Gunnison

Snowpack

John MacKinnon · Dec 30, 2012 · Gunnison

Weather

Overcast skies trending to obscured. Scattered snow began around noon and increased throughout afternoon to S1. Total daytime accumulation of ~2 cm. Winds were light to moderate from the south with light blowing snow near and above treeline. Observed airtemp of -9 C at 1400.

Snowpack

Got onto all aspects but west. S and SE slopes below treeline have about 20 cm of snow from this past week--mostly DFs and some NSFs-- on a buried crust. SE aspects near treeline had a thin wind crust on the surface. NW aspects above treeline were pretty scoured, but snowpack increased in depth and continuity as I moved to treeline. North and NE aspects near treeline had average HS of 100 cm. Upper snowpack from this past week's storm was 25-30 cm of F-4F hard snow and resting on the 12/23 SH/NSF layer. Also observed some mid-storm instabilities where tilt tests showed clean "pops" and compression tests showed repeatable resistant fractures--CTM (RP) x 2 down 20 cm. "Mid-pack" (ie persistent slab) was about 50 cm of 1F-P hard snow resting on facets and depth hoar. 30 cm of F hard FC/DH still showing sudden drops in compression tests--CTH (SC) x 2. Didn't see any recent avalanche activity or observe any signs of instability while skiing.