Pro Field Report

Basic Information

Observation Details

Observation Date:
February 21, 2023
Submitted:
February 21, 2023
Observer:
SAC - Jon Preuss
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Titus Ridge (N-E-SE; 8700-9900')

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
I observed cracking and collapsing along wind-affected ridgelines. I experienced about seven collapses today on wind pillows near or on ridgelines.

Bottom Line

Most of the avalanches observed appeared to be wind-driven from the moderate to strong NW winds and failed in the new/old interface. The areas with more storm snow (like the western Smoky and Sawtooth mountains) and slopes exposed to recent winds are the most concerning. The new/old interface was composed mainly of facets or a crust-facet combo and doesn't seem to behave well with the storm snow. All the avalanches observed were in the "prime time" avalanche terrain. Weak layers buried in January showed propagation, which appears more sensitive on sunny-facing slopes.

Media/Attachments

(2/21/23) These wind slab and loose snow avalanches released naturally on E aspects near 10,000' in the Smiley Ck drainage, likely on Tuesday, Feb 21st. 
(2/21/23) Multiple thin crowns likely failing in the new/old interface.
(2/21/23) Wind slab released naturally near Titus Ridge.
(2/21/23) A natural avalanche that released Tuesday morning near the summit of Galena Pass.
(2/21/23) Multiple crowns that released Tuesday morning, naturally near the summit of Galena Pass.
(2/21/23) Natural avalanche on a SE aspect near Galena Summit.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Wind:
Light , NW
New/Recent Snowfall:
HN 4-6" (10-15cm); HST 8" (20cm)

My drive to Galena Pass was mostly sunny skies until snowfall from 1130-1300hr. Snow fell at S2-3 rates briefly, and skies began to break. The Smoky and Boulder mountains remained in the sun for most of the day, while the Sawtooth and White Cloud mountains appeared to have snow squalls. Winds were light from the NW and only occasionally had drifting snow. There is plenty of light-density snow available for transport.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
4 Feb 21, 2023
(+/- 1 day) 		Smiley Creek near Vienna Peak
E 10000ft 		D2 SS-Soft Slab N-Natural
(2/21/23) These wind slab and loose snow avalanches released naturally on E aspects near 10,000' in the Smiley Ck drainage, likely on Tuesday, Feb 21st. 
Report
Smiley Creek near Vienna Peak
 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Titus Ridge "Walcher's Bowl"
NE 9600' 		D1.5 SS N-Natural
(2/21/23) Wind slab released naturally near Titus Ridge.
3 Upper Titus Wx Station
NE 9400' 		D1 SS I-New/Old Interface N-Natural Multiple thin crowns likely failing in the new/old interface.
(2/21/23) Multiple thin crowns likely failing in the new/old interface.
4 Galena Summit
SE 8800' 		D1 SS I-New/Old Interface N-Natural These occurred in the early afternoon near the top of Galena Summit. They appeared to fail on a crust layer at the new/old interface of the storm snow.
(2/21/23) Natural avalanche on a SE aspect near Galena Summit.

Snowpack Observations

After taking many measurements of the new snow in sheltered areas, I'm pretty confident that this area has received 4-6 inches in the last 24 hours and storm totals of 8-9 inches. Most of the small column tests showed sudden planar failures ~15cm down marking a break in the storm yesterday and ~20cm down depicting the new/old interface which was comprised of facets.

In my shady snow pit, the extended column test showed propagation with repeated hard results. This layer was 2mm facets on top of a firm 4finger layer down 52cm.

In my sunny snow pit, a layer of facets sitting on top of a decomposing crust propagated with moderate ECT results down 44cm.