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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Saturday, December 22nd 2012
Created: Dec 22nd 6:52 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

A MODERATE danger continues above treeline, on upper mid slopes in areas with stronger surface snow.  A LOW danger rating describes the areas below treeline where nearly all the snowpack consists of loose weak layers.  We are unlikely to go to Low above treeline while we still find periodic collapsing and pit tests like the ones in the video here.


Primary Concern

A shallow persistent slab is causing the greatest problems in the snowpack.  Looking through the observations photo gallery, a clear pattern emerges among the recent natural and human triggered avalanches over the last week.  We aren't finding those avalanches all the way at the ridge tops, but rather on wind loaded mid slopes below the ridges.  This pattern directly helps us make some travel decisions by showing us the specific terrain to avoid this weekend. 

An observation from yesterday in Moose Pass showed clear red flags of collapsing (whumpfing).  This underscores the problem of a stronger slab overlying the persistent weak layers, and tells us that avalanches are still possible to trigger on steeper slopes that hold the right combination of strong snow over weak snow. 

Overall, we can assume that the likelihood of finding avalanches is decreasing slowly over time since the last snowfall.  The size potential may be decreasing as well.  Due to the persistence of the weak layers (they don't get stronger easily or quickly) and the cold temperatures we've had recently, the trend is nearly stabilized.  This means that current problems aren't getting better or worse, but are likely to stay at the same danger until we get a change in the weather.  Distribution is widespread on all aspects, but most common on upper mid slopes with wind loading. 


Mountain Weather

It's been a cold week, but on the positive note we gain 11 seconds of daylight today!  A chance of snowshowers is possible for the eastern Turnagain Arm, but don't get your hopes up for much snow.  A weakening high pressure across Alaska is still keeping the moisture stream to the south, giving snow to everybody in the lower 48 and Canada...

Expect cold temperatures to continue today.  A strong temperature inversion can be found on the Kenai, with some low spots reading in the -20s.  Ridge tops are balmy by comparison in the low teens.  Wind is a little breezy up high, but probably not strong enough to move our old snow or contribute to avalanche danger.


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). 

Wendy will issue the next advisory Sunday morning, December 23rd.

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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