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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Wednesday, March 19th 2014
Created: Mar 19th 6:16 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.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
 Show the Complete North American Avalanche Danger Scale
Deuter USA
Special Announcement

Our deepest condolences go out to the family and friends of Aaron Karitis. He passed away from injuries sustained following a recent avalanche in Haines, AK.

http://freeskier.com/stories/heli-guide-aaron-karitis-dies-following-haines-avalanche


The Bottom Line

The avalanche danger is MODERATE in terrain over 35 degrees above treeline today.  Deep slab avalanches up to 5 feet in depth have the potential to release in steep terrain.  This is a low likelihood/high consequence situation.  Conservative terrain selection is the best practice for this specific avalanche concern.

Below treeline and on slopes under 35 degrees the avalanche danger is LOW today.


Primary Concern

It has been 4 days since any avalanche activity has been reported.  This most recent activity involved deep slab avalanches pulling out on layers buried 3-5 feet below the surface.  While the likelihood of triggering this type of avalanche is waning, the consequences remain high.  Slabs up to 5 feet in depth have the potential to pull out across entire slopes and do a significant amount of damage.

What’s tricky with this avalanche problem is that you will not encounter it everywhere.  The slab that built up last week is now strong and able to hold a lot of weight.  Because of this it is possible to get onto steep terrain without incident.  Now is not the time to let your guard down.  We know that some areas still harbor weak reactive snow below the March slab.  (See VIDEO and OBSERVATION for a more detailed desrciption)

Areas where you would be more likely to trigger a deep slab are in rocky areas, transition zones between wind scoured and wind loaded, steep terrain, and slopes with an overall shallower snowpack.  Avoiding these areas is the best way to tip toe around this problem.

Photo below: Deepest part of the crown face (8') of the Widow Maker avalanche (March 15); a prime example of a deep slab avalancheWendy Widow Maker Crown

Click HERE for a detailed write up of this avalanche.


Secondary Concern

Cornices have become sufficiently large over the course of the winter.  It is difficult to predict when these monsters will release themselves.  Strong solar radiation and an absence of wind are two factors that can encourage cornices to drop onto slopes.  Avoiding being on or under cornices is a good habit to get into.  Know where the cornice begins and the underlying terrain ends.  If you are traveling below cornices, spread your group out and only expose one person at a time.


Additional Concern

The sun will be strong today on mainly South through West facing terrain.  Daytime heating will last into the evening hours, given that sunset is now after 8pm.  Low volume loose snow avalanches will not be a concern on their own.  In steep terrain above terrain traps it will be important to be on the lookout for wet loose avalanches, as they have the potential to knock you off your feet and into trees, gullies or over cliffs.


Mountain Weather

In the past 24 hours no new precipitation has fallen.  Temperatures at the Sunburst station (3,812’) have averaged 19 degrees F.  Winds there have been light, averaging 7mph out of the Northwest with a max gust of 23.

A pleasant day in the mountains is on tap.  Expect clear skies, winds out of the North at 15mph and temperatures at 1,000’ reaching into the high 30s F.

A large area of high pressure is establishing itself over most of the state.  This will bring clear and dry conditions over the next several days.

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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