Avalanche Advisory

Turnagain Area Avalanche Advisory
Sunday, February 2nd 2014 7:00 am by Kevin Wright
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
Previous ForecastNext Forecast
The Bottom Line

Above treeline - a MODERATE danger rating continues for deep buried persistent weak layers and windslab concerns.  

Below treeline - cold temperatures continue to freeze the rain soaked layers of snow below the surface.  Strength continues to build as the crust gets thicker.  At this point the chance of causing an avalanche below treeline is LOW.  The crust is completely supportable for people traveling on skis.   

 Show the Complete North American Avalanche Danger Scale
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
1 Low Treeline / 1,000'-2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Special Announcement
  • Coming up on Saturday, February 8th is the Hatcher Pass Avalanche Center 2014 Fundraiser. An eventful evening with a slide show, live music, silent auction and more are on tap. Tickets are selling fast so get yours today and support avalanche information in the Hatcher Pass area!!

Avalanche Problem 1

We have relatively little information from the last 5 days because so few people are getting into the backcountry right now.  Conditions are challenging with a hard "chattering" crust below treeline that is a prerequisite before you gain the slightly softer zone above treeline.  

The last major high elevation deep slab that we know of was a week ago on Goat Mountain in the Girdwood valley.  Remember that this problem doesn't stabilize quickly like a storm slab problem.  

Above treeline the snowpack is thick, with weak snow at and near the ground.  We have been able to cause failures on these layers in test pits.

Managing this low likelihood, high consquence problem can be accomplished by limiting travel in steep terrain.  If that isn't an option, then exposing one person at a time to steep terrain will reduce risk exposure.  

Avalanche Problem 2

Recent wind has been limited, so wind slabs are generally older.  Above treeline there can be found some soft snow and some wind stiffened snow.  Watch out for pockets of stiff wind slab that may fail in small avalanches.  Unstable cornices are another subcategory that fits into wind slab concerns.  

Additional Concern

Wendy posted this summary yesterday, which gives us a good look at the recent weather.

With many days of unseasonably warm weather during January, some of us are wondering just where did we stack up in the monthly averages. There is more data to crunch so stay tuned - but we do have a few sets of interesting numbers. Below are graphs of precipitation, SWE (Snow Water Equivalent) and Temperature. 



Mountain Weather

We have not had any significant precipitation for the past week.  

Current weather has a temperature inversion across the region.  Sea level temperatures are in the mid to high teens, ridge top temperatures are in the high 20s.  Valley fog has dominated Turnagain Arm for a few days, and this will likely continue today.  Wind has been light for several days now.  These conditions are building surface hoar crystals, which could become a buried weak layer the next time it snows.

The blocking high pressure pattern is expected to continue this week.  By the end of the week - computer models are showing a pattern change but the exact nature of that weather remains uncertain.


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).

Winter snowmachine use open/closed status and riding conditions updates

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Oct 05, 2019 )

Glacier District
Johnson Pass: ClosedClosed
Placer River: ClosedClosed
Skookum Drainage: ClosedClosed
Turnagain Pass: ClosedClosed
Twentymile: ClosedClosed
Seward District
Carter Lake: ClosedClosed
Lost Lake Trail: ClosedClosed
Primrose Trail: ClosedClosed
Resurrection Pass Trail: ClosedClosed. Will be open for the 2019/20 season pending adequate snow cover.
Snug Harbor: ClosedClosed
South Fork Snow River Corridor: ClosedClosed
Summit Lake: ClosedClosed

Subscribe to the Turnagain Area Avalanche Advisory:

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur. This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.

If you have comments or questions regarding CNFAIC operations or winter recreation management, please email
© 2019 Chugach National Forest Avalanche Information Center. All rights reserved.