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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Graham Predeger  
Tuesday, March 10th 2015
Created: Mar 10th 6:02 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'
 Show the Complete North American Avalanche Danger Scale
Special Announcement

Join us this Thursday evening in downtown Anchorage for the Alaska Premiere of The Unrideables, a film highlighting speed-flying in the Alaska range! Doors open at 7:00pm and showtime is at 7:30pm.  All ages are welcome!  Tickets available at http://alaskapac.centertix.net/eventperformances.asp?evt=1451

This fun evening event will benefit the Friends of the Chugach National Forest Avalanche Information Center and the Alaska Avalanche School.


The Bottom Line

Pockets of MODERATE danger exist in the alpine today for a skier to trigger a wind slab 1-2’ deep on steep, wind-loaded terrain and cross-loaded gullies.  Loose snow avalanches (sluffing) should also be expected and prove manageable if skiing in steeper, wind-sheltered terrain. 

Below treeline, the danger is LOW and an avalanche is unlikely, as cooling temps have acted to lock up what snow we do have beneath the alder line.


Primary Concern

Sustained moderate winds yesterday continued to strip ridges of available snow and load leeward slopes.  Much of the loading occurred on north and east aspects as the bulk of the wind was blowing up Turnagain arm from the west.  A hike up Sunburst yesterday showed evidence that these 1-3 day old wind slabs are increasing in strength and bonding with underlying layers.  That being said, steep slopes (greater than 40 degrees) add further stress to this wind slab interface and should be avoided for another day while this problem continues to heal.  Look to bypass steep leeward slopes and cross-loaded gullies that have a smooth and fat look, or if the surface feels stiff or sounds hollow seek out mellower, low consequence terrain. 

It’ll be important to recognize where these wind slabs exist today as your obvious signs of instability (recent avalanches, cracks or whoomphing) may not be present.

Sustained westerly winds on Sunburst ridge yesterday acting to erode away this cornice.  Note this is an atypical direction for winds in the Turnagain area. 

As with all of your days in the mountains, safe travel protocol is the name of the game.  Ski slopes one at a time and talk thru plans with your group before executing.  No matter how benign or extreme a slope may be, it’s always good habit to think through a few questions: “What will I do if this slides?  Where is my escape route?  Where is my safe zone?”


Secondary Concern

Cold temperatures will promote a loosening of the snow surface and provide for potentially fast moving sluffs.  If anticipated, these should be low enough in volume to not be much of a concern, unless travelling above a terrain trap such as a cliff or deep gully.


Mountain Weather

Temperatures began their free fall yesterday bottoming out at 0 degrees F on Sunburst ridge as a cold front pushed into our region from the northwest.  Skies were mostly clear and winds were sustained in the 20's, gusting up to the 40's mph on Seattle ridge mostly from the west.

Today you can expect temperatures again in the single digits at ridge tops and winds subsiding to the teens, as flow direction changes to more northerly.  Though cold ambient temperatures, the sun will be out in full force today for us all to work on our spring break goggle tans!

Temps look to stay cold going into the weekend with our next chance at a few snowflakes coming Friday as a low approaches the gulf coast.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880')  12 43 
Summit Lake (1400')
Alyeska Mid (1700')  12 28 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812')  W 27 
Seattle Ridge(2400')  W 20  54 

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

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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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