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PROFESSIONAL OBSERVATION FORM
 Start Date: 02.03.19 Name: Lundy Operation: SAC
 Drainage/Route:  Copper Observed Terrain:  6900-8900 Zone/Region:  Banner Summit
WEATHER OBSERVATIONS
 HN24: 35 HST: 35 Sky: X Precip: S1 Temps:
 Ridgeline Wind: Moderate and Gusty from the W
 Blowing Snow: I Snow Available for Transport: Large amounts
 Comments: Classic end to the storm with snow continuing to trickle in on Banner. 23cm HN measured at highway at 1100. 35cm measured later in the afternoon at upper elevations. HN was lower density than I thought, probably around 10%. Gusty Moderate winds were moving lots of snow, some drifts were up to 60cm in depth.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 2 Copper ridgeline Today 1.5 SS N NE 8900 two wind slabs, looked to be around 30cm deep. See photo. Pretty sure these were running within new snow.
 1 Copper ridgeline Today 1.5 SS AS NE 8900 Small stomp on wind pillow produced a wind slab avalanche in chute adjacent to naturals. Similar depth.
 1 Low elevation slope above creek Today 1.5 SS N N 7100 150' wide, about 30cm deep. Ran on near surface facets that were quite developed in this low elev cold sink. There was a thin zipper crust at the old surface, couldn't tell if it ran above or below crust. Poking in bed surface, there seemed to be a crust there still. See photo
SNOWPACK OBSERVATIONS
 HS: 8000', WNW: HS 175cm. Basal facets were ~140cm deep 
 Upper Pack: 35cm HN on FCsf 
 Middle Pack: 1F RG 
 Lower Pack: 20-30cm of DH, 1F, slightly moist, strongest I've seen yet 
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
30-60cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Isolated
Terrain
  Primary Concern Comments: Predictable wind slabs below ridge crest
 
Avalanche Characteristics
Character/Avalanche Problem:
Storm Slab

Layer/Depth:
20-35cm

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Widespread
Terrain
  Problem 2 Comments: Despite the natural slab at low elevation, I cut a few steeper slopes and pushed on little rolls and things generally stayed put. Concern is the old snow surface and mid storm about 20cm down
 
Avalanche Characteristics
Character/Avalanche Problem:
Deep Persistent Slab

Layer/Depth:
11/22 & 12/11, 100-140cm+

Likelihood of Triggering
Sensitivity:
Not Observed

Spatial Distribution:

Terrain
  Problem 3 Comments: 
STABILITY TESTS
 Stability Test Results: 8000', WNW: CTE RP and ECTN results on 2/2 interface - no slab.
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
 Comments (aspects and elevations of instability, etc): Borderline High danger at upper elevations, except the slides are generally less than D2.
FILE ATTACHMENTS

190203_copper_HN.jpg
Storm snow with 2/2 surface facets visible beneath

190203_copper_wind_slab_1.jpg
D1.5 natural wind slab

190203_copper_storm_slab.jpg
D1.5 storm slab that released at low elevation on the 2/2 surface facets