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Observation: Summit

Location: Manitoba

Date:
Observer:
Route & General Observations

Two days of touring on Manitoba_SW aspect, standard approach to West aspect on Dec 16&17 as new stormy pattern rolled into the Kenai Peninsula. New snow on evening of Dec 16 made for reasonable skiing and finally enough coverage on the access road. Good powder skiing below 2500′, highly variable above.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?No
Observer Comments

4 natural D1-D2 size avalanche on South aspects of Wilson south (slopes >45 degrees) from wind loading on night of Dec 16.
Dec 17: cracking around skis below 2500'
cracking/easy shears on pockets of 4-6" wind slabs above 2500' on W-NW aspects

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.
Weather

Dec 16: 8"-12" of new snow night of Dec 15 falling on the cold, faceted snowpack from the past 15-day dry spell. NW winds on Dec 16 above 2500 feet with storm snow at higher elevations, but light winds below 2500'. Temps in the high 20s to near 30F

Dec 17: 2 cm new snow. with moderate winds out of the S-SE on the evening of Dec 16 creating variable thickness and hardness wind slabs above 2500' that were reactive on Dec 17. Below 2500', surface snow largely unaffected. Total snowpack depth: 20" at road, 24 at 2000', and 36-40" above 2500 (highly variable). Temps 26-28F, falling in the afternoon/evening into the low 20s. Clear skies until 2am.

Dec 18: heavy snow fall begins around 4:30 am. 4" of new snow by 11 am. with moderate winds at elevation.

Snow surface

Dec 17: W aspect: 8-12" new snow with limited wind effect below 2500'. Med-hard new wind slabs and some sastrugi above 2500'

Snowpack

Pit at 2600' revealed 24" of fist to 4F hard snow (soft slab) sitting on thick layer of faceted snow above a rain/melt-freeze crust 60 cm down (poor structure). ECT x2 generated no failure on faceted layer, but easy shovel shears. PST test showed full column propagation after only 10cm (PST 10/100 End down 60cm.)

Photos & Video
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