Observation: NWAC Observer

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Basic Information

Observation Details

Observation Date:
January 19, 2023
Submitted:
January 19, 2023
Observer:
NWAC Observer - Willie Webster
Zone or Region:
East North
Location:
Tiffany Mountain area (all aspects 6500' to 8200')

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
Isolated

Media/Attachments

NE bowl of Little Tiffany Mountain
Crown lines from a recent Avalanche near Clark Peak. Probably released on buried surface hoar. (N 6900', HS-N-D2-R2-O)
Recent avalanche. Red lines are drawn to show crown line. (N 6900', HS-N-D2-R2-O)
A 1 foot deep slab that released on buried surface hoar in an extended column test near Tiffany Mountain.
A 6mm surface hoar crystal. This layer is found about a foot down in the Tiffany Mountain area
Wind rippled snow surface
Rime covers all rocks and trees on ridgelines above treeline in the Tiffany area. They indicate a South wind sometime recently.
A wind sculpted feature was built with a South wind
Good quality boot deep powder was found in the trees
Clear skies and low angle slopes make for great ski days
Rime on the snow surface has been building towards the South, the direction winds have been coming from.
Snow profile near Tiffany Mountain in the far Eastern part of the East North forecast zone
https://youtube.com/shorts/88bkja3mwpE

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Temperature:
23°F
Wind:
Moderate , NW

Mostly clear skies and sunshine throughout the day. In the morning moderate winds were blowing snow off Tiffany and other peaks in the zone. Winds were coming out of the North and Northwest today, but all the wind scooped snow features and riming indicated a history of South winds.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 19, 2023
() 		Slope near Clark Mountain
N 6900ft 		D2
R2 		HS-Hard Slab O-Old Snow 1ft N-Natural
Recent avalanche. Red lines are drawn to show crown line. (N 6900', HS-N-D2-R2-O)
observed avalanche near Clark Peak
Crown lines from a recent Avalanche near Clark Peak. Probably released on buried surface hoar. (N 6900', HS-N-D2-R2-O)
Report
Slope near Clark Mountain

Snowpack Observations

Skinning up towards Tiffany Mountain we experienced three propagating/ wumphing collapses in the snowpack below our feet on West and South low angle slopes. The snow depth was variable due to wind transport and sounded hollow in places. We also spotted a somewhat recent avalanche to the South of us in some North facing trees. Above treeline the wind effect is quite dramatic with large sculpted features, cornices, and rime ice building on surfaces. Ski quality was great once you got in the trees on low angle slopes. We ran into some other backcountry travelers who also reported wumphing collapses in the snowpack. On our way out we stopped to dig a pit to the ground to take a look inside the snowpack. Overall we found a thinner and more faceted snowpack than we're finding around highway 20. The bottom half of the snowpack is facets. There is a buried surface hoar layer about 30cm down with a cohesive slab above. This layer failed in an Extended Column Test (ECTP 12 @ 29cm) which indicates some propagation potential. Our Propogation Saw Test also indicates some readiness for propagation. Videos below. Throughout the terrain the height of snow varied from 60cm to 100cm. There is a fine melt freeze crust just a couple inches down. There is small buried surface hoar on this recently buried thin crust.

This part of the East slopes North forecast area sees fewer observations than the highway 20 zone. If you recreate out here, please help improve the forecast by adding observations of instability or other snowpack/ weather signs.

Some long column snow pack tests seen below:

https://youtu.be/KVdIb5HuK2Q

https://youtu.be/EGe3PspDfwM

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