Widespread instabilty below treeline on Elephants Hump.

Location Name: 
Elephants Hump
Region: 
Carson Pass Area
Date and time of observation: 
Tue, 01/09/2018 - 12:00
Location Map: 
United States
38° 41' 27.024" N, 119° 58' 26.868" 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
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Widespread skier triggered cracking and whumpfing in near and below treeline terrain on N-NE-E aspects above 8,200' in this area. All snowpack failure was occurring on faceted snow below the old/new snow interface. This is the weak layer that has been well advertised in the persistent slab avalanche problem. It is also the same failure layer for the nearby natural persistent slab avalanche (see other observation from same day). Faceted snow was moist to wet from recent rain on snow and wet snow accumulation. The facets formed very easily into a snowball. Despite this, the density change from the slab to the significantly less dense facets below was sufficient to keep instability ongoing. See the photos for numerous natural and skier triggered shooting cracks in the area. Whumpfing associated with snowpack collapse covered areas up to 10 m (33 ft) away from the trigger point.

Snowpit data was collected at one of the sights of naturally triggered cracking.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
Mixed rain and snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
More detailed information about the weather: 

Snow level around 8,500' in this area.