CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Graham Predeger  
Thursday, March 14th 2013
Created: Mar 14th 6:36 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.
2 Moderate Treeline / 1,000'-2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Below Treeline / Below 1,000' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
 Show the Complete North American Avalanche Danger Scale
TOTE Maritime
The Bottom Line

The avalanche danger will start out low and trend toward MODERATE at all elevations as increased snowfall and easterly winds move through the Turnagain Pass area today.  Fresh wind slabs, small storm snow avalanches and potential cornice fall will all be possible today, though should prove manageable with good terrain choices.


Primary Concern

In the last 48 hours we have seen some big lines skied between Girdwood and Turnagain Pass; it’ll be a good idea to approach big terrain with extra caution today until you can answer the question: How well is todays new storm snow and fresh wind slabs bonding with yesterdays snow surface?  Forecasters found the gamut of surface conditions yesterday from impenetrable crusts at lower elevations to stiff wind board and soft wind textured powder growing surface hoar and facets at upper elevations.  Lots of quick hasty snowpits (hand pits or pole pits) to look at the storm interface may give you good information today before committing to a specific slope. 

Wind slabs forming yesterday and today are expected to be shallow in the 6-18” range proving manageable in most terrain, however pockets still exist where deeper, large avalanches are possible in isolated areas (see photo below).  As always, escape routes and zones of safety are critical when recreating in these mountains.

 

6-8’ hard slab likely ran on a buried crust sometime between March 8th and March 11th. Debris was 10-15’ deep at the toe of this avalanche.  This is a good example of a large, unmanageable avalanche that can be found in isolated areas. Notice how low on the slope the crown face is; likely due to 100+ mph winds last Thursday loading this slope well below the ridgeline.


Secondary Concern

Cornice fall is still very much on our radar and will be a genuine concern again today.  The good news with cornices is that they are generally easy to manage.  The fact that we can see them means we can avoid them, and avoidance is key.  Don’t spend excessive time underneath cornices and stay much further back than you think necessary when travelling along a corniced ridge.  Cornice fall is quite unpredictable, but expect them to become more unstable late in the day as temperatures and any direct sunlight warm the snow surface.

If you haven’t read Wendy’s write up on the large cornice fall and subsequent avalanche in the Goldpan area, take a few minutes and check it out here.


Mountain Weather

Three days in a row of sunshine and blue sky in the backcountry produced a lot of smiles in the parking lots for those of us lucky enough to find a day off mid-week. Today we can expect moderate winds from the east in the 20-35mph range and mostly obscured skies as a weak surface low moves through our area.  Snow is expected throughout the day in the eastern Turnagain Arm region with totals in the 4-8” range.  Temperatures look to stay cool enough that snow is expected at sea level.

We may squeeze another inch or two of snow out tonight as this low dissipates and skies begin clearing again overnight and into tomorrow.


Fitz will issue the next advisory Friday morning, March 15th.

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
© 2017 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC