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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Aleph Johnston-Bloom  
Thursday, March 9th 2017
Created: Mar 9th 5:39 am
1 Low Alpine / Above 2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
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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AMH
Special Announcement

There will be an Alaska State Trooper Helicopter in the Turnagain Pass area this afternoon conducting avalanche rescue training operations.

Consider showing your support for public avalanche centers when applying for your PFD!! Friends of the Chugach National Forest Avalanche Center is an official Pick. Click. Give. organization!

 


The Bottom Line

The avalanche danger is LOW at all elevations.  Avalanches are unlikely today.  Exceptions to this are possible, mainly in the form of old wind slabs, loose snow avalanches and cornice falls.  Big alpine terrain and steep slopes in the lower elevations will be the most likely places to encounter these issues. Remember to give glide cracks a wide berth and limit exposure under them. 

Good travel habits remain important.  These include exposing only one person at a time on a slope, watching your partners closely and having an escape route planned in case the snow moves. 

Summit Lake area:  A thinner snowpack exists with a poor structure and heightened avalanche danger remains in this zone. Please see the Saturday Summit Summary HERE


Primary Concern

Not surprising but there is nothing new or exotic to report today. Sunshine, cold temperatures and light winds again greeted folks in the mountains yesterday and are forecasted again today with the exception of slightly warmer temperatures. Despite the weather and snowpack conditions being mostly stable, it is important to remember if you choose to venture into steep terrain, LOW danger doesn't mean NO danger. Snow is complex and it often seems that once we let our guard down, something happens. So, keep up your safe travel habits and always watch for changes in the snowpack as well as weather. Below are the 'Normal Caution' concerns that underscore the current green conditions: 

Glide Avalanches:
Glide cracks continue to slowly open above popular terrain on Seattle Ridge and in other areas of the advisory area. These could release at any time, watch for these cracks and avoid being under them, photo below.

Wind Slabs:
Old and hard winds slabs are easy to find but for the most part they are locked into place. Steep rocky areas, where they are not supported from below, will be the most suspect zones for someone to pop one out. These areas are also where slabs are likely sitting on weak faceted snow. Even a small wind slab can have big consequences if a person is knocked over cliffs or down steep terrain. Watch for hard snow over weak loose snow as well as shooting cracks and whumphing noises. 

Loose Snow Avalanches (Sluffs):
Watch your sluff. Dry sluffs on steep slopes are probable and are getting larger by the day. Although many steep South slopes have a sun crust, a slight change in aspect still sports soft snow and sluff concerns. As temperatures rise over the next few days wet loose activity on the southerly slopes, both natural and human triggered, may be possible.

Cornices:
Cornices should always be given a wide berth from above and limit exposure time traveling underneath.

Persistent Slabs and Deep Slabs: 
There are various weak layers in our thin snowpack. Buried surface hoar sits 1-3+' below the surface and faceted snow sits in the mid and base of the pack. These weak layers with varying degrees of strength are in a dormant stage due to plenty of time to adjust with a lack of changing weather. Although this means the layers are not producing avalanches, it doesn't mean an outlier can't occur which could cause a large avalanche breaking deeper in the pack. 

Glide cracks along Seattle Ridge

Glide crack south of Repeat Offender


Mountain Weather

Yesterday brought another day of sunshine, calm winds and cold temperatures. There was a slight warming trend that will progress today with temperatures forecasted to climb into the low 20Fs. Winds will be light and northerly. Temperatures will dip down again tonight but not as low as the past week. 

There is a chance a few clouds will sneak in overnight into tomorrow. In general the pattern we are in persists into early next week. Then... Fingers crossed... There is a chance for snow. Stay tuned.
 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880')  0 61 
Summit Lake (1400') 6  0   29 
Alyeska Mid (1700')  12  0  57

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812')  WNW 17 
Seattle Ridge(2400')  11  W 6  12

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: May 16, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedThanks all for a safe and fun season on the Chugach NF! Stay tuned for the 2017/18 season. #playsafe #snowtosealevel
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: ClosedResurrection Pass trail will be 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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