Observation: NWAC Observer

All Observations

Basic Information

Observation Details

Observation Date:
December 17, 2022
Submitted:
December 18, 2022
Observer:
NWAC Observer - Brooke Maushund
Zone or Region:
East Central
Location:
Glacier Peak Wilderness — Trinity Area (NE-E-SE)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Wind transport evident in the alpine.
Wind effect was evident across many aspects and elevations from the top of the col.
Multiple past D1-D2 wet slides were visible on ESE terrain on our approach.
More D1+ past (24-48hr prior) wet slides on ESE terrain.
Wind affected snow surfaces very visible in alpine.
Sizeable (2-4cm) Surface Hoar present across snow surfaces BTL & NTL. The snow surfaces of today are the potential bed surfaces of tomorrow.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Temperature:
Below 32°F
Wind:
Moderate , SW
New/Recent Snowfall:
NO

Winds increased moderate to strong out of SW ATL in the afternoon. Skies started clear and shifted toward FEW @14:00 and SCT @16:00. Wind transport evident, snow surfaces provided adequate snow to transport.

Multiple recent (24-48hr prior) D1-D2+ wet slides were visible on the ESE facing ridge features / bowls on climbers right heading up to the col. Slides look 1-2 days old

Snowpack Observations

-While wind pressed snow and punchy surfaces existed, we did not find large slabs on the NE facing slope that we skied. There was about a 4cm crust on top of loose, soft dry snow.
-Did not see evidence of large slides running close to the ground on the basal facets involved in the persistent slab problem anywhere near us or within view from our route. Does not mean they were not present. HS was over 100cm (120-160) BTL and NTL until we were in the alpine. Felt weakness near the ground working our way up the drainage NTL on mostly E facing aspects at times, but this varied spatially without a consistent pattern.
-Sizeable (3-4cm) Surface Hoar present on snow surfaces BTL and NTL. The snow surfaces of today could be the bed surfaces of tomorrow.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
Persistent Slab
Unknown
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Weak Layer(s): Nov 22, 2022 (FC)

Wind Slab: While wind pressed snow and punchy surfaces existed, we did not find large slabs on the NE facing slope that we skied. There was about a 4cm crust on top of loose, soft dry snow that was not cohesive. Transport was visible on ridgelines and evident on snow surfaces, winds increased from moderate to strong at ridgeline in the afternoon out of the SW

Persistent Slab: Did not see evidence of large slides running close to the ground on the basal facets involved in the persistent slab problem anywhere near us or within view from our route. Does not mean they were not present. HS was over 100cm (120-160) BTL and NTL until we were in the alpine. Felt weakness near the ground working our way up the drainage NTL on mostly E facing aspects at times, but this varied spatially without a consistent pattern. Did not take out the probe ATL