Avalanche: Turnagain

Location: Seattle Ridge

Route & General Observations

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
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger SnowmachinerRemote Trigger No
Avalanche Type Hard SlabAspect Southeast
Elevation 2600ftSlope Angleunknown
Crown Depth 24inWidth 50ft
Vertical Run 30ft  
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.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
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 & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

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!


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.

Photos & Video
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