Summit & Central Kenai Mtns

The Summit Lake area saw a handful of natural avalanches that likely occurred over the weekend and during the stormy weather Monday and Tuesday (Dec 18-19). Some of these avalanches were big enough to bury a person and we believe most failed within the new storm snow. More concerning were reports of an avalanche on the southwest side of Wrong Mountain with an estimated 6’ crown that may have failed on the Thanksgiving crust. Glide avalanches were also observed on the south side of Manitoba. 

Weather Recap: In the past week, Summit Pass has received roughly 15” of low-density snow with ridgetop winds gusting to 50 mph. Winds calmed, and clouds began to break up on Wednesday and Thursday. Earlier in the week temperatures averaged 20-30 F followed by a colder trend towards the weekend around 5-10 F as skies cleared.

Weather Forecast: We are anticipating an active storm cycle beginning today that will increase in intensity overnight. We are expecting winds starting to increase Friday night averaging 20-40 mph from the east with higher gusts in the 50-60 mph range, continuing all day Saturday and finally decreasing Sunday evening. Snowfall in Summit Pass could amount to 6” by Saturday morning with another 6” throughout the day. By Sunday the snow should be decreasing with another 2-6” throughout the day.  This storm will come in warmer with the rain line creeping as high as 1200’ on Saturday morning.

On Manitoba peak looking at a storm slab and glide cracks on the ridge to the north. Photo by Elias Antaya 12.21.2023

As this storm ramps up, we are expecting up to 12-20” of new snow and strong east winds averaging 20-40 mph. Snowfall will be at its heaviest early Saturday morning continuing throughout the day into Sunday evening. To make matters worse, there have been reports that this snow could be falling on surface hoar creating the perfect recipe for a touchy storm slab 1-2′ thick. Where this layer is preserved it could create the classic storm slab over weak layer situation where these avalanches may release in lower angle slopes less than 30 degrees that are usually considered safer to travel.  

If the storm verifies, this amount of wind and snow will place a lot of stress on the snowpack. This will be a widespread issue affecting all aspects and elevations where avalanches are very likely to release naturally and will be large enough to bury a person. Traveling in avalanche terrain is not recommended. That includes traveling under avalanche terrain where avalanches will likely run a long distance into low angle terrain. If you are itching to get out for a holiday tour this weekend it may be a good time to enjoy cross country skiing in the flatlands or choosing fun low angle pow turns. 

Avalanche crown with numerous fractures on S aspect of Manitoba. Glittering surface hoar on foreground slope. Photo by Elias Antaya on 12.20.23

We are keeping track of a layer of facets buried around 3’ deep that has been found either just above or in the middle of the Thanksgiving Crust (TC).  We believe that this layer was the culprit in a large natural avalanche observed on Wrong Mtn near the Sterling Wye, which likely released on Tuesday during the stormy weather, Otherwise, we know of no recent avalanches that look to have failed in these buried facets. Snow pits and stability tests have not shown alarming results yet this weekend’s storm could overload and “wake up” this layer. If this was the case, avalanches may be 3-5’ thick or more. This storm will be a great natural “test” to see how fragile the weak layer is. We do not advise traveling in avalanche terrain, including flat areas under large avalanche paths. Once again this could be a great day to play Catan or stick to safe angles not on or under avalanche hazards. 

This past week multiple glide avalanches were observed, and new glide cracks are opening in the Summit area. Because these avalanches release to the ground it can be easy to spot them 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. 

Glide cracks and glides avalanches, on the south side of Manitoba. Photo by John Sykes 12.20.23