Deep slab avalanches continue to be our biggest concern. The number of avalanches that are occurring is low, but the potential size and destructive force is very high. We received another wake up call on Tuesday, as a snowmachiner remotely triggered a very large avalanche on Seattle Ridge where amazingly no one was buried or injured. This avalanche had the potential to do a lot of damage. This is the second such event in the last week.
Clear skies yesterday gave us a chance to look around the Turnagain Pass area. We were able to see a lot of old crowns that have filled in as well as one recent natural avalanche above Seattle Creek that caught our attention. With forecasted weather not likely to change the overall hazard in the coming days, the potential for large destructive avalanches will remain.
Typically a person or snowmachine can affect a weak layer within a few feet of the surface. The new slab formed over the Christmas through New Years period is 6-10 feet in many areas. The most likely places to find a thin spot in the slab is above treeline where winds have created greater variation in slab depths.
Weak layers formed between October and December are widespread. It is safe to assume that almost anywhere you go in the mountains there is a weak layer somewhere below you. This thick slab/weak layer combo is what is allowing for these large avalanches to occur.
Traveling on lower angled slopes and avoiding large open terrain is your best bet for avoiding this unmanageable problem today.
Light to moderate winds have created small pockets of shallow new wind slab. Light density snow resting on the surface will get blown around easily today. The consequences of this problem increase in steep terrain and above terrain traps.
In the past 24 hours temps have remained in the 20s F, winds have been light to moderate averaging in the teens/twenties out of the E and SE with gusts to 38mph. Light snow has begun to fall on Turnagain Pass and in the Girdwood Valley this morning.
In the mountains today we should expect to see light snowfall mainly in the morning with a few inches of accumulation possible. Ridgetop winds will be out of the SE averaging 15-20mph and temps at 1000′ will be in the mid 20s F.
The extended outlook calls for light precip each of the next 3 days with temps warming as a series of weak low pressure systems move through the area.
Wendy will issue the next advisory tomorrow morning, January 11th.
|01/15/21||Turnagain||Observation: Sunburst||Schauer/ Wunnicke Forecaster|
|01/13/21||Turnagain||Observation: Tincan||Johnston-Bloom / Moderow Forecaster|
|01/13/21||Turnagain||Observation: Center Ridge Meadows||Alaska Avalanche School Rec Level 1 Roberts|
|01/12/21||Turnagain||Avalanche: Seattle Ridge/Center Ridge||A Schauer Forecaster|
|01/11/21||Turnagain||Observation: Tincan Trees||Schauer/ Roberts Forecaster|
|01/10/21||Turnagain||Observation: Center Ridge Meadows||Alaska Avalanche School Pro 1 Course Latosuo|
|01/10/21||Turnagain||Avalanche: Tincan trees||Anonymous|
|01/09/21||Turnagain||Observation: Johnson Pass||Anonymous|
|01/08/21||Turnagain||Observation: Sunburst meadow between Hemlocks||Anonymous|
|01/08/21||Turnagain||Avalanche: Seattle Ridge||Wagner / Schauer|
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.