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PROFESSIONAL OBSERVATION FORM
 Start Date: 03.05.19 Name: Davis, O'Connor Operation: SAC
 Drainage/Route:  Lake Creek, Triple Peak Observed Terrain:   Zone/Region:  Wood River Valley
WEATHER OBSERVATIONS
 HN24: 0 HST: Sky: BKN Precip: Temps:
 Ridgeline Wind: Calm
 Blowing Snow: Prev Snow Available for Transport: Small amounts
 Comments: Very calm, mostly overcast with some breaks of filtered sun. Mild air temps.
AVALANCHE OBSERVATIONS
None Reported
 Comments: Several recent slides from the past storm cycle but nothing that obviously ran post-storm.
SNOWPACK OBSERVATIONS
 HS: We dug on a SW (135 cm) and a NW (175 cm) near 8,000'. 
 Upper Pack: HST - SW: 35 cm, NW: 55 cm 
 Middle Pack: Early Feb snow. (2/2) down 85 cm on SW and indiscernible on NW  
 Lower Pack: Old FC and DH - 50 cm thick on SW, 65 cm thick on NW.  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
35-55 cm

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Widespread
Terrain
  Primary Concern Comments: New/old interface (2/23). Based on pit data, this layer appears to continue to be a greater concern on more southerly slopes.
 
Avalanche Characteristics
Character/Avalanche Problem:
Deep Persistent Slab

Layer/Depth:
135-175 cm

Likelihood of Triggering
Sensitivity:
Unreactive

Spatial Distribution:
Widespread
Terrain
  Problem 2 Comments: The poor structure remains. This weak layer was accessible in shallower, wind-swept areas on SW-S-SE. In fatter areas I'd bet it would take a colossal thump or rapid spring thaw to get anything moving.
STABILITY TESTS
 Stability Test Results: SW: CT6 SC, and ECTP12 down 40 cm @ new/old (2/23).
NW: ECTX and PST (90/100) END down 60 cm @ new/old (2/23).

//No notable results below this at (2/2). We did not assess the basal weak layers.

OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Collapsing (isolated)    
 Comments: We felt one collapse on a SW at 7800'. It seemed to have involved both the new/old and FC near the ground. I was in a shallow, wind-swept area at the time, so could have only felt it at the ground and Terry was a bit further out in a thicker slab that harbored both layers.
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
 Comments (aspects and elevations of instability, etc): Fair to good stability. Locally worse on SW-S-SE than on NW-N.
BOTTOM LINE
 Comments: We set out to better understand mid-pack weaknesses and compare them to observed activity patterns from the last cycle. Based on crown depth it looks like a good portion of the natural activity in this area ran on the new/old interface (2/23). This layer was easily picked out in pits on both N and S aspects but collapses and snowpack tests point toward souths remaining touchier. There were no notable results at (2/2).