Close

Professional Observation

Basic Information

Observation Details

Observation Date:
November 26, 2022
Submitted:
November 26, 2022
Observer:
WCMAC - Cam Mackenzie
Zone or Region:
Southern Bitterroots
Location:
Lost Trail Backcountry

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Stability Trend: 

Bottom Line

Poor snowpack structure overall. North aspects developing depth hoar but bridged by pencil hard melt freeze crust above. The biggest concern moving forward into the next storm is the widespread layer of buried surface hoar.

Media

North Aspect, 8000' Poor Snowpack Structure
SW aspect, 7800' Buried Surface Hoar present
4mm Buried surface hoar
North Aspect, 8000' Example of area holding buried surface hoar
Evidence of past wind loading and minor cornice development
South Aspect of Saddle Mountain
Looking south onto Salmon-Challis from Stateline Yurt

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
29F
Wind:
Light , N

5cm (2 inches) of new snow overnight. Light wind, no transport noted. Average snow depths along the state line were between 70 and 80 cm (25-30 inches).

Snowpack Observations

Today we dug one full profile and multiple test pits around the compass. Not surprisingly, northern and shaded aspects are holding early season snow from October which has advanced towards depth hoar. The thick melt freeze crust above it seems to be bridging it effectively, and I do not anticipate this layer being active until we add a significant load to the snowpack.
My biggest layer of concern moving forward is a widespread layer of buried surface hoar found on all aspects. The only areas where we did not find this layer were in tight green timber. Surprisingly, we also found this layer in areas where I would have expected it to be destroyed by winds. Currently, we do not have a slab above it to propagate as the surface snow is a layer of noncohesive near surface facets. Once we add a load or a slab to this, expect this layer to fail.

Close