Pro Field Report

Basic Information

Observation Details

Observation Date:
March 1, 2023
Submitted:
March 4, 2023
Observer:
SAC - VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Pole Creek (7,200-10,100', most aspects)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Widespread
This was the most collapsing I've experienced since late December.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Low
Stability Trend: 

Media/Attachments

This small soft slab was observed above the Pole Creek drainage on a NW-facing slope at 8,400'. It appears to have stepped down to a deeper weak layer in the snowpack.
This slide failed on a N/NW-facing slope at 9,500' above the Pole Creek drainage.
This slab avalanche was observed in the Pole Creek on a N-facing slope at 9,000'. It appears to have failed in a relatively sheltered piece of terrain. As the slab overlying the layers of weak snow in the upper snowpack grows thicker, avalanches in terrain sheltered from the wind become possible.
This slab avalanche was observed in the Pole Creek on a N-facing slope at 9,000'. It appears to have failed in a relatively sheltered piece of terrain. As the slab overlying the layers of weak snow in the upper snowpack grows thicker, avalanches in terrain sheltered from the wind become possible.

Advanced Information

Weather Summary

Wind:
Light , W

Cloudy throughout most of the morning, with skies clearing over the valley by late morning. Periods of sun and clouds+snow were observed in the mountains throughout the day. Winds blew light with occasional moderate gusts out of the W, occasionally transporting small amounts of snow. .

Avalanche Observations

I observed several recent avalanches that appeared to involve the new snow failing on the weak layer of facets we developed in early February. None of these were large, but they all point to likely issues in wind loaded areas and when we see additional loading. See photos below.

Snowpack Observations

Mostly moving observations today, looking for avalanche activity and hand pitting and pole probing. I dug a single pit on a NW-facing slope at 8,400'. Here, I found just 20-25cm of snow overlying the February facet layer (2/18). The bottom half of this snow was much denser (4F+) and a bit older, while the upper half was largely new. As I climbed and moved around the compass, it seemed like this slab averaged around 25-30cm thick. This weak facets under this slab produced widespread collapsing as I traveled, on both solar and shaded slopes. Generally these collapses occurred in areas affected by the wind. Some of the collapses were large and booming, involving starting zone sized pieces of terrain.