CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Heather Thamm  
Sunday, January 10th 2016
Created: Jan 10th 6:03 am
3 Considerable Alpine / Above 2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
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
Tesoro Foundation
Special Announcement

Filing for the PFD this week? Remember, The Friends of the CNFAIC is part of PICK.CLICK.GIVE. Your donations are greatly appreciated and an integral part to making the CNFAIC possible and sustainable.

 


The Bottom Line

A CONSIDERABLE avalanche danger exists in the Alpine where wind slabs 1-2’ thick are possible on steep windloaded features. Careful snowpack evaluation and cautious routefinding are recommended in places where winds are actively loading slopes. The avalanche danger at and below Treeline is MODERATE where rain saturated the snowpack yesterday and triggering a wet loose avalanche in a terrain trap will be difficult to escape. Wet snow will be more likely in Girdwood where more rain and lower elevation terrain exists.

In areas such as Summit Lake, the snowpack is shallower and harbors more weak layers. Click HERE to read yesterday's Summit Lake Summary. 


Primary Concern

In Turnagain Pass storm snow instabilities due to recent snow, rain and active wind loading are today’s primary concerns. 

Wind Slabs – Today Easterly ridgetop winds are expected to be in the 30-40’s mph for the second day in a row with an additional 3-5” of new snow. This means avalanches will be composed of the new storm snow from the last two days and are not expected to break into layers deeper in the pack. Isolated windslabs 1-2’ deep are possible on windloaded features. This problem is manageable by avoiding slope angles over 35° where the snow is windloaded. Pay attention for stiff hollow snow, shooting cracks, and snow being transported off of ridge tops.

Wet Loose – A saturated snow pack was observed yesterday below 1500’ causing the snow to be loose and unconsolidated. This problem is stabilizing in places where temperatures cooled enough to form a crust. Should you encounter wet saturated snow, this is an additional reason to avoid gullies and steep channeled terrain. This problem is more developed in Girdwood where more over an 1" of rain saturated the snowpack yesterday at lower elelvations. 

Should a break in the weather today allow for easier travel remember to practice safe travel rituals. 

  • Only expose one person at time on a slope
  • Regroup in safe zones
  • Always have an escape route

Yesterday two very small natural windslabs were observerd on Southeast aspects near Johnson Pass. These crossloaded gully features are examples of terrain that could harbor tender windslabs today.


Secondary Concern

Glide cracks have been appearing throughout Turnagain Pass over the last week. Warm temperatures and rain have been adding stress to these very unpredictable hazards. Pay attention for large open cracks in the snow, 'crevasse looking' features that can release without any warning. Similar to managing a cornice, it is best to avoid traveling on or under slopes with glide cracks. 


Additional Concern

Cornice features have grown large over the last few weeks, and todays blowing snow may be adding stress to their unstable nature. They have the potential to fall naturally or be triggered by the weight of a person or machine and can be very dangerous. Travel under or on them should be avoided. They have the tendency to break farther back from the ridge than expected. As you approach ridgelines, ensure you aren't accidently traveling on overhanging snow. 


Mountain Weather

Yesterday 36F temps caused rain along Turnagain Pass (1000’), and by afternoon temps cooled to 32F with scatted snow showers in the afternoon. 4-8" of new snow fell in the upper elevations. Rain/snow line was estimated to have reached 2000' early yesterday morning. Easterly Ridgetop winds averaged in the 30’s mph with gusts in the 60’s mph. 

Today Easterly ridgetop winds are expected to average in the 30-40’s mph.  Gust could reach into the 60’s mph. Up to 5” of snow is expected above 1100’ today and light rain at lower elevations. Temperature should hover around freezing 32F along road level at Turngain Pass.

Expect warm temperatures, snow and rain to continue through mid-week.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 31  0.4  85 
Summit Lake (1400') 33  0.1  25 
Alyeska Mid (1700') 32  10  1.22  66 

 

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

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 23  ENE  28  64 
Seattle Ridge(2400') 28  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.
FCNFAIC