Not-so-noisy Noisy Basin

Location Name: 
Noisy Basin
Observation date: 
Wednesday, December 12, 2018 - 15:00
Is this an Avalanche Observation: 
Yes
Observation made by: Forecaster

Location

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Quick Observation

This area - and likely the Swan Range in general - wasn't favored by the 12/11-12 storm.. And was much quieter - few red flag signs of danger.

Snowpack, Avalanche, Weather Images: 
Travel Details
Region: 
Swan Range - West Side (Flathead Valley access)
Route Description: 

Up road from Switchback Trail parking to Camp Misery, then to Pt. 6437. Down north ridge to road and return. 

Activity: 
Skiing
Snowpack Details
Snowpack and Weather Details: 
Hide Terrain
Elevation of observation: 
3500-5000 ft
5000-6500 ft
Aspect(s) of observation: 
N
NE
E
S
W
NW
Red Flags: 
Blowing snow
Persistent Weak Layers: 
Facets or Faceted Crust
Buried
New Snow in the past 24 hours: 
5.00in.
Total Snow Depth: 
110 cm
More comments about the snowpack and weather: 
Broken skies early afternoon, with patches of sun. Then lowering clouds; by midafternoon, ridgeline and basin obscured. Snow showers, with some graupel. An hour of gusty, strong winds mixing down below 4500 feet. Calm in basin; moderate-strong south winds on ridge to Pt. 6437. Graupel at base of storm snow. CT11 a few inches below 12/11 interface - possibly 12/10 interface. CT30 SC in old snow 40 cm below surface. Northerly slope, 6100 feet.
Blowing Snow: 
Moderate
Wind Speed: 
Moderate (Small trees sway)
Wind Direction: 
South
Air temperature: 
Below Freezing
Sky Cover: 
Mostly Cloudy (BRK)
Highest Precipitation Rate: 
Very Light Snowfall (S-1)
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Wednesday, December 12, 2018 - 05:00
Avalanche Type: 
Hard Slab
Failure Plane/Weak Layer: 
Old snow
More information or comments about the avalanche: 

2 slides below cornice on ENE side of ridge. Blocky debris in start zone with only an inch or so of new snow. One appeared to have broken on weak basal facets. HS closer to 50 cm than 100 cm of nearby areas. 

Hide Trigger
Trigger: 
natural
Trigger Modifier: 
Cornice Fall Triggered
Hide Terrain
Start Zone Slope Angle: 
40
Aspect: 
Northeast
Starting Elevation: 
above-treeline
Hide Size
Destructive Size: 
D1.5
Relative Size: 
R2 Small
Crown Height: 
2 ft
Avalanche Length (Vertical Run): 
150ft.
Avalanche Width (Average width): 
60ft.
Avalanche Location: