Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Jeff T.
Observation Date:
December 15, 2020
Submitted:
December 15, 2020
Zone or Region:
Snoqualmie Pass
Activity:
Skiing/Snowboarding
Location:
Bench above No Fog

Triggered Avalanches

Did you trigger any avalanches? 
Yes
Was it intentional? 
Yes
Avalanche Type:
Soft Slab
Size:
Size 1: Relatively harmless to people
Elevation:
~4400
Aspect:
NE
Comments:
SS-ASc-R2-D1-l Slope Angle: 45+ degree convexity Slab width: 10-15m Slab Thickness: 15-20cm Slab Hardness: F Vertical Fall: 10-12m
Photo:

Signs of Unstable Snow

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

Observations

The new snow is not bonding well to old snow surfaces. A Hand Shear Test resulted in new snow separating in 3 distinct layers. The two bottom layers on clean interfaces as seen in the attached photo.

Media

Used pole increments for rough slab height (15-20cm)
Bottom of Pineapple Basin
Cracking on similar convexity that failed

Advanced Observations

Observed Avalanche Problem #1: 

Comments: 
WordPress Lightbox