THIS AVALANCHE FORECAST EXPIRED ON April 6, 2018 @ 6:56 am
Avalanche Forecast published on April 5, 2018 @ 6:56 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

MODERATE avalanche danger will exist at all elevations due to loose wet avalanche problems becoming possible again today. Rain on snow and warm temperatures will allow this problem to continue through the night. Expect the avalanche danger to increase on Friday and Saturday as a strong storm impacts the area through Saturday.  

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.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
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    Very Likely
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Little to no freeze may have occurred last night due to above freezing overnight temperatures and overnight cloud cover. Warm weather today and a chance for light rain this afternoon should melt whatever refreeze did occur and loose wet avalanche activity will become possible again today.  Loose wet instability should continue through the night as rain continues to fall. Rising snow levels may also allow rain to fall on small amounts of new snow in areas above 8000 ft. Wet snow instabilities could include pinwheels, rollerballs, and loose wet avalanches. Some of the loose wet avalanches could involve enough snow to injure a person. Loose wet instabilities could form on any aspect today and tonight.

Rain on snow (especially new snow), boot-top-deep wet snow, active roller balls or pinwheels, and other loose wet avalanches can indicate increasing wet snow instability.  Once signs of wet snow exist, move lower angle slopes or call it a day.

recent observations
Submit Observations

* Spring snow conditions with 2 to 3 inches of wet corn snow resting on top of a supportable melt-freeze crust existed on E aspects of Mt. Houghton below 10000 ft and on NW-N-NE-E aspects of Elephants Hump between 7600 and 8300 ft. by 11 am. yesterday. 

* Observations targetting the Feb. facet layer on Silver Peak, Jakes Peak, and on Elephants Hump this week have shown that this layer remains loose and that fractures could still travel along the layer if it breaks. Data has also indicated that it would take a very large trigger to get enough force through the strong snow above it to break this layer. A large loading event like the forecasted atmospheric river type storm could overload this layer. This layer was responsible for the widespread deep slab avalanche cycles in March.

Weather and CURRENT CONDITIONS
weather summary

Air temperatures remained above freezing under mostly cloudy skies during the night. The forecast calls for increasing clouds and continued warm temperatures today. By this afternoon some light precipitation may start to fall as a an atmospheric river approaches the area. Snow levels may start around 8000 ft. this afternoon and evening but as the storm arrives over the area tonight it will bring warmer air and push snow levels up to over 9500 ft. during the night. By tomorrow when the heavy precipitation starts to fall snow levels are forecasted to rise to at least 10000 ft. Expect a light rain and snow mix this afternoon and evening before most of the precipitation becomes rain during the night and tomorrow. 

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 35 to 40 deg. F.
Max. temperature: 49 to 52 deg. F.
Average ridgetop wind direction: Southwest
Average ridgetop wind speed: 10 to 20 mph
Maximum ridgetop wind gust: 38 mph
New snowfall: 0 inches
Total snow depth: 60 to 95 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Thursday Thursday Night Friday
Weather: Mostly cloudy with a slight chance of rain in the afternoon. Snow level 8000 ft. Cloudy with a chance of snow in the evening while snow levels remain close to 8000 ft. Precipitation increasing and becoming all rain after midnight as snow levels rise to 9500 ft. Rain. Snow level 10000 ft.
Temperatures: 47 to 52 deg. F. 34 to 39 deg. F. 43 to 49 deg. F.
Mid Slope Winds: Southwest Southwest Southwest
Wind Speed: 15 to 20 mph with gusts to 40 mph 15 to 20 mph with gusts to 40 mph 15 to 20 mph with gusts to 45 mph
Expected snowfall: 0 to trace Snow up to 1 in. | Rain up to .15 Rain: .40 to .65
For 8000 ft. to 9000 ft.
Thursday Thursday Night Friday
Weather: Mostly cloudy with a slight chance of snow in the afternoon. Snow levels 8000 ft. Cloudy with rain and snow likely. Snow levels 8000 ft. increasing to 9500 ft. after midnight. Rain. Snow levels 10000 ft.
Temperatures: 42 to 48 deg. F. 32 to 37 deg. F. 38 to 43 deg. F.
Ridge Top Winds: Southwest Southwest Southwest
Wind Speed: 20 to 30 mph with gusts to 55 mph 20 to 30 mph with gusts to 55 mph increasing to 65 mph after midnight 25 to 40 mph with gusts to 70 mph increasing to 80 mph in the afternoon
Expected snowfall: 0 to trace Snow: up to 1 in. | Rain: up to .15 Rain: .40 to .70
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory 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 advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258