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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Graham Predeger  
Thursday, January 24th 2013
Created: Jan 24th 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

Fresh wind slabs above tree line coupled with our deep slab potential will keep the avalanche danger at MODERATE today.  Below tree line the avalanche danger is trending toward LOW as we see temperatures and the rain/ snow line descend throughout the day.


Primary Concern

Snowfall and winds above tree line were not exceptionally impressive yesterday and overnight but consistent enough to build tender, shallow wind slabs throughout the day.  Snow falling at ridge top locations was dense, though easily transportable by the moderate southeasterly winds.  Expect wind slabs to form on north and west aspects above tree line where small human triggered avalanches will be possible today.  Below the rain/ snow line where wind slabs have not formed there is a generally low avalanche danger.  Yesterday that level was about 1700’ in the Turnagain pass area.  We should see that dropping to around 1000’ today.

Cornice fall-

Cornices are growing quite large in the forecast area with one natural failure noted on Magnum last week that resulted in an avalanche.  The moderate winds and dense snow will continue to add weight and mass to these backcountry bombs.  It is wise to recognize cornices and give them a wide berth when travelling through the mountains.


Secondary Concern

As we continue to add weight to our snowpack we cannot forget about the deep slab issue we are dealing with this winter.  It’s unlikely a person will trigger a deep slab avalanche today however; either of the previous mentioned issues (wind slabs and cornice fall) can act as the catalyst to affect deeper weak layers resulting in a cataclysmic deep slap avalanche.


Mountain Weather

Below about 1800’ we have continued to lose depth in our snowpack due to warm temperatures and precipitation falling mostly as rain the past several days.  Overnight, temperatures have begun a downward slide and we will see our rain/ snow line descend back to sea level by Friday evening.

Today we can expect 1-2” of new snow with winds shifting from east to southwesterly, calming by this evening.  For the weekend, temperatures appear to be more of what we come to expect for January in Alaska in the 10 – 20 degree range.

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Fitz will issue the next advisory tomorrow morning, January 25th.

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 25, 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
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