On Monday we got a report of a disconcertingly large skier triggered avalanche in the Girdwood valley. It appears to have been remotely triggered near the 2700 foot elevation and slid on or under a 2 week old crust which is now buried 2-3 feet deep. Yesterday we confirmed the reactive nature of that weak layer. See the full test results on our observations page. Our testing found a specific elevation band between 2000 and 3000 feet contains a series of crusts and facets that can collapse under the weight of a person and propagates large distances. Snow pit testing shows only moderate strength, and failure happens in a clean and fast nature.
We don’t know how widespread this problem is. It appears to be common in the Girdwood valley, but so far we have few reports across Turnagain Pass that correlate to a reactive ice crust. However, it should be assumed to be common at the mid-elevation band regionwide until we prove otherwise. This problem is not likely to go away quickly, and may get worse before it gets better.
Wind slabs, large cornices, and building storm snow will be a problem above treeline. Over the last week, no single day has brought a large amount of snow, but the combined 7 days equals close to 20 inches of new snow at Turnagain Pass and perhaps double that amount in Girdwood. Wind has been consistently strong. We can expect to find areas of stiffer and deeper wind deposited snow which may be triggerable by a person. Any steep wind loaded terrain above treeline should be approached with caution corresponding to the terrain consequences.
Over the last week, each day has brought 1-4 inches of snow to Turnagain Pass. The last 24 hours was similar with about 3 inches new snow. Temperatures have been in the mid 20s with a moderate east wind reaching into the 30s and 40s yesterday.
Today looks like more of the same. An inch of snow is expected this morning, with snowfall tapering off by noon. Tonight 4-8 inches is expected and increasing wind 40-60mph as the next frontal system moves across southcentral Alaska.
Wendy will issue the next advisory tomorrow morning, February 14.
|01/31/23||Turnagain||Observation: Johnson Pass area||Megan Guinn / W Wagner Forecaster|
|01/29/23||Turnagain||Observation: Tincan Backdoor||AAS-Level 1 1/27-1/30|
|01/28/23||Turnagain||Observation: Sunburst||Brooke Edwards|
|01/28/23||Turnagain||Avalanche: Seattle Ridge||W Wagner|
|01/28/23||Turnagain||Observation: Tincan Common||Tony Naciuk|
|01/27/23||Turnagain||Observation: Sunburst||John Sykes|
|01/27/23||Turnagain||Avalanche: Lynx Creek||Megan Guinn / W Wagner|
|01/25/23||Turnagain||Observation: Cornbiscuit||John Sykes Forecaster|
|01/22/23||Turnagain||Avalanche: Tincan||Schauer/ Guinn|
|01/21/23||Turnagain||Avalanche: Seattle Ridge||Elias Holt|
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: email@example.com
|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.