Sustained 40-60 mph winds on Saturday (two days ago) helped to form large dense wind slabs in many areas. Most of the new snow that fell over the weekend is well bonded to the old snow surfaces. In areas that received wind loading this bonding is not as good and it is easy to find “upside down” snow on ridgelines, in starting zones and above cross loaded gullies. While these slabs have been reluctant to move under the weight of a snowmachine or skier, they still warrant respect, as they are large in size and able to do damage to a person once released. Avoiding starting zones above 35 degrees, wind affected snow above terrain traps and isolated areas below treeline that have these slabs will be your best bet today.
The winds and snow that formed wind slabs over the weekend also helped to increase the size of cornices. Always give cornices a very wide berth. When approaching from below try to envision what would happen if that cornice you’re looking up at came towards you. When traveling above cornices in the higher elevations, always avoid the edge. If you can’t see what is below you or a cornice is looming above you it’s probably time to back off. Try to view cornices from the side to see where the ground is and where the snow is overhanging & unsupported. Heating from the sun combined with an absence of wind could increase the likelihood of cornices releasing today.
Loose Snow Avalanches
Several inches of light density snow will be found on the surface today. The potential for relatively small shallow loose snow avalanches exists. These will become a greater problem in steeper terrain. Avoiding these surface slides in steep terrain above cliff bands and gullies will help to minimize your exposure to this hazard.
We are still monitoring the weak snow at the base of the snowpack that formed in the first part of the season. Above 2,000 feet and in areas with less overall snow this problem is more pronounced. While it is unlikely to trigger a deep slab today, it can’t be ruled out. Assess the terrain you are on and ask yourself some questions. What is the overall snow depth? Are there potential trigger points where the snow is shallow? Continuing to follow good travel habits, i.e. only putting one person at a time on a slope and using true islands of safety will help to mimimize your exposure to this problem.
The mountains around Turnagain Pass have picked up 2-4″ of new snow with .2-.3″ of water in the past 24 hours. The Girdwood Valley has had up to 6″ of new snow with .3-.6″ of water. Winds at 3,800′ have averaged in the high teens out of the E and SE and temperatures have been in the low 20s F.
Veering winds have slowed down this morning and temps are on the decline. Light snow is falling at sea level.
Snowfall will taper off this morning. Ridgetop winds will be light, blowing 10-15 mph out of the W and NW. Temperatures at 1,000′ will be around 30 degrees F and skies will be clearing through the morning hours.
The next chance for snow will come tonight and into tomorrow morning, with generally low amounts expected.
Graham will issue the next advisory tomorrow morning February 12th.
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/15/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|04/13/21||Turnagain||Observation: Turnagain Pass Road Obs||A Schauer Forecaster|
|04/12/21||Turnagain||Observation: Tincan||Johnston-Bloom / Latosuo Forecaster|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: firstname.lastname@example.org
|Area||Status||Weather & Riding Conditions|
This is 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.