Obs-Snow Profile: Uintas 1/26/2011

Observer Name: 
reid persing
Region: 
Uintas
Observation Date: 
01/26/2011
Location or Route: 
Smith and Moorehouse, Slader Ridge
Weather
Sky: 
Clear
Wind Speed: 
Calm
Weather Comments: 

 Perfect day in the mountains.  Warm in the sun, cool in the shade.  

Snow Characteristics

New Snow Depth: 
5"
New Snow Density: 
Low
Snow Surface Conditions: 
Powder
Melt-Freeze Crust
Snow Characteristic Comments: 

 3 in new at TH, 5-6 inches at 9000'.  Low density, lots of preserved stellars.  Little wind effect, though we stayed in sheltered terrain.  Punching down to and through the rain crust in most locations.  

Red Flags

Recent Avalanches
Cracking
Collapsing
Red Flag Comments: 

 Several natural avalanches observed on tour, lots of human triggered avalanches reported recently.  Cracking and collapsing under rain crust with provocation, Though not particularly thunderous.

Primary Concern

Primary Concern: 
Persistent Slabs
Probability: 
Considerable
Aspect: 
North
Northeast
East
Northwest
Elevation: 
High
Mid
Low
Trend: 
Same
Primary Concern Comments: 

 The party might not be over, but the theme has certainly changed.  Structure rules the day.  Did lots of digging to try to understand characteristics of weak layers that have lead to so many recent avalanches in this region.  Rain crust is 6 - 12 inches below surface, thin and easily breakable in this region.  1-2 cm thick with 1 cm being the norm.  Breakable on skis, sleds, and boards.  Snow beneath the crust shows advanced faceting in areas and is a potential player.  Surface hoar found ~5cm below crust and ubiquitious.  Continues to be the weakest layer in our current structure.  Lots of hand and pole pits.  Some hand pits failing on surface hoar as isolated.  Q1.  Others taking a little more provocation, stronger where weak layers are more than 12 inches below surface.  Some pits fracturing below rain crust and on SH simultaneously.  Fracture below rain crust is clean, but with slightly less energy than SH.  

All this academic though.  Whether you get the SH or the facets below the crust, one will likely lead to the other.  And the slide, as evidenced by recent events, are big, scary, and not likely to be forgiving.  We backed off of steep terrain and rode comically tight trees.  

Slader Ridge, 1-26.jpg
snow_profile_location: 
United States
40° 47' 12.408" N, 111° 0' 18.6228" W
Comments - Photos - Videos (group 1)

 Quick pit showing SH failure in relation to 1 cm thick rain crust.

IMG_3586.jpg
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Comments - Photos - Videos (group 2)

 same pit as above showing failure depth.  thicker than average in this location, maybe 12 - 18 inches deep?  

IMG_3587.jpg
Observed Danger Rating: 
Considerable
Forecast Danger Rating: 
Considerable
Snow Profile Location
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