Good morning. This is Graham Predeger with the Chugach National Forest Avalanche Information Center on Tuesday, January 3rd 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 Turnagain Pass area is experiencing generally safe avalanche conditions. Small human triggered avalanches in specific areas where shallow wind slabs exist are possible today. Watch for unstable snow in isolated terrain features such as gullies or in steep, cross-loaded terrain (>45 degrees). If you produce an avalanche, it will likely be small and manageable.
Well it’s back to work for most of us, but if you are lucky enough to extend your holiday one more day, you are likely to find great skiing and snowmachining conditions in the Turnagain Pass area today. Surface conditions yesterday consisted of smooth, fast snow showing signs of early faceting. These near-surface facets (aka recycled powder) pose no problem today but may act as a weak layer once buried by subsequent storms. Surface hoar has also been spotted throughout the forecast area, specifically below tree line.
Winds were abnormally light yesterday at ridge top weather stations. Sunburst had a max wind speed of 16mph last night and only 10mph during the day. 12mph is often referred to as the lower threshold of what is required to transport snow. Scattered wind plumes were observed in the Turnagain Pass region on Sunday at upper elevations allowing the formation of shallow wind slabs. Localized cracking as well as a change in the feel of the surface snow will let you know if you encountered a wind slab.
Our CNFAIC Staff primary concern today will be loose snow avalanches or sluffing in steep terrain. Though controllable and fun for many, entrained loose snow can pack a punch and knock a skier down if not properly managed. Also of note is a glide crack on the south face of Magnum that released most likely on Saturday, Dec. 31st. Any glide cracks left from our early season glide cycle still deserve a wide berth as these photo’s illustrate.
Generally our snowpack is strong and growing stronger in the Turnagain Pass and Girdwood areas with recent cold temperatures, light winds and precipitation. Please keep in mind that south of Turnagain Pass, mainly in the Summit Lake region, the snowpack has notable differences in its strength and structure. More caution and snowpack evaluation should be used in this area.
The monthly weather chart for December can be found HERE.
Upper level clouds today should make for warmer temperatures than we have experienced over the last several days. Expect daytime temperatures to be in the 10-20 degree range. Winds will start out light this morning but could gain strength by this afternoon with gusts up to 45 mph from the east.
Light flurries will also be possible throughout the day with little or no accumulation. Our next best chance for snow appears to be Wednesday night or Thursday morning as an upper level trough moves through south central Alaska.
CNFAIC Weather Page and the NWS forecast
Kevin will issue the next advisory tomorrow 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.