Pockets of unstable snow may still be present in wind loaded areas at high elevation. Most slopes where people are skiing have weakened to the point where the entire snowpack is one big weak faceted layer. This actually makes the backcountry safer now than it was a couple weeks ago, except that it’s easier to tag rocks on the way down…
The analogy I’ve come up with compares the snowpack to engineering a building. We all know that we can construct a tall stable skyscraper that can withstand significant stresses from wind and earthquakes. The strength of that building relies fundamentally on the strength of the foundation. If you build a skyscraper on top of a weak foundation, failure and catastrophic collapse is likely. If you make a smaller and lighter building, the foundation doesn’t need to be as strong to support the structure above. Our snowpack right now is a tent, without any foundation. The tent itself is inherently weak, but collapse of that tent isn’t nearly as catastrophic as a collapse of the skyscraper. In fact, the tent will bend when stressed before it breaks and collapses. The big problem will happen when the next snow storm (new construction) gets placed on top of the tent. How much weight can that tent support?
Why did the snowpack turn into one big weak layer? Check out Wendy’s temperature profile graph HERE. It’s all about weeks of high temperature gradients caused by shallow snow (only 22 inches in November) and cold air temperatures.
The forecasted high wind over the last couple days has not affected the Turnagain Pass region. Clear, sunny, and cold weather will continue today and through the weekend. A temperature inversion is still present, making higher elevations warmer than the valleys below. Portage this morning is reading -18 degrees, while Sunburst at 3812 ft is reading 15 above.
A pattern change is beginning to show up in the extended forecast. A chance of snow is predicted for next Wednesday!
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).
Wendy will issue the next advisory Sunday morning, December 2nd.
|05/06/20||Turnagain||Avalanche: Pastoral Peak, north face||Andy Duenow|
|04/10/20||Turnagain||Avalanche: Wolverine||Mike Records|
|04/10/20||Turnagain||Observation: Eddies lookers right shoulder||Matt Yoder|
|04/09/20||Turnagain||Observation: Bench Peak||Mike Records|
|04/04/20||Turnagain||Observation: Pete’s North||Anonymous|
|03/26/20||Turnagain||Avalanche: Tincan – Proper (SW facing)||CNFAIC Staff|
|03/26/20||Turnagain||Avalanche: Seattle Ridge||W Wagner Forecaster|
|03/25/20||Turnagain||Avalanche: Sunburst Uptrack @ 2000′||J. Boisvert|
|03/24/20||Turnagain||Observation: Turnagain – Road Observations||W Wagner 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: 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.