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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Thursday, December 26th 2013
Created: Dec 26th 6:31 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.
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.
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The Bottom Line

The danger rating continues to be MODERATE above treeline for the persistent weak layer around the December drizzle crust.  We've had a number of small, low volume avalanches on this layer in the last week.  As the weather has not contributed to instability in the last few days, the avalanche likelihood is slowly decreasing.  

 


Primary Concern

The weak layer above the crust continues to show signs of poor strength and a tendency to propagate.  Somebody traveling in the wrong place may still pop a slab avalanche.  

The photo below illustrates the full depth (31 inches) of the snowpack at 2000 ft.  The most pertinent result from the test was the failure above the crust, which propagated in an extended column test.  The snowpack is showing moderate strength, with poor structure and a slick crust interface.

As recently as yesterday we got a report of whoomphing from the Tincan area.  This tells us that a person can still initiate a collapse.  A collapse occurring on a steep slope may trigger an avalanche.


Secondary Concern

Spontaneous, natural avalanches were observed during the windy conditions on Monday.  We know that areas near ridgetops, above treeline are still holding pockets of stiff wind slab from that wind event.  As is normal, a little more caution is warranted when approaching ridgelines where wind blown snow will be expected.  The denser and stiffer layers near the snow surface complete the recipe for the most probable way to find an avalanche today.  


Mountain Weather

It has not snowed since Sunday.  Weather over the last few days has been clear and cold with light wind.  

A temperature inversion can be found in some areas.  It is quite a bit warmer than Anchorage this morning.  Sunburst sits at 23 degrees, Center ridge at 18, and Seattle ridge at 25 degrees.  Wind at the ridgetops is very light.  Mostly clear skies are expected today with patchy fog in the valleys.  

There is snow in the forecast for Friday night and Saturday!  Cross your fingers...

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: May 16, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedThanks all for a safe and fun season on the Chugach NF! Stay tuned for the 2017/18 season. #playsafe #snowtosealevel
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: ClosedResurrection Pass trail will be open to snowmachine use during the 2017/18 winter season.
Snug Harbor: Closed
South Fork Snow River Corridor: Closed
Summit Lake: Closed

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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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