Seward & Southern Kenai Mtns

Recent Avalanches: Over the past week we’ve observed avalanches throughout the Seward zone, including a natural avalanche cycle after the holiday storm where an avalanche crossed the highway near the Sterling Wye. The storm cycle was followed by multiple natural wind slab avalanches later in the week. We saw old wind slabs near Lost Lake yesterday as well as avalanches that likely occurred from last weekend’s storm. Glide cracks and glide avalanches have also been identified throughout the advisory area. 

 Weather Recap: In the past week Seward has received roughly 15” of snow equaling 2.6” snow water equivalent (SWE) accompanied by strong ridgetop winds. The holiday storm came in warm, bringing rain to 1500’. Winds decreased, skies cleared, and temperatures dropped to single digits on Tuesday (12/26). Temperatures the rest of the week averaged between 5 F and 20 F. 

Weather Forecast: Northerly winds on Friday will increase to 20 mph overnight before decreasing during the day Saturday. We are anticipating a brief storm to reach the peninsula late Saturday afternoon into Sunday. Clouds will begin to move in Saturday afternoon accompanied with east winds averaging 10-15 gusting to 20 mph and up to 5” snow. Below 300’ may receive rain or a rain snow mix. Temperatures will be near 0 F rising to the low 30’s F by Sunday evening.  

Avalanches observed after the 12/22-12/23 Holiday Storm. Photo by Sam Mclain 12.26.2023 

Our primary concern is another round of reactive wind slabs forming over the weekend. We are expecting strong northerly winds Friday night, switching southerly by Sunday morning along with a few inches of new snow. Wind slabs 1-2’ deep may be found on multiple aspects with wind changing direction in the middle of the weekend. Wind slabs tend to form below ridgelines, across gully features and below rollovers and are most reactive during and immediately following wind events. Watch for red flags such as blowing snow, recent avalanches, cracks that shoot out from your machine, board, or skis and whumpfing sounds. These clues can give you a clear sign that conditions are dangerous, but keep in mind that you won’t always see all of these red flags even if the snowpack is capable of producing an avalanche.

Yesterday, surface hoar was observed in a few isolated areas on Lost Lake. If this layer gets buried it might make wind slabs more reactive in isolated slopes and it will be important to assess. We have more info in our observation from Lost Lake you can read here.

Wind Slab releasing below the ridge of a wind loaded hill. 12.28.2023

Wind on ridgetops and peaks transporting snow. 12.28.2023

Last weekend’s storm covered a layer of surface hoar that had developed across the region. We have not seen or heard of any avalanches failing on this layer in the Seward zone, and based on the limited info we have, it does not seem to be a major concern in large parts of the Seward area. However, with limited information in the region, especially Snug Harbor, it is possible that this weak layer exists on some slopes and is capable of creating an avalanche that could bury a person or machine. These layers can be tricky to identify. If you are touring or snowmachining, it is a good idea to travel a bit more cautiously than normal until you are confident in your snowpack assessment. If you feel like sharing your findings, take some pictures and help us out by submitting observations!

After the Holiday storm, glide avalanches were observed near Kenai Lake. Although we have not seen evidence of widespread glide avalanche activity in the Seward area, it is worth mentioning because it has been a concern in other forecast regions. Because these avalanches release to the ground, glide cracks can be easy to spot as “brown frowns” as they open or “brown spots” when they release. It is important to minimize exposure under these glide cracks because they can spontaneously release and be large and dangerous.