Wet Slide on Half Moon

Location Name: 
Half Moon, southern Whitefish Range
Region: 
Whitefish Range - Southern (south of Coal Creek)
Date and time of avalanche (best estimate if unknown): 
Sat, 12/09/2017 - 15:45


Red Flags: 
Recent avalanche activity
Rapid warming
Obvious avalanche path
Terrain Trap

Observation made by: Public
Avalanche Observations
Avalanche Type: 
Wet
Slope: 
40degrees
Trigger type: 
Skier
Crown Height: 
Less than 1 ft
Aspect: 
South
Weak Layer: 
New/old snow interface
Avalanche Width: 
60ft.
Terrain: 
Below Treeline
Elevation: 
6 400ft.
Bed Surface: 
Old Snow
Avalanche Length: 
350ft.
Number of similar avalanches: 
1
More detailed information about the avalanche: 

Checked out Half Moon late afternoon after noticing trees shedding snow in the sunny windless weather.  Amazingly, the weak December sun still had the power to completely bake the surface snow on southerly aspects. My first few turns on the upper headwall released slow moving wet snow on the Thanksgiving crust which quickly gained momentum as I cut out of the fall line. The slide ran all the way to the trees and piled up 3-4 ft deep so I'd call it a D2. Definitely the type of slide which could hurt somebody in consequential terrain. Perhaps after today's baking the south facing snow will gain enough integrity to hold up to the sun? Hard to say. A similar small slide had released naturally on the same slope either today or yesterday. In the photo the slide path is to the skier's left of the lower tracks.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Below Freezing
Air temperature trend: 
Static
Activity: 
Skiing