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PROFESSIONAL OBSERVATION FORM
 Start Date: 04.02.18 Name: VandenBos Operation: SAC
 Drainage/Route:  McDonald Peak Observed Terrain:   Zone/Region:  Sawtooth Mountains
WEATHER OBSERVATIONS
 HN24: HST: 15cm Sky: Precip: Temps:
 Ridgeline Wind:
 Blowing Snow: Snow Available for Transport:
 Comments: Clear skies and plenty of solar for the first few hours in the morning. Low and mid level clouds rapidly moving in around noon. Snowing up to S1 after arrival of clouds. Skies were overcast over the mountains for the remainder of the day but the valley was clearing up a bit around 1700. Intermittent, moderate NW winds with strong gusts, moving plenty of snow.
AVALANCHE OBSERVATIONS
None Reported
 Comments: No recent activity observed
SNOWPACK OBSERVATIONS
 HS: 175cm @ 8,250' on WNW slope 
 Upper Pack: 15cm fresh overnight, sitting on a ~30cm stack of interlayered melt-freeze crusts and PP/DF 
 Middle Pack:  
 Lower Pack:  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
20-60cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Specific
Terrain
  Primary Concern Comments: Your classic, straight forward wind slab problem
 
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Problem 2 Comments: Not sure how widespread this problem is. I suspect the layer of concern was buried in the big storm on 3/22.
ECT and PST scores were eyebrow raising. Not sure anyone else has been seeing this and will need to get a bit more information on the distribution on this layer before calling this a true problem as opposed to a localized phenomenon.
 
Avalanche Characteristics
Character/Avalanche Problem:
Deep Persistent Slab

Layer/Depth:


Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Problem 3 Comments: The valentine's day date that just won't end. Suspect that this is going to be on the list for the remainder of the forecast season. This structure is pretty darn similar to what we've been seeing further south, but (based on somewhat limited obs) which failed to produce much activity on deeper layers in the sawtooths.
STABILITY TESTS
 Stability Test Results: ECTP17 and ECTP16 down 41cm on 1-2mm facets sitting on 2cm thick MFcr, I suspect this is the 3/22 interface (?). PST 45/120 (END) down 41cm (3/22?). PST 50/120 (END) down 112cm (2/14?) on degrading MFcr capped with some subtle, fine-grained facets.
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Cracking (widespread)    
 Comments: Widespread cracking in fresh wind slabs on any slope greater than ~30°
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend: