Professional Observation - John F. Stevens Canyon, southern Glacier NP

Location Name: 
Professional Observation - John F. Stevens Canyon, southern Glacier NP
Region: 
Flathead Range/Glacier National Park - John F. Stevens Canyon
Date and time of avalanche (best estimate if unknown): 
Mon, 12/21/2015 - 12:30


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Professional Observer
Avalanche Observations
Avalanche Type: 
Dry
Trigger type: 
Other - explain below
Crown Height: 
1 ft
Aspect: 
East
Weak Layer: 
Within storm snow
Avalanche Width: 
100ft.
Terrain: 
Near Treeline
Elevation: 
6 800ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
100ft.
More detailed information about the avalanche: 

GENERAL INFORMATION:Toured up the Shed 6/7 ridge to the Shed 7 Weather Station. Conducted maintenance on the Shed 7 weather station mast. All okay for now. Ascent and descent was of moderate difficulty due to early season snowpack conditions that consisted of shallow and unconsolidated snow. However, we were able to ski from ridgeline elevation to the Canyon floor. Very conservative skiing required below 5200’ elevation.DATE SUBMITTED: 12/21/2015TIME SUBMITTED: 1800OBSERVATION LOCATION: Shed 6/7 RidgeOBSERVATION DATE: 12/21/2015SUBMITTED BY:Steiner

SNOWPACK OBSERVATIONS:

 Conducted ski cuts and belayed stability tests in Test slopes 1, and 3. No Results No formal snow profiles conducted today. No audible failures, collapsing, or shooting cracks during tour..AVALANCHE OBSERVATIONS:Observed recent natural slab avalanche in the starting zone of Shed 7 West at approximately 1100. Aspect was easterly and activity consisted of two separate slab releases; D1 and D2 in size. SZ elevation was between ~6800 and ~6600 feet. Debris appeared to consist of soft and harder slab material in both releases. Both avalanches appear to have been triggered by cornice fall and terminated in the upper 1/3 of path. Photos attached.BNSF AVALANCHE SAFETY FIELD OBSERVATIONS SUBMITTED TO FLATHEAD AVALANCHE CENTER AND GLACIER NATIONAL PARK ARE BEING PROVIDEDED IN ACCORDANCE WITH THE TERMS AND CONDITIONS SPECIFIED GLACIER NATIONAL PARK SPECIAL USE PERMIT.THESE OBSERVATIONS REPRESENT SITE SPECIFIC INFORMATION INTENDED FOR THE BNSF AVALANCHE SAFETY PROGRAM AND IN NO WAY ARE TO BE CONSTRUED AS A PUBLIC/ RECREATION AVALANCHE FORECAST.BNSF RAILWAY AVALANCHE SAFETYVOLUNTARY FIELD OBSERVATIONS(406) 863-0476 Email: richard.steiner@bnsf.com

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Below Freezing
Wind Speed: 
Light (Twigs in motion)
Precipitation: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Broken and cloudy skies, light snow in the afternoon, and sporadic light west winds. Air temperatures in low to mid-twenties throughout the day. Only trace amounts new snow during the day. No windloading during the day however, previous windloading on southerly through easterly aspects was evident.