| Trigger | Skier | Remote Trigger | No |
| Avalanche Type | Dry Loose Snow | Aspect | Southwest |
| Elevation | 3700ft | Slope Angle | 35deg |
| Crown Depth | 8in | Width | 30ft |
| Vertical Run | 600ft |
Avalanche: Turnagain
Location: Sunburst
10:30am- My partner and I ascended the standard approach track from Sunburst parking lot intending on skiing the Southern face of Sunburst. We conducted snowpack tests below the broad bench at 3,100ft, from 12:30-3pm reviewing specific snowpack skills. We ascended to Sunburst’s upper Ridgeline to assess the ” Elevator Shaft” and decided to ski an untracked SW facing gulley which runs to the main valley. After triggering a Loose Release, we assessed, gathered details and skied back to the standard approach track at 2,000 ft+. We encountered an AGC Level 2 Avalanche course and skinned to the bench on the NW ridge at 2,400ft, descending by 4pm+ to parking lot.
Avalanche Details
My Partner descended at 3:45pm from 3,700 ft into South-west facing gulley on Sunburst, triggering a point release on 2nd turn with high volume sluff that built momentum within 5 seconds. Sluff extended from 10ft to 20ft wide and was funneled into a 35° gulley which created an unobstructed pathway until its terminus, totaling 600 vertical ft.
Simultaneously, my partner triggered two Loose-Dry release on his 11th turn that was directly above a steep convex roll (40°) with rock exposure, which created another point release, adding compounding momentum and volume onto the first gulley release. Both approx. 10 feet wide.
The release terminated at 3,100 feet, approximately 30 feet wide with dry, doft debris.
Skier was not caught and descended to valley out of the runout zone to view my descent and evaluation of the slide.
We evaluated the release as L-ASu-D2-R2-I.
Observer Comments
N/O
Weather
Calm, Clear , No Precip throughout the entire day (10:30-4:15pm) with a light Northerly breeze encountered when exposed on Ridgeline above 2,000ft.
Snow surface
Snow surface was a variable from wind-loaded aspects to wind-scoured along ridges above 2,000ft.
We identified prominent,standing Surface Hoar feathers until 2,500ft, but identified decomposing, planar Surface Hoar grains at 3,000+ (SW Aspect).
Widespread wind loading but very isolated wind crusts, which were encountered in proximity to Ridgelines and exposed terrain features.
Snowpack
We conducted four snowpack tests at 12:30 pm on Sunburst's NW Ridge, below the common transition bench at 3,120 ft.
-250° W Aspect
-CLR, No precip
-Calm wind
-10°C
HS155cm
STM, 34cm down on facets (LOC)
1. CTN
2. ECTX
3. PST 98/100 END, 20200118, on faceted LOC, 34cm below surface.
4. DTTN ( Deep LOC is F Hard .5 -1mm Facets that exist above a MF basal crust, 145cm below surface. )
(Identified in Hardness Profile Photo)
Full View of both skier-triggered releases that funneled into Gulley.
Momentum of Point Release propagating to Loose Release.
Avalanche Path and Terminus. Partner can be seen in upper-right corner
Avalanche Path, 3,100 feet on Sunburst, SW Aspect, 28° Slope
Terminus of Release with dry, faceted grains
Hardness Profile with LOC 34cm below Surface (Facets), as well as Deep LOC, Facets, sitting 145cm below surface
Deep Tap Test (DTTN) No Results on LOC, F Hard Facets 145cm Below Surface