General Conditions and Slope Tests on San Joaquin Ridge

SNOWPACK OBSERVATION
Submission Info
Forecaster
Saturday, December 23, 2017 - 11:45am
Red Flags: 
Recent loading by new snow, wind, or rain
37° 41' 7.8" N, 119° 3' 51.84" W
Snowpit Observations
More detailed information about the snowpack: 

Toured along San Joaquin Ridge to check general conditions and to test lingering wind slabs. Exposed areas on all aspects had wind affected snow: icy scalloped wind crust, P to 4F hard sastrugi and soft wind slabs 1-15cm thick on specific features like the leeward sides of trees, ridges, and roll overs. Sheltered areas where generally surface facets or decomposing and fragments snow crystals from the recent short wave. S aspects had melt-freeze crusts forming in areas not already wind scoured. Many areas had been stripped of much snow by recent wind events. Snow depth ranged from 0-40cm. Coverage is confined to high elevations and chutes and gullies in many places (see photos of snow coverage NW and SE of Deadman Pass).

Jumped on many test slopes on E and W aspects with few positive results -- mostly localized cracking in 4F+ wind drifts. One slope, N facing near Deadman Pass proper resulted in a very small D1 wind slab 15cm deep and 4F hard that slid on the old wind scoured snow surface. Total size was about 5'x5' and slide 20 vertical ft. Extrapolating to the larger, steeper wind loaded slopes below on the NE aspects of the Deadman Pass Bowl and Chutes there does still seem to be the potential for skier trigger in the right situation. Skiing was not so good anywhere except in sheltered areas below treeline.

Sky was Broken- cloud cover most of the day. Winds began light in the morning and increased to moderate by 1pm, all from the WSW. Not much snow still available from transport, but some localized creep and saltation was observed blowing onto E and NE slopes.

Snowpack photos: 
Coverage NW of Deadman Pass
Coverage SE of Deadman Pass
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

At 1030am at 9131': Tair = 1 deg. C, Tsuf = -1.5 deg. C. Air temps hovered slightly above freezing, but wind chill was significant and kept the snow cold and wintry above about 8800'.
 

ESAC receives significant financial support from ...