Pro Field Report

Basic Information

Observation Details

Observation Date:
February 16, 2021
Submitted:
February 16, 2021
Observer:
SAC - Scott Savage, Terry O'Connor
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Baker Ck (6700-9200': NE-E-SE-S-SW)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
Isolated
Some soft cornice at exposed ridgelines, but no propagating cracks. We had 1 small collapse, and a nearby party had a couple. None traveled very far, and they seemed to be at the Feb 11 old snow/new snow interface and crust (on southerly aspects).

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
High
Stability Trend: 

Bottom Line

Good stability in sheltered terrain, poor stability where wind-loaded. We saw a few sizable natural slides in generally S-E facing alpine terrain. Moderate N-NW winds were loading slopes near exposed ridgelines above about 9000'. The deeper persistent instabilities buried in December and January continue to show signs of improvement (lack of collapsing, better-looking structure, improving test scores)...but I don't trust them yet.

Media/Attachments

https://youtu.be/-PT4DOByw84

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Temperature:
Teens and low 20s F (based on wx stations)
Wind:
Moderate , NW
New/Recent Snowfall:
At 8000': 10cm overnight, 2-3cm today by 2:30 PM. Settled storm total=15-35cm in sheltered terrain depending on elevation and aspect (more settlement on solars).

Snowing lightly when we left. Lots of low-density snowfall available for transport at middle elevations. At upper elevations, we saw a lot of scoured rock patches in the Smoky and Boulder Mtns when visibility allowed; winds have been moving snow up high.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Feb 16, 2021
(+/- 1 day) 		Boulder Peak
S 9800ft 		D2 SS-Soft Slab N-Natural Report
1 Feb 16, 2021
(+/- 1 day) 		Norton Ck
SE 9300ft 		D2 SS-Soft Slab N-Natural Report
1 Feb 16, 2021
(+/- 1 day) 		Norton Ck - Big Lost Lake
SE 9600ft 		D2 SS-Soft Slab N-Natural Report
Boulder Peak
Norton Ck
Norton Ck - Big Lost Lake

Lots of small cornice fall and little D1 loose snow dribbles coming off the ridgelines. The crowns we could see were triggered by small slides hitting them from above.

Snowpack Observations

8000-8800' S-SW: HS=100-130cm with prominent crusts at 2/11 and 1/27. 12/11 is looking better. See attached photo and SnowPilot profile.

Snow pit profile in Baker Ck drainage, 8600' SW.
Snowpit in Baker Ck drainage on a SW aspect near 8600'.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
 Unknown
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: 30-45cm
Comments: Specific to at/near ridgelines, lee aspects from NW winds where we were. Lots of hand pits tugging and tapping and pulling on wind slabs: they were failing 12-18" down on a mid-storm layer and/or on the 2/11 interface. Wind deposits were mostly "soft" where we were.
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: 65-86cm (2-3 ft)
Weak Layer(s): Jan 27, 2021 (FCsf) Dec 11, 2020 (FCsf)
Comments: 12/11 looking at lot better structure wise, no bad test results...but it's still there. 1/27 looks a lot different on this SW aspect (crust matrix) - seems like it's still capable of doing something, but it probably needs a wind event or big load at middle elevations to reactivate.

Terrain Use

We planned to avoid wind-loaded starting zones and all large, consequential avalanche paths. We did not see anything to change our plan. We skied non-consequential avalanche terrain (no terrain traps or trees in the runouts) and without wind-loading, below 35*.