| Trigger | Snowmachiner | Remote Trigger | Unknown |
| Avalanche Type | Soft Slab | Aspect | Southwest |
| Elevation | 1000ft | Slope Angle | 40deg |
| Crown Depth | 8in | Width | 50ft |
| Vertical Run | 80ft |
Avalanche: Portage / Placer
Location: Placer Valley - above Spencer Glacier
Rode into and above the Placer Valley, Spencer Glacier and Skookum Glacier to see the extent of the northwest wind event.
Avalanche Details
Small snowmachine triggered wind slab avalanche.
*Additionally - we had a report of a skier triggered persistent slab avalanche nearby in more treed terrain at 800' in elevation, W aspect. That photo is below and from another party, no one caught. This avalanche was 12-16" deep at the maximum and failed on buried surface hoar. It was small terrain so not a big avalanche.
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | Yes |
Observer Comments
Strong northwest wind transporting snow off the high terrain all day.
One small wind slab triggered, mentioned earlier.
Some cracking in new wind blown snow, but we did not venture into steep suspect terrain.
Weather
Clear skies and cold, single digits.
Strong NW winds.
Snow surface
Variable. Wind scoured, anti-tracks to soft settled powder in sheltered areas. In general however, most places are wind damaged.
It appeared that 6-8" of new snow fell last Tues/Wed (Feb 16-17). This was not enough to cover old tracks.
Snowpack
We dug one pit at 3,400' on a sheltered West aspect. Snow depth deeper than probe.
ECTN down 10" on a layer of decomposing particles and old graupel of all things.
Surface was 4 finger hardness becoming pencil hard 16" down. Right side up in top 2.5 feet that we tested.
*We were looking for weak layers of buried surface hoar and facets, but found none - likely do to the area seeing too much wind over the past month.
Small snowmachine triggered wind slab at 1,000' above Placer Valley.
Skier triggered persistent slab avalanche 12-16" deep failing on buried surface hoar at 800' above Placer Valley. Photo taken by a different group and sent in to us.
Wind plumes and snow transport off Byron and Carpathian Peaks.
More snow transport and plumes over the Spencer Glacier.
Snow pit at 3,400' on a W aspect. Thank you Alaska Mining and Diving Supply for use of this new Ski Doo Summit 850 for field work!!
Comet Peak with old and new tracks.
Variable snow surfaces, lots of wind effect in the Placer Valley.