Rotten snow can be found nearly everywhere right now, and in some cases those weak facets will collapse when stressed. The recipe that caused the recent skier triggered avalanches is relatively simple to understand. All the October snow sat around during cold temperatures and turned to sugary facets before it got buried by subsequent storms. Shallow, weak snow is easily triggered by the weight of a person. If you are interested in investigating snow pits, now is a great time to look at textbook instability. Which makes it a bad time to explore farther into the backcountry.
On our backcountry patrols we’ve been quite conservative in our route and slope choices. Skiing “lightly” to avoid hitting submerged rocks, and avoiding the steeper slopes is a good idea until our situation changes. Examples of recent avalanches can be found HERE and HERE.
Besides the bulls-eye information of skier triggered avalanches, our pit tests are showing a collapsible weak layer and a tendency to propagate. Most stability tests are showing low to moderate strength, and will propagate across an extended column when the underlying weak layer collapses. This is very pertinent information! When a professional guide sees evidence like this, he/she will very deliberately alter travel plans to stay on conservative lower angle terrain.
The nature of avalanches breaking to the ground in our shallow snow situation is another good reason to stay conservative. Taking a ride through the rocks increases the chance of major injury.
Lower elevation slopes below treeline are more stable than up high due to a slightly better snowpack structure. Shallow snow cover in the trees will make travel challenging however, until we get more snow.
It’s been mostly clear and cold over the last couple days. Minimal precipitation has not contributed much to the avalanche equation. The jet stream pattern is bringing colder arctic air across Alaska and currently diverting most of the Pacific moisture to Washington and British Columbia. Light wind and a strong temperature inversion is happening this morning between Girdwood and Summit. The outlook for a pattern change doesn’t look good until sometime next week. Don’t expect much precipitation in the next few days. The cold temperatures and shallow snow are forming a strong temperature gradient that continues to weaken the snow we already have on the ground…
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).
I will issue the next advisory on Thanksgiving morning, Thursday November 22nd.
|04/19/21||Turnagain||Avalanche: Triangle, Seattle creek||Will Morrison|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/18/21||Turnagain||Observation: Seattle Ridge, approximately 300 yards south of the up track||Brent Byrne|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|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|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|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|
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.