| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
Observation: Turnagain
Location: Tincan
CNFAIC team tour to Tincan. We set out to take a look at near-surface facets in the upper snowpack and get a better idea of the extent of wind transport from the past few days. Wind loading seemed to be confined near upper elevation ridgelines, with undisturbed snow below 2500′. We found increasingly developed facets in the upper 1.5′ of the snowpack, including larger facets at the Halloween crust interface and a very obvious layer of surface hoar buried about 6″ deep. We also saw fresh glide activity, with at least one avalanche releasing since yesterday afternoon.
We stopped to check out an older skier-triggered avalanche that looked to be a few days old and had failed on facets at the Halloween interface. It was about 12″ deep, 50′ wide, and had run approx. 200 vertical feet.
The snow coverage is still thin down low, making for a challenging first part of the skin track and an equally challenging ski out.
Obvious signs of instability
Observer Comments
We did a quick investigation of an avalanche that looked to be a few days old and had failed on facets above the Halloween crust. It was about 12" deep, 50' wide, and had run approx. 200 vertical feet. The slab was fairly stiff (1F hardness), and the slope that failed was a steep convexity. It looked to be big enough to carry somebody and maybe bury them.
Classification: SS-As-R1-D1.5-O
Weather
Sunny and still cold, although slightly warmer than yesterday. -3F at the parking lot, but it did get to single digits above zero once we gained some elevation. Not a breath of wind.
Snow surface
Still mostly soft snow at the surface- with plenty of ski tracks. At elevations above 2500' there was some wind loading from the past few days near ridgelines. But the wind effect seemed more like the exception rather than the rule. Surface hoar on the surface at all elevations on all aspects.
Snowpack
We dug pits at 2220' and 3140', both on SW aspects. The upper snowpack was similar in both pits. Key features:
-Halloween crust buried 12-16" deep.
-1mm facets on top of the crust.
-Surface hoar buried 6" deep (the Veteran's Day layer).
-.5mm facets on top of the surface hoar.
-Surface hoar on the surface.
Big picture is that there is a fat layer of facets on top of the Halloween crust, but the terrain that hasn't been wind loaded still lacks a slab on top to make an avalanche.
Stability test results:
Pit 1: ECTN11 down 8" on the VD surface hoar layer.
Pit 2: ECTN12, ECTN11 down 6" on the VD surface hoar, ECTN22 and ECTN16 down 12" on the Halloween crust/facets
Glide avalanche that released sometime after 2 p.m. yesterday. 11.19.2021
Near-surface facets in the upper snowpack on a 1mm grid. 11.19.2021
An older avalanche that failed on facets on top of the Halloween crust. 11.19.2021