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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   John Fitzgerald  
Tuesday, March 3rd 2015
Created: Mar 3rd 6:17 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 tonight for a FREE avalanche awareness talk and discussion on the state of the snowpack at REI in Anchorage from 6-7:30pm!!  Cost is zero dollars.


The Bottom Line

The avalanche danger is MODERATE in the Alpine, where slabs 1-2’ in depth could be triggered in steep terrain.  Triggering these slabs is on the low end of the scale but consequences remain high enough to warrant careful snowpack and terrain assessment.

The danger is LOW at Treeline and below where triggering an avalanche is unlikely.

Despite it being early March, early season conditions exist on the approaches.  Ice, alder stumps and rocks are hazards to avoid when traveling to and from the treeline elevations today.


Primary Concern

Weak snow that has been buried for 3 weeks continues to lurk 1-2 feet below the surface.  This layer has gained significant strength in that time.  Bonding between the “late January” facets and overlying slabs has improved to the point where it has become difficult to trigger an avalanche on this layer.  Some intermediate weak layers can be found in isolated locations and are buried about 1 foot deep.  Slabs resting on these layers are also generally difficult to trigger.   Tests have been showing propagation potential on the decline, but it is still possible for an avalanche, if triggered, to propagate across portions of slopes.  

Despite these improving trends it is still important to treat steep and complex terrain with suspicion in the Alpine.  Today it will be important to follow good travel protocol.  Assess the terrain you are on and minimize your exposure accordingly.  Avoid trigger points on terrain over 35 degrees, travel one at a time on suspect slopes, use islands of safety and communicate your decisions and plans within your group.


Secondary Concern

Ridgetop winds have been in the 20-30 mph range since yesterday morning.  Very shallow stiff slabs may be encountered today on steep (40 degrees and over) leeward slopes.  These slabs will be small, around 4-6” deep and exist in small pockets.  While the volume of any wind slabs triggered will be low, it will be important to avoid them when travelling above terrain traps such as cliffs, gullies and trees.


Mountain Weather

The past 24 hours saw mild temps with moderate ridegtop winds.  Skies were mostly cloudy and less than a trace of new snow fell in the upper elevations.

Today expect more of the same.  Winds will be out of the East at 15-20 mph.  Very light snow under mostly cloudy skies will fall with a max of 2” of accumulation.  Rain/snow line will be around 1,000’.  Temperatures at 1,000’ will be in the low to mid 30s F.

The extended outlook is showing a continuation of showery precipitation through the week, as a series of weak lows move through the area.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 34 0 0 40
Summit Lake (1400') 34 0 0 7
Alyeska Mid (1700') 34 trace .06 22

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 24 ENE 20 51
Seattle Ridge(2400') 26 NW 29 59

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 11, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenPlease park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: OpenWide swaths of open river in the Placer Valley. Travel with extreme caution!
Skookum Drainage: ClosedSKOOKUM DRAINAGE CLOSED TO MOTORIZED USE ON APRIL 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: ClosedClosed for the remainder of the 2017 season.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenPlease 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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