These observations document past conditions at a small and variable scale. They are not to be confused with an avalanche forecast. They come from a variety of sources. We can only vouch for the quality of those produced by the SAC forecasters and professional observers.
Date and time of observation or avalanche occurrence Location Media Observation made by
12/30/2021 - 12:45
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Small cornice on Andesite Ridge Cornice formation on Andesite Peak Educator
Tahoe Mountain Scho
12/02/2017 - 12:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Photo 1: Average height of snow near summit of AndesitePhoto 2: South Face of Castle Guide
Alpenglow Expeditio
12/13/2020 - 13:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Public
11/29/2018 - 10:15
Avalanche Observation 		Andesite Peak
Donner Summit Area 		Forecaster
04/15/2017 - 15:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Intentionally skier triggered loose wet avalanche on test slope entraining about the top 1 foot of the snowpack.Closer up view of same loose wet test slope avalanche.Skier triggered roller ball, ~2 ft diameter.Skier triggered roller ball, ~2.5 ft diameter. Forecaster
01/07/2016 - 10:50
Avalanche Observation 		Andesite Peak
Donner Summit Area
Guide
Tahoe Mountain Scho
04/06/2022 - 10:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Good coverage and smooth surfaces exist on open E facing aspects on Andesite Ridge. 1-2 inches of soft wet corn snow had formed on the E aspects by 10:30 am. These slopes also still had a supportable 6-8 in thick frozen melt freeze crust below the wet surface snow. Very uneven snow surfaces existed in some areas. More dirt and debris continues to appear as the snow melts. Lots of dirt showing on the SW side of Castle Peak. Impressive amounts of debris exist on the snow surface in wooded areas. Forecaster
12/01/2019 - 11:00
Snowpack Observation 		Andesite Peak
Mount Rose Area 		Small cornice kicks on test slopes did not initiate any avalanches. HS=95cm Some starting zones not filled in yet with rocky terrain. Forecaster
02/16/2017 - 11:30
Avalanche Observation 		Andesite Peak
Donner Summit Area
Split-board kicks triggered a refrigerator sized cornice failure onto the wind loaded test slope. This resulted in a 12-14 inch deep wind slab failure.
The other side of the wind slab that resulted from the cornice drop.
Wind slab cracking in an undercut wind-loaded slope
 Forecaster
01/06/2019 - 12:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		One of the skier triggered wind slabs near the top of Andesite Peak Small wind slab failure on a test slope. A second ski kick at the spot just after the photo was taken triggered a large whumpf. Skier triggered D1 wind slab avalanche on NE aspect at 8000'. 50' wide x 70' long. Another small D1 skier triggered avalanche in similar terrain. Cracking started at the trailhead 8 inches of new snow acculumated at the trailhead while we were out. My pole is pushed into the level of our skin track when we started the day. Forecaster
02/24/2018 - 16:15
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Shooting crack on an E facing wind loaded test slope @ 7900 ft. after a few hard stomps The same test slope after a few more stomps. The wind slab slid down the small test slope. Forecaster
03/23/2021 - 12:45
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Public
12/01/2018 - 11:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		One of several natural wind slab avalanches on Andesite Peak, E aspect, ~8,100'. Cracking triggered while breaking trail below treeline. Early signs of the instability in the area. The first wind loaded feature we approached at treeline, E aspect,~7,900'. Intentional remote skier triggered avalanche. View from triggering location. 20' shooting crack to where avalanche occurred. Pointing to far flank on the large bump in low visibility. 20' skier triggered shooting crack in near treeline terrain, ENE aspect. Another natural wind slab avalanche, above treeline terrain, ENE aspect, ~8,100'. Still another natural wind slab avalanche, above treeline terrain, ENE aspect, ~8,100'. Wide propagation with the far flank about 2/3rds of the way across the open slope in the background. Easily 200' wide. Forecaster
01/13/2016 - 10:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Forecaster
04/17/2022 - 10:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Large pinwheel approaching 3 feet in diameter. Rime crust at 7,200'. Rime on trees near the summit at about 8,200'. Mix of supportable crust and deeper wet snow at 9:30 am on S aspect terrain at 7,300'. Forecaster

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