Pro Field Report

Basic Information

Observation Details

Observation Date:
December 31, 2021
Submitted:
January 1, 2022
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Central Boulders

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced
Unsure on timing of reported avalanches, likely a bit older than 48 hours, but light was tough.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Stability Trend: 
Improving

Bottom Line

Weak layers are developing at the snow surface and have been buried by recent storms, even in areas that lacked snow prior to 12/11.

Media/Attachments

This avalanche in Prairie Creek occured sometime during or just after the Christmas storm. E/NE aspect at 9,500'.
NE on Norton, 9,600'.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
cold
Wind:
Moderate , NW

HN48 of 15cm, pretty hard to tell thanks to wind during this snowfall. Cold NW wind blowing at light increasing to moderate speeds. I could tell that winds were putting significant amounts of snow into play across the valley in the Smokys as well, but can't say whether or not any effective loading was happening.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Dec 29, 2021
(+/- 3 days) 		Prairie Creek
E 9500ft 		D2 N-Natural
This avalanche in Prairie Creek occured sometime during or just after the Christmas storm. E/NE aspect at 9,500'.
Report
1 Dec 29, 2021
(+/- 3 days) 		Norton Peak
NE 9600ft 		D2 N-Natural
NE on Norton, 9,600'.
Report
Prairie Creek
Norton Peak

Unsure on the timing of slides, but based on continued snowfall and wind it seems likely that they occurred within the past few days or so.

Snowpack Observations

Continuing my search for weak layers in the upper snowpack. I looked pretty hard to the buried surface hoar that exists further south and did not find any. For those keeping track, I believe the furthest north observation of buried SH (down ~40-50cm) is from Ethan, just east of Boulder Creek. At roughly this same interface I found FCsf and FCsf+MFcr combos (there is actually a trio of weird interfaces here, buried 12/19, 12/22, and 12/24 depending on location, but it is very hard to tell which you're looking at). These produced variably propagating and not propagating scores in ECTs in the mid-teens.