Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 8, 2023
Submitted:
January 8, 2023
Observer:
NWAC Forecaster - Matt Primomo
Zone or Region:
East Central
Location:
Icicle Creek (NW-E 2,500-6,800)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

Profile on a NE aspect at 6,200ft
Two small loose dry slides N at 6,700ft
Small glide slab on rock slab above Icicle Rd.
Wet loose slide covering part of Icicle Rd.

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Light

S1-S2 snowfall throughout the day. At times heavier snowfall occurred, but it was somewhat shortlived.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 8, 2023 3:00 pm
() 		Between Doctor Crk and Victoria Crk
N 5500ft 		D2
R2 		SS-Soft Slab I-New/Old Interface 0.5ft AR-Snowboarder
c-Intentional
Wide propagation with a slightly wind affected soft slab on a North aspect at 5,500ft.
Debris from a widely propagating soft slab. N at 5,500ft in Icicle Creek.
Report
Between Doctor Crk and Victoria Crk

See attached Avy ob.
Could easily ski trigger small loose avalanches on steeper slopes, both dry and moist at respective elevations.

Snowpack Observations

Moist snow below about 3,500ft, dry above that. The Xmas crust was freezing rain up to about 4,500ft and down 25-35cm. A Profile at 4,700ft showed failure on small grained rounded facets a few cm's above Xmas IFcr, down 25cm (Rutschblock 4, ECTN M). Hand shears showed variable results on this crust.

Slopes that were touched by the wind were sensitive, and in a couple places produced long fractures. Skin track tests would often fail down about 15cm on a subtle density inversion between yesterdays storm snow and todays. Informal tests would also sometimes fail down 15-20cm on the interface from the 4th, which was either a very thin drizzle crust or temperature crust. In a couple places I could make out small, decomposing and rounding facets or surface hoar beneath.
See profile for layering structure. Throughout the day, instabilities were subtle but still there.

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