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PROFESSIONAL OBSERVATION FORM
 Start Date: 04.09.17 Name: Davis, Linnet, Head Operation: SAC
 Drainage/Route:  Galena Shoulder Observed Terrain:  7,300-10,600', N-W-S Zone/Region:  Smoky & Boulder Mountains
WEATHER OBSERVATIONS
 HN24: HST: 30 cm Sky: FEW Precip: Temps:
 Ridgeline Wind: Light and Intermittent from the W
 Blowing Snow: Prev Snow Available for Transport: Small amounts
 Comments: Observed flagging and stronger winds over the Boulders in the morning but died down by about 1030. Appeared less wind affected in the Smokys.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 1 Prairie Creek Yesterday 1.5 U N E 9,600' Could see debris but could not identify start zone.
 2 Prairie Creek Yesterday 1 L N E 9,600' A couple loose slides in very steep terrain. One triggered a small slab ~200' across? beneath a rock band.
 Comments: No other obvious recent avalanche activity.
SNOWPACK OBSERVATIONS
 HS: n/o 
 Upper Pack: 5-30 cm HST. Friday's snow and yesterday's snow started to appear as distinct layers around 8,500' suggesting a rain line in that ballpark on Friday. General funkiness at that elevation band where Friday's snow and rain line fluctuated. Evened out into right-side-up storm snow by 9,000' or so.  
 Middle Pack: n/o 
 Lower Pack: n/o 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
15-30 cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Specific
Terrain
  Primary Concern Comments: Wind last night and early this morning formed thin touchy wind slabs lee to north wind. We found them to be easy to spot and avoid. Observed up to 15 cm thick but some of the larger cross-loaded slopes on the west-face of Galena looked to have a bit thicker slabs. Still found 15 cm of soft powder along sections of upper elevation ridgeline. Older slabs (Friday) were obscured and more widespread but unreactive.
 Comments: No loose wet concerns by 1430. Southwest-facing slopes were moist and headed toward wet at ~8,500'.
STABILITY TESTS
 Stability Test Results:
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (isolated)   Length: 20'
 Comments: On exposed middle elevation ridge.
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: MODERATE Trend: Improving
 Comments (aspects and elevations of instability, etc): Wind slabs would be triggered by light loads in specific areas but no naturals were expected. MOD at middle and upper. LOW at lower.
BOTTOM LINE
 Comments: Recent slabs were thin where we encountered them and easy to spot. Friday's slabs were obscured by new snow but unreactive. Still good skiing and quite a bit of soft snow to be found at upper elevations.
FILE ATTACHMENTS

170409_ThinSlabOnRidge_Galena_ED.jpg