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PROFESSIONAL OBSERVATION FORM
 Start Date: 12.21.18 Name: Lundy Operation: SAC
 Drainage/Route:  Copper Mountain Observed Terrain:  6900-8800', most aspects Zone/Region:  Sawtooth Mountains
WEATHER OBSERVATIONS
 HN24: 8cm HST: Sky: OVC Precip: Temps:
 Ridgeline Wind: Moderate from the NW
 Blowing Snow: L Snow Available for Transport: Small amounts
 Comments: Some periods of S-1. Low density HN24.
AVALANCHE OBSERVATIONS
None Reported
 Comments: Got a closer look at the slides reported by Sara yesterday. The crowns and bed surfaces were more filled in today with new snow and wind transport, and the light was flat, but check out the attached photo. They were +/- 60cm deep, D1.5-2 in size, and ran to the depth hoar. They were in steep, rocky terrain - the basal facets/depth hoar may have been even weaker in these areas. Propagation was not very extensive, more pockety in nature.
SNOWPACK OBSERVATIONS
 HS: 70cm at the highway level. 80-100cm in mid elevation terrain. 100-120cm in upper elevation, north facing terrain where the snowpack tends to be deep. See attached photos. 
 Upper Pack: 40cm of PP and DF, F going to 1F. 
 Middle Pack: 12/11 layer showed up in 2 shady pits, presenting as SH and minor FC. SH crystals very small and hard to discern, but obvious stripe on pit wall. 12/11 facet layer does not appear to be prominent in this zone. Lower portion of the slab is 1F. 
 Lower Pack: 10-25cm of F DH. There's a thin DH layer even at the valley bottom that is obvious with a pole poke. The DH layer becomes thicker as you increase in elevation, reaching 25+cm on high norths. Hand pits on solars at mid elevations showed some faceting near the ground but not particularly weak and slightly moist. 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
11/22, 80-90cm

Likelihood of Triggering
Sensitivity:
Reactive

Spatial Distribution:
Widespread
Terrain
  Primary Concern Comments: Weaker, thicker, and more problematic with increased elevation
 
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
12/11, 40cm

Likelihood of Triggering
Sensitivity:
Unreactive

Spatial Distribution:

Terrain
  Problem 2 Comments: 12/11 SH distribution is a bit unknown. Found it in two pits on shady/sheltered slopes
STABILITY TESTS
 Stability Test Results: 8000, W: Large collapse on approach to pit site. ECTP14 75cm down on 11/22 F DH. No results on 12/11 SH. 8700, N: This is a known deep area. ECTP22 on 12/11 SH and ECTP28 on 11/22 DH.
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Collapsing (isolated) Depth: 60-70cm Length: 50'?
 Comments: Several smaller, localized collapses and one large collapse.
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
BOTTOM LINE
 Comments: Feel reasonably confident that the 11/22 depth hoar is the primary stability problem in this area, and that it's most concerning on mid to upper elevation shady aspects. Also feel reasonably confident that there's not much going on on solar aspects. 12/11 facets don't seem to be prominent here, although SH may be. The SH layer didn't seem particularly alarming but that's based on limited data.
FILE ATTACHMENTS

181221_copper_pit1.jpg

181221_copper_pit2.jpg

181221_copper_crown.jpg
The crowns were slightly obscured by new snow, but appeared to be around 2' deep and ran on depth hoar near the ground