Observation: NWAC Observer

All Observations

Basic Information

Observation Date:

March 17, 2023

Submitted:

March 17, 2023

Observer:

NWAC Observer - Brooke Maushund

Zone or Region:

Stevens Pass

Location:

Lichtenberg Area (All aspects // 3400'-5800')

Recent Avalanches?

Yes

Cracking?

Isolated

Collapsing?

None Experienced

Navigating wind sculpted snow near ridgeline takes careful navigtion.

Creeks are beginning to open with the rising temps, creating new potential hazards.

The wet loose cycle on Lichtenberg's western slope is in full swing.

Small 2-3mm surface hoar was observed in wind protected terrain.

Wind rolls displayed past wind transport near ridgeline.

New, small wet loose slides abounded on solars even before noon.

Advanced Information

Cloud Cover:

Clear

Temperature:

>32°F

Wind:

Light , NE

Wind fluctuated between calm and light out of the NE throughout our tour, with mostly clear skies moving into few thin high clouds later in the morning into the mid afternoon. Some snow was still available for transport, but much less than yesterday with only a very small amount visibly being moved at the highest ridgelines.

Getting an earlier start to be out of the mountains before the afternoon's wet loose cycle really ramped up, we saw yesterday's snow surface refrozen overnight with slick skinning surfaces in the morning on W-S-E slopes. As the temperatures rose, we saw new small wet loose slides running and sometimes overlapping older slides from the past 48hrs on solar slopes before 11am. There was a thin, 1-2cm sun melt-freeze crust on top of the snowpack on our approach in the morning that was unsupportable.

As we gained the ridgeline, we saw many cornices of varying sizes hanging towards the NW side of the ridge. A small test cornice was able to be knocked off with low to moderate force, and we increased our travel margins accordingly. Along with wind sculpted rolls near ridgeline, there was wind loading on the top portion of leeward slopes, but wind slabs appeared to be trending towards stubborn in smaller supported features. 2-3mm surface hoar was in wind-sheltered terrain. By the time we were exiting, we were able to push around some small wet loose debris, noting that the deepest these small slides ran was around 7cm (not through the previous crust). Creeks were beginning to open even further where we travelled, and present a non-avalanche related hazard for the rider or skier who doesn't know what's just past that blind roll.

Problem	Location	Distribution	Sensitivity	Size	Comments
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	Comments: While no WL slides we observed were larger than D1.5, the snow was wet and heavy enough near surface that if it entrained your board or skis in the wrong spot, you easily could be pushed off your feet.
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	Comments: While it seems that overall the smaller wind slabs are getting more stubborn to trigger in smaller supported features, the possibility for a large one to slide on steep unsupported slopes remains. Active wind transport the past 2 days has been loading leedward sides of slopes.
Cornice	N E S W	Isolated Specific Widespread	Unknown	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Comments: There were many past cornices along ridgelines that were becoming more wet with the heat during the day. While we were only able to break off small pieces of ones we intentionally tested, cornices appear to be loosing strength from their past state.