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PROFESSIONAL OBSERVATION FORM
 Start Date: 02.10.17 Name: Davis Operation: SAC
 Drainage/Route:  Dry Canyon Observed Terrain:  6500-8500', W-S-E Zone/Region:  Smoky & Boulder Mountains
WEATHER OBSERVATIONS
 HN24: 15 cm HST: Sky: SCT Precip: Temps:
 Ridgeline Wind: Moderate and Steady from the W
 Blowing Snow: L Snow Available for Transport: Small amounts
 Comments: Periods of sun and dark clouds. Dark clouds winning toward the pass and sun winning at times in the WRV. Moderate wind along exposed middle elevation ridge. Perfect loading speed but not much (here) to move.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 2 Boulder Peak Within past week 2 U W 9700' Looked like cross-loaded pockets of wind slab. Couldn't see debris piles.
 1 Easley Within past week 2.5 U S 9700' Wide crown ~500'. Mid-bowl just above treeline.
 1 Warm Springs above Penny Lake Within past week 2 U E 7800' Wind-loaded pocket below cornice.
 Comments: Had periods of good visibility and did not see much for avalanche activity at middle and upper elevations.
SNOWPACK OBSERVATIONS
 HS: >150 cm. The pack was entirely saturated below about 7,500' in sheltered areas. Above that the wet layer thinned out quickly and gave way to fresh moist, spongy feeling wind slabs. 
 Upper Pack:  
 Middle Pack:  
 Lower Pack:  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
15-30 cm

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Specific
Terrain
  Primary Concern Comments: Fresh wind slabs were forming on and below exposed ridges >8,000'. The SAFT and thickness of the slabs increased quickly until I turned around at 8,500'. Slabs were soft 4F+ and spongy. Stomps produced very small slabs that ran quickly in very steep terrain.
 Comments: By afternoon, wet problems had run their coarse in this location. Low elevation snowpack was well drained and firming up. The squishiest snow was found in wind affected terrain at ~7,500 feet where the wet snow had trouble draining through older wind slabs. I ski cut some of these sloppy spots sitting on old drifts with no results. Rain line was about 7,800'.
STABILITY TESTS
 Stability Test Results:
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (isolated)    
 Collapsing (isolated) Depth: 130 cm  
 Comments: I felt and heard one loud collapse in the pack in an unusually shallow (~130 cm) area. The snowpack was completely saturated in this location. I did feel one noticeable crust down 70 cm but I can't imagine that it occurred anywhere else than at the ground considering how far I dropped and how loud it was.
SNOW STABILITY
 Snow Stability Rating for your observed area: Good Confidence: MODERATE Trend: Steady
 Comments (aspects and elevations of instability, etc): MODERATE at middle elevations and LOW at lower elevations.
BOTTOM LINE
 Comments: I'd expect wind slabs to be larger and touchier above 8,500' where there is more SAFT. Low elevations will lock up tonight.
FILE ATTACHMENTS

170210_WindLoading_DryCanyon_E_8500.jpg
Active wind-loading along middle elevation ridges.