Observation: Turnagain

Location: Sunburst

Route & General Observations

A fairly standard trip up Sunburst today. It was snowing lightly the whole trip with a few breaks in the weather early where the visibility improved enough to see the recent glide crack activity including at least one recent glide avalanche on the SW Face of Sunburst. Below the standard skin track, a glide crack had even failed on a classic test slope not far below the ridge. The wind picked up out of the WSW, especially above 2500ft, and was actively transporting snow.

Dug a snow pit near our high point around 3100ft on a 31 deg slope at aspect 280. The results were a CT2 Q2 at 20cm at an interface between new heavier wind affected snow and a lighter lower density snow from the previous snow event. I repeated the CT Test a few feet away with exactly the same results. While I was writing up some notes in my field book a group on their second lap passed by and told me that they had trigger a small wind slab on a more southerly aspect at slightly higher elevation. They estimated the wind slab to have been 8″ thick, they didn’t specify the width of the release or how far it ran but they did decide to stick to the lower angle west facing terrain near the ridge for the second run. Our group made two laps on the lower angle west facing terrain and didn’t observe any avalanche activity but the wind from the WSW picked up and actively transported enough snow to fill in my pit all the way within an hour.

Snow Pit — 3100 ft on Sunburst, 31 degree angle, 280 degree aspect, 2:00pm on

130 cm total snow depth.

Test Results CT2 Q2 at 110 cm (20 cm below snow suface)

130 cm — 111 cm: new wind affect snow, 4 finger density

110 cm — 90 cm: older lower density snow, fist density trending to four finger-

89 cm — 71 cm: older decomposing snow, finger density

70 cm — 68 cm: ice crust, knife hard

67 cm — 50 cm: decomposing snow finger density trending to pencil

49 cm — 48 cm: ice crust, knife hard

47 cm — 15 cm: decomposing snow