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PROFESSIONAL OBSERVATION FORM
 Start Date: 01.31.18 Name: VandenBos Operation: SAC
 Drainage/Route:  Pioneers Observed Terrain:   Zone/Region:  Wood River Valley
WEATHER OBSERVATIONS
 HN24: HST: 2 cm Sky: VAR Precip: Temps:
 Ridgeline Wind: Moderate and Intermittent from the W
 Blowing Snow: Snow Available for Transport: None
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 1 SW aspect of Cobb Within past week 2 SW Not particularly fresh, looked like it was probably a wind slab that did not activate deeper weak layers.
 2 N aspect above Big Basin, facing Cobb Within past week N Two size 2 or 2.5 in heavily wind loaded terrain. Couldn't see crowns well so tough to say what culprit weak layers is, but it is safe to say that wind played a big role.
SNOWPACK OBSERVATIONS
 HS: 80-85cm on E-S-W aspects ~9,000'.  
 Upper Pack:  
 Middle Pack:  
 Lower Pack:  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Primary Concern Comments: 
 
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Problem 2 Comments: 
STABILITY TESTS
 Stability Test Results: ECTP 11 and 13 down 40-50cm (SE at 8,800'). ECTP 18 and 20 down 40-50cm (SW at 9,100'). Fracture sets propagate across entire column and column displaces ~1cm vertically and along slope. Fractures are complex and anastomosing, not straight and simple.
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (isolated)    
 Collapsing (isolated)    
 Comments: Cracking and collapsing in middle elevation terrain.
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend: