Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Friday, January 13th 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 today for aging storm snow and wind slabs. We are a couple days out from the peak of the last storm, but not far enough out to really trust the snowpack quite yet. Natural avalanches are unlikely today, human triggered avalanches are still possible. Enough uncertainty in the snowpack remains today that starting out on lower consequence slopes will be prudent until we understand the new layers better.
The big obvious avalanche signs are becoming harder to find since the hurricane on Tuesday, but the residual effects from that storm remain the primary concern today. On the drive to Girdwood, take note of the large avalanche across the road in Bird Flats. There were only a couple of large explosive triggered slides over the last few days, with the obvious one on Bird Flats from Tuesday and anCNFAIC Staff one yesterday. This is a good reminder that even a couple days out from the storm there remains the possibility of finding anomalies in the backcountry.
Digging into the snow yesterday at Turnagain Pass we found the concerns isolated to the upper 2 feet of the snowpack. It is possible to find some clean and relatively easy shears in the storm snow interface and around the rime crust from last Sunday. That rime crust and the denser storm snow is sitting on top of the older fluff from last week. This is a heavy-snow-over-weaker-snow combination that deserves some scrutiny. Snow pit analysis should emphasize these upper layers and determining if the rime crust is still a problematic layer.
Our current understanding of the new storm snow is limited, giving us fair to low confidence in the forecast today. Very few people have been in the backcountry since Monday, and clouds and snow have obscured the view of the mountains in the region. This is a great day to play low key in the mountains until we get a better idea of the conditions. The new snow is strengthening every day, so the avalanche danger is continuing to drop. Cold temperatures, light wind, and limited snowfall will keep us on the decreasing trend going into the weekend.
Yesterday we got continued snowfall with rapidly dropping temperatures. This is a great combination, creating a “right-side-up” finish to the recent storm events. The 6-7 inches of surface snow is dry and low density as a result. Wind yesterday was blowing in the Girdwood region and through Portage Valley, but CNFAIC Staff areas were getting only light wind.
Today will be the beginning of a significant weather pattern change. High pressure, clear skies, and cold temperatures are the trend for the weekend. A North wind up to 30mph is possible at higher elevations today. Light snow showers in the morning may give way to partly sunny skies this afternoon.
CNFAIC Weather Page and the NWS forecast
I will issue the next advisory Saturday 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.