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PROFESSIONAL OBSERVATION FORM
 Start Date: 03.20.17 Name: Davis Operation: SAC
 Drainage/Route:  Copper Mtn Observed Terrain:  7,000-9,000', W-S Zone/Region:  Banner Summit
WEATHER OBSERVATIONS
 HN24: HST: Sky: OVC Precip: RV Temps:
 Ridgeline Wind: Moderate and Gusty from the SW
 Blowing Snow: L Snow Available for Transport: Small amounts
 Comments: Some broken skies and sun near Thompson on the drive in. Overcast by Banner and stayed that way throughout the day. Very light rain during tour but it picked up as I skinned out.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 4 Decker Within past week 1.5 SS N 10,000' SE-E failed at ridge.
 Many Heyburn Within past week 2 WL N SE 9,300' Steep shots facing Grand Mogul. Most gullies had substantial roller balls or slides.
 1 Grand Mogul Within past week 2 SS N E 9,300' Wider than the others, through trees.
 1 Upper Bowl of Peak 10,084 (near Williams) Within past week 1 SS N NE 9,600'
 Comments: It's likely that many of these slabs failed on (3/18) or (3/19) with continued wind.
SNOWPACK OBSERVATIONS
 HS:  
 Upper Pack: Unsupportable slush (ski pen of 30-40 cm) at 7,000' that gradually stiffened and switched to 20 cm moist DF by 8,500'. Generally moist and well bonded to the (3/15) interface. 
 Middle Pack: Weak/no freeze in older snow from last weeks warm up. Wet, melt forms. Firmed up with a stiffer crust on top by ~8,500'. 
 Lower Pack:  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
20-40 cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Specific
Terrain
  Primary Concern Comments: Cracking in fresh wind slab on exposed middle elevation ridge. Didn't get on more loaded E-facing slopes, but saw active loading and fresh avalanches on the drive in. Moist snow at this elevation leaves little left to move. Would be more of a concern at colder upper elevations.
 
Avalanche Characteristics
Character/Avalanche Problem:
Loose Wet

Layer/Depth:
10-40 cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Widespread
Terrain
  Problem 2 Comments: Cooler temps kept most middle elevations cool, but rain was moving in as I left. Slush at lower elevations.
STABILITY TESTS
 Stability Test Results:
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (isolated)   Length: Ski width
SNOW STABILITY
 Snow Stability Rating for your observed area: Good Confidence: MODERATE Trend: Steady
 Comments (aspects and elevations of instability, etc): Above the gloppy, wet snow in elevations that harbor sheltered, moist snow the danger was LOW. Higher up, wind loading pointed to MODERATE and low down it was MODERATE with WL glop. Rain may have raised all elevations to MODERATE shortly after I left.
BOTTOM LINE
 Comments: 20 cm of moist DFs remain to be striped from steep slopes with a solid bout of sun or spike in temps at middle and upper elevations.