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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Monday, January 14th 2013
Created: Jan 14th 6:18 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.
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The Bottom Line

The hazard is CONSIDERABLE above treeline today, where human triggered avalanches are most likely in steep wind loaded starting zones.  Below treeline the hazard is MODERATE, where it is still possible for skiers, riders and snowmachiners to trigger avalanches.


Primary Concern

Deep slab avalanches continue to be our greatest concern.  This most recent load of snow, while dense, is probably not enough to drastically increase the likelihood of triggering these large and destructive avalanches.  The weak layers formed in October and November are now buried 4-10 feet in many areas, and are getting more difficult to impact with the weight of a person or snowmachine. 

Areas to avoid today are trigger points in upper elevation starting zones, where those weak layers are only covered by 1-3 feet of slab.  If you're able to hit one of these spots, the potential for avalanches to propagate across large areas remains very high.  What this means is that the chances of starting one of these avalanches is low to moderate but the consequences are very high.  Human triggered deep slab avalanches in the past two weeks have produced impressive amounts of debris, and still warrant our attention. 


Secondary Concern

With a gradual rise in temps over the past 2 days, we have an "upside down" scenario in the upper layers of the snowpack.  Pit tests at treeline yesterday on Tincan revealed this weakness and showed potential for propagation across slopes.  AKDOT was also able to trigger many avalanches around Bird Flats and Girdwood in the storm snow yesterday.  While the storm snow totals were higher in these areas, the general trend of warming over the past 48 hours is similar in both places.  Expect this problem to resolve itself more quickly than the deep slab problem.


Mountain Weather

In the past 24 hours Turnagain pass has received ~8" of new snow with .8" water.  Winds have been light to moderate out of the East averaging in the teens with gusts to 49 mph.  Temps at 1800' have been around 32 with temps at ridgetops in the mid twenties.
The biggest news in weather is that the forecasted rise in temperature and heavy precip did not come to fruition on Turnagain Pass.  The Girdwood Valley has seen almost twice the amount of precip in the past 24 hrs.
Look for precip to taper off today and temps to start gradually dropping with freezing levels descending to sea level by tonight.
The extended outlook calls for a break in precip later today into Tuesday with snowfall returning by midweek.  Temps will be significantly cooler through the next 3 days.

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Wendy will issue the next advisory tomorrow morning, January 15th.

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
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