Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 30, 2023
Submitted:
January 30, 2023
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
West South
Location:
Mt St Helens (E-S-W aspects 2700ft-5600ft)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

You can see the two avalanches we found on very similar terrain features and aspects.
Large wind textured snow features. Not the scourted icy slope adjacent to the wind affected pockets.
Very shiny icy surfaces were found in many wind stripped locations.
https://www.youtube.com/watch?v=CE60BfezprA&t=2s

Advanced Information

Weather Summary

Cloud Cover:
Clear
Wind:
Light , E
New/Recent Snowfall:
No new snow.

Beautiful day! Clear skies, cool temperatures, and a very light breeze.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 29, 2023
() 		Mt St Helens
S 4496ft 		D2
R2 		HS-Hard Slab I-New/Old Interface 2ft N-Natural
A natural wind slab avalanche on Mt St Helens. Likely from Sunday 1/29. SSW 4500ft, HS-N-D2-R2-I, 2ft deep.
A natural wind slab avalanche on Mt St Helens. Likely from Sunday 1/29. SSW 4500ft, HS-N-D2-R2-I, 2ft deep.
Hard slab debris from a natural wind slab avalanceh on Mt St Helens, likely from 1/29.
A natural wind slab avalanche on Mt St Helens likely from Sunday 1/29. SSW 4500ft, HS-N-D2-R2-I, 2ft deep
Report
1 Jan 30, 2023 2:30 am
() 		Mt St Helens
S 4000ft 		D2
R2 		HS-Hard Slab 1.5ft AS-Skier
u-Unintentional
The avalanche was triggered from the adjacent slope that was lower angled.
Hard slab debris in this terrain trap gully could have made for a deep buiral.
Deeper sections of the crown. Note the striated layers within the wind slab. This is typical of hard wind slab avalanches.
Large hard slab debris blocks from a human triggered avalanche on Mt St Helens.
Most of the crown was 1/5ft thick, but sections were much deeper, up to p3ft thick.
The crown and debris in the terrain trap gully from a human triggered wind slab avalanche on Mt St Helens Monday 1/30. SSW 4000ft HS-ASu-D2-R2-I
A unal triggered wind slab avalanche on Mt St Helens. SSW 4000ft, HS-ASu-D2-R2-I, 1.5ft thick (max 3ft thick)
Report
Mt St Helens
Mt St Helens

Other than the two avalanches we recorded we did not see any other slides.

Snowpack Observations

Wind: The strong winds from the weekend wreaked havoc on Mt St Helens. Many slopes above 4500ft were scoured down to a very firm (and sometimes icy) crust. The few wind-loaded pockets that remained were often in deep gullies or on the W sides of sharp ridges. These "softer" pockets were large textured features (sastrugi, see photo below).

At mid elevations (5000-4000ft), wind slabs were much easier to find. They were often on unusual aspects like the two avalanches (SSW). However, we also found them on the E and SE sides of features. Slabs were frequently hard and up to 3-4ft thick.

Below 4000ft, several inches (3-6in 7-15cm) of soft snow sat over a robust crust. This made for fun, fast travel on lower angled slopes.

Despite the sunshine, we did not see any significant signs of wet surface snow developing during the day.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Layer Depth/Date: 2-48in
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