Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 29, 2022
Submitted:
January 29, 2022
Observer:
NWAC Forecaster - Josh Hirshberg
Zone or Region:
Stevens Pass
Location:
Big Chief Mtn (NW-N, SE-S 3,900-5,600ft)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Large near surface facets (1-2mm) on the surface. N, 5180ft, Big Chief Mtn
Rough and textured surfaces on a sun-exposed slope. 4400, E, Stevens Pass
A profile of the upper snowpack. The surface was surprisingly weak, but frozen melt forms. A stout layer of knife hard melt forms makes up the top 1.5 feet. SE, 5550ft, 35 degree slope Big Chief Mtn.
A "bathtub ring" of frost on the trees shows where temperature inversions rested overnight, and possibly where you might find surface hoar persisting on shaded aspects. Nason Ridge, 3600-5200ft, SW
https://youtu.be/z3vNEWdOiJw

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Wind:
Calm

Increasing high clouds still allowed the sun to warm surfaces up to at least noon. Strong temperature inversions with cold air in the valley up to 4500ft.

No new slides. D3 wet slab on Andromeda Face from aprx Jan 12th is still visible

Snowpack Observations

Tracked surface conditions and upper snowpack structure.
The very surface of steep SE slopes softened slightly by 12p. The upper snowpack on steep solar aspects is a very thick layer of melt forms at 5,600ft and below. Some low to mid angle solars still hold 5-15cm on the surface from 1/20 that hasn't fully transformed to melt forms. Many shaded slopes, and even low-angle solars, held well-developed near surface facets. We didn't observe surface hoar, but suspect it may exist in some locations below 4500ft.
Profiles:

At 5180ft, NNW, 10deg slope
surface form 1-2mm near-surface facets
0-10cm F hard, 1mm near-surface facets
10-20cm K hard, melt forms
20-23cm P+ hard
<23cm K hard, melt forms

At 5550ft, SE, 35deg slope- See photo
0-1cm F hard, 2-4mm melt-forms w some faceting
1-40cm K+ hard, melt forms
40-63cm P+ hard, melt forms and rounds, moist
63-95cm P+ hard, rounds, moist

Avalanche Problems

No avalanche problems

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