Wind loading, wind slabs, and soft slabs on Hidden Peak

Location Name: 
Hidden Peak
Region: 
West Shore Area
Date and time of observation: 
Thu, 03/01/2012 - 13:30
Location Map: 
United States
38° 58' 34.7556" N, 120° 7' 27.2676" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Obvious avalanche path
Terrain Trap
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Strong winds created widespread wind slabs and wind affected snow on most open slopes at all elevations today. The thickest wind slabs existed on near and above treeline N-NE slopes. These winds remained strong all day and continued to transport significant amounts of snow onto the leeward slopes.

Hand pits and ski pole probes revealed that a density inversion still exists near the base of the storm snow. Snowpit tests showed that this layer remains reactive and that fractures can travel along this dentistry change once it breaks. About 80 cm of new snow exists on top of about 70 cm of old snow above 8000 ft in this area. 45-60 cm of new snow existed at the lower elevations.

Ski cuts on steep wind affected test slopes in near and below treeline terrain produced shooting cracks. One ski cut did trigger a small 6 inch deep, 10 ft wide soft slab failure within the new snow.

Photo 1: Extended Column Test results on a NE facing wind affected slope at 9000 ft.

Video 1: Extended Column Test on a NE facing wind affected slope at 9000 ft.

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

ECTP on Hidden Peak

video 2012 03 01 13 11 41

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Gale Force
Precipitation: 
Snow
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Wind loading would refill the skin track and ski tracks within an hour at all elevations on the peak.