Strong winds, snow, and rain will add weight to a fragile snowpack and make for dangerous avalanche conditions. We may see some natural avalanche activity, and it is likely a person could trigger a large avalanche failing 1 to 2' deep or deeper on weak layers buried in the snowpack. Glide avalanche activity is also expected to continue.
The ongoing glide avalanche cycle is not showing any signs of slowing down. Today's wet and warm weather is unlikely to help. These avalanches are large and destructive, and they have been releasing over popular routes in Summit Lake and Turnagain Pass. These are impossible to predict and the only way to manage them is to avoid traveling under open glide cracks.
Today's storm is going to push the snowpack closer to its breaking point. With at least three layers of buried surface hoar and just two days out from a widespread avalanche cycle in Turnagain Pass on a similar snowpack, we have no reason to trust the current setup. Large natural and human-triggered avalanches are likely to fail 1 to 2' deep in the snowpack. There is some uncertainty as to just how reactive these weak layers will be, but we saw multiple remote-triggered avalanches on one of these layers a week ago, and there is a good chance we could see that again today. Daniel also reported a continuous layer of very large surface hoar on Fresno just before the Thanksgiving storm, which hasn't really had a big test yet in Summit Lake.
This is a concerning setup which has proven very reactive in Turnagain Pass, and has yet to really wake up in Summit Lake. Strong winds and new snow in the alpine will be adding stress to these layers. It will be good to treat steep terrain cautiously today, and be aware that people have been triggering these avalanches in lower-angle start zones and from flat terrain connected to steeper slopes.
(11/22/2025) Looking down the slide path from the crown of a remote-triggered avalanche on Tenderfoot last weekend. Debris ran roughly 700 vertical feet Photo: Peter Wadsworth
We're only expecting to receive 2 to 4" of new snow in the alpine today, but that is arriving with strong easterly winds that are already at work drifting snow into touchy slabs a foot deep or deeper. This is sitting on top of a snowpack with multiple weak layers (see Problem 1 for more). These wind slabs may be failing naturally, and they will be easy to trigger. Avoid traveling in steep wind-loaded terrain, which is often found just below ridgelines, on convex rollovers, and in steep gullies. We also expect to see wet loose avalanches at mid elevations where we may see up to 0.5" of rain by tonight. Given the concerns related to the deeper buried weak layers, it may be a good idea to avoid steep terrain entirely for now.
(11/30/2025)
Predicted snowfall totals from Sunday morning through Monday morning.
Photo: NWS Anchorage
