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PROFESSIONAL OBSERVATION FORM
 Start Date: 11.29.18 Name: VandenBos - OFF DUTY Operation: SAC
 Drainage/Route:  4th of July Creek Observed Terrain:  to 10,500' Zone/Region:  other
WEATHER OBSERVATIONS
 HN24: HST: Sky: Precip: Temps:
 Ridgeline Wind:
 Blowing Snow: Snow Available for Transport:
AVALANCHE OBSERVATIONS
None Reported
 Comments: Many small avalanches had occurred on the northern quarter of the compass during the previous loading event. In many cases the crowns and debris were partially obscured by additional snowfall and wind transported snow.
SNOWPACK OBSERVATIONS
 HS: 60cm 
 Upper Pack: 30 cm PP 
 Middle Pack: 15cm 2-3mm facets (4F) 
 Lower Pack: 10 cm of 3-6mm chained DH (F), capped with 5cm MFcr (1F) 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
30 cm

Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Primary Concern Comments: 11/22 interface. More problematic where overlying slab had been thickened and stiffened by the wind
STABILITY TESTS
 Stability Test Results: ECTP 6 down 30cm (twice). PST 11/100 and 14/100, both to end down 30cm.
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (widespread)   Length: 10s of meters
 Collapsing (widespread) Depth: 30cm Length: 10s of meters
 Comments: Widespread cracking and collapsing, particularly on shady aspects. Experienced a few rolling collapses that propagated out at least 35m
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
BOTTOM LINE
 Comments: Oh boy, its shaping up to be another tricky year, at least in areas where the Thanksgiving storm fell on older snow that had been hanging around for awhile. We've got an excellent weak layer just sitting there waiting for a nice load/slab. Additionally, I observed widespread SH growth up to 10,500', generally increasing in size as I gained altitude, approaching 1cm at 10,500'.
FILE ATTACHMENTS

P1100219-001.JPG
NE aspect, 9,500'

P1100288.JPG
Widespread cracking and collapsing

P1100325.JPG
ECTP 6 down 30cm. ENE aspect at 9,800'.

P1100316.JPG
SH