Test Cornice

Location Name: 
Test Cornice
Region: 
BWRA
Date and time of avalanche (best estimate if unknown): 
Thu, 01/17/2019 - 14:22
Location Map: 


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Rapid warming

Observation made by: Avalanche Specialist
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
50degrees
Trigger type: 
Snowmobiler
Crown Height: 
2 ft
Aspect: 
Northeast
Weak Layer: 
Old Snow
Avalanche Width: 
55ft.
Terrain: 
Below Treeline
Elevation: 
8 500ft.
Bed Surface: 
Old Snow
Avalanche Length: 
15ft.
Number of similar avalanches: 
5
Number of people caught: 
0
Number of partial burials: 
0
Number of full burials: 
0
Did the avalanche hit a building, vehicle, or structure?: 
No
More detailed information about the avalanche: 

The practice avalanche involved 2 curious snow-workers & a safe test cornice. The cornice was located in a meadow filled with chest-deep snow, accumulation building upon a lone rock. With very little force, the weight of a human, the cornice collapsed with a propagating crack. The crown in areas was over 2' deep, failing at the old snow/ new snow interface. The evidence of rapid failure here correlates to instabilities that our snowpack is harboring; including Storm Slab, Wind Slab, & Cornice Fall. Multiple mid-storm avalanche remnants were visible, especially where rain occurred. The mountain were very hard to see & our travel was limited.

Avalanche Photos: 
Snowpit or crown profile photo or graph: 
Test Cornice
Human Trigger
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Heavy falling & blowing snow made snowmobile travel & visibility difficult. Wind chill values were low. Evidence of rain to almost 9000' was apparent. Wet heavy snow below 7500' became a breakable crust at 8500' & by 9000' creamy wind-blown snow was deeply drifted. Gale winds have broken tree limbs & cast wet snow far up trees on their SW sides.