| Trigger | Snowmachiner | Remote Trigger | No |
| Avalanche Type | Hard Slab | Aspect | Southeast |
| Elevation | 2600ft | Slope Angle | unknown |
| Crown Depth | 24in | Width | 50ft |
| Vertical Run | 30ft |
Avalanche: Turnagain
Location: Seattle Ridge
Psyched to get out for the motorized opener! We rode around the weather station and down into Main Bowl before heading over to look into Warm Up bowl and up to Barbeque Hill. We stopped to take a look at a small snowmachine-triggered avalanche that failed on facets below a buried wind slab (see attached video for more details). We also saw several remote-triggered avalanches on the east side and in Warm Up bowl. Some of them were small, but others would have been big enough to bury a person and would have been even more dangerous simply because they were running down into the alders. As far as we could tell nobody was caught in any of the avalanches.
There were a ton of people out riding around today, and the avalanche conditions are tricky right now. We were really happy to see people making good choices with terrain use, staying off of the steeps for the most part. We did witness some non-avalanche related carnage, and picked up a few pieces of snowmachine debris during the day. This includes an incident with one of our own riders and a rider from another group in which luckily nobody was hurt, and the machines only suffered some superficial damage. Important to remember that in addition to the current snowpack, there are other hazards right now with a lot of other people out and thin coverage at lower elevations.
Avalanche Details
Snowmachine triggered slab avalanche on a small slope near the weather station. The avalanche failed in the faceted layer that formed in early November. The slab consisted of a 6" thick hard wind slab that had been buried by 12-18" new snow over the past few days.
We saw three similar pockets that released in Warm Up bowl. They were slightly bigger, and they appeared to have been triggered remotely. Similar slab thickness, most likely failing on the same facets.
We also saw some larger avalanches on the east side of Seattle Ridge. The were most likely remotely triggered from above on the ridge, which was remarkably far away from the avalanches. The two larger avalanches were 100-200' wide, running for around 750 vertical feet. The crown depth looked to be similar to the smaller avalanche we investigated.
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
Observer Comments
- Snowmachine triggered avalanche below the weather station.
- Remote-triggered pockets in Warm Up Bowl.
- Larger remote-triggered avalanches on the east side of Seattle Ridge.
This was enough to keep us cautious with terrain use.
Weather
Cold, clear, and calm. The weather station was showing temps hovering right around 0 F for most of the day. Really cold in the shade on our way down in the afternoon. A thick valley fog broke up mid-morning, with mostly sunny skies for the rest of the day. Hardly any wind at all.
Snow surface
2' of storm snow on top of mixed surfaces. At times you could feel an older wind slab below the last round of snow, especially on top of the ridge. There is just barely enough snow to navigate the alders down low. Beware of stumps and creek crossings!
Snowpack
The snowmachine-triggered avalanche in the video below failed on a layer of facets that formed earlier this month. The facet layer is sitting on top of the Halloween crust, and is now about 6" thick. That facet layer was capped by a 1F hard wind slab, which was covered by 12-18" really soft snow.
Conditions are tricky right now. A lot of avalanche activity we saw today was relatively small pockets releasing, but we also saw two large slides that would have been really dangerous. Most of the avalanches we saw were triggered remotely, some from hundreds of feet away.
Photo of the crown of a small snowmachine-triggered avalanche. 11.27.2021
Two larger avalanches (right and center) and one small pocket (left) on the front side of Seattle Ridge. The avalanches were remotely triggered from above on the ridge sometime during the day. 11.27.2021
Three pockets that were triggered remotely in Warm Up Bowl. 11.27.2021
We weren't the only ones out there enjoying incredible riding conditions on opening day today! 11.27.2021