| Trigger | Natural | Remote Trigger | Unknown |
| Avalanche Type | Unknown | Aspect | Southeast |
| Elevation | 2500ft | Slope Angle | unknown |
| Crown Depth | unknown | Width | unknown |
| Vertical Run | unknown |
Avalanche: Turnagain
Location: Sunburst
Toured up to 2800′ on Sunburst. Based on cold, windy conditions and good visibility for spotting avalanches we decided to turn around and drive down to Summit Lake to look for fresh avalanches with all the active wind loading.
Avalanche Details
We saw multiple natural wind slabs along the E and S aspects of Seattle ridge. They all looked like D 1.5 or D 2 size. See photos
Obvious signs of instability
| Recent Avalanches? | No |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | Yes |
Observer Comments
We were able to release some small pockets of wind slab and get shooting cracks around 2200' on the gully features before gaining the Sunburst ridge line skin track.
Weather
Clear skies and moderate to strong winds. Strongest gusts we felt were probably in the 20s, but we were still pretty low along the Sunburst ridge line. Lots of snow transport from the strong winds.
Snow surface
Mixture of soft snow in areas still sheltered from the wind and variable wind affected snow. On the Sunburst ridge line the winds had stripped the snow down to a melt freeze crust. The skiing on the way down was actually surprisingly good. We were expecting breakable wind crust but it was still pretty soft.
Snowpack
We dug a set of pits around 2700' to see if the wind slabs on top of the 12/6 buried facets would be reactive. Results were similar to what I saw on Wednesday, it was easy to initiate a failure underneath the wind slab (ECT N 5) and moderate to initiate a failure at the top of the facet layer about 30 cm down (ECT N 12). Neither of these layers had propagation, which I think is due to not having a strong enough slab on top.
Natural Wind Slab on E aspect of Seattle Ridge
More natural wind slabs on Seattle Ridge
More natural wind slabs on Seattle Ridge
This one is far away but we confirmed on our drive out that it was a wind slab near repeat offender.
We were able to trigger some shooting crack and small slabs in a wind loaded gully at 2200' on Sunburst