Heavy Snow and Gale Force Winds on Andesite Peak

Location Name: 
Andesite Peak
Region: 
Donner Summit Area
Observation Date & Time: 
Thursday, January 5, 2023 - 12:30
Location: 
39.351020, -120.366689
Is this an Avalanche Observation?: 
No


Conditions Alerts:


Terrain Alerts: 
Slopes Steeper than 30 degrees
Obvious Slide Path
Trigger Points
Terrain Traps
Terrain Matches the Advisory

Observation made by: Forecaster

Tabs

Observation
Description of Snow, Weather, and Avalanche Conditions: 

We went to Andesite Peak today to make observations in familiar terrain.  Rain overnight and into this morning in town turned to heavy snow by 7am.  This heavy snow continued until a break in the storm occurred around 10am-11:30am.  Digging around at the lower elevations, we were able to find a rain layer under the 10'' of new storm snow up to around 7300' on the Castle Valley Road.  Above this 7300-7400' level we couldn't find the rain layer and just had a heavier snow layer and more total storm snow.  We experienced very few signs of storm slab instabilities while breaking trail up towards Andesite Ridge.  Once we entered more wind loaded and closer to near treeline terrain we propagated some large shooting cracks from the ridge near an avalanche slope.  Digging a test pit at 7800', just past where we had the shooting cracks we had an ECTP-12.  This ECT failed on a density change at the new snow/old snow interface where heavier and wetter snow fell earlier in the storm.  Snow depths here were around 12-14'' deep.  The storm started back up with moderate snow and continued gale force winds as we continued up towards Andesite Peak.  We observed a small natural wind slab avalanche on a test slope that was partially covered by additional storm snow and wind transport.  Visibility was very poor and we gave ourselves a wide safety margin and avoided all avalanche terrain today. 

Hide Terrain Details
Terrain: elevations: 
Near Treeline
Below Treeline
Terrain: aspects: 
NE
E
Hide Weather Details
Elevation of Observation: 
7000 - 8000 ft.
8000 - 9000 ft.
Blowing Snow: 
Intense
Wind Direction: 
Southwest
Wind Speed: 
Gale Force
Sky Cover: 
Overcast - Cloudy - 8/8 covered
Highest Precipitation Rate: 
Moderate Snowfall (S2 = 2 cm /~1 in per hour)
Precipitation: 
Snow
Air temperature: 
Below Freezing
BESbswy