Forecaster Observation - Nyack Peak, Middle Fork, Flathead Range

Location Name: 
Forecaster Observation - Nyack Peak, Middle Fork, Flathead Range
Region: 
Flathead Range - Middle Fork Corridor
Date and time of avalanche (best estimate if unknown): 
Sat, 01/02/2016 - 10:00
Location Map: 

Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
Dry
Slope: 
45degrees
Trigger type: 
Natural
Crown Height: 
1 ft
Aspect: 
North
Weak Layer: 
Old snow
Avalanche Width: 
30ft.
Terrain: 
Above Treeline
Elevation: 
7 400ft.
Bed Surface: 
Old Snow
Avalanche Length: 
40ft.
More detailed information about the avalanche: 

We witnessed a small natural wind slab avalanche in extreme, rocky terrain on a wind loaded N aspect on Nyack Peak at the head of Wahoo Creek drainage. The avalanche was small (~30-40 feet wide and 1 foot deep), but as it traveled through a couloir and over 100 ft. cliffs. The steep terrain made it very dramatic as it flowed over the cliffs. This is the type of terrain where even a small slide can be deadly. 

The image above is another small older (maybe 1-2 day old) natural wind slab. I wasn't able to capture the wind slab in action today. The other image is wind transport on the ridge near Nyack Peak.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
Clear
Air temperature: 
Below Freezing
Wind Speed: 
Moderate (Small trees sway)
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
South
Accumulation rate: 
None
More detailed information about the weather: 

Wind transport evident above 5500 feet on northerly and easterly aspects.

Activity: 
Skiing