New Snow and Wind on Hidden Peak

Location Name: 
Hidden Peak
Region: 
West Shore Area
Date and time of observation: 
Thu, 02/18/2016 - 12:30
Location Map: 
United States
38° 58' 31.1736" N, 120° 7' 27.3936" W
See map: Google Maps
US


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

14'' of new storm snow at 6600' and up to 18-22'' of new storm snow above 8000' as of 1 pm. Strong to gale force winds at higher elevations moving snow with near white out conditions on summit. 2 main density changes were observed within the new storm snow where failures were occurring. One was ~ 3'' above the old snow/new snow interface and the other was about 6'' below snow surface. Hand pits and Extended Column Tests did show ongoing instabilities associated with the density changes in the storm snow at all elevations. Localized cracking and larger shooting cracks occurred at these 2 locations.  No natural avalanche activity was observed and ski cuts and weighting numerous convexities and test slopes in below, near, and above treeline terrain produced limited shooting cracks and only 1 intentionally triggered wind slab avalanche on a previously undercut test slope (see photo). These slopes ranged in steepness from 33 to 39 degrees.

Photo 1: Small wind loaded test slope where a human triggered avalanche occurred after the test slope was undercut. The slope was 38 degrees in steepness and faced NE in near treeline terrain near the summit of Hidden Peak. 

Photo 2: Skier triggered shooting cracks on a wind loaded N-NE facing test slope on the summit ridge of Hidden Peak.

Photo 3: Shooting cracks on a small below treeline test slope. 

Video: Wind transport along the summit of Hidden Peak

Snowpack photos: 
Snowpit videos (tests, etc): 

Wind Transport on the Summit of Hidden Peak - Tahoe area

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Gale Force
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Winds increased into the mid day with snow slowly decreasing.