Close
PROFESSIONAL OBSERVATION FORM
 Start Date: 12.25.18 Name: Davis Operation: SAC
 Drainage/Route:  Dollarhide - Shaw Mountain Observed Terrain:  7,900-9,600, SW-S-SE Zone/Region:  Wood River Valley
WEATHER OBSERVATIONS
 HN24: 0 cm HST: Sky: BKN Precip: Temps:
 Ridgeline Wind: Calm
 Blowing Snow: Prev Snow Available for Transport: Small amounts
 Comments: No precip, heavier clouds to the south and breaks of sun to the north. There was a period of sun mid-morning then it socked in around 1300.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 1 Dollarhide Mountain Within past week U E 9,100' Not sure if this was from folks kicking cornice or a natural cornice break that pulled out a deep looking slab pocket. It was a ways away so hard to say.
SNOWPACK OBSERVATIONS
 HS: 45-80 cm 
 Upper Pack: Decomposing recent snow. 
 Middle Pack: Below 8,500' there were two notable crusts, one down 35-40 cm at the (12/11) interface and another 10 cm above that. By 9,000' these crusts were barely discernible. I looked for surface hoar at these interfaces in 3 locations but couldn't find any.  
 Lower Pack: (12/11) interface with 2-3 mm facets below.  
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
40 cm

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Specific
Terrain
  Primary Concern Comments: While the (12/11) layer is everywhere I am starting to believe it's hard to get moving without the perfect setup (like the remote trigger reported by SVHS here Saturday). I could not find SH at this interface on the SW-S-SE aspects where I dug.
 Comments: I did not find the (11/22) DH layer on the SW-S-SE aspects where I traveled.
STABILITY TESTS
 Stability Test Results: (12/11) tests from three locations: ECTP14 Irregular, ECTN17, ECTX, CT29
OBVIOUS SIGNS OF INSTABILITY
 Marked with checkmark if observed:
 Collapsing (isolated) Depth: 40 cm Length: 10' radius
 Comments: Some small collapses around 8,500' and again near 9,000' (collocated with ECTP14). Some small collapses in older sastrugi and windboard along the summit ridge.
SNOW STABILITY
 Snow Stability Rating for your observed area: Fair Confidence: MODERATE Trend: Improving
 Comments (aspects and elevations of instability, etc): LOW danger due to low snow below 8,500' and MODERATE above. I did not assess slopes with the (11/22) DH.
BOTTOM LINE
 Comments: Collapses were small and the weak layer + slab duos that I observed were not particularly exciting despite traveling in heavily wind-affected terrain. I believe the slopes where (12/11) remains a problem may be narrowing to steeper terrain with legit wind slabs and a weak layer that's more than just our "pile of sand" facets. I'll have a couple photos to add this evening.
FILE ATTACHMENTS

181225_Dollarhide_CorniceBreak.jpg
Cornice break on an east aspect of Dollarhide Mountain.

181225_Dollarhide_ECTP_on1211.jpg
One irregular propagating result on the 12/11 facets on a 9,000' south aspect. Several other ECTN's and ECTX's otherwise.