Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Zack Wentz
Observation Date:
February 21, 2023
Submitted:
February 21, 2023
Zone or Region:
Snoqualmie Pass
Activity:
Skiing/Snowboarding
Location:
Friendly Trees

Triggered Avalanches

Did you trigger any avalanches? 
Yes
Was it intentional? 
Yes
Avalanche Type:
Dry Loose (Sluff)
Size:
Size 1: Relatively harmless to people
Elevation:
4400’
Aspect:
SW
Comments:
Numerous sz 1 dry loose sluffs were triggered on steep (40 degree) openings in the BTL elevation band during ski cuts. Slides entrained a fair amount of surface snow and slid easily on the Feb. 19th rain crust.

Signs of Unstable Snow

None reported

Observations

Avalanche Obs: As stated above.

Snowpack Obs: 10-15cms of very light (F-) new HST sits atop the Feb. 19th rain crust in dense forested areas BTL. HST depth increases to 30-40cms in forest openings. Feb. 19th rain crust exists up to 4100,’ and above 4100’ the new HST is bonding well to the old snow interface. Snowpack is generally right side up, with very slight changes in storm snow hardness (F- to F+), and new HST is composed of a mixture of new stellars & graupel. Surface form is 2mm graupel.

Weather Obs: Mostly cloudy with short (5-10minute) sun breaks. Convective flurries were fairly consistent all afternoon, with snow falling btwn S-1 & S1. Light winds from the west in forested openings at tree line.

Advanced Observations

Observed Avalanche Problem #1: 
Storm Slab
Comments: 
Very soft storm slab was observed down 15-20cms in a storm density change on an open S aspect at 4700’. Cracking was localized to immediately around the ski, and occurred while breaking trail.
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