Observation: Summit

Location: Manitoba

Date:
Observer:
Route & General Observations

We toured up Manitoba to see how the Christmas storm snow was bonding to the old snow.  We observed a large slab avalanche on Spirit Walker that likely released during the Christmas storm.  Great skiing despite the flat light towards the end of the day.

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

The day started clear, calm and cold with -15 degrees F at the parking lot. It warmed to 7 degrees F by the time we returned at 3:15pm. Snow was occasionally pluming from ridgetops with easterly winds.

Snow surface

There was about 12” of new snow all the way up to our pit location at 3,275’. The snow was very light with intact sparkly stellars on the surface. There was a little bit of wind effect above 3,000' with a few features on the surface, but it did not affect the good skiing.

Snowpack

We dug a pit at 3,275’. Total depth in that location was 6.5’ (200cm). We did not get any significant test results (CTN, ECTX), although we did get a moderate result on a shovel shear of the CT column. The block broke in two places very clean. One fracture occurred at the surface hoar layer although I couldn’t see any actual surface hoar crystals (the grey line was visible 45cm down). The other fracture occurred just above the Thanksgiving crust 4’ (140cm) below the surface. A hard shovel shear of the ECT block produced a similar result. (see video) This block failed just above the Thanksgiving crust.

Photos & Video
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