Turnagain Pass Avalanche Forecast

Sunny skies yesterday provided a good look around at any recent avalanches that occurred during Wednesday’s snowfall event (Feb 12) and also yesterday’s wind event (Feb 13th). The winds spared much of Turnagain Pass, but did create plumes and at least four natural avalanches in the Summit Lake and Lost Lake areas. We also received a report of a possible human triggered avalanche on the backside of Seattle Ridge.

Natural large wind slab occurring yesterday on Roaring Ridge in the Summit Lake Area. 2.13.20. Photo: Alex McLain

Two natural wind slabs were triggered by winds cross-loading slopes on the SE face of Seattle Ridge sometime on Wednesday, Feb 12th. This photo was taken Feb 13th  from the motorized parking lot at Turnagain Pass.

Natural slab avalanche on the lower norther ridge of Wolverine (SW facing)  that appears to have released early in the storm on Feb 12th. Likely triggered by a cornice fall. 

After a dose of 10-18″ of new snow and wind over the past two days, today’s partly cloudy skies and light winds are not expected to affect the snowpack. As the pack slowly adjusts, we are trending into a ‘SCARY MODERATE’ avalanche danger. What this means is there is still a chance a person could trigger a large and dangerous avalanche, but that likelihood is decreasing. We are heading into a Low Probability / High Consequence situation (click HERE for more insight into this).

We can’t forget that 2-4′ below the snow surface lies weak faceted snow and in places buried surface hoar. These layers caused several avalanches over the past two weeks and with small snowfall events incrementally adding to the slab, the size of these potential avalanches is growing. What can we do? We know the snowpack isn’t likely to give us signs of instability until it’s too late. It could be the 10th person on the slope that triggers the slab and it could even be triggered remotely, from below or the top. We can choose to stick to lower angle terrain and avoid slopes ending in terrain traps. We can think to ourselves, ‘where will I end up if the slope slides?’ Approaching the backcountry with a conservative mindset is key now and will be for the foreseeable future.

Video link HERE.

For today, triggering a wind slab, or soft slab composed of the new snow from Wednesday is still possible. Watch for slopes that have been previously wind loaded or steep gullies that have been cross-loaded. These slabs could be anywhere from 6″ thick to 2′ and quite hard in places the wind was strong and softer where winds were more moderate. Cracking in the snow around you, a hollow/drum like feel of the snow surface and a generally stiffer layer of snow over softer snow are all signs of a wind slab. Heads up that a wind slab avalanche may overload deeper weak layers and initiate a much larger slab.

Cornices:  These have grown over the past 36 hours and we can’t forget to give them a wide berth from above and limit time under them from below.

Plumes in the Summit Lake and Seward areas of the Kenai Mtns. 2.13.20. Photo: Alex McLain