Professional Observation - BNSF Avalanche Safety - JFS Canyon

Location Name: 
Professional Observation - BNSF Avalanche Safety - JFS Canyon
Region: 
Flathead Range/Glacier National Park - John F. Stevens Canyon
Date and time of observation: 
Wed, 03/08/2017 - 12:00
Location Map: 


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

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

Toured up to the Shed 11 weather station via the ridge separating the Shed 11 and Shed 10.7 avalanche paths above the rail grade. Most notable today were the west winds which were heavily loading easterly aspects. Above 5000 feet we were able to trigger several small wind slabs with ski cuts. Also heard and felt several collapses in the snowpack as we travelled up and down the ridge and had cracks shooting out from under our skis on multiple occassions.

After working on the weather station we dug a pit at 6400 feet on a south aspect. HS-200 cm. We dug down until just below the Feb. 10 crust. At this location there was about 80-90 cm of snow on top of the crust, 4F hardness near the snow surface, stiffening to 1F hardness down near the crust. In three different ECTs we had propagation across the column with hard force (video).

Snowpack photos: 
Snowpit videos (tests, etc): 

3 8 17 Shed11 ECT

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate (Small trees sway)
Precipitation: 
Snow
Air temperature trend: 
Warming
Wind Direction: 
West
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Moderate winds with strong gusts for most of the day. Winds died down a little bit by late afternoon. Skies alternated between overcast and broken with occasional very light snowfall intermixed with periods of sun. Picked up a trace amount of snow over the course of the day. Temperatures were just above freezing at the Canyon floor, and about -4 to -3 deg C at the Shed 11 weather station at 6300 feet elevation.

Activity: 
Skiing
Precip Rate: 
S -1; very light snowfall, trace to 0.5cm/hour
High Temp. (C): 
2
Low Temp. (C): 
-5