Observation: Avalanche Professional

All Observations

Basic Information

Observation Date:

November 28, 2022

Submitted:

November 28, 2022

Observer:

Avalanche Professional - Zack Wentz

Zone or Region:

Snoqualmie Pass

Location:

Alpental Ski Area - Edelweiss Bowl (All aspects, 3100'-5100')

Recent Avalanches?

Yes

Cracking?

Isolated

Collapsing?

None Experienced

Very small wind slab that was observed on a W aspect at 4500' in the Edelweiss Bowl.

Coverage is still quite rocky and without much of a base. Early-season hazards are quite prevalent.

Low coverage overall with many bushes and branches to be mindful of

Advanced Information

Cloud Cover:

Mostly Cloudy

Wind:

Light , SE

New/Recent Snowfall:

27-31cms HST

AM: Cold with sunny breaks. Light winds, gusting moderate from the SE. Precip: S-1 (less than 1cm/hr)
PM: Cold and stormy. Light-moderate SE winds. Precip: S1 (1cm/hr)

Foot pen: 45cms

Avalanche Observation Comments:

One sz 0.5 old wind slab crown was observed on a 35 degree convex roll at TL on a W aspect at 4500'.

Numerous sz 0.5 loose dry avalanches (sluffs) were observed and triggered in terrain steeper than 35 degrees

Snowpack Summary:

Regardless of elevation, snowpack consists of 3 specific layers and two interfaces. Depending on elevation, the depth of these interfaces change. Light (F- hardness) new snow sits atop the 11/22 rain crust, which is widespread and not supportive to skis. Below that sits slightly harder snow (4F), before encountering the 11/4 interface with melt forms below. Above 4500', surface conditions are a mix of light new snow and wind affected snow (4F+), that is forming shallow wind slabs in lee & cross-loaded features.

Depths of the various interfaces changed based on elevation. I took two total HS measurements, which I'll detail below:

At 4700' in sheltered open area:
-11/22 rain crust down 31cms
-11/4 melt forms down 52cms
-HS: 90cms

At 5000' on a 35 degree SE facing slope:
-11/22 rain crust down 27cms
-11/4 melt forms down 42cms
-HS: 93cms

Problem	Location	Distribution	Sensitivity	Size	Comments
Wind Slab	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Layer Depth/Date: 5-15cms Comments: Found immediately at or below ridge crest
Dry Loose	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Comments: Specific to slopes greater than 35 degrees

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