Gator hunting in the moat

Location Name: 
Forecaster Observation - Lost Johnny, Swan Range
Observation date: 
Tuesday, January 22, 2019 - 15:30
Is this an Avalanche Observation: 
No
Observation made by: Forecaster

Tabs

Quick Observation

Toured on various aspects in the middle-elevation "moat" hunting for surface hoar concerns. We found spatially variable results.

  • Several pits on east aspects above Lost Johnny Road showed no buried surface hoar, no reactive pit results, and no other signs of instability.  However, the 1/17 interface, down 15", consists of a faceted rain crust which could be an issue with more loading
  • Several pits on a northwest-facing slope showed reactive surface hoar up to about 5700' and but not above.  The surface hoar layer produced one shooting crack but no other instabilities on short, steep pitches.
  • Winds increased this afternoon and were blowing snow at ridgelines.  Moderate snowfall rates through the day with a few inches of accumulation.  
  • Snow surfaces are low-density stellar dendrites, which could be an issue with tomorrow's snowfall
  • Minimal evidence of recent avalanche activity; some small natural sluffs today and a few debris piles from last weekend's storm.  
Snowpack, Avalanche, Weather Images: 
Snowpack, Avalanche, Weather Videos: 

January 22, 2019. Surface hoar concerns on the rise!

Travel Details
Region: 
Swan Range - East Side (Hungry Horse Reservoir access)
Route Description: 

Lost Johnny Creek to 6400'

Activity: 
Skiing
Snowmobiling
Snowpack Details
Snowpack and Weather Details: 
Hide Terrain
Elevation of observation: 
3500-5000 ft
5000-6500 ft
Red Flags: 
Shooting cracks
Blowing snow
Persistent Weak Layers: 
Surface Hoar
Facets or Faceted Crust
Buried
New Snow in the past 24 hours: 
3.00in.
More comments about the snowpack and weather: 
On east aspects: the 1/17 rain crust existed up to about 6,000', with 1mm facets above and below. Unclear why the SH isn't here...perhaps sun or the NE wind event on 1/17. On NW aspect at 5100'. ECTP moderate results, down 40 cm on surface hoar. Same structure noted at 5700' but not above that.
Blowing Snow: 
Moderate
Wind Direction: 
West
Air temperature: 
Below Freezing
Snow line: 
Valley
Sky Cover: 
Overcast (OVC)
Highest Precipitation Rate: 
Moderate Snowfall (S2)
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Tuesday, January 22, 2019 - 15:30