State of the Snowpack for 4/3/2021 - 4/9/2021

Dates of the Week: 
4/3/2021 to 4/9/2021
Avalanche Problems: 
General Snowpack Structure: 
  • Melt freeze crusts have developed on most E-SE-S-SW-W aspects at all elevations. Transitional snow, wind-scoured surfaces, and crusts exist on most on NW-N-NE aspects.
  • Poor to non-existent snow coverage exists on many S aspects with adequate snow coverage on most other aspects.
  • Significant melting occurred this week.
Weather Events: 
  • Mostly sunny and clear with periods of below-freezing overnight temperatures and times with mountain inversions and warm overnight temperatures at higher elevations.
  • Persistent SW winds especially during the afternoons.
  • Some unsettled weather with a trace of precipitation on Monday.

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
04/10/2021 - 14:30 Andesite Peak Donner Summit Area Snowpack Observation South Side of Castle Peak losing snow quickly Educator
Tahoe Mountain School
04/10/2021 - 10:00 Elephant's Back Carson Pass Area Snowpack Observation Street shoes would have done just fine today, as boot penetration was never more than 1" until our departure at 11am. Lots of texture in the snow surface from previous tracks, wind, and early stage sun cupping. Winnemucca Lake had some refrozen meltwater on the surface. Our sunny descent route still had plenty of snow, but connected options are becoming limited. Creek banks eroding, but still crossable where we needed to. There were even some geese in this meadow! Professional Observer
04/09/2021 - 11:00 Mt. Judah Donner Summit Area Snowpack Observation Multiple loose wet avalanches and cornice fall over the last week Superficial refreeze with punchy conditions in the shade at 10:45am on south aspect This slope was snow covered 1 week ago. Forecaster
04/08/2021 - 11:30 Mt. Houghton Mount Rose Area Snowpack Observation Mt. Houghton SE/E aspects Strong refreeze with 6''+ melt freeze crust Looking south to Relay Peak Firm crusts near the top of Mt. Houghton, 10,200'. Forecaster
04/07/2021 - 11:15 Castle Peak Donner Summit Area Snowpack Observation Boot-top deep wet snow on S-SE aspects in wind sheltered areas below treeline at 11:20 Runnels on the snowpack indicating water draining through the snowpack Firm surfaces on wind exposed W and SW aspects in above treeline terrain at 11 am. S-SE aspects had 1-2 inches of soft wet snow on them. Snowpack melting out at lower elevations Areas of unsupportable wet snow under the tree canopy 10:30 Forecaster
04/06/2021 - 13:22 Round top to Kirkwood Carson Pass Area Snowpack Observation Frozen surfaces on ascent. Trace amounts of snow above 9000' Old firm wind effected snow 3-4" of loose snow @ 9000' on S-facing aspect. Professional Observer
04/06/2021 - 11:30 Relay Peak Mount Rose Area Snowpack Observation Strong refreeze of the top 9 inches of the snowpack. Several inches of wet snow and tiny roller balls but still ski supportable at 11:30 am on S aspect near 9,500'. Forecaster
04/05/2021 - 11:30 South Side Red Lake Peak Carson Pass Area Snowpack Observation Looking south from Red Lake Snow coverage on the south side of Red Lake Peak Wet surface snow just after midday.  Looking north from Carson Pass Forecaster
04/04/2021 - 12:00 The Sisters Carson Pass Area Snowpack Observation Firm and textured snow surface as we gained our high point at The Sisters. As we lost elevation, the snow became punchy and unsupportable, with many turns resulting in deep trenches. Not much snow remaining on steep, sunny aspects in this area. A few roller balls were observed initiating from rocks. Several cornices in the area appeared threatening. Professional Observer
04/04/2021 - 11:30 Castle Peak Donner Summit Area Snowpack Observation S aspects provided good spring snow at 11am. S aspects were unsupportable before noon. Guide
Tahoe Mountain School
04/04/2021 - 10:30 Rubicon Peak West Shore Area Snowpack Observation Shin deep wet snow on an E aspect of Rubicon at ~ 8100 ft at 10:30 am Wet snow and small roller balls on an E aspect near the summit of Rubicon Firm and uneven snow surfaces on the upper elevation N aspects of Rubicon Thin refreeze crust on top of wet transistional snow on mid and lower elevation N aspects on Rubicon. By 11 am this thin refreeze crust had melted. Forecaster
04/04/2021 - 10:20 Crater Lake Carson Pass Area Snowpack Observation Roller balls on the east face of slope View of cornices on ridge just south of Stevens Peak Reduced cornices further south of Stevens Peak as well as wind blown crusty hard snow Wind blown and melted snow near ridge line Dry ridge line between Red Lake and Stevens Peak (looking south) Public
04/04/2021 - 09:00 Silver Peak Cabin Creek, Deep Creek, or Pole Creek Area Avalanche Observation Public