Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Wednesday, December 28th at 7am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).
The avalanche danger is MODERATE for wind slabs, and cornices. Watch for localized problems in areas where the wind has been blowing the recent cold light powder into deeper and stiffer pockets. Areas sheltered from the wind will have only loose snow sluffing issues.
Just to be clear on the avalanche problem today, I consider it to be obvious and manageable if approached with respect. The soft slabs that are forming in the cold dry powder from the last week should be showing their character in obvious signs. If the loose powder changes suddenly to a more cohesive slab that shoots cracks in front of your skis or sled, then it’s time to investigate further. These soft slabs have potential to entrain more snow on the way down gulleys or steeper slopes, but they won’t be producing wide propagation or deep and destructive avalanches.
The stiff and unpredictable slabs you might find today are cornices. Yesterday we found well developed cornices above the West facing bowls of Seattle ridge. In some places they were peeling away from the edge, leaving yawning crevasse-like cracks near to the edge of the ridge. These features are unstable, dangerous, and deserve more extra room than you might think. It could take just an extra 150 pounds of force to release several thousand pounds of snow onto the steep slope below.
If you find the shooting cracks, consider checking the depth of the cracking. Is it only the top 6-12 inches of light density fluff, or does it go deeper into older layers? Shooting cracks are an indication of an unstable slab layer, but that layer could be only a shallow and minor variation to the softer snow around it. As always, keep your guard up when the consequences below you become more severe. It only takes a small avalanche to become a problem when it drags you over cliffs or into anCNFAIC Staff type of terrain trap.
Cold temperatures and a chance of snow will persist for the near future. The recent weather over the holiday weekend brought small amounts of cold dry snow to Turnagain Arm and the Kenai, and that trend will continue. Yesterday we had minor snow showers with wind up to 47mph recorded on Sunburst. The light density snow is easily blown around with even minor wind, so expect the snow to be moved in exposed areas. Today, 2-4 inches of snow is possible with temperatures below 20 and light to moderate wind.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory Thursday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.