CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Wednesday, December 12th 2012
Created: Dec 12th 6:23 am
3 Considerable Alpine / Above 2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
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
Alaska Mining and Diving Supply
The Bottom Line

A modest amount of new snow today will raise the danger rating to CONSIDERABLE for storm snow over the old persistent weak layers.  Snowfall amounts and wind through the day will determine how much the avalanche danger rises.  The tender wind slabs we saw over the weekend are likely to become active again today during the storm as more stress gets added to the snowpack. 


Primary Concern

Old wind slabs built last Saturday by redistribution of the snow during high wind are probably the most dangerous specific concern today.  A fresh blanket of snow will make it more difficult to identify those areas that are stiffer and deeper.  New storm snow today will add to the stress and make them more likely to be triggered by a skier.  This problem is generally confined to above treeline on specific wind loaded features steeper than 35 degrees.  Fresh wind slabs from today's event are also likely on north and west facing slopes.  Watch the snow build today and make decisions accordingly.


Secondary Concern

This storm doesn't look very intense by our standards.  However, any new weight on the weak layers from November will be cause for concern.  Above and below treeline, watch for standard red flags (fresh avalanche activity, shooting cracks, whoomphing sounds, wind loading, new snowfall...).  In less wind affected areas we may be dealing with more of a sluff issue than slabs, but due to bad persistent weak layers it's still worth keeping your guard up.


Mountain Weather

NWS predictions are for 5-7 inches of snow today with SE wind gusting to 30mph at the ridges. This is similar to the expected snow amount in Anchorage today. 

This storm is hitting us with a Western flow (source of the storm is in the Bering Sea), which usually doesn't give Girdwood and Turnagain Pass as much snow as Anchorage and Hatcher Pass.  We should expect some snow, but not a lot.  As of this morning snow has begun, with a few inches in Girdwood already.  Intensity should drop by noon today with snow showers continuing through this evening.  Temperatures are expected to keep precipitation below freezing in the mountains through this storm.


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). 

Graham will issue the next advisory Thursday morning, December 13th.

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