Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, January 7th 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).
20 Mile drainage is open to motorized use! Park at the Portage rail depot and cross the RR tracks at the designated spot ONLY! Please follow bamboo poles from the parking area.
More snow today with wind will increase the avalanche danger proportionately to the snowfall amount. Watch for areas of MODERATE avalanche danger for soft windslabs. Small and shallow human triggered windslabs are possible today. Significant natural avalanches are unlikely unless today’s snowfall exceeds the prediction.
Thursday’s snowfall brought 6-8 inches to our region and a little bit of wind redistributed that snow somewhat. Yesterday we were finding occasional small windslabs that would crack at your skis, although the depth and force within those slabs was minor. Today a storm predicted to drop an additional 3-6 inches with wind up to 29mph will increase the avalanche possibility.
Looking back into our weather and snowpack history gives us good insight into today’s avalanche likelihood and character. We have a deep and strong snowpack right now, with no buried surface hoar, no reactive facet layers, and no buried crusts above 2800 feet. The small amount of snow Thursday and today is very unlikely to provide enough stress to affect deeper layers in the snowpack. The only real concern today is finding unstable snow within the top storm layer. This makes avalanche prediction much easier.
Today, pay attention to the surface snow and how it varies and reacts to skis, board, or sled. If it transitions from soft and shallow to stiff and deep then you are moving onto a wind slab. Monitor the slab depth, relative strength, and reaction to being trod upon. Shooting cracks indicate a stronger slab above weaker snow, so your criticism of the snow should increase immediately if you see this. Higher elevations, rollovers, and ridge transitions are the most likely areas to find surface instability. Avalanche size potential will be small and lower volume.
The storm out in the Gulf that is hammering Valdez and Cordova will just graze our region with a little bit of snow and wind today. Snowfall just started this morning and it will continue through the day. 3-6 inches of snow is predicted, with East wind to 29mph and temperatures into the mid 20s.
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.