Turnagain Pass

Three new glide avalanches were seen yesterday at Turnagain Pass. One was confirmed to have released midday, pictured below on Cornbiscuit, and the other two on Seattle Ridge and in the Seattle Ck drainage. Otherwise, we heard of no other avalanche activity. The last known avalanches, other than glides, were from the end of the Holiday storm on Sunday when a widespread storm snow avalanche cycle occurred.

Glide avalanche that occurred yesterday between 11:30am and 2:30pm on the south face of Cornbiscuit. Note the tracks above and to the left. Seen and photoed by Allen Dahl, 12.27.23. 

Cold and clear weather is over us again today along with valley fog in places near Turnagain Arm. The two players in the avalanche game also remain similar. These are the winds and a questionable layer of buried surface hoar around 2 feet deep, give or take.

Wind Slab Avalanches:  The snow surface has seen a fair amount of wind effect over the past several days and finding a lingering wind slab should be on our radar. Ridgetop winds are blowing from the northwest 5 to 15mph the morning and look to remain in this range through the day. The only places new wind slabs might develop are the high peaks and ridgelines where the strongest wind should be. Be on the lookout for both old and new slabs, stiff snow over softer snow, and cracks that shoot out from you.

Persistent Slab Avalanches:  Despite several days with no human triggered avalanches and generally stable pit results, we are still thinking about that layer of buried surface hoar that sits under the Holiday storm snow (anywhere from 1.5-3′ deep). This layer could be tricky to find and may have only survived in some places. But at the end of the day, we know it was there before the storm and there could be some booby traps out there. If you are thinking about heading into the bigger terrain and steep slopes, we hope everyone knows this layer might be lingering and triggering a scary avalanche around 2 feet deep could happen.

A brand new crop of surface hoar is developing to ridgetops. This one is on a harder wind affected surface and could be more concerning than the one we keep talking about above. Time will tell once it gets buried. Thanks to Allen Dahl for the photo, 12.27.23. 

It seems this cold weather is inducing a glide avalanche cycle. Meaning many of the “brown frowns”, full depth cracks in the snowpack, are releasing into avalanches. The short story is avoid being under glide cracks. They exist in well traveled zones, such as along Seattle Ridge and above the motorized up-track, as well as on Cornbiscuit and Magnum.

Recent glide avalanche on southeast facing lower shoulder of Big Chief photographed by Kellie Okonek, 12.27.23. This is across from Seattle Ridge and the avalanche spills into Seattle Ck drainage.

The old Thanksgiving crust/facet combo is now sitting under 4-6 feet or more of snow. We have not seen avalanches releasing on this layer for around two weeks and no known naturals failed on this layer during the Holiday storm last weekend. Those are great signs this issue is dormant. Meaning the layer is not producing avalanches even though it still exists deep in the pack. The one exception is the Summit Lake area where the snowpack is thinner and an outlier avalanche may not be out of the question. That said, we are not forgetting about it and will continue to look for any evidence that it could be reactive.