Pro Field Report

Basic Information

Media/Attachments

https://www.youtube.com/watch?v=2KkQJ37VdmE

Advanced Information

Weather Summary

Scattered high clouds gave way to broken skies in the afternoon. Winds were L gusting M with very little snow available for transport.

Avalanche Observations

#	Date	Location	Size	Type	Bed Sfc	Depth	Trigger	Photos	Details
1	Mar 1, 2022 (+/- 1 day)	Top of Copper NE 8900ft	D1.5	SS-Soft Slab			N-Natural		Report
1	Mar 1, 2022 (+/- 1 day)	South of Copper E 8400ft	D1.5	SS-Soft Slab	O-Old Snow		N-Natural		Report
1	Mar 1, 2022 (+/- 1 day)	Swamp Creek E 8500ft	D1.5	SS-Soft Slab	O-Old Snow		N-Natural		Report
2	Mar 1, 2022 (+/- 1 day)	Trap Creek E 8800ft	D2	SS-Soft Slab	O-Old Snow		N-Natural		Report

Glassing the ridge from Copper south to Elk Creek revealed a handful of persistent slab avalanches, but they seemed less widespread than what Ben observed near Bulltrout Point.

There were numerous D1 wet loose slides similar to what was seen elsewhere from the rain on snow event.

Snowpack Observations

Lower elevations: 1-2cm thick crust from weak freeze overnight. On a N aspect at 7100', was surprised to find FC 10cm below the surface that were still very weak, dry, and seemingly unaffected by the rain event. Once the surface freezes, it would likely take a large load to create an issue. Coming out in the mid-afternoon, the top 30-40cm was a wet, mushy mess.

Middle elevations: N, 7800' - very weak FC down about 15cm, but surface capped by stout rain crust. Top 30-40cm of solars were wet and mushy.

Upper elevations: Perhaps due to previous wind effect, upper elevation solars were more supportable and semi-skiable. Lost rain crust on N aspects at around 8500', with surface snow mostly dry but dense above 8700'.

I dug 4 pits at upper elevations on aspects ranging from N to E to look for the persistent slab problem responsible for observed avalanche activity. N aspects at 8460' and 8600': FC and shards of SH found 30-35cm down, but not particularly weak (4F-) or well-defined. This layer produced ECTX or ECTNs in the hard range. NE, 8750': FC not remarkable but a well-developed/standing layer of SH was found 32cm down (see photo). It produced an ECTPV (failed when I set my shovel on column) and an ECTP12 (see video). E, 8800': 10cm thick FC layer much more well-developed and weak (F) - see photo. Some SH shards but FC seemed the problem layer. ECTN12 (x2), ECTP8.

Based on these limited obs from a small area, the current weak layer (FC, SH) is just over 30cm down and maybe more problematic on E aspects than N - at least at upper elevations where many N aspects were wind-affected. It seemed like you needed to be above at least 8000', and maybe closer to 8500', to get out of elevations where a rain crust isn't muting the instability. I think because the layer is spotty and the slab is fairly thin, there is probably not a widespread likelihood of human triggering.

Avalanche Problems

Problem	Location	Distribution	Sensitivity	Size	Comments
Persistent Slab	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Layer Depth/Date: 30-35cm Weak Layer(s): Jan 20, 2022 (FCsf) Comments: Rose indicates forecasted presence of problem based on today's obs.
Wet Loose	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5

Terrain Use

Went into field day with stepping back/assessment mindset. I avoided avalanche terrain due to uncertainty about persistent slab problem.