Observation: NWAC Forecaster

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Basic Information

Observation Details

Observation Date:
January 9, 2022
Submitted:
January 9, 2022
Observer:
NWAC Forecaster - Katie Warren
Zone or Region:
East South
Location:
HWY 12 Corridor East South and West South

Signs of Unstable Snow

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

Media/Attachments

Blowing snow actively wind loading west aspects during East winds on Sunday January 9th.
Evidence of a natural cycle of very large avalanches in alpine areas during the Jan 5-7th storm in areas near White Pass and the Goat Rocks.
Evidence of a natural cycle of very large avalanches in alpine areas during the Jan 5-7th storm in areas near White Pass and the Goat Rocks.
During the storm warming temperatures and rain produced a wet loose avalanche cycle and created rain tunnels on the snow surface near and west of the Cascade crest, like you can see here on Sprial Butte, White Pass, WA.
Evidence of a wide spread avalanche cycle in the East South zone. Many D1 - D2 sized crowns were visible in steep open terrain.
Small avalanches in Lowland areas were common on the East Slopes of the Cascades during the Jan 5-7th storm. This occurred north of Hwy 12, near the town of Naches, WA.
Small avalanches in Lowland areas were common on the East Slopes of the Cascades during the Jan 5-7th storm. This occurred south of Hwy 12, near the town of Naches, WA.

Advanced Information

Weather Summary

Cloud Cover:
Clear

Clear skies
Temperatures in the teens east of the pass with warming to above freezing by the afternoon.
Extensive blowing snow was observed in alpine terrain.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
20 Jan 7, 2022
() 		East Slopes South: Naches, WA
N 2500ft 		D1
R1 		SS-Soft Slab N-Natural
Small avalanches in Lowland areas were common on the East Slopes of the Cascades during the Jan 5-7th storm. This occurred north of Hwy 12, near the town of Naches, WA.
Small avalanches in Lowland areas were common on the East Slopes of the Cascades during the Jan 5-7th storm. This occurred south of Hwy 12, near the town of Naches, WA.
Report
1 Jan 7, 2022
() 		West Slopes South: Chimney Peak, White Pass
NE 6000ft 		D3.5
R4 		SS-Soft Slab N-Natural
Evidence of a natural cycle of very large avalanches in alpine areas during the Jan 5-7th storm in areas near White Pass and the Goat Rocks.
Report
1 Jan 7, 2022
() 		West Slopes South: White Pass
NE 6000ft 		D3.5
R4 		SS-Soft Slab N-Natural
Evidence of a natural cycle of very large avalanches in alpine areas during the Jan 5-7th storm in areas near White Pass and the Goat Rocks.
Report
East Slopes South: Naches, WA
West Slopes South: Chimney Peak, White Pass
West Slopes South: White Pass

I took advantage of the good weather to do a road tour and document the recent avalanche cycle from the Jan 5-7th storm.

You could see quite the assortment of different types of avalanches from the road. Many D1- D2 storm slabs and wind slabs were visible at all elevations. Southern aspects had a widespread wet loose cycle during the warm temperatures and rain. The sunny day with mild temperatures extended some small wet loose activity into today.

Alpine terrain showed evidence of a few very large avalanches extending through entire terrain features. I estimate some to be 500-1000ft wide.

I also observed many small slab avalanches in low-land areas surrounding the town of Naches. Although these would not have been large enough to injure or bury a person, they occurred in locations that may never or very rarely see avalanche activity and are a testament to how unique this storm was to the region.

Snowpack Observations

Snowpack surfaces in shady locations were either refrozen melt-freeze crusts with 1-2 inches of soft snow, in some areas this snow also had a small layer of surface hoar growth as well. Snow surfaces on solar aspects were moist.

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