Instability persist in Southern GNP

Location Name: 
Forecaster Observation - Upper Shields Basin, Southern GNP
Observation date: 
Tuesday, April 10, 2018 - 13:15
Is this an Avalanche Observation: 
No
Observation made by: Forecaster

Tabs

Quick Observation

Toured into Southern GNP to look for similar instabilities found in this area on Sunday.

  • Found warm air temps and moist/ wet surface conditions on all aspects up to 6300'
    • Air temp was above freezing at the start of our tour and 5.5 degrees Celsius at 6300' (1 pm)
  • Isolated collapsing observed above 5000' without shooting cracks
  • No recent slab avalanche activity visible
  • Loose wet activity (D1) appeared to occur yesterday on the south and east aspects at all elevation bands
  • ECTs produced propagating results on buried facet/ crust combo
  • Wind and precipitation (both rain and snow) began around 2 pm
    • Snow observed above 6000' with a rain/ snow mixture below
Snowpack, Avalanche, Weather Images: 
Snowpack, Avalanche, Weather Videos: 

April 10, 2018 - Instability persist in Southern GNP

Travel Details
Region: 
Glacier National Park - Southern Lewis Range
Route Description: 

Upper Shields Basin to 6300'.

Activity: 
Skiing
Snowpack Details
Snowpack and Weather Details: 
Hide Terrain
Aspect(s) of observation: 
N
NE
E
Red Flags: 
Collapsing / whumpfing noises
Persistent Weak Layers: 
Buried
New Snow in the past 24 hours: 
0.00in.
Total Snow Depth: 
345 cm
More comments about the snowpack and weather: 
Extended Column Test produced propagating results (ECTP 23 & 27) on a facet/ crust combo 64 cm down on both north (6300') and east (5600') aspects. Non-propagating results observed in dense storm snow that's fallen since Sunday (4/8). Lower density snowfall from last week has consolidated into a 1F to 1F+ slab. Warm and moist surface conditions observed between 5000 - 6300'. Below 5000', snow surface was wet with thickness down 10 cm from the surface. A lot of rollerballs and pinwheels from yesterday's warm-up on sunny aspects. Numerous isolated collapses observed above 5000' without shooting cracks. Test slopes and kicking small cornices didn't produce any signs of instability.
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Tuesday, April 10, 2018 - 20:45