| Trigger | Snowmachiner | Remote Trigger | 0 |
| Avalanche Type | Hard Slab | Aspect | East |
| Elevation | 2500ft | Slope Angle | unknown |
| Crown Depth | 18in | Width | 300ft |
| Vertical Run | 200ft |
Avalanche: Other Regions
Location: Snug Harbor to Lost Lake
Rode from Snug Harbor to Lost Lake and the new Lost Lake weather station site (~3miles NNW of Lost Lake). Encountered a snowmachine triggered wind slab en-route – details below.
Avalanche Details
Snowmachine triggered wind slab by a party earlier in the day on a short but wide slope in the gully of Martin Ck. Looks to have been triggered while descending from above. Presumable no one caught or carried. Slab did propagate quite wide - 300' wide and running 200', the length of path. Crown was 1-2' deep.
Natural wind slab seen on a SE face just above Lost Lake. Around 1-2' deep and ~200' wide, running ~3-400'.
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
Observer Comments
Active wind loading all day. Natural wind slab avalanche and one human triggered.
Weather
Partly sunny skies, temperatures in the single digits and strong NW winds. Ground blizzard made travel difficult at times. Many plumes seen off peaks. Winds blowing all elevations except for the most sheltered areas.
Snow surface
Wind damaged surfaces - scoured, sastrugi, wind drifts. Only in the Lost Lake trees did we find some softer snow out of the wind.
Snowpack
Dug one pit in the Lost Lake trees in a sheltered zone - 2000', East aspect, ~15 deg slope. Roughly 16-18" of soft snow (Fist to 1F hardness) over a 1" layer of weak facets that sit on the mid Jan crust. ECTP 19 Sudden Collapse. A layer of buried surface hoar sits ~12" down and a few inches above the facets but this layer was not reactive.
Poor structure exists in the Snug and Lost Lake riding areas.
Snowmachine triggered large wind slab into terrain trap in upper Martin Creek.
View of slide looking North - note the wind plumes off the peak in the back ground
ECTP 19 sudden collapse in a test pit at 2,000' on an E aspect in Lost Lake - poor structure
Wider view of the pit and Lost Lake zone
Hard and wind affected surfaces in this area