UDOT PLANNED AVALANCHE CLOSURES!!

Avalanche: Syncline Gully (Spencers Line)

Observer Name
Erik Syrstad
Observation Date
Sunday, December 20, 2015
Avalanche Date
Sunday, December 20, 2015
Region
Logan » Logan Canyon » Coyote Canyon » Syncline Gully (Spencers Line)
Location Name or Route
The Syncline Gully of Certain Doom
Elevation
8,300'
Aspect
North
Slope Angle
37°
Trigger
Skier
Trigger: additional info
Remotely Triggered
Avalanche Type
Hard Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
5'
Width
175'
Vertical
Unknown
Comments
I was out on a ridge walk today and triggered this large hard slab avalanche from a distance. I was about 200' down the ridge, when I set off a large collapse on a fairly flat area. A deep crack propagated up and down the ridge for quite some distance, and although I didn't immediately see or hear any other collateral damage, I was suspicious of the large slide path starting where the Syncline trail wraps around the ridge separating Dry and Logan canyons. When I skinned back up the ridge I saw that nearly the entire bowl above this slide path had released, between about 3 and 7 feet deep. From a distance, it appeared to release initially and cleanly on the facets near the ground, with no intermediate interfaces playing a role. It looks like this starting zone was loaded heavily from wind ripping across the far NW end of the Folly; 100 meters away on a windward aspect, there was less than a foot of snow total. There were numerous deep cracks shooting across the relatively low-angle section of the ridge, but ultimately the avalanche released a bit lower and didn't quite 'pull the carpet out'. Because of this, there was a lot of hangfire remaining, so I didn't attempt to check out the bed surface below the crown.
Comments
Photo 4 shows the location of the remote trigger, about 200 feet down the ridge and WNW of the crown.
Coordinates