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 This website also has a quick video and user guide on how to use create snowpits. Please send us your observations using the button above.
Date and time of observation or avalanche occurrence Location Region Observation Type Photos Snowpack, Avalanche, Weather Videos Snowpit videos (tests, etc) Observation made by
02/15/2020 - 15:00 Castle Peak Donner Summit Area Snowpack Observation Periods of cloud cover like this move through the area today 5-8 cm of corn snow on a supportable base on a SW aspect at 2:30 pm Debris on the snow surface in the trees Variable and crusty surfaces on northerly aspects below treeline Forecaster
04/21/2020 - 11:00 Rubicon Peak West Shore Area Snowpack Observation Ankle deep boot pen before 11am on E aspect, 8200'. Rapidly warming and deteriorating, but still supportable conditions before 11am. Glide cracks developing out in Desolation Wilderness. Forecaster
01/25/2020 - 11:00 Lincoln Valley Yuba Pass Area Snowpack Observation A rain crust existed on the surface on all aspects and elevations in this area. Ski penetration through melted rain crust. Forecaster
12/08/2019 - 11:30 Rubicon Peak West Shore Area Snowpack Observation Small reactive wind slabs along the summit ridge of peak. Below 7800', 6-8'' of lighter density snow on top of 6'' of rain soaked snow. Forecaster
01/16/2020 - 13:00 Castle Peak/Andesite Peak Donner Summit Area Snowpack Observation Small cornice drops and ski cuts produced limited loose dry sluffing of upper new snow. ECTP-21 on faceted snow below Jan 4 rain crust. NW aspect, 8000', near treeline terrain. Weak snow below Jan 4 rain crust.  Storm snow from today along with recent storm snow on top Forecaster
04/28/2020 - 11:00 Incline Lake Peak Mount Rose Area Snowpack Observation Increased snow melt this past week with above average temperatures and sunny skies. Mostly supportable conditions on SE aspects before 10am. E aspects were deep and wet by 10am, all other aspects became unsupportable by 11am. Forecaster
02/04/2020 - 12:00 Castle Peak Donner Summit Area Snowpack Observation Patchy mix of wind scoured and wind deposits on snow surface on W aspect to the N of Castle Pass. Wind scoured, thin breakable surface rain crust at treeline on a NW aspect at ~8,800'. Thick, breakable rain/melt-freeze crust over F hard dry facets in Round Valley (nil aspect, ~8,000'). Castle-Basin Ridge showing very little wind loading from NE winds. Forecaster
03/20/2020 - 10:00 Fireplug Mount Rose Area Snowpack Observation Failure layer in recent Pint Glass wind slab avalanche. Failure layer in recent Pint Glass wind slab avalanche. 5-7 mm surface hoar formed last night in open areas of Fireplug trees. D1 wind slab avalanches on Far East Ridge of Tamarack Pk. Sun crust on solar aspects, flat areas, and low angle northerly aspects. Forecaster
02/10/2020 - 11:00 Tamarack Peak Mount Rose Area Snowpack Observation Wind scoured features on NNE aspect near the top of Tamarack Variable wind scoured surfaces and small amounts of recent snow on a NW aspect The largest drift of snow we saw today Wind affected snow surfaces on a semi-sheltered NE aspect 1 inch of wet surface snow on a supportable melt-freeze crust on a SE aspect. Forecaster
12/20/2019 - 11:00 Mt. Judah Donner Summit Area Snowpack Observation Drifting snow over Wildflower Ridge cornice. Soft wind slabs lower on the peak. Forecaster
03/11/2020 - 13:00 Castle Peak Donner Summit Area Snowpack Observation Afternoon cloud cover slowed down the warming instabilities. Small ski kick triggered roller balls and pinwheels on a SE facing slope at 8000 ft around noon. Small sluff of wet snow and some small pinwheels on a similar slope around 3 pm. Forecaster
12/09/2019 - 11:30 Tamarack Peak Mount Rose Area Snowpack Observation The line in photo pointed to is buried surface hoar. 4-6mm buried surface hoar down 1.5' Previous cornice failure and wind slab avalanches Plenty of soft snow available for transport along ridges if winds increase tomorrow. Forecaster
02/26/2020 - 11:30 Jake's Peak West Shore Area Snowpack Observation Wet snow on E aspect at ~9,000', moving towards loose wet instability. Punchy, still transitional snow on E aspect, mid elevation terrain Dry surface facets in the shade on NE aspects above ~8,500'. Forecaster
03/28/2020 - 11:00 Tamarack Peak Mount Rose Area Snowpack Observation 1 of several ECTN results on the old snow/new snow interface. Breakable crust conditions developing on E/SE aspects at lower elevations. Forecaster
01/06/2020 - 11:45 Rose Knob Mount Rose Area Snowpack Observation Upper Rose Knob with supportable snow conditions above 8000'. At 8000' and below, deeper wet snow existed by 12 noon. Previous small point releases on SW aspects near 8000'. Previous small additional loose wet activity. Jan 4 rain crust.  Variable from strong and up to 2'' thick to thin and breakable.  Facets developing below the crust. Forecaster


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