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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Friday, December 4th 2015
Created: Dec 4th 6:30 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.
0 NO RATING Below Treeline / Below 1,000'
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The John Byrne Family
The Bottom Line

The majority of terrain in the heart of Turnagain Pass has a generally LOW avalanche danger, this includes the upper elevations. Areas of MODERATE danger exist both on very steep slopes and in terrain within the 'periphery' forecast zones, such as Girdwood Valley, Silvertip and Summit Lake on the Kenai. 

*Weak snow near the ground does remain in scattered areas, although triggering a slab avalanche breaking near the ground is trending toward unlikely, this set up warrants caution. When pushing into steeper terrain, be sure to practice safe travel techniques such as exposing one person at a time on a slope, discussing potential consequences if the slope does slide and always watch for signs of instability before committing. 


Primary Concern

For almost a week now intermittent snow showers have added a welcome 8-12" of low density snow at the mid-mountain elevations. Another round last night added 2-3" of this. Snow quality continues to be reported as "excellent" - especially above treeline where "dust-on-crust" conditions disappear. Winds have been light over the past few days and are expected to be light again today, however, with such loose snow available for transport, keep in mind it can be blown into slabs easily. Otherwise, watch for sluffing on steep slopes.


Additional Concern

How is the 'snowpack structure' looking as a whole? In general, pretty good. However, we are tracking a layer of old faceted snow that sits near the ground. This layer is likely responsible for some very sizeable natural avalanches during the Thanksgiving weekend storm, yet signs point to the layer adjusting since then and becoming unreactive. Until we gather enough data to rule this potential weak layer out, it's something to keep in mind.


Mountain Weather

Generally mild weather has been over us for the past 6 days. We have seen light Easterly winds, isolated snow showers and temperatures in the mid 20's F on the ridgetops and near freezing at sea level.

Overnight, a quick moving disturbance added roughly 2-3" of light snow at Turnagain Pass and Summit Lake while Girdwood Valley looks to have seen around 4". Winds are light and variable currently and slated to turn back Easterly in the 5-10mph range today. Skies should be partly cloudy this morning before filling back in later today with a chance for another 1-2" of low density snow this evening. Temperatures have dropped to the lower 20's F on the ridgetops where they should remain today.

This weekend looks to be nice with partly cloudy skies, temperatures in the 20's F and light winds. Stay tuned.

 

PRECIPITATION 24-hour data (6am - 6am)

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 26  0.2  25 
Summit Lake (1400') 24  0.2  12 
Alyeska Mid (1700') 27  3.5  0.25  20 

 

RIDGETOP 24-hour data (6am - 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 22  NE  16 
Seattle Ridge(2400') 24  N/A  N/A  N/A 

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: Jan 18, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenAccess is thru the gate on the right side of the parking lot as you drive toward the outhouse. Please park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: OpenPlease cross Railroad tracks at 90 degrees to the rails and clear the corridor. It is Illegal to ride up and down Railroad tracks. Tracks are currently active. Please observe and stay off PRIVATE PROPERTY adjacent to the Portage Valley.
Skookum Drainage: Open
Turnagain Pass: Open
Twentymile: OpenPark at Portage rail depot. Cross tracks and follow marked corridor (Bamboo poles) approx. 3 miles up Valley to open riding areas.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenOpen to motorized use 1/15. Please STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenOpen to motorized use 1/15. Please 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

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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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