Forecaster Observation - Peak 6996', southern Glacier Park

Location Name: 
Forecaster Observation - Peak 6996', southern Glacier Park
Region: 
Flathead Range/Glacier National Park - John F. Stevens Canyon
Date and time of observation: 
Sun, 02/26/2017 - 12:10
Location Map: 

Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Terrain Trap
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

We chose Peak 6996', in southern Glacier Park, for today's tour so that we could observe wind slab development in a favored windy location.

  • We were surprised to find little snow in the valley floor from West Glacier to the Peak 6996' trailhead east of John F. Stevens Canyon. This was the result of strong easterly winds, associated with a cold front, which effectively restricted the eastward movement of the moist storm that affected the Whitefish and Swan Ranges.
  • Substantial wind loading on easterly aspects had occurred in the hours prior to my tour. This snow was tender and reactive to the weight of my skis. Propagation was limited.
  • Substantial wind loading occurred during my tour on westerly aspects from the moderate to strong easterly winds. This snow was tender and reactive to the weight of my skis. Propagation observed was more than on easterly aspects.
  • Up to 16" (40 cm) of low density surface snow sat on top of the February 16 rain crust. 
  • The February 16 and February 9 rain crusts were separated by a 2 cm layer of weak (4F) snow. 
  • A 45 cm layer of strong (1F) snow sat between the February crusts and the January 19 crust.
  • Below the January 19 crust the snowpack was comprised of 100 cm of weak (4F) snow.
  • Stability test results showed failure around the February crusts but no propagation was observed.
  • The snowpack structure in this area is poor and is held together only by the crusts and the thick 1F hard layer that comprise the upper half of the snowpack.
Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate (Small trees sway)
Precipitation: 
Air temperature trend: 
Static
Wind Direction: 
Northeast
Accumulation rate: 
More detailed information about the weather: 

Moderate to strong easterly winds arrived early this morning which shut off the precipitation to the Flathead Range and southern Glacier Park. The precipitation line was approximately midway between Hungry Horse and West Glacier. Terrain to the west of this line was snowy and overcast all day while terrain to the east received little snow overnight and had partly cloudy skies all day. 

Activity: 
Skiing
High Temp. (C): 
-12