CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Tuesday, December 17th 2013
Created: Dec 17th 6:34 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 tonight, Tues Dec 17th at 6:30pm at the Alaska Avalanche School in Anchorage.  The topic is Snowpack & Mountain Weather.


The Bottom Line

We continue to have an overall MODERATE avalanche danger again today. Human triggered soft slab avalanches 12-18" deep remain possible on steep slopes approaching 40 degrees. Watch for these slabs on all aspects and elevations.


Primary Concern

There were a handful of small soft slab avalanches triggered yesterday. These were relegated to steep rocky zones, ridgelines and rollovers. In the photo below you can see several crowns on the ridge as well as the rollovers around the sun/shade line. Today's concerns mirror those of yesterday. Though the slab continues to weaken with the cold weather, there are likely still pockets where someone could kick off a slab. These areas are most pronounced in the steep rocky zones and on steep convex rollovers.

Photo: Tincan soft slabs (SW facing ~3,300')

 

The weekend's storm that deposited 14-18+" of very low density snow has been settling quickly - around 6" in fact. This has helped the snow become more cohesive and hence the slab avalanche activity we have seen over the past couple days. However, counteracting this is the cold and clear weather which is loosening the snow surface and weakening the slab. For anyone headed out today, the majority of the snow surface should feel loose and unconsolidated but keep a close eye for any areas with denser snow.

The snowpack in general has some significant concerns within it for our next load, possibly Wednesday night. Under the new snow is the December drizzle crust which caps a very weak layer of facets. We had reports yesterday of collapsing under the crust in the faceted layer. How will this weak snow/crust/facet combo react as snow continues to pile up is the big question and something we are watching closely.


Secondary Concern

The cold northerly wind has picked up slightly this morning and is expected to level off in the 15mph range through the day. This should be enough to create soft wind slabs out of the light snow sitting on the surface. Though much of the terrain could remain wind free today, I'd expect there will be some areas the wind will move snow around, most likely on the higher peaks and ridges.


Mountain Weather

Cold arctic air continues to spill over us from the north. Temperatures have stalled out in the minus single digits to single digits during the past 24 hours. Summit Lake is reading -17F this morning, burr. Wind that has been calm is just starting to bump up with averages in the 10mph range from the North.

Today, we will remain in the cold north flow with clear skies and single digit temperatures. The only change from yesterday will be the wind which is expected to increase slightly, averaging 15mph with gusts in the 20's from the North.

Another round of snowfall is looking promising for Wednesday night into Thursday. Models are showing around .8" of water (~8-10" snow). Temperatures should remain plenty cold for snow to sea level. Stay tuned.

 

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: Mar 15, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenPlease park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: Open
Skookum Drainage: OpenSkookum drainage closes to motorized use on April 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: Open
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Resurrection Pass Trail: ClosedClosed for 2016/17 winter season. This is a non-motorized season. This alternates every other year and will open again during the 2017/18 winter.
Snug Harbor: Open
South Fork Snow River Corridor: Open
Summit Lake: Open

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