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PROFESSIONAL OBSERVATION FORM
 Start Date: 12.04.16 Name: VandenBos Operation: SAC
 Drainage/Route:  Galena Pass to Upper Titus WX station and back Observed Terrain:   Zone/Region:  Smoky & Boulder Mountains
WEATHER OBSERVATIONS
 HN24: 45 cm HST: Sky: X Precip: S2 Temps:
 Ridgeline Wind: Moderate and Gusty from the W
 Blowing Snow: Snow Available for Transport: Large amounts
 Comments: Lots of snow being moved around by wind during the storm.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 10 Today 1.5 SS N E 9500
 Comments: Difficult to determine size due to lack of visibility and continued loading by new snow and wind.
SNOWPACK OBSERVATIONS
 HS:  
 Upper Pack: > 45 cm new snow, hard to be precise due to significant wind loading.  
 Middle Pack:  
 Lower Pack:  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Storm Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:
Not Observed

Spatial Distribution:
Widespread
Terrain
  Primary Concern Comments: Very poor visibility, hard to be certain on distribution and size. Given amount of new snow I would expect distribution to be widespread, but only observed on reported aspects. Slabs releasing naturally during storm. Debris piles on highway 75 at and near pass from roadcuts.
 
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:
Specific
Terrain
  Problem 2 Comments: Suspected but not observed.
 
Avalanche Characteristics
Character/Avalanche Problem:
Deep Persistent Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Problem 3 Comments: Suspected but not observed.
 Comments: Storm slabs were most immediate concern this evening, given active natural releases. However, as the wind continues to blow, both wind slabs and deeper slabs releasing on pre-exisitng weak layers could become very significant problems.
STABILITY TESTS
 Stability Test Results:
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (isolated)    
 Collapsing (isolated) Depth: 30 to 90 cm  
 Comments: Experienced some shooting cracks, particularly on wind loaded slopes at ridgetops. Collapsing experienced on same slopes.
SNOW STABILITY
 Snow Stability Rating for your observed area: Poor Confidence: MODERATE Trend:
 Comments (aspects and elevations of instability, etc): Hard to decide on danger level given lack of visibility. On the border between considerable and high. I would NOT have put myself in avalanche terrain this evening. Numerous avalanches were observed anytime visibility improved. Storm slab danger is likely peaking this evening but deeper instabilities exist. Clear skies tomorrow should help to resolve uncertainty.