Small shooting cracks and small storm slabs initiated by ski cutting and jumping on wind loaded unsupported test slopes.
Observation: Turnagain
Location: Tincan
Standard Tincan up-track to 2650′. Tracking the distribution of the recent crust interfaces, as well as the overall existence and reactivity of the most recent buried surface hoar (1/21)
Observer Comments
Weather
Overcast
Temp in the mid 20s
Light Winds
Light Precip (S1)
Wet Snow/Moist Snow line right around 1300'
Snow surface
Increasing snow accumulation from road to high point - most being 15cm.
1000'-1700' - knife hard rain crust with 5-8mm BSH directly under recent precip.
1700-2500' - pencil-1F melt freeze crust with 3-10mm BSH directly under recent snow (approx 10cm)
2500-2650' - 1/21 BSH found ~15cm down in a few hand pits, and found in a few windward spots with 1-2cm new snow capping the 1/21 BSH.
Snowpack
Primary snowpack focus was the existence and reactivity of the (1/21) buried surface hoar layer at different elevation bands, and on different surface interfaces. The BSH exists throughout ranging from the 3mm-10mm on top of rain crust, melt freeze crust, and at upper elevations above 2500' on older snow surface.
The 1/11 BSH layer was also found in a pit at upper elevations but didn't hold any propagation propensity.
We dug multiple hand pits and test pits, all on NW Aspects. The hand pits showed an easy shear on the 1/21 BSH layer, but across the board didn't have a cohesive slab formed yet.
Test Pit 1- Upper Tincan Trees - NW - 2030' - HS:260cm (windloaded)
Rightside up snowpack (F to 1F+) under the MF/BSH interface
CTN
Test Pit 2- Tincan - NW - 2650' - HS: 235cm
Rightside up snowpack
ECTN6 down 12cm - right above the 1/21 BSH
ECTN7 down 15cm on the 1/21 BSH
Multiple CT results (CT3-5) down 12cm above 1/21 BSH layer
Multiple CT results (CT4-10) down 15cm on the 1/21 BSH layer
Multiple CT results (CT19-22) down 30cm on the 1/11 BSH
Overall the PWL exists, but there is currently low propagation propensity in areas that do not have slab formation.
Tincan 1000' surface - raincrust facet interface
Tincan 1200' - Crust Surfacehoar interface
Tincan 1600' - Raincrust reduces to MF Crust - 3-5mm BSH leads to planar surface
Tincan 1600' - MF crust in snowpack beneath 10cm of recent snow
Tincan 2000' - Planar surface in a hand shear test on BSH 5-8mm
Tincan 2650' - NW Aspect - 15cm down 1/21 BSH - 30cm down 1/11 BSH
Tincan 2650' - 1/21 BSH on a 2mm Grid
Tincan 2000' - Shooting cracks on small unsupported test slope
Tincan Trees - Small ski cut storm slabs on small test slope