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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Monday, December 7th 2015
Created: Dec 7th 6:23 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.
 Show the Complete North American Avalanche Danger Scale
Special Announcement

Fireside Chat #2 - Avalanche Rescue - Dec 10th!! Join CNFAIC forecaster Heather Thamm Thursday night from 6:30-8:00pm at the Alaska Avalanche School for a presentation on "Rescue Fundamentals". A successful rescue of a buried individual can hinge on even a little bit of knowledge, we hope to see you there!


The Bottom Line

A generally LOW avalanche danger exists in the mountains surrounding Turnagain Pass. Triggering an avalanche is unlikely but not impossible. The most suspect slopes are in steep terrain at the high elevations where someone just might be able to break off a slab 1-2' thick. Good travel habits, such as exposing one person at a time, watching your partners and grouping up in safe zones are, as always, key ways to minimize risk.

*If venturing into the 'periphery' forecast zones, such as Girdwood Valley, Silvertip and Summit Lake areas, more caution is advised due to limited information about the snowpack in these areas.


Primary Concern

As our extended period of clear weather continues, we are sitting in the "normal caution" phase of avalanche issues. These include:

1- Sluffs on steep slopes. These have been small to medium in volume, but are getting larger by the day as the surface becomes weaker under clear skies.

2- Triggering an outlier avalanche. This would most likely be an 'unsupported slab' that sits above a cliff or steep rocky terrain. Check out video HERE for an example.

3- Triggering a cornice fall. The cornices maybe be small(ish) right now, but they are clearly large enough to take you down somewhere you don't want to go. As always, give them a wide berth.

Photo: You can see the boot pack to the top of Tincan Proper steers clear of the cornices, however it looks as if someone may have triggered a piece of cornice recently from the boot pack, or possibly veering off of it. A good reminder for us to err of the side of caution when traveling near cornices.


Additional Concern

Below is a glimpse of the high elevation snowpack (3,700'). We are finding the old faceted snow from the mid-November cold snap being compressed below roughly 1-3' of dense and hard Thanksgiving snow. Other than Graham's pit on Friday, we have seen no reactivity in these old facetd. This includes both snowpack stability tests as well as a large number of folks testing the slopes in the region.


"No results" mentioned in pit = a stabilized snowpack.

As we may be approaching the end of our clear spell, we are watching for the next possible weak layer(s) develop - the surface. Check out the recent reports for more on this HERE.


Mountain Weather

Yesterday was another stunning day in the backcountry; sunny skies, calm winds and temperatures in the mid 20's F. This was all above the fog and inversion. However, down along the road corridor, temperatures in the single digits existed along with valley fog extending up to 1,500'. 

Today (and tomorrow) will be much the same, mostly clear skies with valley fog. Winds should remain light and variable yet are forecast to increase from the East tonight to the 10-15mph range. Temperatures will again be in the mid 20's F on the ridgetops and in the single digits in the parking lots - that's quite an inversion.

Our next shot for snow looks to be Thursday or Friday. Stay tuned!

 

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 17    0    0  24 
Summit Lake (1400')  0  0 11 
Alyeska Mid (1700') 17   0   0  14 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812')  26  10 
Seattle Ridge(2400') 19 N/A  N/A  N/A 

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.
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