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 Region Observation Type Photos Snowpack, Avalanche, Weather Videos Snowpit videos (tests, etc) Observation made by
12/13/2021 - 11:10 Far East Ridge of Tamarack Peak Mount Rose Area Avalanche Observation Intentional trigger point for 900' wide R5 avalanche on Dec 11 layer. Avalanche failed across all of this terrain and more out of sight in the background. Terminus of cracks, just under 900' from trigger point, going down to Dec 11 layer. Cracks and debris More cracks and debris Still more cracks and debris Cracking and whumpfing while breaking trail. Digging out a crack down to the Dec 11 facet layer while breaking trail. Forecaster
12/13/2021 - 10:00 Far East Ridge of Tamarack Peak Mount Rose Area Avalanche Observation Natural wind slab avalanche most likely caused by cornice collapse Wide propagation wrapping around terrain features Avalanche debris running down into larger gully feature. Avalanche debris Forecaster
12/12/2021 - 11:30 Lincoln Ridge Yuba Pass Area Snowpack Observation 50 foot long shooting crack on wind loaded NE aspect near treeline. 4F+ hard slab over F hard old snow. Wind loaded road cut test slope with only 1 inch of old snow below new slab, but enough to allow shooting cracks over smooth ground. If we undercut the road cut test slope with a track, these cracking wind slabs would move a short distance down the test slope. Forecaster
12/11/2021 - 11:00 Castle Peak Donner Summit Area Snowpack Observation Recent wind scouring showing previous rain crust Small wind slabs forming from recent blowing snow. 4-6mm surface hoar below 8000', with decomposing and wind destroyed V at upper elevations. Pit wall showing layering Forecaster
12/11/2021 - 08:10 Base of Elephants Back Carson Pass Area Avalanche Observation Public
12/10/2021 - 11:03 Tamarack Peak Mount Rose Area Avalanche Observation First wind slab triggered R1D1 2nd wind slab triggered by another party. R2-D2. Guide
Blackbird Mountain GuideshB
12/10/2021 - 11:00 Black Butte Carson Pass Area Snowpack Observation Professional Observer
12/10/2021 - 11:00 Tamarack Peak Mount Rose Area Snowpack Observation The mid section is made up of decomposing rain crusts and weak faceted snow. Weak snowpack structure is pretty consistent from below treeline to near treeline terrain on NW-N-NE aspects Small cracking around skis failing on a small thin crust below the recent storm snow. Forecaster
12/09/2021 - 15:03 NE Face of Elephants Back Carson Pass Area Avalanche Observation D2 wind slab naturally triggered Filled in skin track from earlier in the day. Public
12/09/2021 - 12:25 Tamarack Peak Mount Rose Area Snowpack Observation Small cracks shooting out from my ski tips on a wind-loaded test slope. The location of our first test pit. ECTN at our first test pit. The facets were still weak there was just not enough of a slab on top of them. PST 40/100 SF on the November 9 facets at our first test pit. The location of our second and third test pits. It had similar snowpack structure but a little more wind loading. PST 25/100 SF on the Nov 9 facets at our second test pit location. RB6 on the Nov 9 facets at the third test pit location. Tamarack Lake had ice all the way across but it looked pretty thin. Forecaster
12/09/2021 - 12:00 Frog Lake Cliffs Carson Pass Area Snowpack Observation Still running water in creeks along the way towards Elephants Back. Snow was close to the minimum necessary for skinning in much of the area we travelled today. ECTN. The weak facets are still there but this ECT did not propagate. Looking down on a PST 20/100 SF The SF crack is visible on the surface. (SF = Slab Fracture where the overlying slab is too uncohesive to keep the fracture below it. Evidence of wind on the fresh snow. Evidence of previous freezing rain. Professional Observer
12/08/2021 - 12:00 Tamarack Mount Rose Area Snowpack Observation Thin breakable crust on the snow surface. The new snow from 12/6-12/7 was just below this thin crust. Rime coated most of the trees on the upper elevations of Tamarack A small surface hoar grain on the thin mist/rain crust on the snow surface. The Nov 9 facets in the snowpack. Forecaster
12/07/2021 - 11:30 Castle Peak Donner Summit Area Snowpack Observation Old facets under surface crust at 7,500', now wet from rain and gaining strength. Roller balls in new wet snow at pit location, 8,680'. Nov 9 facet layer. Fog at pit location. Snow cover vs bare ground on N vs S aspects at 8,200'. Forecaster
12/06/2021 - 14:30 Castle Pass Donner Summit Area Snowpack Observation Guide
Outdoor Adventure ClubhO
12/06/2021 - 11:15 Frog Lake Cliffs Carson Pass Area Snowpack Observation Nov 9 facet layer that appears in poor condition to handle new snow loading. 12 inches of boot penetration into weak snowpack near snowpit site. Forecaster

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