. F.
Mid Slope Winds: Southwest 15 to 25 mph. Gusts up to 35 mph increasing to 55 mph in the afternoon. Southwest 20 to 30 mph with gusts to 70 mph. Southwest 15 to 30 mph increasing to 25 to 35 mph in the afternoon. Gusts up to 65 mph.
Expected snowfall: 80% probability of 1 to 3 inches. 20% probability of 3 to 4 inches. | SWE = up to 0.30 inch. 70% probability of 1 to 2 inches. 30% probability of 2 to 4 inches. | SWE = 0.20-0.45 inch. 60% probability of 6 to 12 inches. 40% probability of 12 to 18 inches. | SWE = 0.55-1.05 inches.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Partly cloudy then becoming mostly cloudy. Slight chance of snow in the morning, then snow likely in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 70%. Mostly cloudy. Snow likely. Snow levels below 7000 feet. Chance of precipitation is 70%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 95%.
Temperatures: 29 to 35 deg. F. 21 to 26 deg. F. 27 to 33 deg. F.
Ridge Top Winds: Southwest 15 to 30 mph with gusts to 50 mph increasing to 30 to 40 mph with gusts to 75 mph in the afternoon. Southwest 30 to 45 mph with gusts to 70 mph. Southwest 30 to 45 mph with gusts to 65 mph.
Expected snowfall: 60% probability of 1 to 3 inches 40% probability of 3 to 5 inches. | SWE = 0.15-0.40 inch. 70% probability of 1 to 3 inches. 30% probability of 3 to 6 inches. | SWE = 0.30-0.55 inch. 60% probability of 8 to 14 inches. 40% probability of 14 to 20 inches. | SWE = 0.60-1.10 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