Vail & Summit County
Snowpackmarkus beck · Jan 30, 2017 · Vail & Summit County
Weather
Over the course of 4 days weather went from overcast with isolated scattered snow showers and cold temps to clear skies and cool temps. Mostly calm to light winds with little blowing snow at higher elevations. NW winds increased on 1/30 to moderate/strong at ridge tops with moderate blowing snow, however little/no blowing snow below treeline. No significant new near-surface nor surface hoar development observed.
Snowpack
Ridglines and generally above treeline are wind affected with variable surface conditions from supportive hard slab to breakable wind skin/crust to wind compacted powder. Observed well developed depth hoar under stout 1F slab. Pockets of wind slab. Unable to find buried surface hoar. Distribution seems to be very spotty, unlikely problem in this area but isolated slopes could be surprising especially in combination with wind loading. Not yet to be disregarded. Observed widespread melt crust on S'ly aspects below to near-above treeline 20-30cm down with near crust facets (1-1.5mm) on both sides. Crust is barely supporting ski pen. Crust was very reactive in tests (various CT-Q1's and ECTP's "easy-moderate", 1 notable intentional skier triggered result on a very steep test slope propagating 10x10m (no release). Crust needs to be observed as slab above develops. Depth hoar is still present on NW-SE near-below to above treeline but not significantly reactive in tests. 1 notable result on a non-intentional skier triggered propagation (no release) 80x30m on a small slope with a steep convexity (hard wind slab) at 11,900 on SSW (shallow HS, on depth hoar). On S'ly slopes below treeline to near-above treeline, snowpack including depth hoar shows signs of rounding.