Observation: NWAC Forecaster

All Observations

Basic Information

Observation Date:

February 13, 2022

Submitted:

February 13, 2022

Observer:

NWAC Forecaster - Irene Henninger, Josh Hirshberg, Nate Hough-Snee, Xander

Zone or Region:

Stevens Pass

Location:

Lichtenberg Mtn (S, SE, 3300-5500ft, N @ 5500ft)

Recent Avalanches?

Yes

Cracking?

None Experienced

Collapsing?

None Experienced

North facing slopes at 5500ft on Mt Lichtenburg. The surface is a 3cm breakable crust. A few small old rollerballs from 2/9 are visibly running from a steep area from when snow surfaces were wet.

NE facing cornices on Lichtenberg Mountain

A pit on the north side of Lichtenberg Mtn. The snow was dry, and mid-pit layers ranged from 1F to P hardness rounds. The late January weak layer was 1F hard and well rounded.

A D2 wet loose avalanche which probably occurred 2/12. It originated in the rock band at about 5000ft on a SSE aspect on Lichtenberg Mtn. Surfaces were not soft enough as we were skiing by at noon for a similar event to take place.

A more distant view of the D2 wet loose avalanche on Lichtenberg Mtn from 2/12. It traveled about 1000 vertical feet on a SSE aspect.

Advanced Information

Cloud Cover:

Clear

Temperature:

45°F

Wind:

Calm

45F in shade on a north aspect at 5500' at noon. An inversion kept temperatures cooler in the valley bottom.

Avalanche Observation Comments:

Wet loose avalanches had not begun by the time we descended at 1200pm. Snow was softening quickly on steep south-facing slopes, with 6 inches of boot penetration and 2 inches of ski penetration by the time we skied the south face. A few D1-D2 wet loose avalanches occurred in the last 2 days, mostly originating from very steep, rocky areas on southerly aspects. As soon as the slope angle reduced the snow was not nearly as soft. In all other areas the snowpack was firm, with no other avalanche concerns where we traveled.

Strong diurnal effect on steep SE and S-facing slopes, softening from about 10am. South-facing snow is fully transformed into spring corn. Change the aspect a bit, or reduce the slope angle and the snow isn't nearly as soft. When we skied the steep slope on the upper half of the south face about 2 inches had released, making for great corn skiing. As slope angles reduced towards the bottom, the snow was still firm.

We dug a pit on a N-facing slope near the top of Lichtenberg. The surface was a 3cm breakable crust. There were 3 knife- hard crusts present in the top 10cm, broken up by 4F layers. Beneath those layers were dry P/1F rounded grains down to the late January facet/crust sandwich at 94cm. The sandwich was still noticeable, however the faceted layer was 1F hard and well-transformed to rounds and was not a defined, consistent layer. Of note was a 2cm crust 20cm deep, and there was a thin line of 1F rounding faceted forms 64cm down (1cm thick).

The valley bottom at 3300ft remained cold and firm all day- although there was not a solid crust. A 3cm breakable crust with dry facets beneath was present. 5mm surface hoar was present in that location as well, but not seen anywhere else.

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	Weak Layer(s): Jan 30, 2022 (FCsf) Comments: Less sensitive than on 11th. Unreactive in AM, Not quite stubborn when descending at 12p. May've trended to stubborn-reactive. Tagging Late Jan to link profile to layer tracking

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