Observation: NWAC Forecaster

All Observations

Basic Information

Observation Date:

March 3, 2022

Submitted:

March 3, 2022

Observer:

NWAC Forecaster - Matt Primomo

Zone or Region:

East North

Location:

Kangaroo W shoulder

Recent Avalanches?

Yes

Cracking?

None Experienced

Collapsing?

None Experienced

One of the Cutthroat slide paths, with some small trees in the wet debris.

Wind drifted snow on an exposed W aspect at 7,000ft.

Crown that came up to very low angle terrain below S Early Winter Spire

Deeper crowns just below ridgeline on very steep NE facing terrain, and on N facing terrain below the sub ridge.

Deeper crown off NE Facing peak above Hairpin Valley

Deeper crown off NE Facing ridgeline above Hairpin Valley

Shallow recent windslabs in the shade in upper L.

Large wet debris off the W side of Kangaroo.

Very large wet debris off the W side of Kangaroo.

Advanced Information

Cloud Cover:

Mostly Cloudy

Wind:

Light

New/Recent Snowfall:

10cm new in past 24hrs above 6,500ft, with less below.

Mostly sunny first thing in the AM, becoming overcast with light snow for a few hours, then becoming broken later. Light winds were enough to drift some snow above 7,000ft or so.

#	Date	Location	Size	Type	Bed Sfc	Depth	Trigger	Photos	Details
1	Mar 2, 2022 ()	Willow Creek NE 7200ft	D2.5				N-Natural	$Debris in Willow Crk below a steep NE facing feature. You can pick out a smaller pocket that pulled out in lower L, along with a fracture line to the L of that.$	Report
5	Feb 28, 2022 ()	NW Kangaroo W 7600ft	D2.5	SS-Soft Slab			N-Natural		Report
2	Feb 28, 2022 ()	South Early Winter Spire NE 6600ft	D1.5	SS-Soft Slab		1.5ft	N-Natural		Report
3	Mar 1, 2022 ()	Hairpin Valley Peaks NE 7500ft	D2.5	HS-Hard Slab	O-Old Snow	4.5ft	N-Natural		Report

Map of listed avalanches:

Willow Creek

NW Kangaroo

South Early Winter Spire

Hairpin Valley Peaks

Avalanche Observation Comments:

Widespread storm slab and loose dry/loose wet cycle observed with most slides in the D2-2.5 range and some D3's. A handful of deeper crowns were spotted. Much of the evidence had been snowed and drifted over, so difficult to tell the true extent and character of many of the slides.
I heard one very small loose wet slide at around 10m from an E facing slope in the Liberty Bell group.

The snowpack is heavily affected by rain below 6,000ft or so, with blotchy runnells and 5-10cm of breakable crust or so and wet to moist snow below that. I did find some dry snow 50cm down in places. Between 6,000 and 6,500ft the crust begins to taper away, becoming weaker. Generally fairly arduous trailbreaking and difficult travel with breakable crust lower, and deep dry snow higher. Some wind affected snow and buried wind slab above 6,500ft.

At a W aspect at 6,500ft I found HS of 280cm with about 100cm of snow since the 26th. Boot pen was about thigh deep, ski pen 30-40cm
The late January crust/facet weak layer was down 115cm and consisted of 1-1.5mm rounded facets at 1F- hardness. These weaker grains were sandwiched beneath a thin translucent ice lens above, and a thicker but stout melt freeze crust below.
Test results were highly variable, but all Compression Tests failed as Sudden Collapse. One test failed upon isolation (VE), another failed with CT 19, and a third CT 31. ECTN, but failed upon manipulation and slid out of the test wall after.

On a SW aspect at 6,900ft HS was 190cm with 10cm new snow. Boot Pen thigh, ski pen 40cm
CT21 SP, CT19 SP ECTP 25, and PST 50/100 (Sfc) down 60cm on 0.5-1mm FC over a 1-2cm thick sun crust, likely buried Feb 26th. Tests were cash registering out on the very smooth crust. Faceted grains were also observed beneath the crust.

I skiied a well supported low-mid 30 degree feature and stayed away from open starting zones.

WordPress Lightbox