Conditions on Tallac

Location Name: 
Tallac
Region: 
Desolation Wilderness Area (including Emerald Bay)
Date and time of observation: 
Thu, 01/28/2010 - 13:00
Location Map: 
United States
38° 54' 22.9068" N, 120° 6' 0.4896" W
See map: Google Maps
US


Red Flags: 
Obvious avalanche path
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Informal tests off the skin track showed a stabilizing snowpack. An ECT performed on a wind loaded N aspect at 9000ft failed to propagate.

 

On the North Bowl of Tallac, just below the summit, I performed two more ECTs which failed to propagate. Each had moderate progressive compression within the top 10cm, and a hard break at 35cm. 40 degree NE aspect, 34 degree slope angle, wind loaded slope. Still a subtle soft layer under the slab, but difference in hand hardness is +/- and not a full step.

 

Just below the North Bowl cliffs, I moved to the ridge on skiers right of Tallac Creek, where I was able to cause small, shallow (10cm) fractures and shallow, dinner table sized slabs to break on this cross-loaded feature - nothing hazardous. Just below the lip of the ridge fractures did not initiate.

Any other comments about the observation or links to outside pages that have more info on the observation: 

North Bowl received heavy traffic with no avalanches, and a few folks chose bold lines elsewhere with no consequences beyond sluffs.

Weather Observations
Blowing Snow: 
Air temperature: 
Above Freezing
Wind Speed: 
Precipitation: 
Air temperature trend: 
Static
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Very warm day, with a +1 degree celsius temp taken on a shaded slope just below summit of Tallac (where ECTs were performed). Some free water was present at the surface on the SW side of Tallac's summit. Rollers occuring on E/SE slopes as high as 9200ft. Skiing surface remained excellent on shaded slopes and good on slopes without a direct solar aspect.