Close
PROFESSIONAL OBSERVATION FORM
 Start Date: 12.02.16 Name: Davis, VandenBos Operation: SAC
 Drainage/Route:  Copper Observed Terrain:  7,000'-9,000', all aspects Zone/Region:  Banner Summit
WEATHER OBSERVATIONS
 HN24: 0 HST: 0 Sky: CLR Precip: Temps: 0
 Ridgeline Wind: Light and Intermittent from the W
 Blowing Snow: Prev Snow Available for Transport: Small amounts
 Comments: Sunny. Increasing clouds @ 1500.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 Comments: No avalanches observed.
SNOWPACK OBSERVATIONS
 HS: South: 20-45 cm; North: 50-80 cm 
 Upper Pack: Settled new snow 
 Middle Pack: North: SH down 30 cm 
 Lower Pack: North: FC above MFcr. Moist @ ground. 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
30 cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:

Terrain
  Primary Concern Comments: 10 mm SH, unsure on spatial distribution: CT3,6 (SC) and ECTP23.
 
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
60 cm

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Widespread
Terrain
  Problem 2 Comments: No results in standard tests. Stomping on pit wall produced fracture.
 Comments: Fresh SH forming at the surface on all sheltered aspects >8,800'
STABILITY TESTS
 Stability Test Results:
SNOW STABILITY
 Snow Stability Rating for your observed area: Good Confidence: MODERATE Trend: Steady
 Comments (aspects and elevations of instability, etc): Only areas of concern were wind-loaded N-NE aspects >8,500'. Storm snow since TG settling into soft slab above SH and FC-MFcr combo. FC-MFcr combo was more compact and closer to the ground at the same elevation on south aspects.
FILE ATTACHMENTS

DSC_0254 (1024x683).jpg
Fresh surface hoar forming on all sheltered aspects (12/2). Photo: VandenBos

DSC_0267.JPG
Stripe of surface hoar plainly seen down about a foot. Photo: VandenBos