Pro Field Report

Basic Information

Observation Details

Observation Date:
January 16, 2020
Submitted:
January 17, 2020
Observer:
SAC - Martin Stefan
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Titus ridge

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
Isolated cracking and collapsing on wind stiffened snow on ridge line. See below for avalanche comments.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Steady

Bottom Line

Persistent weak layers, especially from New Years, are still active and can cause large avalanches now that the overlying slab has become thicker and stiffer, but at the same time the likelihood for triggering decreases. A dangerous gamble.

Media/Attachments

AC slide path seen from above
Natural slide from earlier this week. Just one part of the crown that spans the whole bowl.
Cracks over 1m deep in HS to DH, but not steep enough to slide. Triggered by cornice drop on Titus ridge.

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Temperature:
mid 20s est
Wind:
Strong , SE

Strong E/SE wind was moving a lot of snow, new drifts up to a meter thick in the skin track and lots of spin drift along the ridge. New cornices forming fast to the W.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Between WX and Titus peak
NE 9800' 		D2 HS O-Old Snow 1m AC-Cornice Drop
c-Intentional 		Dropped >100kg of cornice and hit a fat spot, crown around 150cm at its thickest, tapering down to around 50cm at the edges. Crown 15-20m wide, ran around 200m. Slope angle high 30s at crown. Slab mostly 1F hard.
In the thickest part it failed on a mid storm interface, maybe 1/10, but quickly stepped down to 12/31. In this location I could not detect 12/7, it might have been destroyed by wind, but there was around 20cm of DH near the ground.
Crown of deep slab triggered by cornice drop close to Titus Peak

Snowpack Observations

Dropped another >100kg cornice at second bump. Too flat to slide but the snowpack cracked down to DH at gnd, around 130 cm down. Did not dig a complete profile due to time constraints.

Could not get to the natural crown in a safe and timely manner. After I dropped the cornice I might have cleaned enough to be able to access it, but time was not on my side this time. From what I could see and from the slide I triggered I would suspect that the natural went on 12/31 too, with potential step down into 12/7 at lower drown from ridgeline where that layer is better preserved. FWIW the crown looked to be in the 50-150cm range, but light was very flat so hard to say for certain.

Crown profile of D2 AC avalanche near Titus Peak. Failure layer is 12/31 FC

Terrain Use

Avoided avalanche terrain except where it already slid.