Observation type
Snowpack

Observer
Marcus Dufort

Keep me anonymous if published
no

Location (general area)
Crystal Lake Rec Area (Pinyon Ridge)

Latitude
34.322137

Longitude
-117.826102

Date (yyyymmdd)
20201229

Time
2:15PM

Road conditions to area
Dry roads on Hwy 39 up to 3,500'. Mix of packed powder and slick refrozen ice. Lots of cars/vans without chains sliding around. Watch the soft shoulders when passing. 

Temperature
47F

Sky
clear (no clouds)

Wind speed
Moderate (17-25mph Small trees sway/ flags stretched)

Wind direction
NE

Wind direction in degrees

Slope aspect
North West

Aspect in degrees

Slope angle
32

Elevation
6000

Snow depth
68 cm

Boot/ Ski penetration
PF 50 cm / PS 15 cm

Precipitation
None

Activity, recent avalanches
No

Brief description
Very liight, dry snow. Lots of wind scour and cross loading due to constant 8 mph winds with strong gusts up to 25 mph

Whumphing noises, shooting cracks. collapsing
no

Rapid warming
no

Obvious avalanche path
no

Terrain trap
no

Comment
1:00pm at the parking area. At 5,500' there was 12" to 14" of storm snow on the ground. Ski penetration was 6" with easy skinning from this point. 

Air temp was 47F and all the trees still had snow on the branches. Some snowmelt from branches falling on the snow make some areas of the trail saturated or punchy. No signs of avalanche or sluffing in the area. 

Above 6000', snowpack held well during uphill. No cracks or slides during jump compression or ski cutting. Dug a snow pit on a 32 degree slope, NW facing aspect. Area had been cross loading all day with consistent 8 mph NE winds. Very easy digging, no crusts or ice encountered.  

Started with an extended column test which failed the first time as I was sawing out the back. Second test I was more delicate with the isolation but still failed after 4 taps from the wrist. Both shears were very energetic and propagated across the entire column. Shear interface was excellent quality. No facets observed. Firm wind slab resting on top of weaker unconsolidated storm layer. Once the wind slab was removed, the rest of the column tipped over at ground.

On the downhill, had some very nice turns. Snowpack was very shallow and soft. Took some caution to keep the turns easy so as not to hit ground. With the next few days of warming/cooling cycles, this first layer should set up a nice stable base for future storms. Be safe. 
 
Publish this observation
Yes I would like this observation Published
 

Pit Profile at Pinyon Ridge (12/29/2020). 4 finger hard wind slab over fist hard storm layer

Very reactive wind slab. Extended column sheared across the whole block during isolation (ECTPV Q1 30cm)