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PROFESSIONAL OBSERVATION FORM
 Start Date: 02.28.19 Name: Lundy Operation: SAC
 Drainage/Route:  Sawtooth Valley/Stanley Foothills Observed Terrain:  Stanley Lake Turnoff on Hwy 21 to Frenchman's Creek on Hwy 75 Zone/Region:  Sawtooth Mountains
WEATHER OBSERVATIONS
 HN24: HST: Sky: OVC Precip: Temps:
 Ridgeline Wind:
 Blowing Snow: Snow Available for Transport:
 Comments: Brief periods of BKN clouds but the visibility in the Sawtooths remained poor
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 ~7 Above Valley Cr west of Stanley Yesterday 2 SS N W 6400-6600 Several persistent slabs. A few were D1.5 and ~50' wide. The largest was a D2.5 across from Elk Mtn Cafe - 3 almost connected slabs with a total crown width of around 1000'. All of these only ran a few hundred vertical.
 ~10 Across Salmon River from Hwy 75 north of Stanley RS Yesterday 2 SS N W ~7000 Numerous persistent slabs, D1.5-2 in size.
 3 N of IRMR ranch Yesterday 2 SS N W 7000 The largest was D2.5, debris piled up quite deeply on the transition close to the highway
 2 Obsidian Yesterday 2.5 SS N NW 7200 Two larger slides, both came within 100' of cabins. Both had deeper sections of crown that were obviously loaded by southerly winds.
 1 Near IRMR ranch Yesterday 2 HS N W 6800 Large wind slab, looked 4+ feet deep, broke into persistent layer
 Comments: These are just the most significant slides I observed. There were others that were less significant or older. See photos below. Most of these persistent slabs were 1-3 feet deep. They became deeper further south from Stanley, likely due to increased wind loading as the valley opens up. Most were on westerly aspects, but I think that has more to do with the visible terrain than a snowpack pattern. Many of the slides closer to Stanley were not there on Tuesday and likely released with additional snow and warming temps yesterday.

Unfortunately the vis in the Sawtooths remained fair to poor. I was able to glass some of the central Sawtooths from the Grand Mogul to McDonald. Didn't see anything large, but likely would have missed smaller naturals or midstorm activity.
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
50-90cm

Likelihood of Triggering
Sensitivity:


Spatial Distribution:

Terrain
  Primary Concern Comments: Based on avy activity
STABILITY TESTS
 Stability Test Results:
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
FILE ATTACHMENTS

190228_elkmtncafe_W_6600_small.jpg
Across from Elk Mtn Cafe. 3 almost connected crowns with total width of around 1000'. W 6600'

190228_hwy75_W_7000_small.jpg
Numerous persistent slabs just south of Stanley across the Salmon R. W 7000'

190228_remberhill_WNW_7000_small.jpg
3 persistent slabs just north of IRMR ranch

190228_irmr_wind_WNW_6800_small.jpg
Deep wind loaded persistent slab near IRMR ranch. NW 6800'

190228_williamsTH_WNW_7000_small.jpg
Larger persistent slab above cabin at Williams Cr Trailhead. WNW 7000'

190228_obsidian_NW_7200_small.jpg
Larger persistent slab above cabin at Obsidian. NW 7200'

190228_stanleyrs_W_6900_small.jpg
Across the highway and river from the Stanley RS. W 6900'