Snowpit and basal facet propagation on Tamarack Peak

Location Name: 
Tamarack Peak
Region: 
Mount Rose Area
Date and time of observation: 
Mon, 11/19/2012 - 10:05
Location Map: 
United States
39° 19' 1.668" N, 119° 55' 6.096" W
See map: Google Maps
US


Red Flags: 
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Basal facet layer that was buried by new snow on Nov 16 is now acting as a weak layer. This weak layer (Nov 16 facet layer) seems to exist only on N and NE aspects above 9,300'-9,500'. The recent new snow above has bonded well and become a cohesive slab above the facet layer. Snowpit test performed on an undisturbed slope show that once weak layer collapse is triggered, propagation is likely. Nearby slopes of the same aspect and similar snowpack structure but with steeper slope angle have been heavily skied without avalanche occurrence. It is possibly that significant skier traffic on these slopes prior to the most recent storm disrupted the basal facet layer to the point that it is behaving differently than on the undisturbed slope where the snowpit data was collected.

Video: ECTP-14 Q1 on Nov 16 facet layer.

Snowpit or crown profile photo or graph: 
Snowpit videos (tests, etc): 

20121119 Tamarack ECTP-14 Q1.MOV

Weather Observations
Blowing Snow: 
No
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: