DATE OF OBSERVATION: 02/25/2015
NAME: Evan Ross
ASPECT: North East
WEATHER: WEATHER: Mostly Cloudy with several snowfall bursts throughout the day. About 1″ new near the top of Coney’s at 2pm. Light to moderate winds where down valley at BTL elevations and westerly at ridgeline.
SNOWPACK: SNOWPACK/AVALANCHE OBS:
Only significant result was an intentionally skier triggered windslab at the top of the bowl. Propagated 40ish feet wide with an average crown of about 4″. Ran 150 feet and was a D1. Windslab failed on lower density storm snow.
Everywhere else we traveled in the bowl we didn’t really find any form of a slab within last weekends storm snow. There were certainly areas to be avoided at all elevations where you likely could have triggered a similarly small windslab.
Dug a pit at 10,700ft. HS 140. Last weekends storm snow was 35cm on a 2cm MFcr. Below this crust was F hard facets that where progressively harder all the way to the ground where they had become 1F hard. The facets just below the MFcr was the layer of concern but needed more of a slab on top to propagate a result. CTH SC, ECTN 20 on this interface.
Shady slopes below treeline have the most concerning structure as the storm snow is sitting on F hard weak facets to the ground. Though we didn’t come across a slope where last weekends storm snow had formed a slab, yet. Unless recent winds had cross loaded the slope. Near the trailhead there had been several storm slabs that failed naturally and where all D1 in size. These storm slabs where shallow and appeared to fail within the storm snow and not on the old snow interface.