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PROFESSIONAL OBSERVATION FORM
 Start Date: 12.27.18 Name: Savage Operation: SAC
 Drainage/Route:  Horton Peak area Observed Terrain:  7200-9300', NW-W-SW-S Zone/Region:  Smoky & Boulder Mountains
WEATHER OBSERVATIONS
 HN24: 1cm HST: 5cm? Sky: X Precip: Temps: 7-12F
 Ridgeline Wind: Moderate and Intermittent from the NW
 Blowing Snow: L Snow Available for Transport: Small amounts
 Comments: Skies ranged from obscured and sputtering/flurries to broken.
AVALANCHE OBSERVATIONS
None Reported
SNOWPACK OBSERVATIONS
 HS: sheltered=30-50cm <8200', 30-70cm>8200' wind-loaded=70-100cm >8500' (see attached pit+photo for example of wind-loaded middle elevation slope) 
 Upper Pack: sheltered=F PP/DF/MF with some stiffer 1F snow a ways below the surface and some crusts on true solars
exposed=mix of stiffer wind affected 1F layers and trapped 4F/F DF 
 Middle Pack: sheltered=degrading crusts and FC
exposed=P hard wind packed layer 
 Lower Pack: sheltered=F FC or DH
exposed=FC/DH, but stronger (1F and 4F) 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
12/11 wind-loaded terrain: 40-60cm

Likelihood of Triggering
Sensitivity:
Stubborn

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

Layer/Depth:
12/11 sheltered terrain: 10-30cm

Likelihood of Triggering
Sensitivity:
Unreactive

Spatial Distribution:
Widespread
Terrain
  Problem 2 Comments: 
STABILITY TESTS
 Stability Test Results: 8800' W aspect, wind-loaded slope with hard slabs above weak layer: ECTPsp 25, 27 @22cm
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Collapsing (isolated) Depth: 30-40cm Length: 5m
 Comments: I stomped on all the drifts and wind-slabs I could find. I only got collapses in areas where the slab was thinner (< about 18") and softer (1F and 4F). In areas where a P hard, thicker slab existed, I didn't get any collapsing - it was behaving more like a low probability/high consequence deep persistent problem in these areas.
SNOW STABILITY
 Snow Stability Rating for your observed area: Good Confidence: MODERATE Trend:
 Comments (aspects and elevations of instability, etc): Stability rating applies to middle elevation, wind-loaded slopes. Stability was very good at lower elevations and in sheltered middle elevation terrain.
FILE ATTACHMENTS

181227_HortonPk_pit_8800W_SS.jpg
Pit in wind-loaded site at 8800', W aspect. This was representative of exposed areas near ridges with hard slabs from previous wind events.

181227_HortonPk_pitphotolabeled_8800W_SS.jpg
Photo of ECTPsp,25, failing at interface between basal facets and hard wind slab above.