Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 10, 2022
Submitted:
January 10, 2022
Observer:
NWAC Forecaster - Katie Warren & Andrew Kiefer
Zone or Region:
East South
Location:
Ahtanum Meadows (N, S, and E aspects from 3000 to 6800ft)

Signs of Unstable Snow

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

Media/Attachments

A large natural avalanche (D2) failed in the east-facing wind-loaded portion of this gully feature around 5400ft where the arrow is. Debris crossed the groomed track on Middle Fork of Ahtanum Creek and broke branches and a few small trees. The avalanche likely occurred sometime 1/7-8.
Looking up the South Fork Valley of the Ahtanum State Forest from Tampico
Small wet avalanches from rain on January 7th in the gravel pit near the Ahtanum Snopark (SW aspect, 3400ft).
Shovel tilt tests resulted in resistant planar fractures on two interfaces in the top 10-14in of the snowpack. Additional tests targeting these layers did not produce repeatable or concerning results.
No propagating fractures or concerning results in snowpack tests at this site near Darland Mountain (E aspect, 6600ft, HS 220cm).

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Moderate , W

We experienced all types of weather today, sunshine, light snow showers, and light to moderate winds. Temperatures stayed cool throughout the day and the lack of intense sun kept most snow surfaces dry.

We observed blowing snow at all elevations where there was dry snow available for transport.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 7, 2022
() 		Ahtanum Meadows; Middle Fork Ahtanum Road
S 6000ft 		D2
R2 		N-Natural Report
Ahtanum Meadows; Middle Fork Ahtanum Road

Snowpack Observations

Traveled up the Middle Fork Ahtanum Meadows to Darland Mountain via snowmobile. This was our first real look into the East South zone and gave us an opportunity to investigate the snowpack through a variety of aspects and elevations.

At about 5400ft on a south aspect, there was debris from a natural D2 avalanche that ran over the groomed snowmobile track. This likely ran on Jan 7th or 8th from a combination of wind loading and warming temperatures. The crown was no longer visible and the starting zone was being reloaded by west winds.

3000-4000ft: The snowpack was moist with a melt-freeze crust on the surface.
4000-5500ft: HS 90cm at 4800ft. A stout melt-freeze crust with 1-3inches of snow on the surface.
5500ft-6800ft: HS 220cm at 6600ft on an East aspect. The crust was not present above approximately 5500ft and the snowpack was generally strong with a variety of storm interfaces from Jan 5-8th. A 25cm deep interface showed resistant planer results in stability tests.

CTM13 ↓25cm RP
ECTN ↓25cm
CTH22 ↓55cm Non-planer break

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