Details

• Date: 2016/12/09

• Observer: Zach Guy
• Organization: CBAC

Location

• BC Zone: Gunnison
• Area Description: Crested Butte Area
• Route Description: Snodgrass Mtn, NE aspects. 9,400-10,600 ft.

Weather

• Weather Description: Overcast, S-1, calm winds below treeline with a few plumes and gusts observed up high, mild temps.

Snowpack

• Snowpack Description: Below treeline, the structure remains shallow and faceted, but we are starting to see signs of instability with the new snow. A few shooting cracks and one collapse observed today on NE aspects below treeline. There is about 6-8" very soft slab over the Dec 6th near surface facet layer (1mm, F hard), with facets to the ground below that. In a few areas, there is some lingering 4F midpack, faceting slab, and we got one collapse where this was overlying ~2mm basal facets. This seemed to be a fairly isolated concern where we traveled, and saw no other signs of instability on various slopes up to 40 degrees in steepness. My biggest concern is when we put a real slab on our Dec 6th facet layer, which was widespread across every slope we traveled on.

Avalanches

• Avalanche Description: We skier triggered one small soft slab, failing on Dec 6th facet layer, about 8" thick and 25 feet wide. Harmless in size, and managed like a storm slab. SS-ASc-R1-D1-I

	Date	Location/Path	#	Elev	Asp	Type	Trig	SizeR	SizeD
	2016/12/09  †	Snodgrass Mountain	1	<TL	NE	SS	AS / c	R1	D1
Date: 2016/12/09 (Estimated) Observer: Zach Guy Organization: CBAC Landmark: Snodgrass Mountain Sliding Surface: O - Within Old Snow Weak Layer: Layer Average Crown: 8 in Average Width: 25 ft Comments: Failing on Dec 6th facet layer

Media

Video

12/9/16 Signs of Instability Below Treeline

Images