Pro Field Report

Basic Information

Observation Details

Observation Date:
March 4, 2023
Submitted:
March 5, 2023
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Galena Peak (7,300-10,100, primarily western half of compass)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
Isolated
I experienced a few small, localized collapses that involved dense wind drifts along a ridgeline. I also experienced a few large collapses on a large, middle elevation slope (where I dug the snowpits described below).

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light , S
New/Recent Snowfall:
7-8cm HST

Intense band of snowfall this morning, followed by a midday lull in activity. I was out in the afternoon/evening, checking on the storm in progress. It snowed a relatively steady S-1 to S1 throughout tour, accumulating an additional cm. Winds were generally calm to light out of the S, with occasional periods of a bit stronger, moderate wind.

Avalanche Observations

I observed one new wind slab avalanche along the roadway between Stanley and the Stanley Ranger Station that appeared to have been triggered by elk.

Snowpack Observations

My primary goal was to see what the storm was doing and to check in on the persistent slab problem in this area. I dug two pits on a W aspects and found a 40+cm thick slab overlying the 2/18 weak layer, which presented as a stack of impressively weak (F--), large-grained (up to 2.5mm), well-developed facets. This layer produced repeated ECTPs with light force, including an ECTPV. It also produced some large collapses both before and after I dug. The slab graded somewhat evenly from F to 4F+ at the base.

Terrain Use

Persistent weak layers in the upper snowpack have caused me to gradually step back as the slab on top of them is built.