Professional Observation - John F. Stevens Canyon

Location Name: 
Professional Observation - John F. Stevens Canyon
Region: 
Flathead Range/Glacier National Park - John F. Stevens Canyon
Date and time of observation: 
Mon, 01/30/2017 - 12:00
Location Map: 

Red Flags: 
Recent loading by new snow, wind, or rain
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 
  • No audible failures, collapsing, or shooting cracks.
  • Active windloading occurring on easterly aspects.
  • Surface ~10 cm (4”) windslab forming on easterly aspects at upper starting zone elevation(s).
  • Below 5000 feet, a prevalent surface or near surface rain and/or melt-freeze crust (formed 1/18-1/19/17) remains as reported on 1/25/17.  However, this crust has softened and is either not supportive or only semi-supportive under skier weight. 
  • Above 5000 feet elevations approximately 5 cm (2”) to 10 cm (4” of new snow is seated on the crust.
  • Also, between ~5800 and ~6100 feet elevation, we toured on a predominately south-southeasterly aspect that consisted of very poor structure (faceted) snow for the entire snowpack depth beneath the mentioned crust.  At this location, the crust was not supportive and under skier weight, skis were penetrating at least 60 cm (2 feet) into facets and pole plants penetrated snowpack to the ground.
  • Above 6000 feet, noted crust also remains present and supportive of skier weight. 
  • Above 6000 feet, faceted snow beneath the 1/18-1/19/17 crust was observed as on 1/25/17 but facets are rounding and appear to have more strength than observed on 1/25/17.
  • A full profile was conducted at ~6330 feet elevation on a 32 degree slope with an easterly aspect.  Snow depth at this location was 140 cm (~5’).
  • Our layer of main concern in at this profile location were related to surface snowpack structure consisting of newly formed thin windslab and previously mentioned rounding facets beneath the crust.
  • Basal depth hoar at this profile was approximately 50 cm in height (0-50cm in profile height) and varied in hardness. 0-30 cm= F hardness and 30-50 cm= 4F hardness.  Snow profile mid-pack was relatively strong and consisted of very small grain, tightly packed, rounding facets/buried windslabs.
  • No significant stability test results.
  • Significant temperature gradient was noted in the surface layers of the snowpack and between the snowpack surface and air.
  • No recent avalanche activity observed.
  • No debris from previous avalanches observed in the Shed 7 West path.
Any other comments about the observation or links to outside pages that have more info on the observation: 

Toured up the looker’s left side of the Shed 7 path to the Shed 7 West path. Continued up the Shed 7 West path on the looker’s left side and climbed to ridge that separates the Shed 8 starting zone (approximately 5800’ elevation) and the Shed 7 West starting zone. Continued to approximately 6300 feet elevation and conducted a full profile on an easterly aspect of Shed 7 West.

BNSF AVALANCHE SAFETY FIELD OBSERVATIONS SUBMITTED TO FLATHEAD AVALANCHE CENTER AND GLACIER NATIONAL PARK ARE BEING PROVIDED IN ACCORDANCE WITH THE TERMS AND CONDITIONS SPECIFIED IN THE 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

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate (Small trees sway)
Air temperature trend: 
Static
Wind Direction: 
West
More detailed information about the weather: 

Overcast and broken skies with no precipitation.  Westerly winds light to moderate with stronger moderate gusts. Snow transport onto easterly aspects occurring at ridgeline elevations.  Air temperatures relatively warm at all elevations with above freezing air temperatures at Canyon floor elevations and in the upper 20s F at upper starting zone elevation(s).

Activity: 
Skiing