CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Monday, December 16th 2013
Created: Dec 16th 6:17 am
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Treeline / 1,000'-2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Below Treeline / Below 1,000' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
 Show the Complete North American Avalanche Danger Scale
Special Announcement

Join us for a FREE Fireside Chat tomorrow, Tues Dec 17th at 6:30pm at the Alaska Avalanche School in Anchorage.  The topic is Snowpack & Mountain Weather.

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

All motorized areas on the Chugach National Forest remain closed due to low snow cover.  We’ve made some headway this weekend towards an opener but we’re not there yet.  Stay tuned later in the week for an update.


The Bottom Line

The avalanche hazard is MODERATE today above and below treeline.  Snowfall that occured over this past weekend has deposited soft slabs up to 18” in depth.  These slabs will be sensitive to human triggers today on all aspects and elevations.  Human triggered loose snow sluffs will also be a concern in steep terrain today. 


Primary Concern

The storm that dropped 12-18” of new snow on Turnagain Pass came down with very little wind and relatively cold temperatures.  The rate of loading was slow enough to not create widespread natural activity.  Over time this new light density snow has formed into more cohesive slabs.  Yesterday we received numerous reports of low volume slab activity around Turnagain Pass.  All activity observed and reported yesterday ran on a crust that formed earlier in December.

The crust that exists below this new snow is fairly uniform in its distribution (i.e. is similar on all aspects and elevations).  The new snow is also uniform in its distribution.  The interface between this crust and new slab has shown poor bonding in many areas.  As such, all aspects above and below treeline are harboring soft slabs that will continue to be sensitive to human triggers.  Throw in the occasional pocket of buried surface hoar into the mix and it becomes trickier to figure out where the most sensitive areas are.  Your best bet for avoiding this problem today is to stick to lower angled terrain.


Graham-Seattle 12-15-13

Soft slabs triggered remotely in steep terrain off of Seattle Ridge.  (photo: Wagner)


Secondary Concern

Loose snow avalanches will begin to come into play a bit more today with cold temperatures helping to weaken the snow surface.  Expect sluffs to run slowly and be low volume.  Pay attention to sluffs in steeper terrain where terrain traps are present.  While the volume will be low the chances for injury will go up if you are knocked over and carried into trees, over rocks or into gullies.


Mountain Weather

The mountains around Eastern Turnagain Arm picked up a trace of new snow in the past 24 hours.  Winds have been light out of the Northwest and temperatures have averaged in the single digits F.  Ridge top temperatures early this morning are hovering around 0 degrees F.

Clear and cold is in store today as a ridge of high pressure has built into the area.  Winds will be light out of the North and Northwest.

Weather conditions will remain similar over the next several days.  The next chance for precipitation looks to be late Wednesday into Thursday.

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: Nov 18, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedOnly a few inches of snow sits at the motorized lot, not enough to open for snowmachining at this time. Updated Nov. 18, 2017
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: ClosedResurrection Pass trail is expected to open to snowmachine use during the 2017/18 winter season.
Snug Harbor: Closed
South Fork Snow River Corridor: Closed
Summit Lake: Closed

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.


USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments or questions regarding CNFAIC operations or winter recreation management, please email staff@chugachavalanche.org
© 2017 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC