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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Monday, February 25th 2013
Created: Feb 25th 6:10 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.
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 avalanche hazard is MODERATE above and below treeline today.  Above treeline be on the lookout for fresh wind slabs that will be sensitive to the weight of a person or snowmachine.  Below treeline new slabs that formed over the weekend sit on a crust that have the potential to produce avalanches.


Primary Concern

In the upper elevations winds have been consistently blowing in the upper teens to low 20s out of the East.  Expect to encounter wind slabs up to 18" in depth today in starting zones.  While the new storm snow that fell over the weekend has in general bonded well to old surfaces, the simple act of windloading can and will create areas of unstable snow.  Continued winds out of the East today will help to increase the size of these slabs.  Be on the lookout for snow that looks smooth, rounded and pillowy.  These areas will be most sensitive while the snow is being transported and slabs are forming.  While the predominant wind direction is out of the East, localized winds will blow in a variety of directions.  With this in mind it is important to recognize wind and loading patterns and stay off of slopes that have been recently loaded.


Secondary Concern

A crust that formed prior to the weekend has shown to be a problem in some areas.  Yesterday my partner and I found weak snow just below this new crust to be reactive and unstable in the lower elevations.  While this is not a widespread problem, it is worth paying attention to, especially if you experience collapsing/whoompfing as we did yesterday.

Deeper weak layers that were reactive in tests and have produced several avalanches over the past two weeks have not shown to be a problem recently.  A mid elevation crust (~1,500'-3,000') with weak snow above, and the old weak snow at the ground have been the two layers we have been tracking.   Despite a lack of activity at these layers it is still worth keeping them in mind as they have the potential to re activate in areas where the snowpack is more shallow.


Mountain Weather

Over the past 24 hours the mountains have picked up to 3" of new snow in the Girdwood Valley, with lesser amounts on Turnagain Pass.  Winds have averaged 15 mph out of the East and temps have been in the high teens F at 3,800' and around 32 F at sea level.

Today we should expect to see light snow showers picking up later in the day as another weak low pressure system moves over the forecast area.  Ridgetop winds will blow 20-30 mph out of the East and temps at 1,000' will be in the mid twenties.

The extended outlook calls for more of the same, as an active weather pattern continues to bring modest amounts of snow to the area.

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Wendy will issue the next advisory tomorrow morning, February 26th.

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: Apr 28, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: ClosedSKOOKUM DRAINAGE CLOSED TO MOTORIZED USE ON APRIL 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: OpenOpen thru May 14th.
Twentymile: Closed
Seward District
Carter Lake: OpenClosed May 1.
Lost Lake Trail: OpenClosed May 1.
Primrose Trail: OpenClosed May 1.
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: OpenClosed May 1.
South Fork Snow River Corridor: OpenClosed May 1.
Summit Lake: OpenClosed May 1.

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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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