Lundy Canyon: Stability and Warming

SNOWPACK OBSERVATION
Lundy Canyon
Submission Info
Forecaster
Wednesday, March 28, 2018 - 2:45pm
Red Flags: 
Recent avalanche activity
Lundy Canyon 38° 0' 59.04" N, 119° 16' 15.6" W
Snowpit Observations
More detailed information about the snowpack: 

Observer: d lewis
Lat/Lon:38.0164, -119.2710
Elevation: 8500 f
Aspect: NNE Angle: 25°
Signs of Instability: Recent Avalanches, Pin Wheels
Sky Cover: BKN
Precipitation: No Precipitation
Wind Speed: Calm Beaufort
Wind Direction: N
Current Temp:0 to 5°C Trend:
Boot Penetration: 20cm
Snow Stability: Fair
Stability on similar slopes: Fair
Avalanche Danger: Moderate 4 Stability Tests: ECTN24 Q2 26cm Failed under shovel only , 30cm CT24 Q2 26cm CT26 Q2 26cm CT21 Q2 26cm

Comments: Drove up the Virginia Lakes to assess the snowpack and stability but the road is still closed, though it appears the county is working on getting it open. On the drive down observed numerous Loose Wet releases on NE-E-SE aspects in the Alpine (~>11,500) that likely occured over the past couple of days. Most were small in nature (D1). Though I did see 2 Loose Wet slides on the lower slopes of Excelsior Mountain that were larger (D1.5). One possibly pushing toward a D2. Of special note: saw a large avalanche crown on the apron below the Dana Plateau from the 3/21-22 storm and given its depth may have involved the persistent weak layer from earlier in the season.

Since the road was closed, I elected to venture up Lundy Canyon. The storm from 3/21-3/22 produced significant avalanche activity throughout the canyon. There were many debris fields at the base of most gullies along the north side of the road. Along the south side of the road, most of the bigger lines have slid and in places have exposed rock at many of the choke points or are filled with rough debris. Continued up toward the head of the canyon. As you begin to enter the upper canyon, the moderate angled slopes appear to have not avalanched as extensively, providing better ski conditions. Snow at the current trailhead (7800’) 10” to 20” (25 to 50cm), Snow was isothermal by afternoon below ~8000’ on all but shaded north to north east aspects. Above ~8000’ the snow began to become somewhat supportive and improved with elevation. Found a small-protected area that was shaded and dug a pit to assess the colder snowpack. The surface snow and down to 10cm was just beginning to become moist. Total depth was 132cm, with 2 to 3cm facets at the base ~0 to 22 cm, above that dense layer ~35cm. Ambient air temperatures varied from 4 to 7C. Surface snow temps, 0, T20 0 to -.5. Stability tests failed consistently 26 cm down from the surface (Q2) on preserved sellars but stubborn in nature and resistant to propagation.  

Pictured avalanche debris: Mt. Scowden, avalanche debris broke through Lundy Lake ice     

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Mt. Scowden, Avalanche Debris Breaks Through Lake Ice
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming
More detailed information about the weather: 

Mid level cloud deck (alto stratus?) letting a fair amount of sun to penetrate with strong re-radiation.  

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