Observation: NWAC Observer

All Observations

Basic Information

Observation Date:

March 10, 2023

Submitted:

March 10, 2023

Observer:

NWAC Observer - Willie Webster

Zone or Region:

East North

Location:

Silver Star zone (West 4000' to 7000' )

Recent Avalanches?

None Observed

Cracking?

Isolated

Collapsing?

Isolated

Brief sun breaks stiffened the surface snow

Low density snow found below Valentines crust is somewhat faceted.

A resistance and planar fracture within the recent storm snow

Small stiff wind slabs in mid elevations indicate potential for larger wind slabs up high.

New snow is adding some significant depth to the snowpack. Eight foot deep snowpack here.

https://youtu.be/tZuK8bMnUOk

Advanced Information

Cloud Cover:

Mostly Cloudy

Temperature:

27°F

Wind:

Calm

New/Recent Snowfall:

8" in in the last 24

Temps felt spring like at the trailhead with a temperature of 33. Once we got into higher terrain temps stayed near 27. Skies were overcast in the morning, the sun broke through briefly around noon, and in the afternoon light snowfall returned. Winds were calm most of the day with occasional light West wind.

Near early Winters Creek at 2200' the snow pack ranges from three feet to bare dirt. Down here all the new snow in March amounts to several inches. On a West aspect at 7000' we found a nine foot deep snow pack, with about three feet of relatively new snow.

Some of the recent storms have had an East to West movement and have outperformed their weather forecasts. In open areas even at 4000' we saw signs of wind stiffened snow. It's not hard to imagine rather deep slabs of recently drifted snow on some terrain features up high.

Today a short sun break triggered roller balls in steep terrain in the sun. Thankfully, the sun only made a short appearance.

While wind slabs and loose avalanches were the most pertinent avalanche problems today, we took some time to check in on the Valentines crust. In some places this is buried by four feet of snow. After feeling a collapse at 5000' we dug to find the Valentines crust about two and half feet down. Below this crust the snow becomes softer and more sugary. Under magnification you can see some faceted forms, although not terribly impressive to look at. In simple hand shear tests this crust will break free under moderate force. Two long column tests indicate some propagation potential (ECTP 17 @ 73cm. PST END 40/100 @73cm). We haven't seen avalanches on this layer and it doesn't seem to be a current hazard. For now, I am keeping track of it with an eye for big loading events or warm ups.

Here are a couple videos of column tests and me talking.

https://youtu.be/tZuK8bMnUOk

https://youtu.be/QtejII1_p5s

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

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