Pro Field Report

Basic Information

Observation Details

Observation Date:
December 17, 2021
Submitted:
December 18, 2021
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Durance and beyond

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
Unsure on the timing of very small avalanches (wind slabs) observed at ridgelines. I saw a bit of cracking and collapsing in wind drifts, did not experience any deeper rumblers but I wasn't in terrain that had snow prior to last week's storm.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Wind:
Calm , NW

Calm to light winds out of the NW. Air felt cold all day. A few bands of high stratus building over the Smokys near sunset.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Dec 14, 2021
(+/- 1 day) 		North Fork Big Wood
SE 11200ft 		D2 N-Natural Report
1 Dec 14, 2021
(+/- 1 day) 		Goat
E 10000ft 		D2.5 N-Natural Report
North Fork Big Wood
Goat

Continuing to observe evidence of widespread avalanche activity from the storm. As observed elsewhere, the timing is pretty variable, with some fresh-ish crowns but many locations where the only evidence is a hint of a crown and a ghost debris pile below.

Snowpack Observations

Mostly just a note to talk about surfaces. Cold temps and direct sun formed a widespread RadRx crust on about SSE-WSW. The crust was 10-15mm thick and the overlying PPxFc were 4-6mm thick. I've seen RadRx crusts here with some frequency, but this was much more widespread than is common. Based on weather observations I suspect we got some variation of a MFcr/RadRx crust on all of the above-described slopes south of Galena Pass. Intermittent clouds may have prevented this further north, or at least made the distribution a little more spotty. It looks like we will be burying this layer in the coming days and may be putting it to the test at Christmas.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Unknown
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Comments: Rose shaded based on obs of the previous month. Distribution is specific to shaded octants.

Terrain Use

Avoiding avalanche terrain with older snow under the storm snow (it is not visually obvious where this is if you weren't looking before the storm).