BC Zone Observation Report
Saturday, November 3, 2018 at 12:00 AM
Dry Gulch, north facing slopes on Mt. Trelease
skinned up dry gulch and across 3 low angle gullies on the north face of Trelease. Pit dug in first gully gave us unstable results. skinned across gully 2 into, and up, gully 3. We noted a steep convexity that we wanted to avoid in gully 2. We descended half way down gully 3 on low angle terrain and got a big collapse with shooting cracks. We crossed back into gully 2 because the exit of gully 3 looked steep. Descending gully 2 we made sure to stay far away from the steep roll we noted on the ascent. skier 1 made a hard turn right to avoid the roll and triggered the slide. He was able to continue skiing onto mellower terrain and was not caught.
sky overcast, temps low 20's, winds light. North facing at 11,500 ft
11,500 ft north aspect. 85 cm height of snow. boot pen to ground. About 12 cm new snow. Strong mid-pack on top of crust/facet combination on top of about 20cm of small grain facets. CT11SC @ 62 down, ECTP15 @62 down. We observed several audible collapses and shooting throughout the day.
Crown was 1-2' high and about 300' wide. The slide ran about 50' downslope onto mellower terrain. Debris was 4-5' deep. The steepest part of the convexity was around 35* but was triggered from terrain under 30*
AS / r
Average Slope Angle:
O - Within Old Snow