Please remember that these observations indicate what was going on in the snowpack at a single point in time and space. They may not represent conditions where you are or where you plan to be. They also come from a variety of sources. SAC cannot vouch for the quality or accuracy of any observations that come from the general public. Some of these may be professional quality observations; some may not. Please use observations listed on this page as part of your information gathering process, but as always don't make decisions based on a single piece of information. If you are looking for more information on how to understand the information on this page, all of the pit data graphs and stability tests are part of what is presented in a Level II avalanche class that follows the American Avalanche Association (AAA) or American Institute for Avalanche Research and Education (AIARE) curriculum guidelines. All of the coding and abbreviations for data presented follows the publication Snow, Weather, and Avalanches: Observational Guidelines for Avalanche Programs in the United States (SWAG) which is the standard for all professional avalanche programs in the US. An electronic copy is available here. Most of what you are looking for is in Chapter 2 and Appendix F part 1. We use a program called SnowPilot to create the snowpit graphs. It is available as an online tool or as a downloadable program at http://www.snowpilot.org/. This website also has a quick video and user guide on how to use create snowpits. Please send us your observations using the buttons below.
Date and time of observation or avalanche occurrence Location Region Observation Type Photos Snowpack, Avalanche, Weather Videos Snowpit videos (tests, etc) Observation made by
11/29/2018 - 11:30 Castle Peak Donner Summit Area Snowpack Observation High intensity wind loading at ridge top above treeline. High intensity wind loading at ridge top above treeline. Minor skier triggered cracking of newly formed wind slabs. Forecaster
12/01/2018 - 03:15 N Judah trees Donner Summit Area Snowpack Observation Public
12/09/2018 - 13:15 E of Boreal ski area Donner Summit Area Snowpack Observation Educator
Donner Summit Avalanche Seminars
01/11/2019 - 10:30 Castle Peak Donner Summit Area Snowpack Observation Skiers right side of the crown drawn in pink. Slide appeared to start close to the ridge Small newly formed cornices easily breaking on the way up. 3x3 foot 4 inch deep wind slab breaking, near cornice photo, on the ascent. A crown from a smaller slide was seen in close proximity to where the larger avalanche occurred. Photo taken prior to the large slide.  Public
12/17/2018 - 13:00 Castle Peak Donner Summit Area Snowpack Observation Small windslab under 4cm of soft snow cracking The wind affected layer that broke in the previous photo. Soft snow removed on left side to show the slab. ECTN 12 @ the new windslab layer. Public
02/17/2019 - 13:00 Below Andesite Peak Donner Summit Area Snowpack Observation Public
12/01/2018 - 07:45 Castle Peak Donner Summit Area Avalanche Observation Public
11/28/2018 - 12:00 NW Castle Peak Donner Summit Area Snowpack Observation Light wind loading occurring off of summit ridge with cornice development. Wind loaded pillows showed minor cracking.  Forecaster
02/19/2019 - 11:15 North shoulder of Judah Donner Summit Area Snowpack Observation Shooting crack in a small windslab Guide
Alpenglow Expeditions
12/09/2018 - 12:00 Castle - Basin Peak Area Donner Summit Area Snowpack Observation Wind slab failure on buried surface hoar on a wind-loaded test slope. Shooting cracks triggered by a ski cut on a near treeline wind-loaded test slope. This slab failed on buried surface hoar. Large surface hoar on the snow surface in a sheltered area , Forecaster
12/15/2018 - 12:15 Castle Peak NE Face Donner Summit Area Snowpack Observation NE Slopes on Castle Peak Steep entrance with cornice NE face access trough hole in rock band Large cornices on N ridge Public
01/14/2019 - 12:00 Johnson Canyon Donner Summit Area Snowpack Observation 10 to 12mm surface hoar in open areas near and below treeline. Forecaster
12/22/2018 - 15:00 Andesite Peak Donner Summit Area Snowpack Observation Educator
Tahoe Mountain School
12/06/2018 - 12:00 Castle Peak Donner Summit Area Snowpack Observation 8-10mm surface hoar in Round Valley at 7900'. Rimmed surface snow above 8000', up to 10mm in size. Forecaster
02/12/2019 - 11:45 Observed from vehicle on Donner Pass Road Donner Summit Area Avalanche Observation Public

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