Large Remote Trigger

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/03/2021
Name: Joey Carpenter


Zone: Southeast Mountains
Location: Ridge btwx West Brush Creek and Deer Creek trail
Aspect: East, South East, South
Elevation: 9.5k-11.1k


Avalanches: R2D2 unintentional remote trigger. About 150 feet away from low angle ridgeline. E aspect. 150 ft wide running 1200 vert. Avg crown 65cm with deepest portions reaching 95cms. Slope angle averaged 37 degrees but propagated onto angles as low as 34 in start zone. Shattering cracks on 31-32 degree slopes adjacent to slide path. Ran on 1-2mm facet capped crust. 1F hardness throughout majority of slab w/ 4f nearing the top from recent transport. This avalanche was small relative to the path but I am certain was unsurvivable. It ran through countless trees, rocks and other terrain traps. It snapped trees 3-4.5inches in diameter. The debris pile was 255cm deep at the bottom of the path and set up very firm. The unaffected snow adjacent to the debris pile was 70cm of fist hard facets to the ground which I’m certain the debris wiped out in the path, essentially making the debris pile over 8 feet deep.
Weather: Weather was sunny and warm around 10am at WBC/Deer creek junction with calm winds. Thin clouds filtered in from the southwest throughout the morning and by 1300 had made it 7/8 coverage with S towards gunnison still holding onto blue skies. Weather got progressively more unsettled making recording crown stats difficult due to snow, cold temps and 10-15mph ridge-top winds. S1- snowfall began around 2pm accompanied by continued 10-15mph sustained winds from the SW. A brief period of S2 came through but settled back out to S1-.
Snowpack: Spx on BTL S&SE tilting slopes was thin and weak. Below ~10.5k there was little slab structure if any. Collapses propagated short distances with minor cracking. As I gained elevation, cracking began to propagate further with more substantial cracking shooting ~70 feet and notable slab structure from pole probes. In attached photos of crown “profile” you can see the P- facet capped crust that acted as the bed surface. There was another P- crust below this with ~5cm of facets above and below. The spx from the 30cm to the ground started at 1f and slowly degraded to about F hard basal facets. The slab was 1F+ to 4f-, bottom up. The unpredictable nature of the avalanche problems this year are terrifying. Please be careful out there friends.