Observation: NWAC Observer

All Observations

Basic Information

Observation Date:

March 16, 2023

Submitted:

March 16, 2023

Observer:

NWAC Observer - Keeley Rideout

Zone or Region:

West North

Location:

Baker Backcountry (4000 - 5600ft, All Aspects )

Recent Avalanches?

Yes

Cracking?

None Experienced

Collapsing?

None Experienced

little roller balls on south facing aspect

refrozen recent sloughs off north facing aspect of Table Mountain area

wet loose sloughing from cliffs on south facing aspect near Mt. Herman

surface hoar and and surface crust layer

CT24RP 36cm deep crust failure.
[Captions courtesy of Irene Henninger]

Advanced Information

Cloud Cover:

Clear

Temperature:

26°F

Wind:

Calm

New/Recent Snowfall:

HN: 0cm

Clear blue skies with sun overhead and calm winds.

Avalanche Observation Comments:

Lots of wet loose activity from days prior on south and east aspects below cliff bands. Isolated activity observed on some north and west slopes.

Started skinning around 8am, before the sun had touched most aspects. A 1.5cm crust was widespread on all aspects aside from a few isolated areas ATL. In some places this crust was firm and supportable, in others it was full-zipper protect-your-knees kind of skiing. Based on this crust, I expect upper elevations may still have wind slab potential.

Atop the crust, a layer of feathery surface hoar formed overnight and was present on all aspects before the sun came up this morning. The surface hoar was especially prevalent on north and west aspects.

Depending on aspect and elevation, the recent storm snow depths ranged from 28-36cm.

Wet loose activity on South and East facing terrain was ubiquitous beneath cliff bands. Small rollerballs were already moving downhill by 10am, and rollerballs from yesterday that crossed the skin track were as large as 3ft in diameter.

A pit at 4860ft on 92º East aspect showed distinct layers the first being the newest storm snow comprising the top 19cm, followed by 15cm of denser old storm snow. The old snow had some needle-like snow grains mixed in. Beneath that was a 1.5cm melt-freeze crust. A compression test failed at CT24RP on this upper crust, making it seem like the lingering storm slab issue may still exist. Lower down lay two more crusts, one at 65cm deep and another 95cm deep.

Problem	Location	Distribution	Sensitivity	Size
Wet 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
Storm Slab	N E S W	Unknown	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5
Wind Slab	N E S W	Unknown	Unknown	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5