State of the Snowpack for 11/14/2020 - 11/20/2020

Submitted by andy on Fri, 11/20/2020 - 15:58
Dates of the Week: 
11/14/2020 to 11/20/2020
Avalanche Problems: 
General Snowpack Structure: 
  • Soft surface snow on top of dense storm in areas without previous snow cover.
  • Soft surface snow on top of dense storm snow on top of a persistent weak layer on NW-N-NE aspects on upper elevation near and below treeline terrain where the early November snow did not melt or blow away.
  • Snowpack shows signs of consolidating by the end of the week. 
Weather Events: 
  • First large winter storm of the season on Nov 17-18. ~15-24 inches of heavy snow at upper elevations with rain at lower elevations. Gale force SW winds
  • The end of the week brought clear calm and weather back with sunny days and cold nights. 

Central Sierra Nevada / Lake Tahoe Snowpack, Weather, and Avalanche Observations for California and Nevada from SAC

Date and time of observation or avalanche occurrence Location Region Observation Type Photos Snowpack, Avalanche, Weather Videos Snowpit videos (tests, etc) Observation made by
11/26/2020 - 08:15 Castle Pass Donner Summit Area Snowpack Observation Graupel on small surface hoar in meadow area Public
11/25/2020 - 11:00 Andesite Peak Donner Summit Area Snowpack Observation Cloud cover along the Sierra Crest with mostly light SW winds below 8000'. Snow available for transport in near treeline terrain. Great opportunity for avalanche rescue practice. Avalanche rescue practice. Forecaster
11/24/2020 - 11:45 Elephant's Hump Carson Pass Area Snowpack Observation Snow surface mix of 4mm graupel and 10mm SH. Snow surface mix of 4mm graupel and 10mm SH. Forecaster
11/23/2020 - 12:00 Incline Lake Mount Rose Area Snowpack Observation Forecaster
11/22/2020 - 12:00 Becker Ridge Echo Summit Area Snowpack Observation Clearly define faceted layer that had sintered together quite robustly The snowpack was shallow at 36 cm, but quite firm Field notes on the snow profile, the sintered faceted layer was quite firm, and well bonded ECT produced no results The ECT column, seen here, was *quite* well bonded. The Rutschblock test (really just for practice/fun) produced no result despite much jumping Sintered faceted crystals between 10-16cm from the ground. Just a really nice day to get outside and get some practice before the season starts in earnest Public
11/22/2020 - 11:00 Lincoln Ridge Yuba Pass Area Snowpack Observation Supportable snow with a thin layer of soft snow on the surface Wind sculpted snow along the ridgeline Soft snow on top of a supportable more dense layer of snow. Compression test on a NE facing slope at 7800 ft. this test did not produce unstable results (CTN). Forecaster
11/22/2020 - 09:00 Donner Ridge Donner Summit Area Snowpack Observation Public
11/22/2020 - 09:00 Sunrise Bowl Donner Summit Area Snowpack Observation Public
11/21/2020 - 12:00 Mt. Lola Far NE Ridge Independence Lake Area Snowpack Observation Supportable travel conditions. Signs of some previous scouring and snow transport along the ridgetop. Evidence of several inches of post storm snowpack settlement. Areas of impressive surface hoar up to 3 cm. Forecaster
11/21/2020 - 11:00 Black Butte Carson Pass Area Snowpack Observation Professional Observer
11/21/2020 - 08:00 Incline Peak Mount Rose Area Snowpack Observation Large surface hoar crystals at Incline Lake. Near flat terrain, open meadow below treeline. Surface hoar this large wasn't observed in tree-covered areas. Public