Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, December 24th 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).
Placer river valley and the Skookum valley are opening today for motorized use. Be aware of thin snow conditions and areas of thin ice over water. 20 mile will remain closed until we get more snow cover at sea level.
The avalanche danger is generally LOW with pockets of MODERATE for wind slabs, and cornices. Our data between Girdwood and Turnagain Pass is showing very few issues to be worried about. Farther South of Turnagain Pass we have limited information, but a couple of observations suggest there could be pockets of lingering instability in that shallower and weaker snowpack.
Thursday night’s storm brought copious amounts of snow to the Anchorage bowl, but only 2-4 inches for Turnagain Pass. That small skiff of light surface snow did almost nothing to increase the avalanche danger, but did improve the riding conditions above treeline. We were finding our tracks could trigger minor sluffing in the soft surface snow, but CNFAIC Staffwise it remained light and unconsolidated.
Digging in, you will find about 4 feet of settled storm snow from the month of December. It’s difficult to pinpoint the exact interfaces between the weekly Sunday storms we got. That difficulty means that the density between the storms was similar (good), and it means that bonding is happening between the storm layers (great!). All of our observations are showing green light conditions.
The primary concern is isolated pockets of unstable snow including cornices and associated wind slabs at the ridges. If you choose to ride steeper and exposed routes this weekend, be aware of those hazards as you drop in. You may find variations if you travel outside our core forecast area.
The 2-4 inches of snow on Thursday night is the latest to hit our area. Storm totals in Turnagain over the last week add up to about 30 inches. Temperatures are dropping and wind has died off over the last couple days. Today, snow is possible in the evening, but expect cloudy skies and a chance of snow showers for the daylight hours.
Weather forecasters are talking about a pattern shift for the storms tracking into Alaska. For much of December the storms were traveling North into the Bering Sea, with fronts spinning off and giving Southcentral snow and high wind. The new trend is tracking the storms into the Gulf of Alaska, with colder air dominating interior Alaska. Snow in Southcentral and below freezing temperatures will be the general trend for the foreseeable future. Check out this link for a short video of our upcoming Christmas weather.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory Sunday 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.