Professional Observation- Noisy Basin, Swan Range

Location Name: 
Professional Observation- Noisy Basin, Swan Range
Region: 
Swan Range - West Side (Flathead Valley access)
Date and time of observation: 
Fri, 03/10/2017 - 11:46
Location Map: 

Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path
Terrain Trap
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Today we snowmobiled/skiied in the Noisy Basin area.  The road on the way up was sloppy with heavy snow.  Once at Camp Misery, however, the rain had turned to snow and things were a little less wet.

We saw numerous recent avalanches.  All aspects and all elevations seemed to have small slab avlanches on them.  All the ones that we could see were the new snow from overnight (approx 5-6 inches) sliding on the dryer, less dense snow beneath it.  While none of these avalanches ran very far they were very abundant.

Our pits all had fractures in them.  Our results from a N facing pit were:

  • CT 1, Q1 @ 13 cm. down. 
  • CT 6, Q1 @ 23 cm. down
  • CT 15, Q2 @ 43 cm. down
  • CT 25, Q1 @ 65 cm. down
  • ECTP 1 @ 13 cm, down

All of these failures were occuring within density changes within the last two weeks storms. 

Snowpit or crown profile photo or graph: 
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light (Twigs in motion)
Precipitation: 
Mixed rain and snow
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Wet.  There was rain on the way up until the end of the road and then the snow started.  When we left the skies were clearing and we could see the valley floor.

Activity: 
Snowboarding
Precip Rate: 
S -1; very light snowfall, trace to 0.5cm/hour