Numerous Remote Triggered Avalanches

Location: Brush Creek Area
Date of Observation: 01/09/2019
Name: Evan Ross

Subject: Fun With Avalanches
Aspect: North, North East, East
Elevation: 9,500-10,800

Avalanches:

Ooo boy. This is going to be long.

The highlights: One bounce, producing a collapse, that remote triggered 1 x D2, 1 x D1.5, and slumped the snow off a another rock outcrop. Two other separate collapse each remote triggered a D2 and separate D1 at the same time. The furthest point from a human triggered collapse to the furthest point of a crown, measured on google earth, was about 2,200ft. Yea baby.

2 x SS-ASr-R1-D2-O, NE, BTL
1 x SS-ASr-R1-D2-O, E, BTL
4 x SS-ASr-R1-D1.5-O, NE, BTL

1 x SS-N-R1-D1.5-I, South, ATL. Fresh Natural today. Steep rocky terrain.

There were many more natural avalanches to D2.5 in size from the 1/6 cycle. Mainly on N to E facing aspects at BTL elevations. Other aspects and elevations had a few old Persistent Slabs, but most avalanches looked to have failed within the storm snow and were often confined to gully features or wind-loaded terrain. 

Weather: High clouds hung around for much of the day. Calm wind. Warm temps.

Snowpack: The holiday slab is the slab… while the January 6th storm just added the load to tip the balance. The 1/6 storm snow was about 10 to 12″ in sheltered terrain at the elevations traveled. The 1/6 snow was very soft on NE and becoming moist on E, and other sunny slopes. The very weak NSF below the holiday slab was the layer of concern. This layer was failing in collapses and triggered avalanches, and those avalanches were either running at the interface or gouging to the ground. Boot pen to hip and ski pen about 25cm. HS in the 100-120cm range.

Collapses that produced human triggered avalanches were very very quiet and subtle. No shooting cracks where ever observed from the same area I got a collapses that remote triggered and avalanche. After a collapses, it was a long 10sec before remote triggered avalanches started running.

Photos: