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PROFESSIONAL OBSERVATION FORM
 Start Date: 03.28.18 Name: Savage Operation: SAC
 Drainage/Route:  Independence/Keystone/Parker/Milligan Gulches Observed Terrain:  6000-8500', all aspects Zone/Region:  Wood River Valley
WEATHER OBSERVATIONS
 HN24: 0 HST: 0-120cm Sky: CLR Precip: Temps: 20s F
 Ridgeline Wind: Strong and Gusty from the NW
 Blowing Snow: None Snow Available for Transport: None
 Comments: Hard to stand up on the ridges at times (due to wind). Not moving much snow though - it rained enough to at least 8500' in this area on 3/22 to lock down the snow from the March storm. The only snow blowing around was the skiff from the past couple days.
AVALANCHE OBSERVATIONS
None Reported
 Comments: No new observations, but some of the Parker and Keystone slides were 800-1000' wide and not the 100-300' that I guessed from looking at them from Baldy. They wrapped abound the cirques, so large portions of the crowns were hidden from that vantage point. Several reported D2 slides are actually D3 events.
SNOWPACK OBSERVATIONS
 HS: Will attach crown profile in Keystone Gulch: 100-110cm at upper portion of crown near 8150', quickly tapered to 40-70cm by 7800'.  
 Upper Pack: March storms. Rain crust on top 5-15cm, then dry DF or RG. 
 Middle Pack: mostly P RG from March storms...weird mess below about 7900'. 
 Lower Pack: FC and crusts, then knife hard frozen DH and melt freeze to ground  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
70cm

Likelihood of Triggering
Sensitivity:
Not Observed

Spatial Distribution:

Terrain
  Primary Concern Comments: Thinking stubborn to unreactive around 8100'. Dormant or done below about 7800' in this area.
 Comments: No wet loose issues due to strong winds today. No wind slabs to worry about below the 3/22 rain line (at least 8500' in this area). Persistent slab: All the 3/22 activity near 8000' appeared to happen when the rain line rose at the tail end of the storm. The wet surface has frozen and it's been 5 days since the storm/wind-loading event, so stability is better. I felt OK booting down a 33-40* slope above the crown line...but I wouldn't have wanted to boot down that slope if the steeper part below hadn't already released.
STABILITY TESTS
 Stability Test Results:
SNOW STABILITY
 Snow Stability Rating for your observed area: Good Confidence: MODERATE Trend:
 Comments (aspects and elevations of instability, etc): Bomber stability on SW-S-SE slopes, no chance of avalanches (they are dirt or very thin). Very good stability on all slopes below about 7800'. I don't fully trust W-NW-N-NE-E aspects above about 8000' in this area (due to persistent slab problem) - slab is about 70cm thick and weak layer remains ugly.
BOTTOM LINE
 Comments: Persistent slab: All the 3/22 activity near 8000' appeared to happen when the rain line rose at the tail end of the storm. The wet surface has frozen and it's been 5 days since the storm/wind-loading event, so stability is better. I felt OK booting down a 33-40* slope above the crown line...but I wouldn't have wanted to boot down that slope if the steeper part below hadn't already released. A lot of paths ran on 3/22, and it's getting harder to trigger the ones that didn't. But I'm not ready to completely trust consequential 40* terrain in this area. Below about 7800', the slides were wet slabs, the snowpack has now frozen, and avalanches are very unlikely (and the skiing is brutal unless it's sunny/corn).
FILE ATTACHMENTS

180322_Keystone_crownprofile_failure layer removed.jpg
110cm total depth. Slide failed at layer that is excavated on left hand side.