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Observation: Turnagain

Location: Magnum Ridge/PMS

Date:
Observer:
Route & General Observations

Route
Magnum to top of PMS bowl (3,500’)

Weather
Mostly clear skies with occasional mid level clouds
Temps @ 1,000’:24 F @ 10am, 34F @ 4:30pm
No Precip
Calm winds

Obvious Signs Of Instability
Recent Avalanches-NO
Shooting Cracks-NO
Collapsing-NO

Observed several glide cracks for the first time that likely formed more than 48
hrs prior. Skied next to one in PMS Bowl around 2,700’ S aspect on 30 degree
rollover (see photo), no recent releases observed today.

Surface Obs
2-5cm/1-2” of low density snow on top of crust from 1,400-2,700’
Refreezing of the crust below the new snow continues with thickness in the 6” range
5-10cm/2-4” of low density snow on top of firm snow from 2,700-3,500’
Observed isolated pockets of wind slab above 3,500’ along Magnum ridge in the
vicinity of Superbowl. Very low volume sluffing occurred in terrain over 40
degrees in steepness.
Snow available for transport (AST)=10 cm/4”

Snow Below the Surface
We dug 2 pits today both on S aspects at 3,200 and 3,500’. Both pits showed
moderate to high strength of weak layers in the 20-30 cm deep range with no
propagation potential. See pit diagram and photo for detailed info of pit at
3,500’.

The structural set up of a slab 1-2′ thick sitting on a very thin crust with a thin layer of Fist hardness rounds (layer of concern) has been consistent over the last 3 days around the 3,400′-3,500′ elevation. The above mentioned crust has been attached to the overlying slab in all tests. With cooler temps it is worth checking to see if this weak layer begins to facet. So far the grain type has been rounds. Today was the first time I’ve not had propagation on this layer.

Mid December Buried Surface Hoar: This layer is difficult to find. I was able to find it by prying on the back of the column today. Grains are still intact and were 5mm in this pit. While this layer is apparently dormant, we will continue to monitor it as it is widespread throughout Turnagain Pass above 3,000′.

Photos & Video
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