Turnagain Pass

Several smaller slab avalanches were triggered by skiers yesterday on Tincan and further back along the Magnum ridgeline in the Goldpan area. These were wind slabs 6-12″ deep and 10-20′ wide created by the northwest winds over the past couple days. The largest slab we know of was in Goldpan, reported to be 12″ deep and 50′ wide. This slab was triggered by the 5th person on the slope with no signs of wind effect present, which leads us to believe there is another weak layer to be watching for in the top of the snowpack.

If you look closely at the character of the crown in the above avalanche, it propagates further down slope on the flanks. This can point to the possibility of buried surface hoar or another weak layer may be at play. More on that in problem 1 below. Thank you to Sam Stark for the photo, 11.18.23.

Small photo of a small wind slab avalanche, one of several that were triggered on Tincan. 11.18.23.

Today is our second forecast of the season and already there are some avalanches to talk about. A big thanks to everyone that has written in about they have seen out there! It’s critical for us, especially as we gather as much intel as possible during the early season.

With another cold and clear day, our main concern remains a weak layer of faceted snow near the ground above 3000-3500′ in elevation. At these higher elevations there is still a chance someone could trigger a large avalanche, up to 3-4′ deep. Even though we have only seen one incident with this type of avalanche, it’s too big and unmanageable to forget about. We are suspect there could be another weak layer just a foot down or so. The avalanche pictured above from Goldpan yesterday could be pointing to this. We know there was a layer of surface hoar buried around a foot deep that hadn’t yet produced avalanches, but if this was the culprit here, it is a sign another weak layer is lurking and not easily identifiable.

Whether it’s the deeper weak layer or the one a foot deep, all these types of avalanches can be triggered remotely, meaning from the side, below, or on top of a slope. They can also release after several people have been on the slope without incident. Things to think about if you are headed to the high elevations today. As always, carefully assessing the snowpack near the ground and using conservative terrain selections will stack the odds in our favor.

The more common, but much smaller, avalanche issue out there are wind slabs. These should be roughy a foot deep or less and may be more stubborn to trigger today as the northwest winds are on the decline before ramping back up tomorrow. That said, be on the lookout for wind deposited snow on leeward slopes. As a reminder, it’s typical for these northwest outflow winds to impact Seattle Ridge and areas along Turnagain Arm rather than the non-motorized side of Turnagain Pass. To identify wind-loaded areas, look for visual cues on the snow surface and ski or ride onto small test slopes to check for shooting cracks or small avalanches.

Wind effect in upper Lynx Ck Drainage, no reported signs of avalanches in this area south of Turnagain Pass. Thanks to Ivan Chikigak-Steadman for the photo! 11.18.23.

Heads up that a few glide cracks have released into avalanches. These have been seen in Girdwood valley as well as along Seattle Ridge. They have been relatively small pockets so far, but I’m guessing we’ll see more of these in the days ahead. They are unpredictable and the best way to avoid them is staying out from under glide cracks.

Glide avalanche that released Saturday afternoon (yesterday) on Raggedtop in the Girdwood Valley. 11.18.23.

Glide avalanche on Seattle Ridge, across from the motorized lot at Turnagain Pass. Andy Moderow 11.18.23.