Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Nate Hough-Snee
Observation Date:
December 19, 2022
Submitted:
December 20, 2022
Zone or Region:
East Central
Activity:
Skiing/Snowboarding
Location:
Tumwater Canyon - Lima Direct

Observed Avalanches

Did you observe any avalanches? 
Yes
Avalanche Type:
Soft Slab
Size:
Size 3: Could bury and destroy a car, damage a truck, destroy a wood frame house, or break a few trees
Elevation:
2700'
Aspect:
W
Comments:
I ripped skins for the day when I ran into an impressively large and recent glide avalanche off a 40-degree rock band at 2800'. It appears to have run on either liquid water/rock interface last week or rock/ice interface over the weekend. Debris fan contents skied cold and soft with recent snow, so it probably was not a wet slide, just a wet snowpack/rock interface (glide?) with a largely soft slab. SS-N-R1-D2-G

Signs of Unstable Snow

None reported

Observations

The season thus far in the lowlands of the East Central has been great, with relatively light wind, a couple banner precipitation events, and cold temps preserving storm snow. With short days and conditions like these, optimal foraging theory dictates that one should "expend the least possible energy for the highest quality snow and fall line skiing."

The other side of this coin though, to quote the Utah Avalanche Center's Craig Gordon, is that structure in the East Central's southwest/west/northwest lowlands is a "gong show." HS is 50-65cm and deeper where avalanche debris has filled in. The upper 20-30cm of the snowpack is the fist hard, and now decomposing 8 Dec storm (and later, lighter snowfall), atop a 1-2cm November storm crust, with 10-20cm of 2mm depth hoar to the ground. Where one tilts aspect toward SW, there is surface hoar (sometimes rimed surface hoar) atop a sun crust from the 11-17 Dec. high pressure, and a similar, shallower weak - crust - weak structure below. With low sun angle and very cold temps, this crust retained SH into mid-afternoon yesterday ahead of the 20 Dec storm event.

Take away: Get while the getting is good, because Santa's sleigh is riding a warmer atmospheric river that is going to test these layers by the weekend (if incoming storms don't).

Media

The Craig Gordon "Gong Show." If this were a video, I'd be shaking basal facets like rock salt and dropping my Insta handle before the incoming storm.
A glide avalanche (soft slab over ice) from 17-18 Dec that was spun in by modest snowfall the 18-19 December. SS-N-R1-D2-G
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