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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Wednesday, March 20th 2013
Created: Mar 20th 6:41 am
1 Low Alpine / Above 2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
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.
 Show the Complete North American Avalanche Danger Scale
The John Byrne Family
The Bottom Line

Stable conditions continue in the backcountry today.  The avalanche danger is LOW throughout our forecast region.

The only minor concerns are near the surface of the snowpack where sluffing can be initiated in steep terrain and occasionally small pockets of wind slab may be triggered.  Cornices continue to be the single most dangerous avalanche concern, as an easily avoidable problem with high consequences.

With our extended period of sunny weather and stable snow people are putting down tracks all over the mountains in our region.  Each track is a slope test, and after thousands of slope tests with favorable results we come out with a clear picture of stability.  Thanks to everyone who has sent us observations and photos from the backcountry.


Primary Concern

Cornices

Cornices remain large and mature, and we continue to find new collapsed cornices with impressive paths of destruction below. 

Here is an account of the fatal cornice failure that happened in Haines earlier this year.  Good reading, photos, and reminders of the dangers we face in the mountains.

 


Secondary Concern

We hit the highest wind speeds overnight that we've seen in the last week.  Even before that wind we could find small natural and skier triggered pockets of wind slab in steep terrain above treeline.  Expect pockets of wind loaded stiffer snow today that could fail with a slabby character.

Loose snow

The picture below is a great example of our current sluffing problem.  Small point releases can entrain impressive amounts of loose snow in steep terrain. 


Mountain Weather

The only notable weather in the last 24 hours was the wind last night.  Seattle ridge weather station recorded sustained wind to 28mph and gusts to 46mph from the northwest.  This is more than enough to create fresh wind slab. 

Colder temperatures are keeping melting and wet snow avalanches from becoming a problem.  The cold weather has also caused large temperature gradients in the surface snow which keeps that snow soft and carveable.  Read Wendy's description of the process here.

Today, clear and cold weather continues.  Expect temperatures to reach into the 20s this afternoon.  Wind will be north to northwest from 14-33mph at the ridgetops. 

The longterm outlook shows an end to our sunny weather coming on Thursday night.  When that happens we can expect snow, warmer temperatures, and an increase in the avalanche danger. 


Kevin will issue the next advisory tomorrow morning, March 21st.

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: Dec 08, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedRain and snow have fallen in Turnagain Pass this week, but not enough to open for snowmachining. Continue to check back to this site for updates.
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
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