Gunnison
AvalancheZach Guy · Jan 11, 2016 · Gunnison
Weather
Thin, few clouds. Cold temps. Light to Moderate north winds. Plumes off of northern portion of our zone this morning; then a lull mid day, then pluming again late this afternoon across whole zone.
Snowpack
About 3-4" of recent new snow. No signs of wind effect except below south/southeast facing ridgelines ATL, where we saw top-heavy windloading with minor cracking a few inches deep. Dug 5 pits on NW to NE to E aspects near treeline across 3 different basins to check out reactivity of PS problem. 1.) NW aspect. HS 165, 105 cm slab (1F to 1F+) over basal facet layer (4F+ hard, 1.5mm rounding facets) ECTX and no signs of failure with additional loading steps. 2.) NW aspect. HS ~50 cm. Faceted snow throughout (4F to F). ECTX, slab crumbled. 3.) NW aspect. HS 150. 1F slab over basal facets (4F-, 2mm facets). ECTX, but SC failure with additional loading 4.) E aspect. HS 125. 1F slab over basal facets (F+, 2 mm facets). ECTX, but SC failure with additional loading 5.) NE aspect HS 115. 1F slab over basal facets (F, 2-3 mm facets) ECTP24, Q1 SC.
Avalanche
Spotted about 3 or 4 recent natural wind slab avalanches (D1 in size, estimated last 24 hours) on S and SE aspects above treeline in the northern portion of our zone. Skier triggered 2 sluffs on steep, shady terrain N/BTL on slopes that had previously avalanched. D1.5 in size (due to their long runout, 1,900 vert), gouging to the ground. See photo.