Heavy snow and Strong winds in the greater Little Truckee Summit Area

Location Name: 
Webber Peak
Region: 
Little Truckee Summit Areas
Observation Date & Time: 
Saturday, January 14, 2023 - 01:00
Location: 
39.490281, -120.435669
Is this an Avalanche Observation?: 
Yes


Conditions Alerts:


Terrain Alerts: 
Slopes Steeper than 30 degrees
Trigger Points
Terrain Matches the Advisory

Observation made by: Public

Tabs

Observation
Description of Snow, Weather, and Avalanche Conditions: 

We utilized snowmobiles and skis today and covered a fairly large area in the greater Little Truckee Summit vicinity from Hobart to Webber Peak.  At our starting location near 6,000' their was around 12" of heavy wet storm snow at 9am.  As we increased elevation snow depth increased dramatically and snow over the hood and to the windshsield became frequent.  We ski cut some roadside test slopes with sleds at lower elevations that produced no results.  We transitioned to skis around 7,200' and began working up the ridge to Webber Peak.  Boot pen was thigh deep and ski pen was ~18".  While breaking trail we were consistently seeing shooting cracks 4-5' in length in upside down F+ over F storm snow.  These fractures were ~22" deep and going down to the most recent rain layer.  Near the ridge we intentionally triggered a wind slab avalanche on a NE facing convexity test slope.  The avalanche wrapped around the nose of a small spur ridge to a width of ~40'.  Crown height ranged from 6-18".  This avalanche sympathetically triggered another avalanche of similar size on a convexity downslope 50' (see picture with red arrow).

Snow fall was constant throughout the day and preciptation rates ranged from light to heavy.  Winds were also very strong to gale force today out of the SW.  We saw lots of snow transport and impressive cornice development.  On our way back to the truck around 3pm there was a very noticable snow density change to heavy wet snow between 6,600' and 6,000'.

 

Hide Terrain Details
Terrain: elevations: 
Below Treeline
Terrain: aspects: 
NE
E
Hide Avalanche Details
Avalanche Type: 
Wind Slab
Failure Plane/Weak Layer: 
New/old snow interface
Additional number of similar avalanches: 
1
Hide Trigger
Trigger: 
Skier
Trigger Modifier: 
Intentionally Triggered
Hide Terrain
Aspect: 
Northeast
Starting Elevation: 
below-treeline
Hide Size
Destructive Size: 
D1 Relatively harmless to people.
Relative Size: 
R1 Very Small
Crown Height: 
1 ft
Avalanche Width (Average width): 
40ft.
Avalanche Length (Vertical Run): 
15ft.
Hide Weather Details
Elevation of Observation: 
7000 - 8000 ft.
Blowing Snow: 
Intense
Wind Direction: 
Southwest
Wind Speed: 
Strong
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
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