Forecaster Observation - Marion Lake/Dickey Creek, Flathead Range

Location Name: 
Forecaster Observation - Marion Lake/Dickey Creek, Flathead Range
Flathead Range - Middle Fork Corridor
Date and time of observation: 
Mon, 12/19/2016 - 13:00
Location Map: 

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

Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

The objective today was to assess new wind slab development and determine snow surface quality on non-wind affected slopes. In the area we visited today, we were able to trigger several small wind slab avalanches on east, northeast, and north aspects. The avalanches were small (12-18 inches deep and 15-20 feet wide) and were very soft slabs (the slabs broke apart very easily as they moved downhill) (see avalanche observation). However, as the day progressed, strong winds continued, and more snow accumulated, the slabs became more cohesive. 

Aside from the avalanches, we also observed cracking on all wind loaded terrain. On non-wind loaded terrain, the snow surface remained cohesionless and ski penetration was 90 cm.

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

December 19, 2016 - Wind Slab Avalanches, Marion Lake/Dickey Creek, Flathead Range

Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong (Whole trees in motion)
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Strong southwest winds occurred all day transporting the new snow. Snowfall rates ranged from 0.5 inches/hour to 2 inches/hour throughout the day. Visibility was poor so we could not see surrounding terrain.

Precip Rate: 
S2; moderate snowfall, 2cm/hour