Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
February 11, 2022
Submitted:
February 13, 2022
Observer:
NWAC Forecaster - Josh Hirshberg
Zone or Region:
Stevens Pass
Location:
Lake Josephine (All aspects, 3800-5700ft)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

The crust in the top 12cm was half melted at 11:30a. By 13:00, it had completely melted and was not supportive to boots on a similar slope. Note, the stout late Jan crust down 20cm from the surface. Profile SE, 5,250ft, Lake Josephine
A 4" (10cm) hard surface crust on northerly aspects. NE, 4,800ft
The west aspects of Big Chiwaukum and Deadhorse Peak.
A large (D2.5) wet avalanche likely ran on Feb 9th near Lake Josephine. Nasikelt Pk (pt 5863), S, 5,600ft

Advanced Information

Weather Summary

Cloud Cover:
Clear
Wind:
Calm

Spring-like day w strong sun, weak temp inversions.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Feb 9, 2022
() 		Lake Josephine, Josephine/Nasikelt Pk
S 5500ft 		D2.5
R2 		WL-Wet Loose N-Natural
A large (D2.5) wet avalanche likely ran on Feb 9th near Lake Josephine. Nasikelt Pk (pt 5863), S, 5,600ft
A large (D2.5) wet avalanche likely ran on Feb 9th near Lake Josephine. Nasikelt Pk (pt 5863), S, 5,600ft
Report
Lake Josephine, Josephine/Nasikelt Pk

Large wet slide on Josephine peak (see avy obs). Numerous small wet loose on steep solars. Some D1.5 rollerballs on N, likely initiated as cornice chunks or treebombs.

Snowpack Observations

In AM, all surfaces were capped w crust. All but steep N were supportive to skis. All solars softened and N w tree cover softened below 5,000ft. Surfaces on open SE-SW were beginning to break down at 11a tho the surface crust remained semi-supportive to boots. By 1p, they were no longer supportive to boots. By 2p I had to be selective about micro-features to not trigger small loose wet slides and areas around rocks became punchy even on skis.

Profile SE, 5,250ft (see photo)
HS 180cm
0-10cm F hard, polycrystals, moist to wet
10-12cm 1F hard, MFcr, dry
12-20cm 4F+ hard, small rounds/MF, moist
20-55cm P+ hard, MFcr, dry, late Jan crust- entirely MF no FC
55-90cm 1F-P hard, rounds, dry

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wet Loose
Isolated
Specific
Widespread
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Weak Layer(s): Jan 30, 2022 (FCsf) Feb 13, 2022 (MFcr)
Comments: unreactive in AM becoming stubborn to reactive w warming. tagging Late Jan crust to link to layer tracking
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