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
12/18/2021 - 12:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Large surface hoar in Castle Valley Large surface hoar in Castle Valley Settlement cone on Andesite Peak Guide
Alpenglow Expeditio
12/14/2016 - 11:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Rain runnels existed up to Peak level (8200'). Forecaster
03/07/2020 - 11:30
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Trace of new snow at the trailhead at 10 am. Thin layer of new snow on very supportable refrozen old snow surface. No new drifting prior to 11 am in traditionally wind loaded areas near the ridgetop. Forecaster
02/13/2019 - 11:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		Long shooting crack on storm snow instability. Natural avalanche that failed early this morning on a storm snow weakness at the beginning of the storm snow Forecaster
02/13/2017 - 13:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		5mm surface hoar wet at 3pm. Professional Observer
12/31/2022 - 12:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		Forecaster
03/10/2014 - 13:00
Avalanche Observation 		Andesite Peak
Donner Summit Area
Professional Observer
12/04/2016 - 13:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Guide
Tahoe Mountain Scho
03/17/2021 - 11:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Cloud cover drastically slowing snow surface melt. Breakable melt-freeze crust on southerly aspects and flat terrain. Surface melt-freeze crust formed in the past 24 hours. Minor amounts of surface wet snow formation on a wind protected, below treeline, open E aspect, at about 7,700'. Forecaster
03/16/2018 - 12:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		Largest wind slab avalanche triggered by small cornice piece dropped onto the ENE facing slope. A secondary slide released and that crown is 3 to 4 ft. deep. Small wind slab that propagated all the way around an E-ENE-NE facing test slope. Triggered from a low angle slope on the side. Storm slab in below treeline terrain triggered from the lower angle slope I am standing on. Wind slab in near treeline terrain on an ENE facing slope. We cleaned the box on the sign off at the start of our tour and ~3 hours later 6 to 8 inches of snow had accumulated on the box. Forecaster
12/06/2014 - 11:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Professional Observer
02/26/2019 - 06:00
Avalanche Observation 		Andesite Peak
Donner Summit Area 		NE aspect below treeline with 2 to 3 ft crown visible. Slope angle ranged from 32 to 44 degrees. Skier's left side of crown and debris. Skier's right side of crown and debris. Crown of 2-3 feet with 8 inches of storm snow on bed surface. ECTX and CTH-Broken results in crown at 11:45am. This is the maximum amount of cracking we observed today in areas of wind slab. Ski cuts such as this in wind loaded terrain above treeline produced no results. Forecaster
03/24/2020 - 11:00
Snowpack Observation 		Andesite Peak
Donner Summit Area 		Developing and fragile new cornices. Cracking in wind loaded areas with 4-8'' wind slabs. Forecaster
03/20/2013 - 09:30
Avalanche Observation 		Andesite Peak
Donner Summit Area
Professional Observer
01/07/2016 - 10:50
Avalanche Observation 		Andesite Peak
Donner Summit Area
Guide
Tahoe Mountain Scho

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