Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Ryan Matz
Observation Date:
January 9, 2021
Submitted:
January 9, 2021
Zone or Region:
Mt Hood
Activity:
Skiing/Snowboarding
Location:
South side/ Timberline vicinity

Signs of Unstable Snow

Did you see shooting cracks? 
Yes, Isolated
Did you experience collapsing or whumpfing? 
No

Observations

Travelled between 5000’ and 9500’ in area W of Timberline ski area. Fresh wind slabs forming under moderate Easterly winds, particularly around 6,000’-7,000’. Minimal signs of instability observed other than in the fresh wind slab. For all cracking observed, failures occurred on or in low density snow immediately above a subtle zipper crust (formed ~1/3?). Crust present at surface specifically on wind exposed ridges.
Test pit at 5,500’, westerly aspect adjacent to Little Zigzag Canyon. CT 11 failing down 20 cm on zipper crust. No propagation or failure at all in ECT (ECT X). Surface snow/slab was soft (F) and minimally wind affected in pit location, greater propagation potential indicated by cracking in more dense fresh wind slabs at slightly higher elevation as noted above. Moist layer of snow found 75 cm down, unknown thickness (50+ cm, I didn’t dig deeper than 120 cm down).

Media

W aspect 6500’, not undercut
SW aspect 5800’, undercut by skin track
W aspect 5500’

Advanced Observations

Observed Avalanche Problem #1: 
Wind Slab
Comments: 
Fresh, reactive, generally small wind slabs actively forming specifically on westerly aspects around 6000’-7000’. Distribution more isolated at higher elevations where less snow available for wind transport.
Older wind slabs seemed stubborn at best, cracking only where undercut by skin track and generally down slope versus shooting cross slope ahead of ski tips.
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