Observation: Turnagain

Location: Magnum - PMS bowl

Date:
Observer:
Route & General Observations

Route: Traveled from 900ft to 3300ft from drainage between Magnum and Corn Biscuit to ridge above
PMS bowl.

Signs of Instability:
Recent Avalanches: None observed
Cracking: None observed
Collapsing: None observed

Weather:
Partly Cloudy becoming more cloudy with precipitation developing around 12:30
Blowing snow observed at ridge tops, Winds around 14-20 mph from the East
Temperatures from 16-20°F

Snow Surface Observations:
900-1400ft: thick crust with about 5cm low density snow on top
1400-1800: thin breakable crust with 15cm low density snow on top
1800-3300: 25cm low density snow with denser snow underneath.

Snowpack Observations:
Dug 1 pit at 2500ft
SW aspect
HS=80cm
22°
50cm of increasingly dense snow on a drizzle crust with 2mm facets underneath, on top of another
crust. All of this is sitting on about 20cm of 2mm basal facets.
ECTP21 SC in 2mm basal facets depth = 50cm

2 pits at 3300ft
SW aspect

Pit 1: see photo
HS=105cm
30°
70cm of increasingly dense snow on the sandwich of crusts with facets in between. Under this are about 30cm of 2mm basal facets.
ECTX
CT 28 SC 2mm facets depth=95cm
The facet and crust combo were attached to the slab.

Pit 2: see photo and video
HS=125cm
31°
Same structure as pit #1 but a deeper snow height and therefore a deeper slab.
ECTX
CT11 SC 2mm basal facets depth= 105cm
PST 35-40?/100 end down 105cm

Test results indicated that it may be difficult to trigger an avalanche, however the potential for propagation across large areas is possible if fracture is initiated. The layer of concern was confined to the basal facets. Also, it may be easier to trigger from mid elevations where the slab is thinner.

Photos & Video
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