Steamboat & Flat Tops
SnowpackAnonymous ยท Dec 19, 2010
Weather
12-18: 26F, light snow, moderate WNW winds
Snowpack
10,550', SE, 20 deg, HS 170cm, HST 35cm Both deeper layers had thin icy crust, upper crust immediately under storm snow was 0.5-1 cm thick, lower crust very thin. storm snow with easy failure on upper ice, deeper snowpack with hard compressive failures- clean planar- on both lower thin ice, and on lower layer (surface hoar?) that was not readily seen in pit. Skiing and probing indicated the N facing slopes did not have (or very reduced) thick ice layer and SW and S slopes had exaggerated upper ice layer (sun crust rahter than melt or rain crust???). Skiing from 10,500' - 8500' indicated snow acting a loose powder, not slab forming. Sunday 12/19 - same area -additional 20+ cm storm snow, getting warmer and damper (fog, wet snow, approx 30F+, with occasional W gusts of 20MPH) into afternoon, storm snow showing increasing slab tendencies. Skiing at 9500' on a S facing coxcomb-like ridge, and playing on the 25 degree SW side,I kicked off a soft cross-loading cornice above the steep SE face (small rockband and 40 degrees + slope). Cornice fell, triggering a 24" soft slab size 1-2, that ran on what appeard to be the more recent near-surface ice crust layer on the lee SE slopes on/below rockband. DID NOT appear to step down. Soft debris ran about 250' and stopped as small soft slab pieces on 15-20 degree slope above trees.