Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Observation Date:
February 19, 2021
Submitted:
February 19, 2021
Zone or Region:
East Central
Activity:
Skiing/Snowboarding
Location:
Icicle Creek 4000'

Observed Avalanches

Did you observe any avalanches? 
Yes
Avalanche Type:
Dry Loose (Sluff)
Size:
Size 2: Could bury, injure, or kill a person
Elevation:
BTL - 4000'
Aspect:
NE
Comments:
Below rock bands, so likely started as a point release and entrained dry snow into a large terrain trap. Ran during 18 Feb 2021 storm/wind event.
Photo:

Signs of Unstable Snow

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

Observations

Last week's mix of storms, west and east winds, and high pressure has created a heterogeneous snowpack in the lowlands with diverse travel conditions. Subtle changes in aspect reflect sun's increasing intensity and multiple wind directions this week. Surface hoar buried above sun crust on any southerly tilt and on density change everywhere else.

Sunday's rain at BTL in this area will void much of this.

Advanced Observations

Observed Avalanche Problem #1: 
Wind Slab
Comments: 
Cross-loaded slopes from east winds during 17-18 February and strong west winds with moderate transport morning of 19 February 2021. Slabs to 45 cm cracking to 3m. Multiple collapses on SE and E
Observed Avalanche Problem #2: 
Persistent Slab
Comments: 
Wednesday 17 Feb sun crust has surface hoar weak layer buried above it (18 Feb) at all elevations on exposed slopes.
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