Turnagain Pass

Skies cleared yesterday for not only a decent look around, but the chance for folks to get back into the mountains and along ridgelines. There were several natural avalanches seen from Sunday’s storm (1.5-2.5′ of new snow). These avalanches were both storm snow slabs and loose snow sluffs. Most noteworthy however were a couple human triggered slab avalanches yesterday, the first day after the storm.

Remote triggered slab on Seattle Ridge:  A group of snowmachiners riding on Seattle Ridge remotely triggered a large slab in Main Bowl, photo below. It is unclear if the weak layer was simply the storm snow that had yet to bond, or possibly a layer of old weak snow that sits under the past two storms (around 4 feet deep). Andrew is headed out today to take a look at this avalanche.

Tincan smaller slab:  Skiers along the Tincan ridge were able to trigger a soft wind slab around 18″ deep and 30-40′ wide.

Remotely triggered slab avalanche off Seattle Ridge and into Main Bowl. Reported by the group that triggered it and also by another rider in the area who snapped this photo, J Ohms 1.8.24. 

Natural slab avalanche seen yesterday in Todd’s Bowl, released tail end of the storm the day before, 1/7. This is the bowl on the north side of Tincan. Thanks to Taz Feldis for the photo. 1.8.24.

Natural slab avalanche on the SW face of Max’s Mtn, seen from our FS office in Girdwood yesterday. 1.8.24.

It is the second day after Sunday’s storm brought 1.5-2.5′ of new snow to the region. Before this, another storm on Wednesday brought 1-3′ of new snow. All this new snow is excellent news for great riding conditions, but it does come with avalanche concerns. That new snow from Wednesday fell on an older weak surface (near surface facets and some patchy surface hoar). The jury is still out whether that older snow (4 feet or so deep) is capable of producing avalanches. Was it the culprit in the Main Bowl avalanche yesterday? Hopefully we will find out today. But the main story is, two big storms just loaded the snowpack and tip-toeing a bit in case more large slabs are hanging in the balance is a good call. 

Looking for red flags, cracking in the snow or whumpfing in the snowpack, is always important, but the lack of red flags doesn’t mean we are in the clear. Anytime a slab is triggered remotely (meaning from the top/side/bottom of a slope) it tells us there is some kind of weak layer lurking, which can lead to more human triggered avalanches down the road. If choosing to get into bigger terrain, be sure to know your safe zones, watch your partners, and understand there is a lot of uncertainty. Sticking to the smaller terrain features and lower angle slopes to let the pack adjust another day is a great way to avoid an avalanche.

Photo taken by the group that believed they triggered this slab. They did not see it in motion, but they did not notice it before, then saw it when they looked back. 1.8.24.

Fresh Wind Slab Avalanches:  Watch for the northwest winds to blow hard enough to move snow into fresh wind slabs. Areas that often see the strongest winds with this flow direction are Crow Pass in the Girdwood Valley, Summit Lake, and Seward. Luckily, Turnagain Pass can often be sheltered. That said, Turnagain is interesting because the east side of the Pass (non-moto side) often sees southerly winds due to terrain channeling; so don’t be surprised if you are on Tincan and the wind is from the south.

Glide avalanches continue to occur in the region. The photo below is the newest known glide release, seen yesterday on Pete’s South ridge (southern end of Turnagain Pass). It is prudent to keep a close eye for any signs of glide cracks and avoid being under them. If choosing to scoot underneath these, be sure and watch the slope and move as fast as possible, having an exit plan in case the crack happens to release into an avalanche. These are full-depth avalanches and very destructive. They are highly unpredictable and not triggered by people.

New glide avalanche on Pete’s S ridge (SW face). Thanks to Kellie Okonek for the arial photo, 1.8.24.